I. Kravchenko

Ultrahigh energy neutrinos are interesting messenger particles since, if detected, they can transmit exclusive information about ultrahigh energy processes in the Universe. These particles, with energies above ${10}^{16}\text{ }\text{ }\mathrm{eV}$, interact very rarely. Therefore, detectors that instrument several gigatons of matter are needed to discover them. The ARA detector is currently being constructed at the South Pole. It is designed to use the Askaryan effect, the emission of radio waves from neutrino-induced cascades in the South Pole ice, to detect neutrino interactions at very high energies. With antennas distributed among 37 widely separated stations in the ice, such interactions can be observed in a volume of several hundred cubic kilometers. Currently three deep ARA stations are deployed in the ice, of which two have been taking data since the beginning of 2013. In this article, the ARA detector ``as built'' and calibrations are described. Data reduction methods used to distinguish the rare radio signals from overwhelming backgrounds of thermal and anthropogenic origin are presented. Using data from only two stations over a short exposure time of 10 months, a neutrino flux limit of $1.5\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}6}\text{ }\text{ }\mathrm{GeV}/{\mathrm{cm}}^{2}/\mathrm{s}/\mathrm{sr}$ is calculated for a particle energy of ${10}^{18}\text{ }\text{ }\mathrm{eV}$, which offers promise for the full ARA detector.

CLEO has studied B decays to πℓν, ρℓν, and ωℓν, where ℓ=eorμ, by incorporating the missing momentum into full B reconstruction. With the B0 and B+ modes combined according to isospin predictions for the relative partial widths, we obtain B(B0→π−ℓ+ν)=(1.8±0.4±0.3±0.2)×10−4 and B(B0→ρ−ℓ+ν)=(2.5±0.4+0.5−0.7±0.5)×10−4, where the errors are statistical, systematic, and the estimated model dependence. We also estimate |Vub|=(3.3±0.2+0.3−0.4±0.7)×10−3.Received 1 July 1996DOI:https://doi.org/10.1103/PhysRevLett.77.5000©1996 American Physical Society

The Askaryan Radio Array (ARA) is an ultra-high energy (>1017 eV) cosmic neutrino detector in phased construction near the south pole. ARA searches for radio Cherenkov emission from particle cascades induced by neutrino interactions in the ice using radio frequency antennas (∼150-800 MHz) deployed at a design depth of 200 m in the Antarctic ice. A prototype ARA Testbed station was deployed at ∼30 m depth in the 2010–2011 season and the first three full ARA stations were deployed in the 2011–2012 and 2012–2013 seasons. We present the first neutrino search with ARA using data taken in 2011 and 2012 with the ARA Testbed and the resulting constraints on the neutrino flux from 1017-1021 eV.

Ultra-high energy neutrinos are detectable through impulsive radio signals generated through interactions in dense media, such as ice. Subsurface in-ice radio arrays are a promising way to advance the observation and measurement of astrophysical high-energy neutrinos with energies above those discovered by the IceCube detector (≥ 1 PeV) as well as cosmogenic neutrinos created in the GZK process (≥ 100 PeV). Here we describe the NuPhase detector, which is a compact receiving array of low-gain antennas deployed 185 m deep in glacial ice near the South Pole. Signals from the antennas are digitized and coherently summed into multiple beams to form a low-threshold interferometric phased array trigger for radio impulses. The NuPhase detector was installed at an Askaryan Radio Array (ARA) station during the 2017/18 Austral summer season. In situ measurements with an impulsive, point-source calibration instrument show a 50% trigger efficiency on impulses with voltage signal-to-noise ratios (SNR) of ≤2.0, a factor of ∼1.8 improvement in SNR over the standard ARA combinatoric trigger. Hardware-level simulations, validated with in situ measurements, predict a trigger threshold of an SNR as low as 1.6 for neutrino interactions that are in the far field of the array. With the already-achieved NuPhase trigger performance included in ARASim, a detector simulation for the ARA experiment, we find the trigger-level effective detector volume is increased by a factor of 1.8 at neutrino energies between 10 and 100 PeV compared to the currently used ARA combinatoric trigger. We also discuss an achievable near term path toward lowering the trigger threshold further to an SNR of 1.0, which would increase the effective single-station volume by more than a factor of 3 in the same range of neutrino energies.

The Askaryan Radio Array (ARA) is an ultra-high energy (UHE, $>10^{17}$ eV) neutrino detector designed to observe neutrinos by searching for the radio waves emitted by the relativistic products of neutrino-nucleon interactions in Antarctic ice. In this paper, we present constraints on the diffuse flux of ultra-high energy neutrinos between $10^{16}-10^{21}$ eV resulting from a search for neutrinos in two complementary analyses, both analyzing four years of data (2013-2016) from the two deep stations (A2, A3) operating at that time. We place a 90 % CL upper limit on the diffuse all flavor neutrino flux at $10^{18}$ eV of $EF(E)=5.6\times10^{-16}$ $\textrm{cm}^{-2}$$\textrm{s}^{-1}$$\textrm{sr}^{-1}$. This analysis includes four times the exposure of the previous ARA result, and represents approximately 1/5 the exposure expected from operating ARA until the end of 2022.

In the hopes of observing the highest-energy neutrinos (E>1 EeV) populating the Universe, both past (RICE, AURA, ANITA) and current (RNO-G, ARIANNA, ARA and TAROGE-M) polar-sited experiments exploit the impulsive radio emission produced by neutrino interactions. In such experiments, rare single event candidates must be unambiguously identified above backgrounds. Background rejection strategies to date primarily target thermal noise fluctuations and also impulsive radio-frequency signals of anthropogenic origin. In this paper, we consider the possibility that ‘fake’ neutrino signals may also be generated naturally via the ‘triboelectric effect.’ This broadly describes any process in which force applied at a boundary layer results in displacement of surface charge, leading to the production of an electrostatic potential difference ΔV. Wind blowing over granular surfaces such as snow can induce such a potential difference, with subsequent coronal discharge. Discharges over timescales as short as nanoseconds can then lead to radio-frequency emissions at characteristic MHz–GHz frequencies. Using data from various past (RICE, AURA, SATRA, ANITA) and current (RNO-G, ARIANNA and ARA) neutrino experiments, we find evidence for such backgrounds, which are generally characterized by: (a) a threshold wind velocity which likely depends on the experimental trigger criteria and layout; for the experiments considered herein, this value is typically O(10 m/s), (b) frequency spectra generally shifted to the low-end of the frequency regime to which current radio experiments are typically sensitive (100–200 MHz), (c) for the strongest background signals, an apparent preference for discharges from above-surface structures, although the presence of more isotropic, lower amplitude triboelectric discharges cannot be excluded.

Based on a sample corresponding to 4.3 million produced tau-pair events, we have studied hadronic dynamics in the decay tau- --> nu_tau pi- pi0 pi0 in data recorded by the CLEO II detector operating at the CESR e+e- collider. The decay is dominated by the process tau --> nu_tau a_1(1260), with the a_1 meson decaying to three pions predominantly via the lowest dimensional (mainly S-wave) a_1 --> rho pi Born amplitude. From fits to the Dalitz plot and angular observables, we find significant additional contributions from amplitudes for a_1 decay to sigma pi, f_0(1370) pi and f_2(1270) pi, as well as higher dimensional a_1 --> rho pi and rho' pi amplitudes. The squared sigma pi amplitude accounts for ~15% of the total tau- --> nu_tau pi- pi0 pi0 rate in the models considered. We have searched for additional contributions from tau --> nu_tau pi'(1300). We place 90% confidence level upper limits on the branching fraction for this channel of between 1.0*10^{-4} and 1.9*10^{-4}, depending on the pi' decay mode. The pi- pi0 pi0 mass spectrum is parametrized by a Breit-Wigner form with a mass-dependent width which is specified according to the results of the Dalitz plot fits plus a coupling to an a_1 --> K* K amplitude. From a chi^2 fit, we extract the pole mass and width of the a_1, as well as the magnitude of the K* K coupling. We have also investigated the impact of a possible contribution from the a_1'(1700) meson on this spectrum. Finally, exploiting the parity-violating angular asymmetry in a_1 --> 3pi decay, we determine the signed value of the tau neutrino helicity to be h_{\nu_\tau} = -1.02 +- 0.13(stat.) +- 0.03(syst.+model), confirming the left-handedness of the tau neutrino.

The RICE experiment seeks observation of ultra-high energy (UHE; ${E}_{\ensuremath{\nu}}>{10}^{17}\text{ }\text{ }\mathrm{eV}$) neutrinos interacting in Antarctic ice, by measurement of the radio frequency (RF) Cherenkov radiation resulting from the collision of a neutrino with an ice molecule. RICE was initiated in 1999 as a first-generation prototype for an eventual, large-scale in-ice UHE neutrino detector. Herein, we present updated limits on the diffuse UHE neutrino flux, based on 12 years of data taken between 1999 and 2010. We find no convincing neutrino candidates, resulting in 95% confidence-level model-dependent limits on the flux ${E}_{\ensuremath{\nu}}^{2}d\ensuremath{\phi}/d{E}_{\ensuremath{\nu}}<0.5\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}6}\text{ }\text{ }\mathrm{GeV}/({\mathrm{cm}}^{2}\text{ }\mathrm{s}\mathrm{\text{\ensuremath{-}}}\mathrm{sr})$ in the energy range ${10}^{17}<{E}_{\ensuremath{\nu}}<{10}^{20}\text{ }\text{ }\mathrm{eV}$, or approximately a twofold improvement over our previously published results. Recently, the focus of RICE science has shifted to studies of radio frequency ice properties as the RICE experimental hardware has been absorbed into a new experimental initiative (the Askaryan Radio Array, or ``ARA'') at the south pole. ARA seeks to improve on the RICE sensitivity by approximately 2 orders of magnitude by 2017 and thereby establish the cosmogenic neutrino flux. As detailed herein, RICE studies of Antarctic ice demonstrate that both birefringence and internal layer RF scattering result in no significant loss of ARA neutrino sensitivity, and, for the first time, verify in situ the decrease in attenuation length with depth into the Antarctic ice sheet.

Using data collected by the CLEO II detector, we have observed two states decaying to ${\ensuremath{\Lambda}}_{c}^{+}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$. Relative to the ${\ensuremath{\Lambda}}_{c}^{+}$, their mass splittings are measured to be $+307.5\ifmmode\pm\else\textpm\fi{}0.4\ifmmode\pm\else\textpm\fi{}1.0$ and $+342.2\ifmmode\pm\else\textpm\fi{}0.2\ifmmode\pm\else\textpm\fi{}0.5\mathrm{MeV}{/c}^{2}$, respectively; this represents the first measurement of the less massive state. These two states are consistent with being orbitally excited, isospin zero ${\ensuremath{\Lambda}}_{c}^{+}$ states.

In a sample of $6.6\ifmmode\times\else\texttimes\fi{}{10}^{6}$ produced $B$ mesons we have observed decays $B\ensuremath{\rightarrow}{\ensuremath{\eta}}^{\ensuremath{'}}K$, with branching fractions $B({B}^{+}\ensuremath{\rightarrow}{\ensuremath{\eta}}^{\ensuremath{'}}{K}^{+})\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}({6.5}_{\ensuremath{-}1.4}^{+1.5}\ifmmode\pm\else\textpm\fi{}0.9)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}5}$ and $B({B}^{0}\ensuremath{\rightarrow}{\ensuremath{\eta}}^{\ensuremath{'}}{K}^{0})\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}({4.7}_{\ensuremath{-}2.0}^{+2.7}\ifmmode\pm\else\textpm\fi{}0.9)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}5}$. We have searched with comparable sensitivity for 17 related decays to final states containing an $\ensuremath{\eta}$ or ${\ensuremath{\eta}}^{\ensuremath{'}}$ meson accompanied by a single particle or low-lying resonance. Our upper limits for these constrain theoretical interpretations of the $B\ensuremath{\rightarrow}{\ensuremath{\eta}}^{\ensuremath{'}}K$ signal.

Ongoing experimental efforts in Antarctica seek to detect ultra-high energy neutrinos by measurement of radio-frequency (RF) Askaryan radiation generated by the collision of a neutrino with an ice molecule. An array of RF antennas, deployed either in-ice or in-air, is used to infer the properties of the neutrino. To evaluate their experimental sensitivity, such experiments require a refractive index model for ray tracing radio-wave trajectories from a putative in-ice neutrino interaction point to the receiving antennas; this gives the degree of signal absorption or ray bending from source to receiver. The gradient in the density profile over the upper 200 meters of Antarctic ice, coupled with Fermat's least-time principle, implies ray "bending" and the existence of "forbidden" zones for predominantly horizontal signal propagation at shallow depths. After re-deriving the formulas describing such shadowing, we report on experimental results that, somewhat unexpectedly, demonstrate the existence of electromagnetic wave transport modes from nominally shadowed regions. The fact that this shadow-signal propagation is observed both at South Pole and the Ross Ice Shelf in Antarctica suggests that the effect may be a generic property of polar ice, with potentially important implications for experiments seeking to detect neutrinos.

To better understand the effect of ice properties on the capabilities of radio experiments designed to measure ultra-high energy neutrinos (UHEN), we recently considered the timing and amplitude characteristics of radio-frequency (RF) signals propagating along multi-kilometer, primarily horizontal trajectories through cold Polar ice at the South Pole. That analysis indicated satisfactory agreement with a model of ice birefringence based on ice crystal (cˆ-axis) data culled from the South Pole Ice Core Experiment (SPICE). Here we explore the geometrically complementary case of signals propagating along primarily vertical trajectories, using extant data from the Askaryan Radio Array (ARA) experiment, supplemented by a refined analysis of older RICE experimental data. The timing characteristics of the South Polar data are in general agreement with the same birefringence model, although a several nanosecond discrepancy is found in comparison to Taylor Dome data. Re-analysis of older RICE data also confirm the correlation of signal amplitudes reflected from internal-layers with the direction of ice flow, similar to previous observations made along a traverse from Dome Fuji to the Antarctic coast. These results have two important implications for radio-based UHEN experiments: (i) if birefringence can be locally calibrated, the timing characteristics of signals propagating from neutrino-ice interactions to a distant receiver might be used to infer the distance-to-vertex, which is necessary to estimate the energy of the progenitor neutrino, (ii) the measured reflectivity of internal layers may result in previously-unanticipated backgrounds to UHEN searches, requiring significantly more modeling and analysis.

The resonant structure of the four pion final state in the decay $\stackrel{\ensuremath{\rightarrow}}{\ensuremath{\tau}}3\ensuremath{\pi}{\ensuremath{\pi}}^{0}{\ensuremath{\nu}}_{\ensuremath{\tau}}$ has been analyzed using 4.27 million ${\ensuremath{\tau}}^{+}{\ensuremath{\tau}}^{\ensuremath{-}}$ pairs collected by the CLEO II experiment at the Cornell Electron Storage Ring. A partial wave analysis of the resonant structure of the $\stackrel{\ensuremath{\rightarrow}}{\ensuremath{\tau}}3\ensuremath{\pi}{\ensuremath{\pi}}^{0}{\ensuremath{\nu}}_{\ensuremath{\tau}}$ decay has been performed; the spectral decomposition of the four pion system is dominated by the $\ensuremath{\omega}\ensuremath{\pi}$ and ${a}_{1}\ensuremath{\pi}$ final states. The mass and width of the ${\ensuremath{\rho}}^{\ensuremath{'}}$ resonance have been extracted from a fit to the $\stackrel{\ensuremath{\rightarrow}}{\ensuremath{\tau}}\ensuremath{\omega}\ensuremath{\pi}{\ensuremath{\nu}}_{\ensuremath{\tau}}$ spectral function. We have searched for second class currents in the decay $\stackrel{\ensuremath{\rightarrow}}{\ensuremath{\tau}}\ensuremath{\omega}\ensuremath{\pi}{\ensuremath{\nu}}_{\ensuremath{\tau}}$ using spin-parity analysis and established an upper limit on the non-vector current contribution.

We have used the CLEO-II detector at the Cornell Electron Storage Ringe (CESR) to study the inclusive production of charmonium mesons in a sample of 2.15 million BB¯ events. We find inclusive branching fractions of (1.12±0.04±0.06)% for B→J/ψX, (0.34±0.04±0.03)% for B→ψ′X, and (0.40±0.06±0.04)% for B→χc1X. We also find some evidence for the inclusive production of χc2, and set an upper limit for the branching fraction of the inclusive decay B→ηcX of 0.9% at 90% confidence level. Momentum spectra for inclusive J/ψ, ψ′, and χc1 production are presented. These measurements are compared to theoretical calculations.Received 13 December 1994DOI:https://doi.org/10.1103/PhysRevD.52.2661©1995 American Physical Society

Using data recorded by the CLEO-II detector at Cornell Electron Storage Ring (CESR), we report the first observation of a narrow state decaying into Ξ+cπ−. The state has mass difference M(Ξ+cπ−)−M(Ξ+c) of 178.2 ± 0.5 ± 1.0 MeV/c2, and a width of <5.5 MeV/c2 (90% confidence level limit). The most likely explanation of this new state is that it is the Ξ*0c, the JP=32+ spin excitation of the Ξ0c charmed baryon.Received 15 August 1995DOI:https://doi.org/10.1103/PhysRevLett.75.4364©1995 American Physical Society

We have investigated $D^{+}\pi^{-}$ and $D^{*+}\pi^{-}$ final states and observed the two established $L=1$ charmed mesons, the $D_1(2420)^0$ with mass $2421^{+1+2}_{-2-2}$ MeV/c$^{2}$ and width $20^{+6+3}_{-5-3}$ MeV/c$^{2}$ and the $D_2^*(2460)^0$ with mass $2465 \pm 3 \pm 3$ MeV/c$^{2}$ and width $28^{+8+6}_{-7-6}$ MeV/c$^{2}$. Properties of these final states, including their decay angular distributions and spin-parity assignments, have been studied. We identify these two mesons as the $j_{light}=3/2$ doublet predicted by HQET. We also obtain constraints on {\footnotesize $\Gamma_S/(\Gamma_S + \Gamma_D)$} as a function of the cosine of the relative phase of the two amplitudes in the $D_1(2420)^0$ decay.

Using a sample of 3.3×106 Υ(4S)→B¯B events collected with the CLEO II detector at the Cornell Electron Storage Ring (CESR), we measure B(→Bρlν), |Vub|, and the partial rate (ΔΓ) in three bins of q2≡(pB−pρ)2. We find B(B0→ρ−l+ν)=(2.69±0.41+0.35−0.40±0.50)×10−4, |Vub|=(3.23±0.24+0.23−0.26±0.58)×10−3, ΔΓ(0<q2<7GeV2/c4)=(7.6±3.0+0.9−1.2±3.0)×10−2ns−1, ΔΓ(7<q2<14GeV2/c4)=(4.8±2.9+0.7−0.8±0.7)×10−2ns−1, and ΔΓ(14<q2<21GeV2/c4)=(7.1±2.1+0.9−1.1±0.6)×10−2ns−1. Here, l=e or μ, but not both, and the errors are statistical, systematic, and theoretical. The method is sensitive primarily to →Bρlν decays with leptons in the energy range above 2.3 GeV. Averaging with the previously published CLEO results for →Bρlν, we obtain B(B0→ρ−l+ν)=(2.57±0.29+0.33−0.46±0.41)×10−4 and |Vub|=(3.25±0.14+0.21−0.29±0.55)×10−3. Received 24 May 1999DOI:https://doi.org/10.1103/PhysRevD.61.052001©2000 American Physical Society

Using the CLEO detector at the Cornell Electron Storage Ring, we have made a measurement of $R\ensuremath{\equiv}\ensuremath{\sigma}{(e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}\mathrm{hadrons})/\ensuremath{\sigma}{(e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}})=3.56\ifmmode\pm\else\textpm\fi{}0.01\ifmmode\pm\else\textpm\fi{}0.07$ at $\sqrt{s}$=10.52 GeV. This implies a value for the strong coupling constant of ${\ensuremath{\alpha}}_{s}(10.52 \mathrm{GeV})=0.20\ifmmode\pm\else\textpm\fi{}0.01\ifmmode\pm\else\textpm\fi{}0.06$, or ${\ensuremath{\alpha}}_{s}{(M}_{Z})=0.13\ifmmode\pm\else\textpm\fi{}0.005\ifmmode\pm\else\textpm\fi{}0.03$.

We consider the decay of \ensuremath{\Upsilon}(1S) particles produced at CESR into a photon which is observed by the CLEO detector plus particles which are not seen. These could be real particles which fall outside of our acceptance, or particles which are noninteracting. We report the results of our search fo the process \ensuremath{\Upsilon}(1S)\ensuremath{\rightarrow}\ensuremath{\gamma}+``unseen'' for photon energies &gt;1 GeV, obtaining limits for the case where ``unseen'' is either a single particle or a particle-antiparticle pair. Our upper limits represent the highest sensitivity measurements for such decays to date.

Abstract The Askaryan Radio Array (ARA) experiment at the South Pole is designed to detect high-energy neutrinos which, via in-ice interactions, produce coherent radiation at frequencies up to 1000 MHz. Characterization of ice birefringence, and its effect upon wave polarization, is proposed to enable range estimation to a neutrino interaction and hence aid in neutrino energy reconstruction. Using radio transmitter calibration sources, the ARA collaboration recently measured polarization-dependent time delay variations and reported significant time delays for trajectories perpendicular to ice flow, but not parallel. To explain these observations, and assess the capability for range estimation, we use fabric data from the SPICE ice core to model ice birefringence and construct a bounding radio propagation model that predicts polarization time delays. We compare the model with new data from December 2018 and demonstrate that the measurements are consistent with the prevailing horizontal crystallographic axis aligned near-perpendicular to ice flow. The study supports the notion that range estimation can be performed for near flow-perpendicular trajectories, although tighter constraints on fabric orientation are desirable for improving the accuracy of estimates.

We have searched for two-body charmless decays of B mesons to purely hadronic exclusive final states including $\omega$ or $\phi$ mesons using data collected with the CLEO II detector. With this sample of $6.6 \times 10^6$ B mesons we observe a signal for the $\omega K^+$ final state, and measure a branching fraction of B($B^+ \to \omega K^+$) = 1.5 +0.7 -0.6 +-0.2 $\times 10^{-5}$. We also observe some evidence for the $\phi K^*$ final state, and upper limits are given for 22 other decay modes. These results provide the opportunity for studies of theoretical models and physical parameters.

Using data recorded by the CLEO II detector at CESR, we report evidence for two new charmed baryons, one decaying into $\Xi_c^+\pi^+\pi^-$ via an intermediate $\Xi_c^{*0}$, and its isospin partner decaying into $\Xi_c^0\pi^+\pi^-$ via an intermediate $\Xi_c^{*+}$. We measure the mass differences of the two states to be $M(\Xi_c^+\pi^+\pi^-)-M(\Xi_c^+)=$ $348.6\pm0.6\pm1.0$ MeV, and $M(\Xi_c^0\pi^+\pi^-)-M(\Xi_c^0)=$ $347.2\pm0.7\pm2.0$ MeV. We interpret these new states as the $J^P = {3 \over{2}}^- $ $\Xi_{c1}$ particles, the charmed-strange analogues of the $\Lambda_{c1}^+(2625)$.

Using data recorded by the CLEO-II detector at CESR, we report evidence of a pair of excited charmed baryons, one decaying into Λ+cπ+ and the other into Λ+cπ−. The doubly charged state has a measured mass difference M(Λ+cπ+)−M(Λ+c) of 234.5±1.1±0.8 MeV/c2 and a width of 17.9+3.8−3.2±4.0MeV/c2, and the neutral state has a measured mass difference M(Λ+cπ−)−M(Λ+c) of 232.6±1.0±0.8 MeV/c2 and a width of 13.0+3.7−3.0±4.0MeV/c2. We interpret these data as evidence of the Σ*++c and Σ*0c, the spin 32+ excitations of the Σc baryons.Received 26 September 1996DOI:https://doi.org/10.1103/PhysRevLett.78.2304©1997 American Physical Society

A Time-of-Flight (TOF) detector, based on plastic scintillators and fine-mesh photomultipliers, has been added to the Collider Detector at Fermilab (CDF)-II experiment at the Tevatron pp̄ collider. The primary physics motivation is to provide charged kaon identification to improve neutral B meson flavor determination. Besides that, the TOF detector found application in the CDF trigger system in implementation of highly ionizing particle, high multiplicity and cosmic rays triggers.

Abstract Using the RICE (Radio Ice Cherenkov Experiment) detector at the South Pole, we have estimated the variation in the index of refraction (n ) of the firn, as a function of elevation (z ) measured from the surface down to z =-150 m. Measurements were made by lowering a dipole transmitter into a dry (5 in (127 mm) caliber) borehole, originally drilled for the RICE experiment in 1998, and determining signal arrival times, as a function of transmitter depth, in the englacial RICE receiver array. We clearly confirm the expected correlation of n (z ) with ice density. Our measurements are in fair agreement with previous laboratory characterizations of the dielectric properties of ice cores. These are the first such in situ measurements to be performed at the South Pole.

We report an upper limit on the flux of relativistic monopoles based on the nonobservation of in-ice showers by the Radio Ice Cherenkov Experiment (RICE) at the South Pole. We obtain a 95% C.L. limit of order ${10}^{\ensuremath{-}18}\text{ }\text{ }({\mathrm{cm}}^{2}\text{ }\mathrm{s}\text{ }\mathrm{sr}{)}^{\ensuremath{-}1}$ for intermediate-mass monopoles of ${10}^{7}\ensuremath{\le}\ensuremath{\gamma}\ensuremath{\le}{10}^{12}$ at the anticipated energy ${E}_{\mathrm{tot}}={10}^{16}\text{ }\text{ }\mathrm{GeV}$. This bound is over an order of magnitude stronger than all previously published experimental limits for this range of boost parameters $\ensuremath{\gamma}$ and exceeds 2 orders of magnitude improvement over most of the range. We review the physics of radio detection, describe a Monte Carlo simulation including continuous and stochastic energy losses, and compare to previous experimental limits.

Owing to their small interaction cross-section, neutrinos are unparalleled astronomical tracers. Ultra-high energy (UHE; E > 10 PeV) neutrinos probe the most distant, most explosive sources in the Universe, often obscured to optical telescopes. Radio-frequency (RF) detection of Askaryan radiation in cold polar ice is currently regarded as the best experimental measurement technique for UHE neutrinos, provided the RF properties of the ice target can be well-understood. To that end, the Askaryan Radio Array (ARA) experiment at the South Pole has used long-baseline RF propagation to extract information on the index-of-refraction (n=ϵr) in South Polar ice. Owing to the increasing ice density over the upper 150–200 m, rays are measured along two, nearly parallel paths, one of which refracts through an inflection point, with differences in both arrival time and arrival angle that can be used to constrain the neutrino properties. We also observe (first) indications for RF ice birefringence for signals propagating along predominantly horizontal trajectories, corresponding to an asymmetry of order 0.1% between the ordinary and extra-ordinary birefringent axes, numerically compatible with previous measurements of birefringent asymmetries for vertically-propagating radio-frequency signals at South Pole. Qualitatively, these effects offer the possibility of redundantly measuring the range from receiver to a neutrino interaction in Antarctic ice, if receiver antennas are deployed at shallow (z ∼ −25 m) depths. Such range information is essential in determining both the neutrino energy, as well as the incident neutrino direction.

We report on analysis of englacial radio-frequency (RF) pulser data received over horizontal baselines of 1–5 km, based on broadcasts from two sets of transmitters deployed to depths of up to 1500 meters at the South Pole. First, we analyze data collected using two RF bicone transmitters 1400 meters below the ice surface, and frozen into boreholes drilled for the IceCube experiment in 2011. Additionally, in Dec., 2018, a fat-dipole antenna, fed by one of three high-voltage ((1 kV)), fast ((1-5 ns risetime)) signal generators was lowered into the 1700-m deep icehole drilled for the South Pole Ice Core Experiment (SPICE), approximately 3 km from the geographic South Pole. Signals from transmitters were recorded on the five englacial multi-receiver ARA stations, with receiver depths between 60–200 m. From analysis of deep transmitter data, we estimate: i) the range of refractive index profiles of Antarctic ice with depth allowed by our measurements, ii) due to birefringence, a time difference between arrival times for vertically polarized vs. horizontally polarized signals (per km) for horizontally propagating signal, and iii) for the first time, the attenuation length for electromagnetic signals in the radio-frequency regime broadcast horizontally (rather than reflected vertically from bedrock). We additionally present data suggesting anomalous ice propagation effects, and contrary to expectations for a transport medium with a smoothly varying refractive index profile. Our results imply negligible uncertainty in overall neutrino detection volume due to refractive index uncertainties. Our birefringence time-difference measurements are fit to the functional form δt(H−V) [ns/km]=acosθ+b, with H/V the signal arrival times for the horizontally/vertically polarized EM signal components, and θ the opening angle in the horizontal plane between the signal propagation direction and the local ice flow direction, extracting a=8.3±1.3 ns/km, and b=-8.6±0.9 ns/km (errors combined statistical and systematic), allowing a ∼15% range estimate for future measurements of in-ice neutrino interactions. Finally, we find attenuation length values clustering around 1.5 km, with measurements from the bicone transmitters yielding Latten=1.43±0.25±0.37 km. Taken together, these measurements support cold polar ice as a near-optimal platform for ultra-high energy neutrino detectors.

In the pursuit of the measurement of the still-elusive ultrahigh-energy (UHE) neutrino flux at energies of order EeV, detectors using the in-ice Askaryan radio technique have increasingly targeted lower trigger thresholds. This has led to improved trigger-level sensitivity to UHE neutrinos. Working with data collected by the Askaryan Radio Array (ARA), we search for neutrino candidates at the lowest threshold achieved to date, leading to improved analysis-level sensitivities. A neutrino search on a data set with 208.7~days of livetime from the reduced-threshold fifth ARA station is performed, achieving a 68\% analysis efficiency over all energies on a simulated mixed-composition neutrino flux with an expected background of $0.10_{-0.04}^{+0.06}$ events passing the analysis. We observe one event passing our analysis and proceed to set a neutrino flux limit using a Feldman-Cousins construction. We show that the improved trigger-level sensitivity can be carried through an analysis, motivating the Phased Array triggering technique for use in future radio-detection experiments. We also include a projection using all available data from this detector. Finally, we find that future analyses will benefit from studies of events near the surface to fully understand the background expected for a large-scale detector.

Using a bistatic radar echo sounding (RES) system developed for calibration of the RICE particle astrophysics experiment at the South Pole, we have studied radio frequency (RF) reflections off the bedrock. The total propagation time of ∼ns-duration, vertically (zˆ) broadcast radio signals, as a function of polarization orientation in the horizontal plane, provides a direct probe of the geometry-dependence of the ice permittivity to a depth of 2.8 km. We observe clear birefringent asymmetries along zˆ in the lowest half of the ice sheet, at a fractional level ∼0.3%. This result is in contrast to expectations based on measurements at Dome Fuji, for which birefringence was observed in the upper 1.5 km of the ice sheet. This effect, combined with the increased radio frequency attenuation expected near the bedrock, renders the lower half thickness of South Polar ice less favorable than the upper half of the ice sheet in terms of its ultra-high energy neutrino detection potential.

Over the last 25 years, radiowave detection of neutrino-generated signals, using cold polar ice as the neutrino target, has emerged as perhaps the most promising technique for detection of extragalactic ultra-high energy neutrinos (corresponding to neutrino energies in excess of 0.01 Joules, or $10^{17}$ electron volts). During the summer of 2021 and in tandem with the initial deployment of the Radio Neutrino Observatory in Greenland (RNO-G), we conducted radioglaciological measurements at Summit Station, Greenland to refine our understanding of the ice target. We report the result of one such measurement, the radio-frequency electric field attenuation length $L_\alpha$. We find an approximately linear dependence of $L_\alpha$ on frequency with the best fit of the average field attenuation for the upper 1500 m of ice: $\langle L_\alpha \rangle = \big( (1154 \pm 121) - (0.81 \pm 0.14) (\nu/$MHz$)\big)$ m for frequencies $\nu \in [145 - 350]$ MHz.

The science program of the Radio Neutrino Observatory-Greenland (RNO-G) extends beyond particle astrophysics to include radioglaciology and, as we show herein, solar physics, as well. Impulsive solar flare observations not only permit direct measurements of light curves, spectral content, and polarization on time scales significantly shorter than most extant dedicated solar observatories, but also offer an extremely useful above-surface calibration source, with pointing precision of order tens of arc-minutes. Using the early RNO-G data from 2022-2023, observed flare characteristics are compared to well-established solar observatories. Also, a number of individual flares are used to highlight angular reconstruction and calibration methods. RNO-G observes signal excesses during solar flares reported by the solar-observing Callisto network and in coincidence with about 60% of the brightest excesses recorded by the SWAVES satellite, when the Sun is above the horizon for RNO-G. In these observed flares, there is significant impulsivity in the time-domain. In addition, the solar flares are used to calibrate the RNO-G absolute pointing on the radio signal arrival direction to sub-degree resolution.

A search for the lepton-family-number-violating decays →e␥ and →␥ has been performed using CLEO II data.No evidence of a signal has been found and the corresponding upper limits are B(→e␥)Ͻ2.7ϫ10Ϫ6 and B(→␥)Ͻ3.0ϫ10Ϫ6 at 90% C.L. ͓S0556-2821͑97͒50207-4͔

We use a data sample of 2.8 \ifmmode\times\else\texttimes\fi{} ${10}^{6}$ produced $\ensuremath{\tau}$-pair events, obtained with the CLEO II detector, to measure $\mathcal{B}({\ensuremath{\tau}}^{\ensuremath{-}}\ensuremath{\rightarrow}{h}^{\ensuremath{-}}{h}^{+}{h}^{\ensuremath{-}}({\ensuremath{\pi}}^{0}){\ensuremath{\nu}}_{\ensuremath{\tau}})$, where $h$ refers to either a charged $\ensuremath{\pi}$ or $K$. These branching fractions are measured with samples of lepton-tagged and 3 vs 3 events. We find $\mathcal{B}({\ensuremath{\tau}}^{\ensuremath{-}}\ensuremath{\rightarrow}{h}^{\ensuremath{-}}{h}^{+}{h}^{\ensuremath{-}}{\ensuremath{\nu}}_{\ensuremath{\tau}})=0.0951\ifmmode\pm\else\textpm\fi{}0.0007\ifmmode\pm\else\textpm\fi{}0.0020$ and $\mathcal{B}({\ensuremath{\tau}}^{\ensuremath{-}}\ensuremath{\rightarrow}{h}^{\ensuremath{-}}{h}^{+}{h}^{\ensuremath{-}}{\ensuremath{\pi}}^{0}{\ensuremath{\nu}}_{\ensuremath{\tau}})=0.0423\ifmmode\pm\else\textpm\fi{}0.0006\ifmmode\pm\else\textpm\fi{}0.0022$. We also measure $\mathcal{B}({\ensuremath{\tau}}^{\ensuremath{-}}\ensuremath{\rightarrow}\ensuremath{\omega}{h}^{\ensuremath{-}}{\ensuremath{\nu}}_{\ensuremath{\tau}})=0.0195\ifmmode\pm\else\textpm\fi{}0.0007\ifmmode\pm\else\textpm\fi{}0.0011$.

Using the CLEO II detector at CESR, we have observed two charmed states, where the higher mass state decays to D0π+ and to D∗0π+, while the lower mass state decays to D∗0π+, but not to D0π+. The masses and widths were measured to be 2425±2±2 MeV/c2 and 26−7−4+8+4 MeV/c2 for the lower mass state, and 2463±3±3 MeV/c2 and 27−8−5+11+5 MeV/c2 for the higher mass state. Properties of these states, including their decay angular distributions and spin-parity assignments have been studied. The results of this analysis support the identification of these states as the charged L = 1 D1 (2420)+ and D2∗ (2460)+, respectively. The isospin mass splittings between these states and their neutral partners have also been measured. This is the first full reconstruction of any decay mode of the D1 (2420)+ and the first observation of the decay of D2∗ (2460)+ to D∗0π+.

We have observed the decay ${B}^{+}\ensuremath{\rightarrow}{\overline{D}}^{0}{K}^{+}$, using $3.3\ifmmode\times\else\texttimes\fi{}{10}^{6}$ $B\overline{B}$ pairs collected with the CLEO II detector at the Cornell Electron Storage Ring. We find the ratio of branching fractions $R\ensuremath{\equiv}B({B}^{+}\ensuremath{\rightarrow}{\overline{D}}^{0}{K}^{+})/B({B}^{+}\ensuremath{\rightarrow}{\overline{D}}^{0}{\ensuremath{\pi}}^{+})\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}0.055\ifmmode\pm\else\textpm\fi{}0.014\ifmmode\pm\else\textpm\fi{}0.005$.

We have observed five new decay modes of the charmed baryon ${\ensuremath{\Lambda}}_{c}^{+}$ using data collected with the CLEO II detector. Four decay modes, ${\ensuremath{\Lambda}}_{c}^{+}\ensuremath{\rightarrow}p{\overline{K}}^{0}\ensuremath{\eta}$, $\ensuremath{\Lambda}\ensuremath{\eta}{\ensuremath{\pi}}^{+}$, ${\ensuremath{\Sigma}}^{+}\ensuremath{\eta}$, and ${\ensuremath{\Sigma}}^{*+}\ensuremath{\eta}$, are first observations of final states with an $\ensuremath{\eta}$ meson, while the fifth mode, ${\ensuremath{\Lambda}}_{c}^{+}\ensuremath{\rightarrow}\ensuremath{\Lambda}{\overline{K}}^{0}{K}^{+}$, requires the creation of an $s\overline{s}$ quark pair. We measure the branching fractions of these modes relative to ${\ensuremath{\Lambda}}_{c}^{+}\ensuremath{\rightarrow}{\mathrm{pK}}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}$ to be $0.25\ifmmode\pm\else\textpm\fi{}0.04\ifmmode\pm\else\textpm\fi{}0.04$, $0.35\ifmmode\pm\else\textpm\fi{}0.05\ifmmode\pm\else\textpm\fi{}0.06$, $0.11\ifmmode\pm\else\textpm\fi{}0.03\ifmmode\pm\else\textpm\fi{}0.02$, $0.17\ifmmode\pm\else\textpm\fi{}0.04\ifmmode\pm\else\textpm\fi{}0.03$, and $0.12\ifmmode\pm\else\textpm\fi{}0.02\ifmmode\pm\else\textpm\fi{}0.02$, respectively.

We have observed new channels for τ decays with an η in the final state. We study 3-prong tau decays, using the η→γγ and η→3π0 decay modes and 1-prong decays with two π0's using the η→γγ channel. The measured branching fractions are B(τ−→π−π−π+ηντ)=(3.4−0.5+0.6±0.6)×10−4 and B(τ−→π−2π0ηντ)=(1.4±0.6±0.3)×10−4. We observe clear evidence for f1→ηππ substructure and measure B(τ−→f1π−ντ)=(5.8−1.3+1.4±1.8)×10−4. We have also searched for η′(958) production and obtain 90% C.L. upper limits B(τ−→π−η′ντ)<7.4×10−5 and B(τ−→π−π0η′ντ)<8.0×10−5.Received 25 June 1997DOI:https://doi.org/10.1103/PhysRevLett.79.2406©1997 American Physical Society

Using a sample of 4.7 ${\mathrm{fb}}^{\ensuremath{-}1}$ integrated luminosity accumulated with the CLEO II detector at the Cornell Electron Storage Ring (CESR), we investigate the mass spectrum and resonant structure in ${\ensuremath{\tau}}^{\ensuremath{-}}\ensuremath{\rightarrow}{K}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\nu}}_{\ensuremath{\tau}}$ decays. We measure the relative fractions of ${K}_{1}(1270)$ and ${K}_{1}(1400)$ resonances in these decays, as well as the ${K}_{1}$ masses and widths. Our fitted ${K}_{1}$ resonances are somewhat broader than previous hadroproduction measurements, and in agreement with recent CERN LEP results from tau decay. The larger central value of our measured width supports models which attribute the small ${\ensuremath{\tau}}^{\ensuremath{-}}\ensuremath{\rightarrow}{K}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\nu}}_{\ensuremath{\tau}}$ branching fraction to larger ${K}_{1}$ widths than are presently tabulated. We also determine the ${K}_{a}{\ensuremath{-}K}_{b}$ mixing angle ${\ensuremath{\theta}}_{K}.$

We have searched for rare and forbidden decays of the eta(') meson in hadronic events at the CLEO II detector. The search is conducted on 4.80 fb(-1) of e(+)e(-) collisions at 10.6 GeV center-of-mass energy at the Cornell Electron Storage Ring. We find no signals, and set 90% confidence level upper limits of their branching fractions: B(eta(')-->e(+)e(-)eta)<2.4x10(-3), B(eta(')-->e(+)e(-)pi(0))<1. 4x10(-3), B(eta(')-->e(+)e(-)gamma)<0.9x10(-3), and B(eta(')-->e&mgr;)<4.7x10(-4). We also fit the matrix element of the eta(')-->pi(+)pi(-)eta Dalitz plot with the parametrization |M|(2) = A|1+alphay|(2), where y is a linear function of the kinetic energy of the eta, and find Re (alpha) = -0.021+/-0.025.

A Time-of-Flight (TOF) detector, based on plastic scintillator and fine-mesh photomultiplier tubes, has been added to the CDF-II experiment. Since August 2001, the TOF system has been fully instrumented and integrated into the CDF-II data acquisition system. The TOF system will provide particle identification of low momentum charged pions, kaons and protons in pp̄ collisions. With a design resolution goal of about 100ps, separation between charged kaons and pions is expected at the 2 sigma level for momenta below 1.6GeV/c, which enhances CDF's b-flavor tagging capabilities. We describe the design of the TOF detector and discuss its on-line and off-line calibration. Some performance benchmarks using proton–antiproton collision data are presented.

The RICE experiment on detection of UHE neutrinos has been running over a decade. The experiment comprises an array of radio antennas buried in ice to the depth of up to 300 m near the geographic South Pole, and is designed to observe neutrino interactions in ice employing the radio Cherenkov technique. We discuss new limits on the diffuse UHE neutrino flux that now include the full dataset accumulated over 10 years and benefit from new analysis techniques. We also present our recent measurements of birefringent properties of ice at the experiment location.

The Radio Neutrino Observatory -Greenland (RNO-G) is an in-ice neutrino detector, using radio emission to target the first measurement of neutrinos beyond PeV energies.In total 35 stations are planned for the detector, resulting in a detection volume of around 100 km³.Each of these stations is equipped with deep antennas embedded ∼ 100 m into the ice and downward-pointing log-periodic dipole antennas (LPDA) buried ∼ 3 m into the snow.At each station, three additional buried LPDA are pointing towards the sky and thus can be used to look for cosmic-ray induced air-showers.These air showers are a background for the RNO-G detector and therefore important to understand, but they also can be used as a calibration tool.In order to find the air-shower signals, we apply an analysis based on template matching to the data.We present the current status of the analysis targeting the detection of cosmic-rays induced air showers.This includes the presentation of a method to create a complete template set and a first look at RNO-G data.

The Radio Neutrino Observatory -Greenland (RNO-G) is an in-ice neutrino detector currently under construction.The detector is designed to make the first measurement of neutrinos beyond energies of ∼10 PeV.Each of the planned 35 stations of the detector includes three log-periodic dipole array antennas (LPDA) pointing towards the sky.The stations cover an area of ∼ 50 km 2 and enable RNO-G to measure the radio emission of cosmic-ray induced air-showers, thus making it a cosmic-ray detector as well.As other experiments have shown, such radio emission can be used to make precision cosmic-ray measurements.Additionally, the location of the experiment at Summit Station, at a height of ∼3000 m, enables RNO-G to study the phenomena of shower cores hitting the air/ice boundary and further developing in the ice itself.Moreover, RNO-G is also able to study high energetic muons, created in cosmic-ray induced air-showers, which penetrate into the ice from above.In this contribution, we will give an overview of the cosmic-ray analysis of RNO-G and report the current status.This includes outlining the method used for identifying the air-shower signals using signal templates, showing the first cosmic-ray candidate events and discussing systematic uncertainties.

Using a data sample of $\Upsilon(2S)$ events collected with the CLEO II detector at the Cornell Electron Storage Ring, we have investigated the hadronic transitions between the $\Upsilon(2S)$ and the $\Upsilon(1S)$. The charged dipion transition $\Upsilon(2S)\to \Upsilon(1S)\pi^+\pi^-$ was studied using two different analysis techniques. Selecting events in which $\Upsilon(1S)$ decays into a $\mu\mu$ or $ee$ lepton pair(``exclusive'' analysis), we measured the branching fraction of B=0.189+-0.004+-0.009, while using a method allowing $\Upsilon(1S)$ to decay into anything (``inclusive'' analysis) we found B=0.0196+-0.002+-0.010. The appropriate average of the two measurements gives B=0.0192+-0.002+-0.010. Combining the exclusive and inclusive results we derive the $\Upsilon(1S)$ leptonic branching ratios B_{ee}=0.0229+-0.0008+-0.0011 and B_{\mu\mu}=0.0249+-0.0008+-0.0013 We also studied $\Upsilon(2S)\to \Upsilon(1S)\pi^0\pi^0$ and obtained the branching fraction of B=0.092+-0.006+-0.007. Parameters of the $\pi\pi$ system (dipion invariant mass spectra, angular distributions) were analyzed and found to be consistent with current theoretical models. Lastly, we searched for the $\eta$ and single $\pi^0$ transitions and obtained the upper limits of 0.0028 and 0.0011 respectively.

Using the CLEO II detector we measure $\frac{\mathcal{B}({D}_{s}^{+}\ensuremath{\rightarrow}\ensuremath{\eta}{e}^{+}\ensuremath{\nu})}{\mathcal{B}({D}_{s}^{+}\ensuremath{\rightarrow}\ensuremath{\varphi}{e}^{+}\ensuremath{\nu})}=1.24\ifmmode\pm\else\textpm\fi{}0.12\ifmmode\pm\else\textpm\fi{}0.15$, $\frac{\mathcal{B}({D}_{s}^{+}\ensuremath{\rightarrow}{\ensuremath{\eta}}^{\ensuremath{'}}{e}^{+}\ensuremath{\nu})}{\mathcal{B}({D}_{s}^{+}\ensuremath{\rightarrow}\ensuremath{\varphi}{e}^{+}\ensuremath{\nu})}=0.43\ifmmode\pm\else\textpm\fi{}0.11\ifmmode\pm\else\textpm\fi{}0.07$, and $\frac{\mathcal{B}({D}_{s}^{+}\ensuremath{\rightarrow}{\ensuremath{\eta}}^{\ensuremath{'}}{e}^{+}\ensuremath{\nu})}{\mathcal{B}({D}_{s}^{+}\ensuremath{\rightarrow}\ensuremath{\eta}{e}^{+}\ensuremath{\nu})}=0.35\ifmmode\pm\else\textpm\fi{}0.09\ifmmode\pm\else\textpm\fi{}0.07$. We find the ratio of vector to pseudoscalar final states, $\frac{\mathcal{B}({D}_{s}^{+}\ensuremath{\rightarrow}\ensuremath{\varphi}{e}^{+}\ensuremath{\nu})}{\mathcal{B}({D}_{s}^{+}\ensuremath{\rightarrow}(\ensuremath{\eta}+{\ensuremath{\eta}}^{\ensuremath{'}}){e}^{+}\ensuremath{\nu})}=0.60\ifmmode\pm\else\textpm\fi{}0.06\ifmmode\pm\else\textpm\fi{}0.06$, which is similar to the ratio found in nonstrange $D$ decays.

We report on a search for ultra-high-energy (UHE) neutrinos from gamma-ray bursts (GRBs) in the data set collected by the Testbed station of the Askaryan Radio Array (ARA) in 2011 and 2012. From 57 selected GRBs, we observed no events that survive our cuts, which is consistent with 0.12 expected background events. Using NeuCosmA as a numerical GRB reference emission model, we estimate upper limits on the prompt UHE GRB neutrino fluence and quasi-diffuse flux from $10^{7}$ to $10^{10}$ GeV. This is the first limit on the prompt UHE GRB neutrino quasi-diffuse flux above $10^{7}$ GeV.

Using the CLEO II detector at the Cornell Electron Storage Ring we have observed the decay modes Ξc+→Ξ0e+νe and Ξc0→Ξ−e+νe by the detection of a Ξ-positron pair of appropriate invariant mass. We find B(Ξc+→Ξ0e+νe)σ(e+e−→Ξc+X)=1.55±0.33±0.25 pb, B(Ξc0→Ξ−e+νe)σ(e+e−→Ξc0X)=0.63±0.12±0.10 pb, B(Ξc+→Ξ−π+π+)/B(Ξc+→Ξ0e+νe)=0.44±0.11−0.06+0.11, and B(Ξc0→Ξ−π+)/B(Ξc0→Ξ−e+νe)=0.32±0.10−0.03+0.05. Assuming the Ξc+ and Ξc0 are equally produced in e+e− annihilation events at 10 GeV, the lifetime ratio of Ξc+/Ξc0 is measured to be 2.46±0.70−0.23+0.33.Received 12 October 1994DOI:https://doi.org/10.1103/PhysRevLett.74.3113©1995 American Physical Society

We measure the τ lepton lifetime with τ+τ− pairs in which one or both of the τ's decays to three charged particles. The data were collected with the CLEO II detector operating at the electron-positron collider CESR at energies on and near the Y(4S). We use displacements of the three-track vertices to determine the τ lifetime. The results is ττ = 289.0±2.8±4.0 fs.

Using the CLEO II detector operating at the e+e− Cornell Electron Storage Ring (CESR), we present evidence for new decay modes of the Ξc+ into Ξ0π+, Ξ0π+π0, and Ξ0π+π−π+. The branching ratios of these decay modes, relative to Ξc+→Ξ−π+π+, have been measured to be 0.55±0.13±0.09, 2.34±0.57±0.37, and 1.74±0.42±0.27, respectively.

Using the CLEO II detector operating at the CESR e+e- collider, we have measured the structure functions in the decay tau+/- --> pi+/- pi0 pi0 nu, based on a sample corresponding to 4*10E6 produced tau-pair events. We determine the integrated structure functions, which depend only on the three pion invariant mass, as well as the structure functions differential in the Dalitz plot. We extract model independent limits on non-axial-vector contributions from the measured structure functions as less than 16.6% of the total branching fraction, at the 95% confidence level. Separating the non-axial-vector contributions into scalar and vector contributions, we measure that scalars (vectors) contribute with less than 9.4% (7.3%) to the total branching ratio, at the 95% confidence level.

The Event Builder and Level 3 systems constitute critical components of the DAQ in the Collider Detector at Fermilab experiment. These systems are responsible for collecting data fragments from the Front End electronics, assembling the data into complete event records, reconstructing the events and forming the final trigger decision. With Tevatron Run IIa in progress, the systems have been running successfully at high throughput rates, the design utilizing scalable architecture and distributed event processing to meet the requirements. Brief descriptions of current performance in Run IIa and possible upgrade for Run IIb are presented.

We use data collected by the CLEO II detector at the Cornell Electron Storage Ring (CESR) to search for ${B}^{+}\ensuremath{\rightarrow}{h}^{+}{h}^{\ensuremath{-}}{h}^{+}$ (nonresonant) decays, where ${h}^{\ifmmode\pm\else\textpm\fi{}}$ can be either ${\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}{,K}^{\ifmmode\pm\else\textpm\fi{}}$, or $p(\overline{p})$. We see no evidence for signals and set upper limits on the branching fractions in the range $(2.8--8.9)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}5}$. If observed, these decays may display CP violating asymmetries.

We have studied the decay ¯B→Dl¯ν, where l=e or μ. From a fit to the differential decay rate dγ/dw we measure the rate normalization FD(1)|Vcb| and form factor slope ^ρ2D, and, using measured values of τB, find γ(¯B→Dl¯ν)=(12.0±0.9±2.1)ns−1. The resulting branching fractions are B(¯B0→D+l−¯ν)=(1.87±0.15±0.32)% and B(B−→D0l−¯ν)=(1.94±0.15±0.34)%. The form factor parameters are in agreement with those measured in ¯B→D∗l¯ν decays, as predicted by heavy quark effective theory.Received 30 May 1997DOI:https://doi.org/10.1103/PhysRevLett.79.2208©1997 American Physical Society

Using the CLEO II detector at the $e^+e^-$ storage ring CESR, we have determined the Michel parameters $\rho$, $\xi$, and $\delta$ in $\tau^\mp \to l^\mp\nu\bar{\nu}$ decay as well as the tau neutrino helicity parameter $h_{\nu_\tau}$ in $\tau^\mp \to \pi^\mp\pi^0\nu$ decay. From a data sample of $3.02\times 10^6$ tau pairs produced at $\sqrt{s}=10.6 GeV$, using events of the topology $e^+e^- \to \tau^+\tau^- \to (l^\pm\nu\bar{\nu}) (\pi^\mp\pi^0\nu)$ and $e^+e^- \to \tau^+\tau^- \to (\pi^\pm\pi^0\bar{\nu}) (\pi^\mp\pi^0\nu)$, and the determined sign of $h_{\nu_\tau}$, the combined result of the three samples is: $\rho = 0.747\pm 0.010\pm 0.006$, $\xi = 1.007\pm 0.040\pm 0.015$, $\xi\delta = 0.745\pm 0.026\pm 0.009$, and $h_{\nu_\tau} = -0.995\pm 0.010\pm 0.003$. The results are in agreement with the Standard Model V-A interaction.

Abstract The CDF II detector contains a time-of-flight detector consisting of 216 scintillator bars of 279 cm length and 4×4 cm2 cross-section located at a radius of 138 cm from the beam axis. The bars are installed on the inner surface of the CDF solenoid, which produces an axial field of 1.4 T. Nineteen-stage fine-mesh photomultiplier tubes are attached at both ends of the scintillator bars. Photostatistics limit the time-of-flight resolution, which is expected to be 100 ps. The primary physics motivation is K± identification for improved neutral B meson flavor determination.

The Event Builder and Level 3 trigger systems of the CDF experiment at Fermilab are required to process about 300 events per second, with an average event size of ∼200 KB. In the event building process the event is assembled from 15 sources supplying event fragments with roughly equal sizes of 12–16 KB. In the subsequent commercial processor-based Level 3 trigger, the events are reconstructed and trigger algorithms are applied. The CPU power required for filtering such a high data throughput rate exceeds 45 000 MIPS. To meet these requirements a distributed and scalable architecture has been chosen. It is based on commodity components: VME-based CPU's for the data read out, an ATM switch for the event building and Pentium-based personal computers running the Linux operating system for the event processing. Event flow through ATM is controlled by a reflective memory ring. The roughly homogeneous distribution of the expected load allows the use of 100 Mbps Ethernet for event distribution and collection within the Level 3 system. Preliminary results from a test system obtained during the last year are presented.

RNO is the mid-scale discovery instrument designed to make the first observation of neutrinos from the cosmos at extreme energies, with sensitivity well beyond current instrument capabilities. This new observatory will be the largest ground-based neutrino telescope to date, enabling the measurement of neutrinos above $10^{16}$ eV, determining the nature of the astrophysical neutrino flux that has been measured by IceCube at higher energies, similarly extending the reach of multi-messenger astrophysics to the highest energies, and enabling investigations of fundamental physics at energies unreachable by particle accelerators on Earth.

Using data recorded by the CLEO-II detector at CESR we have searched for four radiative decay modes of the $D^0$ meson: $D^0\to\phi\gamma$, $D^0\to\omega\gamma$, $D^0\to\bar{K}^{*}\gamma$, and $D^0\to\rho^0\gamma$. We obtain 90% CL upper limits on the branching ratios of these modes of $1.9\times 10^{-4}$, $2.4\times 10^{-4}$, $7.6\times 10^{-4}$ and $2.4\times 10^{-4}$ respectively.

Using $4.68{\mathrm{fb}}^{\ensuremath{-}1}$ of ${e}^{+}{e}^{\ensuremath{-}}$ annihilation data collected with the CLEO II detector at the Cornell Electron Storage Ring, we have studied $\ensuremath{\tau}$ radiative decays ${\ensuremath{\tau}}^{\ensuremath{-}}\ensuremath{\rightarrow}{\ensuremath{\nu}}_{\ensuremath{\tau}}{\ensuremath{\mu}}^{\ensuremath{-}}{\overline{\ensuremath{\nu}}}_{\ensuremath{\mu}}\ensuremath{\gamma}$ and ${\ensuremath{\tau}}^{\ensuremath{-}}\ensuremath{\rightarrow}{\ensuremath{\nu}}_{\ensuremath{\tau}}{e}^{\ensuremath{-}}{\overline{\ensuremath{\nu}}}_{e}\ensuremath{\gamma}$. For a 10 MeV minimum photon energy in the $\ensuremath{\tau}$ rest frame, the branching fraction for radiative $\ensuremath{\tau}$ decay to a muon or electron is measured to be $(3.61\ifmmode\pm\else\textpm\fi{}0.16\ifmmode\pm\else\textpm\fi{}0.35)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}$ or $(1.75\ifmmode\pm\else\textpm\fi{}0.06\ifmmode\pm\else\textpm\fi{}0.17)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}2}$, respectively. The branching fractions are in agreement with standard model theoretical predictions.

The dynamics of the decay Ds+ → φe+ve are studied using a sample of 474 events recorded by the CLEO II detector. A three dimensional fit to the decay angles and q2 is performed to extract the ratios of form factors R2=A2(0)/A1(0) and Rv=V(0 )/ A1(0), where A1(0) and A2(0) are the two axial vector form factors and V(0) is the vector form factor evaluated at q2 =0. By assuming the single pole parameterization for the form factors, we obtain: R2=1.4±0.5±0.3 and Rv=0.9±0.6±0.3.

An examination of leptons in $\ensuremath{\Upsilon}(4S)$ events tagged by reconstructed $B$ meson decays yields semileptonic branching fractions of ${b}_{\ensuremath{-}}=(10.1\ifmmode\pm\else\textpm\fi{}1.8\ifmmode\pm\else\textpm\fi{}1.5)%$ for charged and ${b}_{0}=(10.9\ifmmode\pm\else\textpm\fi{}0.7\ifmmode\pm\else\textpm\fi{}1.1)%$ for neutral $B$ mesons. This is the first measurement for charged $B$ mesons. Assuming equality of the charged and neutral semileptonic widths, the ratio $\frac{{b}_{\ensuremath{-}}}{{b}_{0}}=0.93\ifmmode\pm\else\textpm\fi{}0.18\ifmmode\pm\else\textpm\fi{}0.12$ is equivalent to the ratio of lifetimes.

The decays $\ensuremath{\Upsilon}(4S)\ensuremath{\rightarrow}B\overline{B}$, followed by $B\ensuremath{\rightarrow}{D}^{*}\ensuremath{\pi}$ and ${D}^{*}\ensuremath{\rightarrow}D\ensuremath{\pi}$, permit reconstruction of all kinematic quantities that describe the sequence without reconstruction of the $D$, with reasonably low backgrounds. Using an integrated ${e}^{+}{e}^{\ensuremath{-}}$ luminosity of $3.1{\mathrm{fb}}^{\ensuremath{-}1}$ accumulated at the $\ensuremath{\Upsilon}(4S)$ by the CLEO-II detector, we report measurements of $B({\overline{B}}^{0}\ensuremath{\rightarrow}{D}^{*+}{\ensuremath{\pi}}^{\ensuremath{-}})\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}(2.81\ifmmode\pm\else\textpm\fi{}0.11\ifmmode\pm\else\textpm\fi{}0.21\ifmmode\pm\else\textpm\fi{}0.05)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}$ and $B({B}^{\ensuremath{-}}\ensuremath{\rightarrow}{D}^{*0}{\ensuremath{\pi}}^{\ensuremath{-}})\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}(4.34\ifmmode\pm\else\textpm\fi{}0.33\ifmmode\pm\else\textpm\fi{}0.34\ifmmode\pm\else\textpm\fi{}0.18)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}$.

The Λ+c→pK−π+ yield has been measured in a sample of two-jet continuum events containing both a charm tag (“¯D”) as well as an antiproton (e+e−→¯D¯pX), with the antiproton in the hemisphere opposite the ¯D (measurement of charge conjugate modes is implicit throughout). Under the hypothesis that such selection criteria tag e+e−→¯D¯pΛ+cX events, the Λ+c→pK−π+ branching fraction can be determined by measuring the pK−π+ yield in the same hemisphere as the antiprotons in our ¯D¯pX sample. Three types of ¯D charm tags are used, π−soft (from D*−→D0π−soft), electrons (from ¯D→Xe−ν), and fully reconstructed D0→K+π− or D−→K+π−π− or D−s→φπ−. Combining our results obtained from the three independent charm tags, we obtain B(Λ+c→pK−π+)=(5.0±0.5±1.2)%. Received 28 March 2000DOI:https://doi.org/10.1103/PhysRevD.62.072005©2000 American Physical Society

We present a brief overview of experimental efforts in Antarctica to search for radio pulses from electron–hadron cascades produced by cosmic ultrahigh-energy neutrinos in Antarctic ice. Thus far, the essential features (energy thresholds, effective recording volumes, etc.) of Antarctic neutrino radio experiments can be classified according to the deployment scheme employed: either (1) on the surface of the glacier—RAMAND-type, (2) in holes in the ice at depths of several hundred meters—RICE-type or (3) on board of a stratospheric balloon at an altitude of 40 km—ANITA-type. We herein propose an alternative possibility, namely to use tethered balloons for placing the radio antennas at modest (compared to ANITA) altitudes above the ice surface (1–2 km). This configuration of antennas will reduce (as compared to ANITA) the energy threshold for detection of neutrinos and increase the observation time.

A limit on the mass of the tau neutrino is derived from 4.5 million tau pairs produced in an integrated luminosity of 5.0 fb^{-1} of electron-positron annihilation to tau pairs at center of mass energies near 10.6 GeV. The measurement technique involves a two-dimensional extended likelihood analysis, including the dependence of the end-point population on the neutrino mass, and allows for the first time an explicit background contribution. We use the decays of the tau to five charged pions and a neutrino as well as the decay to three charged pions, two neutral pions and a neutrino to obtain an upper limit of 30 MeV/c^2 at 95% C.L.

A study of charm fragmentation into Ds*+ and Ds+ in e+e− annihilations at s=10.5 GeV is presented. This study using 4.72±0.05 fb−1 of CLEO II data reports measurements of the cross sections σ(Ds*+) and σ(Ds+) in momentum regions above x=0.44, where x is the Ds momentum divided by the maximum kinematically allowed Ds momentum. The Ds vector to vector plus pseudoscalar production ratio is measured to be PV(x(Ds+)>0.44)=0.44±0.04. Received 25 April 2000DOI:https://doi.org/10.1103/PhysRevD.62.072003©2000 American Physical Society

We have used the CLEO II detector to study the multiplicity of charged particles in the decays of B mesons produced at the Υ(4S) resonance. Using a sample of 1.5×106 B meson pairs, we find the mean inclusive charged particle multiplicity to be 10.71±0.02+0.21−0.15 for the decay of the pair. This corresponds to a mean multiplicity of 5.36±0.01+0.11−0.08 for a single B meson. Using the same data sample, we have also extracted the mean multiplicities in semileptonic and nonleptonic decays. We measure a mean of 7.82±0.05+0.21−0.19 charged particles per B¯B decay when both mesons decay semileptonically. When neither B meson decays semileptonically, we measure a mean charged particle multiplicity of 11.62±0.04+0.24−0.18 per B¯B pair.Received 8 September 1999DOI:https://doi.org/10.1103/PhysRevD.61.072002©2000 American Physical Society

We have searched for the rare decay of the $\ensuremath{\eta}$ meson $\ensuremath{\eta}\ensuremath{\rightarrow}{e}^{+}{e}^{\ensuremath{-}}$ using the CLEO II detector. The $\ensuremath{\eta}$'s were produced in ${e}^{+}{e}^{\ensuremath{-}}$ collisions with 10 GeV center-of-mass energy at the Cornell Electron Storage Ring (CESR). We find with $90%$ confidence the upper limit on the branching fraction $B(\ensuremath{\eta}\ensuremath{\rightarrow}{e}^{+}{e}^{\ensuremath{-}})&lt;7.7\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}5}$. The application of conventional elementary particle theory to this decay predicts a branching fraction of about ${10}^{\ensuremath{-}9}$.

We have measured the spectral shape Michel parameters $\ensuremath{\rho}$ and $\ensuremath{\eta}$ using leptonic decays of the $\ensuremath{\tau}$, recorded by the CLEO II detector. Assuming $e\ensuremath{-}\ensuremath{\mu}$ universality in the vectorlike couplings, we find ${\ensuremath{\rho}}_{e\ensuremath{\mu}}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}0.735\ifmmode\pm\else\textpm\fi{}0.013\ifmmode\pm\else\textpm\fi{}0.008$ and ${\ensuremath{\eta}}_{e\ensuremath{\mu}}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}\ensuremath{-}0.015\ifmmode\pm\else\textpm\fi{}0.061\ifmmode\pm\else\textpm\fi{}0.062$, where the first error is statistical and the second systematic. We also present measurements for the parameters for $e$ and $\ensuremath{\mu}$ final states separately.

We have found the first evidence for the Cabibbo suppressed, color suppressed decay B− → ψπ− in a data sample of 4 million B decays obtained by the CLEO detector at the Cornell Electron Storage Ring (CESR). The branching ratio is found to be (4.3±2.3)% of the Cabibbo allowed B− → ψK− decay mode, which is consistent with theoretical expectations.

A measurement of the spin alignment of charged D^* mesons produced in continuum e^+ e^- \to c \bar{c} events at \sqrt{s}=10.5 GeV is presented. This study using 4.72 fb^{-1} of CLEO II data shows that there is little evidence of any D^* spin alignment.

We present new measurements of photon energies and branching fractions for the radiative transitions Υ(2S)→γχb(J=0,1,2)(1P). The masses of the χb states are determined from the measured radiative photon energies. The ratio of mass splittings between the χb substates, r≡(MJ=2−MJ=1)/(MJ=1−MJ=0), with M the χb mass, provides information on the nature of the b¯b confining potential. We find r(1P)=0.542±0.022±0.024. This value is somewhat lower than the previous world average, but more consistent with the theoretical expectation that r(1P)<r(2P); i.e., that this mass splitting ratio is smaller for the χb(1P) states than for the χb(2P) states.Received 12 March 1998DOI:https://doi.org/10.1103/PhysRevD.59.032003©1999 American Physical Society

A Time-of-Flight detector (TOF) has been incorporated into the CDF-II experiment in order to provide charged kaon identification to improve neutral B meson flavor determination. With an expected time-of-flight resolution of 100 ps, the system will be able to provide 2 standard deviation separation between K± and π± for momenta p < 1.6 GeV/c, complementing the specific ionization energy loss dE/dx measured with the new drift chamber.

Increased event statistics will be required to definitively answer the question of the origin(s) of Ultra-High Energy Cosmic Rays (UHECR). Using current technologies however, achieving the necessary statistics may be financially and practically impossible. We describe the status and plans of the TARA project, an effort to detect Ultra-High-Energy Cosmic Rays by their forward scattered or “bistatic” radar signature. Bistatic radar holds promise as a new remote sensing technique for UHECR, without the duty cycle limitations of nitrogen fluorescence detectors. Such a technique could prove key in advancing the study of UHECR beyond the constraints of the current generation of cosmic ray observatories. TARA consists of a low-VHF television transmitter illuminating the air above the Telescope Array (TA), and a set of radio receivers on the far side of TA approximately 50 km distant from the transmitter. We have collected radar data since April 2011 using a 2 kW transmitter at 54.1 MHz. Recently, we received permission to increase our broadcast power to 40 kW and our effective radiated power (ERP) to 6 MW. On the receiver end, we are employing software-defined radio receivers and developing real-time trigger algorithms based on the expected air shower radar echo. In addition to presenting an overview of the project status and future plans, we will present the most recent results of searches for coincidences between radar echoes and Telescope Array air shower events.

We have searched for the decay of the lepton into seven charged particles and zero or one 0 .The data used in the search were collected with the CLEO II detector at the Cornell Electron Storage Ring ͑CESR͒ and correspond to an integrated luminosity of 4.61 fb Ϫ1 .No evidence for a signal is found.Assuming all the charged particles are pions, we set an upper limit on the branching fraction B" Ϫ →4 Ϫ 3 ϩ ( 0 ) …Ͻ2.4ϫ10 Ϫ6 at the 90% confidence level.This limit represents a significant improvement over the previous limit.͓S0556-2821͑97͒50221-9͔

We have searched for the decays $B\ensuremath{\rightarrow}\ensuremath{\mu}{\overline{\ensuremath{\nu}}}_{\ensuremath{\mu}}\ensuremath{\gamma}$ and $B\ensuremath{\rightarrow}e{\overline{\ensuremath{\nu}}}_{e}\ensuremath{\gamma}$ in a sample of $2.7\ifmmode\times\else\texttimes\fi{}{10}^{6}$ charged $B$ decays collected with the CLEO II detector. In the muon channel, we observe no candidates in the signal region and set an upper limit on the branching fraction of $\mathcal{B}(B\ensuremath{\rightarrow}\ensuremath{\mu}{\overline{\ensuremath{\nu}}}_{\ensuremath{\mu}}\ensuremath{\gamma})&lt;5.2\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}5}$ at the 90% confidence level. In the electron channel, we observe five candidates in the signal region and set an upper limit on the branching fraction of $\mathcal{B}(B\ensuremath{\rightarrow}e{\overline{\ensuremath{\nu}}}_{e}\ensuremath{\gamma})&lt;2.0\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}$ at the 90% confidence level.

The Askaryan Radio Array (ARA) is an ultra-high energy (UHE) neutrino ( > 10 17 eV) detector at South Pole.ARA aims to utilize radio signals detected from UHE neutrino interactions in the glacial ice to infer properties about the interaction vertex as well as the incident neutrino.To retrieve these properties from experiment data, the first step is to extract timing, amplitude and frequency information from waveforms of different antennas buried in the deep ice.These features can then be utilized in a neural network to reconstruct the neutrino interaction vertex position, incoming neutrino direction and shower energy.So far, vertex can be reconstructed through interferometry while neutrino reconstruction is still under investigation.Here I will present a solution based on multi-task deep neural networks which can perform reconstruction of both vertex and incoming neutrinos with a reasonable precision.After training, this solution is capable of rapid reconstructions (e.g.0.1 ms/event compared to 10000 ms/event in a conventional routine) useful for trigger and filter decisions, and can be easily generalized to different station configurations for both design and analysis purposes.

Using data collected on the $\ensuremath{\Upsilon}(4S)$ resonance and the nearby continuum by the CLEO-II detector, we have studied combinations of baryons with leptons produced in the process $\ensuremath{\Upsilon}(4S)\ensuremath{\rightarrow}B\overline{B}$, $B\ensuremath{\rightarrow}\mathrm{lepton}+X$, $\overline{B}\ensuremath{\rightarrow}\mathrm{baryon}+X$. Our results do not support models which attribute the bulk of ${\ensuremath{\Lambda}}_{c}$ production in $\overline{B}$ decay to the process $b\ensuremath{\rightarrow}{\mathrm{cW}}^{\ensuremath{-}}{,W}^{\ensuremath{-}}\ensuremath{\rightarrow}\overline{c}s$.

In the technical design report the event building process at Fermilab's CDF experiment is required to function at an event rate of 300 events/sec. The events are expected to have an average size of 150 kBytes (kB) and are assembled from fragments of 16 readout locations. The fragment size from the different locations varies between 12 kB and 16 kB. Once the events are assembled they are fed into the Level-3 trigger which is based on processors running programs to filter events using the full event information. Computing power on the order of a second on a Pentium II processor is required per event. The architecture design is driven by the cost and is therefore based on commodity components: VME processor modules running VxWorks for the readout, an ATM switch for the event building, and Pentium PCs running Linux as an operation system for the Level-3 event processing. Pentium PCs are also used to receive events from the ATM switch and further distribute them to the processing nodes over multiple 100 Mbps Ethernets. Studies with a prototype of up to 10 VME readout modules and up to 4 receiving PCs are presented. This system is also a candidate for the CMS experiment at CERN.

Abstract. Following pioneering efforts in East Antarctica, we herein report on the amplitude and temporal characteristics of polarized surface radar echo data collected in South Polar ice using radio sounding equipment with 0.5-ns echo-time precision. We observe strong echoes at 6, 9.6, 13.9, 17, and 19 μs following vertical pulse emission from the surface, in the upper half of the ice sheet. The synchronicity of those echoes for all broadcast azimuthal polarizations affirms the lack of observable birefringence over the upper half of the ice sheet, in contrast to East Antarctica measurements in the vicinity of Dome Fuji, and signifies a dramatic difference in the character of the ice sheet in the intervening 1400 km. Of the five strongest echoes, three exhibit an evident correlation with the local surface ice flow direction, qualitatively consistent with measurements in East Antarctica. Our radio sounding measurements also permit the most precise determination to date of the ice thickness at South Pole.

A search for new physics is performed in multijet events with large missing transverse momentum produced in proton-proton collisions at √ s = 8 TeV using a data sample corresponding to an integrated luminosity of 19.5 fb−1 collected with the CMS detector at the LHC. The data sample is divided into three jet multiplicity categories (3–5, 6–7, and ≥8 jets), and studied further in bins of two variables: the scalar sum of jet transverse momenta and the missing transverse momentum. The observed numbers of events in various categories are consistent with backgrounds expected from standard model processes. Exclusion limits are presented for several simplified supersymmetric models of squark or gluino pair production.

In the ultra-high-energy (UHE) regime, the low predicted neutrino fluxes are out of reach for currently running neutrino detectors.Larger instrumented volumes are needed to probe these low fluxes.The Radio Neutrino Observatory Greenland (RNO-G) detects in-ice radio waves emitted by neutrino induced particle showers in the Greenlandic ice sheet.Radio waves have a large attenuation length (∼1 km), and therefore RNO-G implements a sparse instrumentation to cover an unprecedented volume.By 2022, seven stations have been deployed, consisting of a deep in-ice component and antennas just below the surface.Apart from measuring UHE neutrinos, RNO-G will be able to detect cosmic-ray air showers with a total effective area of close to O(100 km 2 ) above 0.1 EeV.Detected air showers can be used as a source for in-situ calibration of the detector and provide an important verification measurement due to the possible backgrounds.Prospects for in-ice signal detection of air showers are developing further: Simulations suggest energy dense cores which propagate though the ice and are visible to deep antennas.In addition, catastrophic energy losses from high energy air shower muons penetrating the ice may mimic the interaction of a neutrino.An efficient surface trigger will provide a veto mechanism for both types of events.The collected data of shallow and deep antennas can be used to verify simulations for in-ice development of air showers.This contribution introduces RNO-G, discusses lessons learned from the first year of data taking and outlines possible backgrounds.

The Radio Neutrino Observatory in Greenland (RNO-G) is an in-ice radio detector for ultrahigh energy neutrinos with the potential to make the first detection of a neutrino shower beyond ∼10 PeV via the Askaryan emission.With a projected 90% CL upper limit below 2 Φ ≈ 10 -8 GeV/cm 2 /s/sr within 10 years of operation, RNO-G will reach realistic models of GZK and astrophysical neutrino fluxes.In 2021, the first three stations of RNO-G were installed and started data-taking.Four additional stations were added in 2022 with some upgrades to the station hardware.Here, we present the current status of the instrument and give an overview of the efforts towards calibration and analysis of the data recorded so far.

NuRadioMC is an open-source, Python-based simulation and reconstruction framework for radio detectors of ultra-high energy neutrinos and cosmic rays. Its modular design makes NuRadioMC suitable for use with a range of past, current and future detectors. In addition, the recent deployment of a complete documentation as well as a pip release make NuRadioMC relatively easy to learn and use. Here, we outline the features currently available and under development in NuRadioMC, with a focus on its usage to simulate and study in-ice radio neutrino detectors.

The Radio Neutrino Observatory in Greenland (RNO-G) is the only ultrahigh energy (UHE, ${\gtrsim}30$~PeV) neutrino monitor of the Northern sky and will soon be the world's most sensitive high-uptime detector of UHE neutrinos. Because of this, RNO-G represents an important piece of the multimessenger landscape over the next decade. In this talk, we will highlight RNO-G's multimessenger capabilities and its potential to provide key information in the search for the most extreme astrophysical accelerators. In particular, we will highlight opportunities enabled by RNO-G's unique field-of-view, its potential to constrain the sources of UHE cosmic rays, and its complementarity with IceCube at lower energies.

The Radio Neutrino Observatory Greenland (RNO-G) is a radio detector for neutrinos with energies above ∼10 PeV.It is currently under construction at Summit Station, Greenland, with 7 out of 35 stations deployed so far.By measuring the radio pulses that are emitted when ultrahigh energy neutrinos interact in ice, each station can detect neutrinos over distances of several kilometer and functions as an independent detector.A station consists of a total of 24 antennas, which are divided into a shallow component of 9 logarithmic-periodic dipole antennas near the surface, and a deep component of dipole and slot antennas inside boreholes down to 100m depth.We present an overview of the calibration efforts for RNO-G and show first results of ice property studies, which are crucial for the RNO-G station calibration.

The Radio Neutrino Observatory in Greenland (RNO-G) is an in-ice radio detector for the detection of ultra-high energy neutrinos beyond ∼10 PeV. The array is under construction and will consist of 35 stations, with the potential to make the first detection of a neutrino-induced particle shower via the Askaryan emission. Stations operate autonomously and consist of both deep antennas deployed down to -100m in the ice, and high-gain log-periodic dipole antennas buried near the surface. In total, seven RNO-G stations were installed during the 2021 and 2022 field seasons and are collecting data since. Here, we present the current status and performance of the experiment. We present results from first analyses using the deep and shallow components of the instrument.

The Radio Neutrino Observatory in Greenland (RNO-G) is a radio-based ultra-high energy neutrino detector located at Summit Station, Greenland.It is still being constructed, with 7 stations currently operational.Neutrino detection works by measuring Askaryan radiation produced by neutrino-nucleon interactions.A neutrino candidate must be found amidst other backgrounds which are recorded at much higher rates-including cosmic-rays and anthropogenic noise-the origins of which are sometimes unknown.Here we describe a method to classify different noise classes using the latent space of a variational autoencoder.The latent space forms a compact representation that makes classification tractable.We analyze data from a noisy and a silent station.The method automatically detects and allows us to qualitatively separate multiple event classes, including physical wind-induced signals, for both the noisy and the quiet station.

Radio detection of ultra-high energy neutrinos via the Askaryan effect has enabled a new generation of immense, cost-effective neutrino detectors due to the long attenuation lengths of radio signals in dense dielectric media.The Radio Neutrino Observatory in Greenland (RNO-G) is one such detector with a unique view of the northern hemisphere; it is being built at the top of Greenland's ice cap to take advantage of the low noise environment and large detection volume available in the pure ice.It currently has 7 fully operational independent autonomous stations spaced roughly 1 km apart and once completed will comprise 35 stations.Each station contains both a shallow component with broadband, high-gain antennas and an in-ice component with three strings of broadband, omnidirectional horizontally and vertically polarized antennas.Both polarization modes are needed to reconstruct the arrival direction of detected neutrinos.Here we discuss the design, simulation, validation, production, deployment, and performance of RNO-G's horizontally polarized antennas.

The Radio Neutrino Observatory in Greenland (RNO-G) seeks to detect the Askaryan radio emission from energetic neutrinos (> 10 PeV) interacting in the Greenland ice sheet. The RNO-G detector comprises an array of independent and autonomous radio-detector stations, each with a hybrid design composed of deep borehole ($\sim$100m) and surface antennas, which require low-power, robust, and scalable low-noise radiofrequency (RF) amplifier and signal-transport systems over a $\sim$80-650MHz bandwidth. In this contribution, we will present the design and performance of the custom RNO-G RF signal chains, including a field-proven and low-cost RF-over-fiber (RFoF) unit.

The Askaryan Radio Array (ARA) is an ultra-high energy (> 10 PeV) neutrino detector located in the Dark Sector of the South Pole.It consists of five in-ice stations of antennas that are designed to detect radiation emitted by relativistic particle showers that are byproducts of neutrino interactions in the ice, which generate a cone of Cherenkov radiation in the radio regime (known as Askaryan radiation).The neutrino direction can be reconstructed through a combination of the direction of the Askaryan radiation, its polarization, and its frequency content.Since neutrinos are unaffected by electromagnetic forces and virtually unaffected by gravity, they travel in a straight line through the universe.This allows us to point them back towards potential sources.Through the use of radio pulser measurements, which are controlled radio emissions with a known polarization signature, we can evaluate our reconstruction techniques.Here I will show our reconstruction resolution after applying our reconstruction methods to pulser measurements.

The Radio Neutrino Observatory in Greenland (RNO-G) is an array of radio detector stations which has been designed to study ultra-high energy (𝐸 ≳ $10^{18}$ eV) neutrinos. The experiment, when completed, will have the best sensitivity in this energy range and will yield a major advancement in our understanding of the sources and propagation of the highest energy cosmic rays. While RNO-G will be sensitive to primarily 𝐸 ≳ 100 PeV neutrinos, the optical-based detectors only have a large enough exposure to study up to ∼ 1–10 PeV, leaving a gap in the energy range between the two detection methods. For RNO-G, the energy threshold is set by our ability to distinguish the Askaryan pulses, created from neutrino interactions, from the irreducible background of thermal noise. Using modern machine learning techniques, an online trigger can be implemented to identify small-amplitude pulses from in-ice cascades and thereby decrease the energy threshold of RNO-G. Such an advancement will increase the expected amount of observed neutrinos, as well as close the gap between radio- and optical-based observatories. We present a convolutional neural network for classification of neutrino events that can be run as a second-stage trigger.

Ultra-High Energy (UHE) neutrinos over 10 16 eV have yet to be observed but the Askaryan Radio Array (ARA) is one in-ice neutrino observatory attempting to make this discovery.In anticipation of a thorough full-observatory and full-livetime neutrino search, we estimate how many neutrino events can be detected accounting for secondary interactions, which are typically ignored in UHE neutrino simulations.Using the NuLeptonSim and PyREx simulation frameworks, we calculate the abundance and usefulness of cascades viewed by multiple ARA stations and observations made of taus, muons, and neutrinos generated during and after initial neutrino cascades.Analyses that include these scenarios benefit from a considerable increase in effective area at key ARA neutrino energies, one example being a 30% increase in ARA's effective area when simulating taus and muons produced in 10 19 eV neutrino interactions.These analysis techniques could be utilized by other in-ice radio neutrino observatories, as has been explored by NuRadioMC developers.Our contribution showcases full simulation results of neutrinos with energies 3 × 10 17 -10 21 eV and visualizations of interesting triggered event topologies.

The Askaryan Radio Array (ARA) is searching for high-energy neutrinos (>10 PeV) from the cosmos using clusters of antennas buried under the South Pole ice sheet at a maximum depth of 200 m. ARA is looking at the radio Cherenkov emission generated when neutrinos interact with the surrounding medium. The array consists of 5 radio stations, each of them monitoring an independent portion of the ice to maximize the detector effective volume. ARA stations use a combination of vertically polarized (VPol) and horizontally polarized (HPol) antennas, as well as in-ice calibration devices (calpulser) for antenna positioning and ice properties studies. One of the newest ARA stations has been equipped with an independent phased array detector allowing to lower the trigger threshold and consequently improve the array sensitivity at low energies. ARA has been taking data since 2012 and analysis of the full data set is ongoing. In this contribution we present the latest results in the ARA search for cosmic neutrinos, which produced the best limit from an in-ice radio detector above 100 PeV. Additionally we discuss calibration efforts and ongoing work in analysis and reconstruction.

The Askaryan Radio Array (ARA) is an in-ice radio detector at the South Pole that targets radio emission from neutrino-induced particle cascades.Designed to detect neutrinos above 10 PeV, ARA has been taking data for over ten years and includes five independent stations.The newest ARA station is equipped with a phased array trigger, which lowers the trigger threshold compared to previous ARA stations and thus increases the neutrino sensitivity.In this contribution, we discuss the newest ARA analysis results from this phased array trigger and show a corresponding improvement in analysis efficiency, rejecting thermal backgrounds and providing vertex direction in the deep ice.We will also discuss the implications of this analysis for future radio-detection experiments.

Abstract We recently reported on the radio-frequency attenuation length of cold polar ice at Summit Station, Greenland, based on bi-static radar measurements of radio-frequency bedrock echo strengths taken during the summer of 2021. Those data also allow studies of (a) the relative contributions of coherent (such as discrete internal conducting layers with sub-centimeter transverse scale) vs incoherent (e.g. bulk volumetric) scattering, (b) the magnitude of internal layer reflection coefficients, (c) limits on signal propagation velocity asymmetries (‘birefringence’) and (d) limits on signal dispersion in-ice over a bandwidth of ~100 MHz. We find that (1) attenuation lengths approach 1 km in our band, (2) after averaging 10 000 echo triggers, reflected signals observable over the thermal floor (to depths of ~1500 m) are consistent with being entirely coherent, (3) internal layer reflectivities are ≈–60 $\to$ –70 dB, (4) birefringent effects for vertically propagating signals are smaller by an order of magnitude relative to South Pole and (5) within our experimental limits, glacial ice is non-dispersive over the frequency band relevant for neutrino detection experiments.

Since Lviv is a popular tourist destination, a major IT center, and a temporary residence for refugees from the eastern part of the state during the war, its role attracts people, and an active modern lifestyle can come in conflict with the restrictions of the preservation of the city's historical heritage. Therefore, the modern state of the city's historical core needs to be evaluated and compared to its past state. This research evaluates spatial metamorphosis by analyzing the old to modern city shift. Svobody Avenue, Lviv’s main street, was chosen to represent the area of analysis. Evaluation of Svobody Avenue was done by the quality criteria of public space, types of subspaces, and spatial problems of the current state of the avenue. The quality criteria were chosen liveliness, identity, comfort, and functionality, subspaces were based on Carmona’s classification, and a systematization of the problems as the outcome of transformation is presented in the end. This work's primary value is considering transformation as a comprehensive process from different angles, which gives a complete picture of the change in the city's main street.

We report the observation of the Cabibbo-suppressed decays ${\ensuremath{\Lambda}}_{c}^{+}\ensuremath{\rightarrow}p{K}^{\ensuremath{-}}{K}^{+}$ and ${\ensuremath{\Lambda}}_{c}^{+}\ensuremath{\rightarrow}p\ensuremath{\varphi}$ using data collected with the CLEO II detector at CESR. The latter mode, observed for the first time with significant statistics, is of interest as a test of color suppression in charm decays. We have determined the branching ratios for these modes relative to ${\ensuremath{\Lambda}}_{c}^{+}\ensuremath{\rightarrow}p{K}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}$ and compared our results with theory.