A. Belloni

We report the observation of B0s−¯¯¯B0s oscillations from a time-dependent measurement of the B0s−¯¯¯B0s oscillation frequency Δms. Using a data sample of 1 fb−1 of p¯p collisions at √s=1.96 TeV collected with the CDF II detector at the Fermilab Tevatron, we find signals of 5600 fully reconstructed hadronic Bs decays, 3100 partially reconstructed hadronic Bs decays, and 61 500 partially reconstructed semileptonic Bs decays. We measure the probability as a function of proper decay time that the Bs decays with the same, or opposite, flavor as the flavor at production, and we find a signal for B0s−¯¯¯B0s oscillations. The probability that random fluctuations could produce a comparable signal is 8×10−8, which exceeds 5σ significance. We measure Δms=17.77±0.10(stat)±0.07(syst) ps−1 and extract |Vtd/Vts|=0.2060±0.0007(Δms)+0.0081−0.0060(Δmd+theor).Received 18 September 2006DOI:https://doi.org/10.1103/PhysRevLett.97.242003©2006 American Physical Society

This Letter describes the first determination of bounds on the CP-violation parameter 2βs using B0s decays in which the flavor of the bottom meson at production is identified. The result is based on approximately 2000 B0s→J/ψϕ decays reconstructed in a 1.35 fb−1 data sample collected with the CDF II detector using p¯p collisions produced at the Fermilab Tevatron. We report confidence regions in the two-dimensional space of 2βs and the decay-width difference ΔΓ. Assuming the standard model predictions of 2βs and ΔΓ, the probability of a deviation as large as the level of the observed data is 15%, corresponding to 1.5 Gaussian standard deviations.Received 14 December 2007DOI:https://doi.org/10.1103/PhysRevLett.100.161802©2008 American Physical Society

We report the first measurements of inclusive W and Z boson cross sections times the corresponding leptonic branching ratios for p pbar collisions at sqrt{s} = 1.96 TeV based on the decays of the W and Z bosons into electrons and muons. The data were recorded with the CDF II detector at the Fermilab Tevatron and correspond to an integrated luminosity of 72.0 +/- 4.3 pb-1. We test e-mu lepton universality in W decays by measuring the ratio of the W->mu nu to W->e nu cross sections and determine a value of 0.991 +/- 0.004(stat.) +/- 0.011(syst.) for the ratio of W-l-nu couplings (g_mu/g_e). Since there is no sign of non-universality, we combine our cross section measurements in the different lepton decay modes and obtain sigma*BR(W->lnu) = 2.749 +/- 0.010(stat.) +/- 0.053(syst.) +/- 0.165(lum.) nb and sigma*BR(gamma*/Z->ll)=254.9 +/- 3.3(stat.) +/- 4.6(syst.) +/- 15.2(lum.) pb for dilepton pairs in the mass range between 66 GeV/c^2 and 116 GeV/c^2. We compute the ratio R of the W->lnu to Z->ll cross sections taking all correlations among channels into account and obtain R=10.84 +/- 0.15(stat.) +/- 0.14(syst.) including a correction for the virtual photon exchange component in our measured gamma*/Z->ll cross section. Based on the measured value of R, we extract values for the W leptonic branching ratio, BR(W->lnu) =0.1082 +/- 0.0022; the total width of the W boson, Gamma(W) =2092 +/- 42 MeV; and the ratio of W and Z boson total widths, Gamma(W)/Gamma(Z) = 0.838 +/- 0.017. In addition, we use our extracted value of Gamma(W) whose value depends on various electroweak parameters and certain CKM matrix elements to constrain the V_CS CKM matrix element, |V_CS| = 0.976 +/- 0.030.

We present an analysis of angular distributions and correlations of the X(3872) particle in the exclusive decay mode X(3872)->J/psi pi+ pi- with J/psi->mu+ mu-. We use 780 pb -1 of data from ppbar collisions at sqrt{s} = 1.96 TeV collected with the CDF II detector at the Fermilab Tevatron. We derive constraints on spin, parity, and charge conjugation parity of the X(3872) particle by comparing measured angular distributions of the decay products with predictions for different JPC hypotheses. The assignments JPC = 1++ and 2-+ are the only ones consistent with the data.

We have measured the polarizations of $\jpsi$ and $\psiprime$ mesons as functions of their transverse momentum $\pt$ when they are produced promptly in the rapidity range $|y|<0.6$ with $\pt \geq 5 \pgev$. The analysis is performed using a data sample with an integrated luminosity of about $800 \ipb$ collected by the CDF II detector. For both vector mesons, we find that the polarizations become increasingly longitudinal as $\pt$ increases from 5 to $30 \pgev$. These results are compared to the predictions of nonrelativistic quantum chromodynamics and other contemporary models. The effective polarizations of $\jpsi$ and $\psiprime$ mesons from $B$-hadron decays are also reported.

We present the first measurement of the Bs-Bsbar oscillation frequency Delta m_s. We use 1 fb^-1 of data from p-pbar collisions at sqrt{s}=1.96 TeV collected with the CDF II detector at the Fermilab Tevatron. The sample contains signals of 3,600 fully reconstructed hadronic Bs decays and 37,000 partially reconstructed semileptonic Bs decays. We measure the probability as a function of proper decay time that the Bs decays with the same, or opposite, flavor as the flavor at production, and we find a signal consistent with Bs-Bsbar oscillations. The probability that random fluctuations could produce a comparable signal is 0.2%. Under the hypothesis that the signal is due to Bs-Bsbar oscillations, we measure Delta m_s = 17.31^{+0.33}_{-0.18} (stat.) +- 0.07 (syst.) ps^-1 and determine |Vtd/Vts| = 0.208^{+0.001}_{-0.002} (exp.) ^{+0.008}_{-0.006} (theo.).

We have performed a search for B0s→μ+μ− and B0→μ+μ− decays in p¯p collisions at √s=1.96 TeV using 2 fb−1 of integrated luminosity collected by the CDF II detector at the Fermilab Tevatron Collider. The observed number of B0s and B0 candidates is consistent with background expectations. The resulting upper limits on the branching fractions are B(B0s→μ+μ−)<5.8×10−8 and B(B0→μ+μ−)<1.8×10−8 at 95% C.L.Received 12 December 2007DOI:https://doi.org/10.1103/PhysRevLett.100.101802©2008 American Physical Society

This article presents a measurement of the top quark mass using the CDF II detector at Fermilab. Colliding beams of protons and anti-protons at Fermilab's Tevatron (sqrt{s}=1.96 TeV) produce top/anti-top pairs, which decay to W^+W^-bbbar; events are selected where one W decays to hadrons, and one W decays to either e or mu plus a neutrino. The data sample corresponds to an integrated luminosity of approximately 318 pb^-1. A total of 165 ttbar events are separated into four subsamples based on jet transverse energy thresholds and the number of b jets identified by reconstructing a displaced vertex. In each event, the reconstructed top quark invariant mass is determined by minimizing a chi-squared for the overconstrained kinematic system. At the same time, the mass of the hadronically decaying W boson is measured in the same event sample. The observed W boson mass provides an in situ improvement in the determination of the hadronic jet energy scale, JES. A simultaneous likelihood fit of the reconstructed top quark masses and the W boson invariant masses in the data sample to distributions from simulated signal and background events gives a top quark mass of 173.5 +3.7/-3.6 (stat.+JES) +/- 1.3 (other syst.) GeV/c^2, or 173.5 +3.9/-3.8 GeV/c^2.

We report on measurements of the inclusive jet production cross section as a function of the jet transverse momentum in pp¯ collisions at s=1.96 TeV, using the kT algorithm and a data sample corresponding to 1.0 fb−1 collected with the Collider Detector at Fermilab in run II. The measurements are carried out in five different jet rapidity regions with |yjet|<2.1 and transverse momentum in the range 54<pTjet<700 GeV/c. Next-to-leading order perturbative QCD predictions are in good agreement with the measured cross sections.4 MoreReceived 29 January 2007Publisher error corrected 25 May 2007DOI:https://doi.org/10.1103/PhysRevD.75.092006©2007 American Physical Society

We measure the dipion mass spectrum in X(3872)--> J/psipi(+) pi(-) decays using 360 pb(-1) of pp collisions at square root s= 1.96 TeV collected with the CDF II detector. The spectrum is fit with predictions for odd C-parity ((3)S(1), (1)P(1), and (3)D(J)) charmonia decaying to J/psipi(+) pi(-), as well as even C-parity states in which the pions are from rho(0) decay. The latter case also encompasses exotic interpretations, such as a D(0)D(*0) molecule. Only the (3)S(1) and J/psirho hypotheses are compatible with our data. Since (3)S(1) is untenable on other grounds, decay via J/psirho is favored, which implies C= +1 for the X(3872). Models for J/psi - rho different angular momenta L are considered. Flexibility in the models, especially the introduction of rho - omega interference, enables good descriptions of our data for both L = 0 and 1.

We measure the time dependence of the ratio of decay rates for the rare decay D{0}-->K{+}pi{-} to the Cabibbo-favored decay D{0}-->K{-}pi;{+}. A signal of 12.7x10;{3} D{0}-->K{+}pi{-} decays was obtained using the Collider Detector at Fermilab II detector at the Fermilab Tevatron with an integrated luminosity of 1.5 fb;{-1}. We measure the D0-D[over ]{0} mixing parameters (R_{D},y{'},x{'2}), and find that the data are inconsistent with the no-mixing hypothesis with a probability equivalent to 3.8 Gaussian standard deviations.

We report the results of a search for a charged Higgs boson in the decays of top quarks produced in pp collisions at a center-of-mass energy of 1.96 TeV. We use a data sample corresponding to an integrated luminosity of 193 pb-1 collected by the upgraded Collider Detector at Fermilab. No evidence for charged Higgs production is found, allowing 95% C.L. upper limits to be placed on BR(t-->H+b) for different charged Higgs decay scenarios. In addition, we present in the minimal supersymmetric standard model (mH+/-, tanbeta) plane the first exclusion regions with radiative and Yukawa coupling corrections.

We report an observation of new bottom baryons produced in pp collisions at the Tevatron. Using 1.1 fb(-1) of data collected by the CDF II detector, we observe four Lambda b 0 pi+/- resonances in the fully reconstructed decay mode Lambda b 0-->Lambda c + pi-, where Lambda c+-->pK* pi+. We interpret these states as the Sigma b(*)+/- baryons and measure the following masses: m Sigma b+=5807.8 -2.2 +2.0(stat.)+/-1.7(syst.) MeV/c2, m Sigma b- =5815.2+/-1.0(stat.)+/-1.7(syst.) MeV/c2, and m(Sigma b*)-m(Sigma b)=21.2-1.9 +2.0(stat.)-0.3+0.4(syst.) MeV/c2.

The Bc+/- meson is observed through the decay Bc+/--->J/psipi+/-, in data corresponding to an integrated luminosity of 2.4 fb(-1) recorded by the Collider Detector at Fermilab II detector at the Fermilab Tevatron. A signal of 108+/-15 candidates is observed, with a significance that exceeds 8sigma. The mass of the Bc+/- meson is measured to be 6275.6+/-2.9(stat)+/-2.5(syst) MeV/c2.

We report the observation and measurement of the mass of the bottom, strange baryon $\Xi^-_b$ through the decay chain $\Xi^-_b \to J/\psi \Xi^-$, where $J/\psi \to \mu^+ \mu^-$, $\Xi^- \to \Lambda \pi^-$, and $\Lambda \to p \pi^-$. Evidence for observation is based on a signal whose probability of arising from the estimated background is 6.6 x 10^{-15}, or 7.7 Gaussian standard deviations. The $\Xi^-_b$ mass is measured to be $5792.9\pm 2.5$ (stat.) $\pm 1.7$ (syst.) MeV/$c^2$.

We report the first observation of two narrow resonances consistent with states of orbitally excited (L=1) B_s mesons using 1 fb^{-1} of ppbar collisions at sqrt{s} = 1.96 TeV collected with the CDF II detector at the Fermilab Tevatron. We use two-body decays into K^- and B^+ mesons reconstructed as B^+ \to J/\psi K^+, J/\psi \to \mu^+ \mu^- or B^+ \to \bar{D}^0 \pi^+, \bar{D}^0 \to K^+ \pi^-. We deduce the masses of the two states to be m(B_{s1}) = 5829.4 +- 0.7 MeV/c^2 and m(B_{s2}^*) = 5839.7 +- 0.7 MeV/c^2.

Inclusive jet cross sections in Z/γ∗ events, with Z/γ∗ decaying into an electron-positron pair, are measured as a function of jet transverse momentum and jet multiplicity in p¯p collisions at √s=1.96 TeV with the upgraded Collider Detector at Fermilab in run II, based on an integrated luminosity of 1.7 fb−1. The measurements cover the rapidity region |yjet|<2.1 and the transverse momentum range pjetT>30 GeV/c. Next-to-leading order perturbative QCD predictions are in good agreement with the measured cross sections.Received 23 November 2007DOI:https://doi.org/10.1103/PhysRevLett.100.102001©2008 American Physical Society

We present a measurement of the cross section for W-boson production in association with jets in p¯p collisions at √s=1.96 TeV. The analysis uses a data sample corresponding to an integrated luminosity of 320 pb−1 collected with the CDF II detector. W bosons are identified in their electron decay channel and jets are reconstructed using a cone algorithm. For each W+≥n−jet sample (n=1−4) we measure the differential cross section dσ(p¯p→W+≥n−jet)/dEnth−jetT×B(W→eν) with respect to the transverse energy ET of the nth-highest ET jet above 20 GeV, and the total cross section σ(p¯p→W+≥n−jet;Enth−jetT>25 GeV)×B(W→eν), for a restricted W→eν decay phase space. The cross sections, corrected for all detector effects, can be directly compared to particle level W+jet(s) predictions. We present here comparisons to leading order and next-to-leading order predictions.Received 26 November 2007DOI:https://doi.org/10.1103/PhysRevD.77.011108©2008 American Physical Society

The Circular Electron Positron Collider (CEPC) is a large international scientific facility proposed by the Chinese particle physics community to explore the Higgs boson and provide critical tests of the underlying fundamental physics principles of the Standard Model that might reveal new physics. The CEPC, to be hosted in China in a circular underground tunnel of approximately 100 km in circumference, is designed to operate as a Higgs factory producing electron-positron collisions with a center-of-mass energy of 240 GeV. The collider will also operate at around 91.2 GeV, as a Z factory, and at the WW production threshold (around 160 GeV). The CEPC will produce close to one trillion Z bosons, 100 million W bosons and over one million Higgs bosons. The vast amount of bottom quarks, charm quarks and tau-leptons produced in the decays of the Z bosons also makes the CEPC an effective B-factory and tau-charm factory. The CEPC will have two interaction points where two large detectors will be located. This document is the second volume of the CEPC Conceptual Design Report (CDR). It presents the physics case for the CEPC, describes conceptual designs of possible detectors and their technological options, highlights the expected detector and physics performance, and discusses future plans for detector R&amp;D and physics investigations. The final CEPC detectors will be proposed and built by international collaborations but they are likely to be composed of the detector technologies included in the conceptual designs described in this document. A separate volume, Volume I, recently released, describes the design of the CEPC accelerator complex, its associated civil engineering, and strategic alternative scenarios.

We measure the masses of $b$ hadrons in exclusively reconstructed final states containing a $J/\psi\to\mu^-\mu^+$ decay using $\rm 220 pb^{-1}$ of data collected by the CDF II experiment. We find: m(B^+) = 5279.10 \pm 0.41_{(stat.)} \pm 0.36_{(sys.)} MeVcc, m(B^0) = 5279.63 \pm 0.53_{(stat.)} \pm 0.33_{(sys.)} MeVcc, m(B^0_s) = 5366.01 \pm 0.73_{(stat.)} \pm 0.33_{(sys.)} MeVcc, m(\Lambda^0_b) = 5619.7 \pm 1.2_{(stat.)} \pm 1.2_{(sys.)} MeVcc. m(B^+) - m(B^0) = -0.53 \pm 0.67_{(stat.)} \pm 0.14_{(sys.)} MeVcc, m(B^0_s) - m(B^0) = 86.38 \pm 0.90_{(stat.)} \pm 0.06_{(sys.)} MeVcc m(\Lambda^0_b) - m(B^0) = 339.2 \pm 1.4_{(stat.)} \pm 0.1_{(sys.)} MeVcc. The measurements of the $B^0_s$, $\Lambda^0_b$ mass, $m(B^0_s)-m(B^0)$ and $m(\Lambda^0_b)-m(B^0)$ mass difference are of better precision than the current world averages.

We report the first evidence for a fully reconstructed decay mode of the B±c meson in the channel B±c→J/ψπ±, with J/ψ→μ+μ−. The analysis is based on an integrated luminosity of 360 pb−1 in p¯p collisions at 1.96 TeV center of mass energy collected by the Collider Detector at Fermilab. We observe 14.6±4.6 signal events with a background of 7.1±0.9 events, and a fit to the J/ψπ± mass spectrum yields a B±c mass of 6285.7±5.3(stat)±1.2(syst) MeV/c2. The probability of a peak of this magnitude occurring by random fluctuation in the search region is estimated as 0.012%.Received 23 May 2005DOI:https://doi.org/10.1103/PhysRevLett.96.082002©2006 American Physical Society

We present the first observation of exclusive e+e− production in hadron-hadron collisions, using p¯p collision data at √s=1.96 TeV taken by the run II Collider Detector at Fermilab, and corresponding to an integrated luminosity of 532 pb−1. We require the absence of any particle signatures in the detector except for an electron and a positron candidate, each with transverse energy ET>5 GeV and pseudorapidity |η|<2. With these criteria, 16 events are observed compared to a background expectation of 1.9±0.3 events. These events are consistent in cross section and properties with the QED process p¯p→p+e+e−+¯p through two-photon exchange. The measured cross section is 1.6+0.5−0.3(stat)±0.3(syst) pb. This agrees with the theoretical prediction of 1.71±0.01 pb.Received 27 November 2006DOI:https://doi.org/10.1103/PhysRevLett.98.112001©2007 American Physical Society

We present a measurement of the tt¯ production cross section using events with one charged lepton and jets from pp¯ collisions at a center-of-mass energy of 1.96 TeV. A b-tagging algorithm based on the probability of displaced tracks coming from the event interaction vertex is applied to identify b quarks from top decay. Using 318 pb−1 of data collected with the CDF II detector, we measure the tt¯ production cross section in events with at least one restrictive (tight) b-tagged jet and obtain 8.9−1.0+1.0(stat)−1.0+1.1(syst) pb. The cross section value assumes a top quark mass of mt=178 GeV/c2 in the acceptance corrections. The dependence of the cross section on mt is presented in the paper. This result is consistent with other CDF measurements of the tt¯ cross section using different samples and analysis techniques, and has similar systematic uncertainties. We have also performed consistency checks by using the b-tagging probability function to vary the signal-to-background ratio and also using events that have at least two b-tagged jets.20 MoreReceived 21 July 2006DOI:https://doi.org/10.1103/PhysRevD.74.072006©2006 American Physical Society

We present a measurement of the Bc+ meson lifetime in the decay mode Bc+ --> J/Psie+nue using the Collider Detector at Fermilab II detector at the Fermilab Tevatron Collider. From a sample of about of 360 pb(-1) of pp collisions at square root of s = 1.96 TeV, we reconstruct J/Psie+ pairs with invariant mass in the kinematically allowed range 4< M(J/Psie) < 6 GeV/c2. A fit to the decay-length distribution of 238 signal events yields a measured Bc+ meson lifetime of 0.463(-0.065)(+0.073)(stat) +/- 0.036(syst) ps.

We present a measurement of the top quark pair production cross section in p¯p collisions at √s=1.96 TeV using 318 pb−1 of data collected with the Collider Detector at Fermilab. We select t¯t decays into the final states eν+jets and μν+jets, in which at least one b quark from the t-quark decays is identified using a secondary vertex-finding algorithm. Assuming a top quark mass of 178 GeV/c2, we measure a cross section of 8.7±0.9(stat)+1.1−0.9(syst) pb. We also report the first observation of t¯t with significance greater than 5σ in the subsample in which both b quarks are identified, corresponding to a cross section of 10.1+1.6−1.4(stat)+2.0−1.3(syst) pb.Received 6 June 2006DOI:https://doi.org/10.1103/PhysRevLett.97.082004©2006 American Physical Society

We present the first observation and cross section measurement of exclusive dijet production in $\overline{p}p$ interactions, $\overline{p}p\ensuremath{\rightarrow}\overline{p}+\mathrm{dijet}+p$. Using a data sample of $310\text{ }\text{ }{\mathrm{pb}}^{\ensuremath{-}1}$ collected by the Run II Collider Detector at Fermilab at $\sqrt{s}=1.96\text{ }\text{ }\mathrm{TeV}$, exclusive cross sections for events with two jets of transverse energy ${E}_{T}^{\mathrm{jet}}\ensuremath{\ge}10\text{ }\text{ }\mathrm{GeV}$ have been measured as a function of minimum ${E}_{T}^{\mathrm{jet}}$. The exclusive signal is extracted from fits to data distributions based on Monte Carlo simulations of expected dijet signal and background shapes. The simulated background distribution shapes are checked in a study of a largely independent data sample of $200\text{ }\text{ }{\mathrm{pb}}^{\ensuremath{-}1}$ of $b$-tagged jet events, where exclusive dijet production is expected to be suppressed by the ${J}_{z}=0$ total angular momentum selection rule. Results obtained are compared with theoretical expectations, and implications for exclusive Higgs boson production at the $pp$ Large Hadron Collider at $\sqrt{s}=14\text{ }\text{ }\mathrm{TeV}$ are discussed.

We report the results of a search for a narrow resonance in electron-positron events in the invariant mass range of 150-950 GeV/c^2 using 1.3 fb^-1 of ppbar collision data at sqrt(s) = 1.96 TeV collected by the CDF II detector at Fermilab. No significant evidence of such a resonance is observed and we interpret the results to exclude the standard model-like Z' with a mass below 923 GeV/c^2 and the Randall-Sundrum graviton with a mass below 807 GeV/c^2 for k/M_pl=0.1, both at the 95% confidence level. Combining with di-photon data excludes the Randall-Sundrum graviton for masses below 889 GeV/c^2 for k/M_pl=0.1.

We report on a study of jet shapes in inclusive jet production in p¯p collisions at √s=1.96 TeV using the upgraded collider detector at Fermilab in Run II (CDF II) and based on an integrated luminosity of 170 pb−1. Measurements are carried out on jets with rapidity 0.1<|Yjet|<0.7 and transverse momentum 37 GeV/c<PjetT<380 GeV/c. The jets have been corrected to the hadron level. The measured jet shapes are compared to leading-order QCD parton-shower Monte Carlo predictions as implemented in the PYTHIA and HERWIG programs. PYTHIA, tuned to describe the underlying event as measured in CDF Run I, provides a better description of the measured jet shapes than does PYTHIA or HERWIG with their default parameters.2 MoreReceived 9 May 2005DOI:https://doi.org/10.1103/PhysRevD.71.112002©2005 American Physical Society

We search for Z' bosons in dielectron events produced in ppbar collisions at sqrt{s}=1.96 TeV, using a 0.45 fb^(-1) dataset accumulated with the CDF II detector at the Fermilab Tevatron. To identify the Z' --> e^+e^- signal, both the dielectron invariant mass distribution and the angular distribution of the electron pair are used. No evidence of a signal is found, and 95% confidence level lower limits are set on the Z' mass for several models. Limits are also placed on the mass and gauge coupling of a generic Z', as well as on the contact interaction mass scales for different helicity structure scenarios.

We present a search for neutral supersymmetric Higgs bosons decaying to $\ensuremath{\tau}$ pairs produced in $p\overline{p}$ collisions at $\sqrt{s}=1.96\text{ }\text{ }\mathrm{TeV}$. The data, corresponding to $310\text{ }\text{ }{\mathrm{pb}}^{\ensuremath{-}1}$ integrated luminosity, were collected with the Collider Detector at Fermilab in run II of the Tevatron. No significant excess above the standard model backgrounds is observed. We set exclusion limits on the production cross section times branching fraction to $\ensuremath{\tau}$ pairs for Higgs boson masses in the range from 90 to $250\text{ }\text{ }\mathrm{GeV}/{c}^{2}$.

We describe a measurement of the W boson mass mW using 200/pb of root-s = 1.96 TeV p-pbar collision data taken with the CDF II detector. With a sample of 63,964 W -> e nu candidates and 51,128 W -> mu nu candidates, we measure mW = [80.413 +- 0.034 (stat) +- 0.034 (sys) = 80.413 +- 0.048] GeV/c^2. This is the single most precise mW measurement to date. When combined with other measured electroweak parameters, this result further constrains the properties of unobserved particles coupling to W and Z bosons.

We have searched for exclusive 2-photon production in proton-antiproton collisions at sqrt{s} = 1.96 TeV, using 532/pb of integrated luminosity taken by the Run II Collider Detector at Fermilab. The event signature requires two electromagnetic showers, each with transverse energy E_T > 5 GeV and pseudorapidity |eta|<1.0, with no other particles detected in the event. Three candidate events are observed. We discuss the consistency of the three events with gamma-gamma, pi0-pi0, or eta-eta production. The probability that other processes fluctuate to 3 events or more is 1.7x10^-4. An upper limit on the cross section of p+pbar --> p+gamma-gamma+pbar is set at 410 fb with 95% confidence level.

Data collected in run II of the Fermilab Tevatron are searched for indications of new electroweak scale physics. Rather than focusing on particular new physics scenarios, CDF data are analyzed for discrepancies with respect to the standard model prediction. A model-independent approach (Vista) considers the gross features of the data and is sensitive to new large cross section physics. A quasi-model-independent approach (Sleuth) searches for a significant excess of events with large summed transverse momentum and is particularly sensitive to new electroweak scale physics that appears predominantly in one final state. This global search for new physics in over 300 exclusive final states in $927\text{ }\text{ }{\mathrm{pb}}^{\ensuremath{-}1}$ of $p\overline{p}$ collisions at $\sqrt{s}=1.96\text{ }\text{ }\mathrm{TeV}$ reveals no such significant indication of physics beyond the standard model.

We search for decays of the type B(s)0-->h+ h'- (where h,h' = K or pi) in 180 pb(-1) of pp collisions collected at the Tevatron by the upgraded Collider Detector at Fermilab. We report the first observation of the new mode B(s)0-->K+ K- with a yield of 236+/-32 events, corresponding to (fs/fd) x B(B(s)0-->K+ K-)/B(B0-->K+ pi-) = 0.46+/-0.08stat+/-0.07syst, where fs/fd is the ratio of production fractions of B(s)0 and B0. We find results in agreement with world averages for the B0 modes, and set the following new limits at 90% C.L.: B(B(s)0-->K- pi+) < 5.6 x 10(-6) and B(B(s)0-->pi+ pi-) < 1.7 x 10(-6).

We measure the ratio of cross section times branching fraction, Rp=sigma chi c2 B(chi c2-->J/psi gamma)/sigma chi c1 B(chi c1-->J/psi gamma), in 1.1 fb(-1) of pp collisions at square root s=1.96 TeV. This measurement covers the kinematic range pT(J/psi)>4.0 GeV/c, |eta(J/psi)<1.0, and pT(gamma)>1.0 GeV/c. For events due to prompt processes, we find Rp=0.395+/-0.016(stat)+/-0.015(syst). This result represents a significant improvement in precision over previous measurements of prompt chi c1,2 hadro production.

We present a measurement of the W-boson mass using 200 pb{-1} of data collected in pp[over ] collisions at sqrt[s]=1.96 TeV by the CDF II detector at run II of the Fermilab Tevatron. With a sample of 63 964 W-->enu candidates and 51 128 W-->munu candidates, we measure M_{W}=80 413+/-34{stat}+/-34{syst}=80,413+/-48 MeV/c;{2}. This is the most precise single measurement of the W-boson mass to date.

We measure the mean lifetime tau=2/(Gamma_{L}+Gamma_{H}) and the decay-width difference DeltaGamma=Gamma_{L}-Gamma_{H} of the light and heavy mass eigenstates of the B_{s}{0} meson, B_{sL}{0} and B_{sH}{0}, in B_{s}{0}-->J/psivarphi decays using 1.7 fb;{-1} of data collected with the CDF II detector at the Fermilab Tevatron pp[over ] collider. Assuming CP conservation, a good approximation for the B_{s}{0} system in the standard model, we obtain DeltaGamma=0.076_{-0.063}{+0.059}(stat)+/-0.006(syst) ps{-1} and tau=1.52+/-0.04(stat)+/-0.02(syst) ps, the most precise measurements to date. Our constraints on the weak phase and DeltaGamma are consistent with CP conservation.

We report on a measurement of the inclusive jet production cross section in pp-bar collisions at sqrt{s} = 1.96 TeV using data collected with the upgraded Collider Detector at Fermilab in Run II (CDF II) corresponding to an integrated luminosity of 385 pb^-1. Jets are reconstructed using the kt algorithm. The measurement is carried out for jets with rapidity 0.1 < | yjet | < 0.7 and transverse momentum in the range 54 < ptjet < 700 GeV/c. The measured cross section is in good agreement with next-to-leading order perturbative QCD predictions after the necessary non-perturbative parton-to-hadron corrections are included.

We describe a search for anomalous production of events with two leptons (e or mu) of the same electric charge in pp[over ] collisions at a center-of-mass energy of 1.96 TeV. Many extensions to the standard model predict the production of two leptons of the same electric charge. This search has a significant increase in sensitivity compared to earlier searches. Using a data sample corresponding to 1 fb(-1) of integrated luminosity recorded by the CDF II detector, we observe no significant excess in an inclusive selection (expect 33.2+/-4.7 events, observe 44) or in a supersymmetry-optimized selection (expect 7.8+/-1.1 events, observe 13.).

We search for pair production of doubly charged Higgs particles followed by decays into electron-tau and muon-tau pairs using data (350 inverse picobarns) collected from proton-antiproton collisions at 1.96 TeV by the CDF II experiment. We search separately for cases where three or four final-state leptons are detected, and combine results for exclusive decays to left-handed electron-tau (muon-tau) pairs. We set a lower mass limit of 114 (112) GeV/cc at the 95% confidence level for left-handed doubly charged Higgs.

We report on a search for narrow-width particles decaying to a top and antitop quark pair. The data set used in the analysis corresponds to an integrated luminosity of 680 pb^{-1} collected with the Collider Detector at Fermilab in Run II. We present 95% confidence level upper limits on the cross section times branching ratio. Assuming a specific topcolor-assisted technicolor production model, the leptophobic Z' with width \Gamma_{Z'}=0.012M_{Z'}, we exclude the mass range M_{Z'} < 725 GeV/c^2 at the 95% confidence level.

We present the first measurement of the production cross section of a $W$ boson with a single charm quark ($c$) in $p\overline{p}$ collisions at $\sqrt{s}=1.96\text{ }\text{ }\mathrm{TeV}$, using soft muon tagging of $c$ jets. In a data sample of $\ensuremath{\sim}1.8\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$, recorded with the Collider Detector at Fermilab II detector at the Fermilab Tevatron, we select events with $W+1$ or 2 jets. We use the charge correlation between the $W$ and the muon from the semileptonic decay of a charm hadron to extract the $Wc$ signal. We measure ${\ensuremath{\sigma}}_{Wc}({p}_{Tc}&gt;20\text{ }\text{ }\mathrm{GeV}/c,|{\ensuremath{\eta}}_{c}|&lt;1.5)\ifmmode\times\else\texttimes\fi{}\mathrm{BR}(W\ensuremath{\rightarrow}\ensuremath{\ell}\ensuremath{\nu})=9.8\ifmmode\pm\else\textpm\fi{}3.2\text{ }\text{ }\mathrm{pb}$, in agreement with theoretical expectations.

We present a measurement of the ratio of top-quark branching fractions R=B(t→Wb)/B(t→Wq), where q can be a b, s, or a d quark, using lepton-plus-jets and dilepton data sets with an integrated luminosity of ∼162 pb−1 collected with the Collider Detector at Fermilab during Run II of the Tevatron. The measurement is derived from the relative numbers of t¯t events with different multiplicity of identified secondary vertices. We set a lower limit of R>0.61 at 95% confidence level.Received 27 May 2005DOI:https://doi.org/10.1103/PhysRevLett.95.102002©2005 American Physical Society

We describe a measurement of the top quark mass from events produced in proton-antiproton collisions at a center-of-mass energy of 1.96 TeV, using the Collider Detector at Fermilab. We identify top-antitop candidates where both W bosons from the top quarks decay into leptons (electron, muon, or tau plus neutrino) from a data sample of 360 inverse picobarns. The top quark mass is reconstructed in each event separately by three different methods, which draw upon simulated distributions of the neutrino pseudorapidity, top-antitop longitudinal momentum, or neutrino azimuthal angle in order to extract probability distributions for the top quark mass. For each method, representative mass distributions, or templates, are constructed from simulated samples of signal and background events, and parameterized to form continuous probability density functions. A likelihood fit incorporating these parameterized templates is then performed on the data sample masses in order to derive a final top quark mass. Combining the three template methods, taking into account correlations in their statistical and systematic uncertainties, results in a top quark mass measurement of 170.1 +/- 6.0 (stat) +/- 4.1 (syst) GeV/c^2.

We present a measurement of the inclusive jet cross section in p¯p interactions at √s=1.96 TeV using 385 pb−1 of data collected with the CDF II detector at the Fermilab Tevatron. The results are obtained using an improved cone-based jet algorithm (Midpoint). The data cover the jet transverse momentum range from 61 to 620 GeV/c, extending the reach by almost 150 GeV/c compared with previous measurements at the Tevatron. The results are in good agreement with next-to-leading order perturbative QCD predictions using the CTEQ6.1M parton distribution functions.Received 12 December 2005DOI:https://doi.org/10.1103/PhysRevD.74.071103©2006 American Physical Society

We present the results of a search for new physics in the jets plus missing transverse energy data sample collected from 368 pb(-1) of pp collisions at square root of s = 1.96 TeV recorded by the Collider Detector at Fermilab. We compare the number of events observed in the data with a data-based estimate of the standard model backgrounds contributing to this signature. We observe no significant excess of events, and we interpret this null result in terms of lower limits on the fundamental Planck scale for a large extra dimensions scenario.

A search for new particles (X) that decay to electron or muon pairs has been performed using approximately 200 pb**(-1) of pbarp collision data at sqrt(s)=1.96 TeV collected by the CDF II experiment at the Fermilab Tevatron. Limits on sigma(ppbar -> X)*BR(X -> ll) are presented as a function of dilepton invariant mass m(ll) > 150 GeV/c**2, for different spin hypotheses (0, 1, or 2). The limits are approximately 25 fb for m(ll) > 600 GeV/c**2. Lower mass bounds for X from representative models beyond the Standard Model including heavy neutral gauge bosons are presented.

We search for pair-produced Dirac magnetic monopoles in 35.7 pb−1 of proton-antiproton collisions at √s=1.96 TeV with the Collider Detector at Fermilab (CDF). We find no monopole candidates corresponding to a 95% confidence-level cross-section limit σ<0.2 pb for a monopole with mass between 200 and 700 GeV/c2. Assuming a Drell-Yan pair-production mechanism, we set a mass limit m>360 GeV/c2.Received 13 September 2005DOI:https://doi.org/10.1103/PhysRevLett.96.201801©2006 American Physical Society

This paper describes the first measurement of $b$-quark fragmentation fractions into bottom hadrons in Run II of the Tevatron Collider at Fermilab. The result is based on a $360\text{ }\text{ }{\mathrm{pb}}^{\ensuremath{-}1}$ sample of data collected with the CDF II detector in $p\overline{p}$ collisions at $\sqrt{s}=1.96\text{ }\text{ }\mathrm{TeV}$. Semileptonic decays of ${\overline{B}}^{0}$, ${B}^{\ensuremath{-}}$, and ${\overline{B}}_{s}^{0}$ mesons, as well as ${\ensuremath{\Lambda}}_{b}^{0}$ baryons, are reconstructed. For an effective bottom hadron ${p}_{T}$ threshold of $7\text{ }\text{ }\mathrm{GeV}/c$, the fragmentation fractions are measured to be ${f}_{u}/{f}_{d}=1.054\ifmmode\pm\else\textpm\fi{}0.018(\mathrm{stat}{)}_{\ensuremath{-}0.045}^{+0.025}(\mathrm{sys})\ifmmode\pm\else\textpm\fi{}0.058(\mathcal{B})$, ${f}_{s}/({f}_{u}+{f}_{d})=0.160\ifmmode\pm\else\textpm\fi{}0.005(\mathrm{stat}{)}_{\ensuremath{-}0.010}^{+0.011}(\mathrm{sys}{)}_{\ensuremath{-}0.034}^{+0.057}(\mathcal{B})$, and ${f}_{{\ensuremath{\Lambda}}_{b}}/({f}_{u}+{f}_{d})=0.281\ifmmode\pm\else\textpm\fi{}0.012(\mathrm{stat}{)}_{\ensuremath{-}0.056}^{+0.058}(\mathrm{sys}{)}_{\ensuremath{-}0.087}^{+0.128}(\mathcal{B})$, where the uncertainty $\mathcal{B}$ is due to uncertainties on measured branching ratios. The value of ${f}_{s}/({f}_{u}+{f}_{d})$ agrees within one standard deviation with previous CDF measurements and the world average of this quantity, which is dominated by LEP measurements. However, the ratio ${f}_{{\ensuremath{\Lambda}}_{b}}/({f}_{u}+{f}_{d})$ is approximately twice the value previously measured at LEP. The approximately $2\ensuremath{\sigma}$ discrepancy is examined in terms of kinematic differences between the two production environments.

We report the first observation of the associated production of a $W$ boson and a $Z$ boson. This result is based on $1.1\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ of integrated luminosity from $p\overline{p}$ collisions at $\sqrt{s}=1.96\text{ }\text{ }\mathrm{TeV}$ collected with the CDF II detector at the Fermilab Tevatron. We observe 16 $WZ$ candidates passing our event selection with an expected background of $2.7\ifmmode\pm\else\textpm\fi{}0.4$ events. A fit to the missing transverse energy distribution indicates an excess of events compared to the background expectation corresponding to a significance equivalent to 6 standard deviations. The measured cross section is $\ensuremath{\sigma}(p\overline{p}\ensuremath{\rightarrow}WZ)={5.0}_{\ensuremath{-}1.6}^{+1.8}\text{ }\text{ }\mathrm{pb}$, consistent with the standard model expectation.

We search for evidence of resonant top quark pair production in 955 pb−1 of p¯p collisions at √s=1.96 TeV recorded with the CDF II detector at the Fermilab Tevatron. For fully reconstructed candidate t¯t events triggered on leptons with large transverse momentum and containing at least one identified b-quark jet, we compare the invariant mass spectrum of t¯t pairs to the expected superposition of standard model t¯t, non-t¯t backgrounds, and a simple resonance model based on a sequential Z′ boson. We establish upper limits for σ(p¯p→Z′)⋅Br(Z′→t¯t) in the Z′ mass interval from 450 GeV/c2 to 900 GeV/c2. A topcolor leptophobic Z′ is ruled out below 720 GeV/c2, and the cross section of any narrow Z′-like state decaying to t¯t is found to be less than 0.64 pb at 95% C.L. for MZ′ above 700 GeV/c2.Received 30 October 2007DOI:https://doi.org/10.1103/PhysRevD.77.051102©2008 American Physical Society

We present the results of a search for pair production of a new heavy toplike quark t' decaying to a W boson and another quark using the Collider Detector at Fermilab II detector in run II of the Tevatron pp collider. Using a data sample corresponding to 760 pb(-1) of integrated luminosity, we fit the observed spectrum of total transverse energy and reconstructed t' quark mass to a combination of standard model processes and t' pair production. We see no evidence for t't' production, and we infer a lower limit of 256 GeV/c(2) on the mass of the t' at 95% C.L. assuming standard strong couplings for the t'.

Abstract As part of its HL-LHC upgrade program, the CMS collaboration is developing a High Granularity Calorimeter (CE) to replace the existing endcap calorimeters. The CE is a sampling calorimeter with unprecedented transverse and longitudinal readout for both electromagnetic (CE-E) and hadronic (CE-H) compartments. The calorimeter will be built with ∼30,000 hexagonal silicon modules. Prototype modules have been constructed with 6-inch hexagonal silicon sensors with cell areas of 1.1 cm 2 , and the SKIROC2-CMS readout ASIC. Beam tests of different sampling configurations were conducted with the prototype modules at DESY and CERN in 2017 and 2018. This paper describes the construction and commissioning of the CE calorimeter prototype, the silicon modules used in the construction, their basic performance, and the methods used for their calibration.

Abstract The upgrade of the CMS experiment for the high luminosity operation of the LHC comprises the replacement of the current endcap calorimeter by a high granularity sampling calorimeter (HGCAL). The electromagnetic section of the HGCAL is based on silicon sensors interspersed between lead and copper (or copper tungsten) absorbers. The hadronic section uses layers of stainless steel as an absorbing medium and silicon sensors as an active medium in the regions of high radiation exposure, and scintillator tiles directly read out by silicon photomultipliers in the remaining regions. As part of the development of the detector and its readout electronic components, a section of a silicon-based HGCAL prototype detector along with a section of the CALICE AHCAL prototype was exposed to muons, electrons and charged pions in beam test experiments at the H2 beamline at the CERN SPS in October 2018. The AHCAL uses the same technology as foreseen for the HGCAL but with much finer longitudinal segmentation. The performance of the calorimeters in terms of energy response and resolution, longitudinal and transverse shower profiles is studied using negatively charged pions, and is compared to GEANT4 predictions. This is the first report summarizing results of hadronic showers measured by the HGCAL prototype using beam test data.

We present a measurement of the top pair production cross section in $p\overline{p}$ collisions at $\sqrt{s}=1.96\text{ }\text{ }\mathrm{TeV}$. We collect a data sample with an integrated luminosity of $194\ifmmode\pm\else\textpm\fi{}11\text{ }\text{ }{\mathrm{pb}}^{\ensuremath{-}1}$ with the CDF II detector at the Fermilab Tevatron. We use an artificial neural network technique to discriminate between top pair production and background processes in a sample of 519 lepton+jets events, which have one isolated energetic charged lepton, large missing transverse energy and at least three energetic jets. We measure the top pair production cross section to be ${\ensuremath{\sigma}}_{t\overline{t}}=6.6\ifmmode\pm\else\textpm\fi{}1.1\ifmmode\pm\else\textpm\fi{}1.5\text{ }\text{ }\mathrm{pb}$, where the first uncertainty is statistical and the second is systematic.

We present a measurement of the $t\overline{t}$ production cross section using $194\text{ }{\mathrm{pb}}^{\ensuremath{-}1}$ of CDF II data using events with a high transverse momentum electron or muon, three or more jets, and missing transverse energy. The measurement assumes 100% $t\ensuremath{\rightarrow}Wb$ branching fraction. Events consistent with $t\overline{t}$ decay are found by identifying jets containing heavy-flavor semileptonic decays to muons. The dominant backgrounds are evaluated directly from the data. Based on 20 candidate events and an expected background of $9.5\ifmmode\pm\else\textpm\fi{}1.1$ events, we measure a production cross section of $5.3\ifmmode\pm\else\textpm\fi{}{3.3}_{\ensuremath{-}1.0}^{+1.3}\text{ }\mathrm{pb}$, in agreement with the standard model.

We report a measurement of the top-quark mass, ${M}_{t}$, in the dilepton decay channel of $t\overline{t}\ensuremath{\rightarrow}b{\ensuremath{\ell}}^{\ensuremath{'}+}{\ensuremath{\nu}}_{{\ensuremath{\ell}}^{\ensuremath{'}}}\overline{b}{\ensuremath{\ell}}^{\ensuremath{-}}{\overline{\ensuremath{\nu}}}_{\ensuremath{\ell}}$ using an integrated luminosity of $1.0\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ of $p\overline{p}$ collisions collected with the CDF II detector. We apply a method that convolutes a leading-order matrix element with detector resolution functions to form event-by-event likelihoods; we have enhanced the leading-order description to describe the effects of initial-state radiation. The joint likelihood is the product of the likelihoods from 78 candidate events in this sample, which yields a measurement of ${M}_{t}=164.5\ifmmode\pm\else\textpm\fi{}3.9(\mathrm{stat}.)\ifmmode\pm\else\textpm\fi{}3.9(\mathrm{syst}.)\text{ }\text{ }\mathrm{GeV}/{c}^{2}$, the most precise measurement of ${M}_{t}$ in the dilepton channel.

We report the first evidence of Z boson pair production at a hadron collider with a significance exceeding 4 standard deviations. This result is based on a data sample corresponding to 1.9 fb(-1) of integrated luminosity from pp[over] collisions at sqrt[s]=1.96 TeV collected with the Collider Detector at Fermilab II detector. In the lll'l' channel, we observe three ZZ candidates with an expected background of 0.096(-0.063)+0.092 events. In the llnunu channel, we use a leading-order calculation of the relative ZZ and WW event probabilities to discriminate between signal and background. In the combination of lll'l' and llnunu channels, we observe an excess of events with a probability of 5.1 x 10(-6) to be due to the expected background. This corresponds to a significance of 4.4 standard deviations. The measured cross section is sigma(pp[over]-->ZZ)=1.4(-0.6)+0.7(stat+syst) pb, consistent with the standard model expectation.

We present the results of a search for new particles that lead to a Z boson plus jets in p¯p collisions at √s=1.96 TeV using the Collider Detector at Fermilab (CDF II). A data sample with a luminosity of 1.06 fb−1 collected using Z boson decays to ee and μμ is used. We describe a completely data-based method to predict the dominant background from standard model Z+jet events. This method can be similarly applied to other analyses requiring background predictions in multijet environments, as shown when validating the method by predicting the background from W+jets in t¯t production. No significant excess above the background prediction is observed, and a limit is set using a fourth generation quark model to quantify the acceptance. Assuming BR(b′→bZ)=100% and using a leading-order calculation of the b′ cross section, b′ quark masses below 268 GeV/c2 are excluded at 95% confidence level.31 MoreReceived 25 June 2007DOI:https://doi.org/10.1103/PhysRevD.76.072006©2007 American Physical Society

We report on a search for Bs -> mu+mu- and Bd -> mu+mu- decays in ppbar collisions at sqrt(S) = 1.96 TeV using 364 pb-1 of data collected by the CDF II detector at the Fermilab Tevatron Collider. After applying all selection requirements, we observe no candidates inside the Bs or Bd mass windows, consistent with the background expectation. The resulting upper limits on the branching fractions are B(Bs -> mu+mu-) < 1.5E10-7 and B(Bd -> mu+mu-) < 3.9E-8 at 90% confidence level.

We present the first evidence of charmless decays of the $B_s^0$ meson, the decay \phiphi, and a measurement of the Branching Ratio $\BR(\phiphi)$ using $180 {\rm pb}^{-1}$ of data collected by the \cdfii experiment at the Fermilab Tevatron collider. In addition, the BR and direct CP asymmetry for the \phik\ decay are measured. We obtain: $\BR (\phiphi) = (14 \ase{6}{5}(stat.) \pm 6(syst.)) \times 10^{-6}$, $\BR (\phik) = (7.6 \pm 1.3(stat.) \pm 0.6(syst.)) \times 10^{-6}$, and $\ACP(\phik) = -0.07 \pm 0.17 (stat.) \ase{0.03}{0.02} (syst.)$. Both decays are governed in the Standard Model by second order (penguin) $b \myto s\bar{s}s$ amplitudes.

We describe a general search for resonances decaying to a neutral $e\ensuremath{\mu}$ final state in $p\overline{p}$ collisions at a center-of-mass energy of 1.96 TeV. Using a data sample representing $344\text{ }\text{ }{\mathrm{pb}}^{\ensuremath{-}1}$ of integrated luminosity recorded by the Collider Detector at Fermilab II experiment, we compare standard model predictions with the number of observed events for invariant masses between 50 and $800\text{ }\text{ }\mathrm{GeV}/{c}^{2}$. Finding no significant excess (5 events observed vs $7.7\ifmmode\pm\else\textpm\fi{}0.8$ expected for ${M}_{e\ensuremath{\mu}}&gt;100\text{ }\text{ }\mathrm{GeV}/{c}^{2}$), we set limits on sneutrino and ${Z}^{\ensuremath{'}}$ masses as functions of lepton family number violating couplings.

We report two measurements of the top quark mass M_top using the CDF II detector at the Fermilab Tevatron in a 318 pb^-1 data sample observed in the lepton + jets final state. One method uses an event-based likelihood technique resulting in M_top = 173.2 +2.6/-2.4 (stat.) +/- 3.2 (syst.) GeV/c^2 or 173.2 +4.1/-4.0 GeV/c^2. The second method reconstructs a top quark mass in each event using the measured invariant mass of the hadronically decaying W boson to constrain the jet energy scale to obtain a value for M_top of 173.5 +3.7/-3.6 (stat.) +/- 1.3 (syst.) GeV/c^2 or 173.5 +3.9/-3.8 GeV/c^2. We take the latter, which is more precise, as our result.

We describe a measurement of the top quark mass using events with two charged leptons collected by the CDF II detector from $p\bar{p}$ collisions with $\sqrt s = 1.96$ TeV at the Fermilab Tevatron. The likelihood in top mass is calculated for each event by convoluting the leading order matrix element describing $q\bar{q} \to t\bar{t} \to b\ell\nu_{\ell}\bar{b}\ell'\nu_{\ell'}$ with detector resolution functions. The presence of background events in the data sample is modeled using similar calculations involving the matrix elements for major background processes. In a data sample with integrated luminosity of 340 pb$^{-1}$, we observe 33 candidate events and measure $M_{top} = 165.2 \pm 6.1(\textrm{stat.}) \pm 3.4(\textrm{syst.}) \mathrm{~GeV}/c^2.$ This measurement represents the first application of this method to events with two charged leptons and is the most precise single measurement of the top quark mass in this channel.

We present a search for long-lived doubly charged Higgs bosons (H±±), with signatures of high ionization energy loss and muonlike penetration. We use 292 pb−1 of data collected in p¯p collisions at √s=1.96 TeV by the CDF II detector at the Fermilab Tevatron. Observing no evidence of long-lived doubly charged particle production, we exclude H±±L and H±±R bosons with masses below 133 GeV/c2 and 109 GeV/c2, respectively. In the degenerate case we exclude H±± mass below 146 GeV/c2. All limits are quoted at the 95% confidence level.Received 3 March 2005DOI:https://doi.org/10.1103/PhysRevLett.95.071801©2005 American Physical Society

We report a measurement of the top quark mass using events collected by the CDF II Detector from ppbar collisions at \sqrt{s} = 1.96 TeV at the Fermilab Tevatron. We calculate a likelihood function for the top mass in events that are consistent with ttbar->bbar l^- \nubar b l^+ \nu decays. The likelihood is formed as the convolution of the leading-order matrix element and detector resolution functions. The joint likelihood is the product of likelihoods for each of 33 events collected in 340 pb^{-1} of integrated luminosity, yielding a top quark mass M_t = 165.2 +- 6.1 (stat.) +- 3.4(syst.) GeV/c^2. This first application of a matrix-element technique to ttbar->bbar l^- \nubar b l^+ \nu decays gives the most precise single measurement of M_t in dilepton events. Combined with other CDF Run II measurements using dilepton events, we measure M_{t} = 167.9 +- 5.2 (stat.) +- 3.7 (syst.) GeV/c^2.

We report the measurements of the t anti-t production cross section and of the top quark mass using 1.02 fb^-1 of p anti-p data collected with the CDFII detector at the Fermilab Tevatron. We select events with six or more jets on which a number of kinematical requirements are imposed by means of a neural network algorithm. At least one of these jets must be identified as initiated by a b-quark candidate by the reconstruction of a secondary vertex. The cross section is measured to be sigma_{tt}=8.3+-1.0(stat.)+2.0-1.5(syst.)+-0.5(lumi.) pb, which is consistent with the standard model prediction. The top quark mass of 174.0+-2.2(stat.)+-4.8(syst.) GeV/c^2 is derived from a likelihood fit incorporating reconstructed mass distributions representative of signal and background.

We search for direct pair production of supersymmetric top quarks and supersymmetric bottom quarks in proton-antiproton collisions at $\sqrt{s}=1.96\text{ }\text{ }\mathrm{TeV}$, using $295\text{ }\text{ }{\mathrm{pb}}^{\ensuremath{-}1}$ of data recorded by the Collider Detector at Fermilab (CDF II) experiment. The supersymmetric top (supersymmetric bottom) quarks are selected by reconstructing their decay into a charm (bottom) quark and a neutralino, which is assumed to be the lightest supersymmetric particle. The signature of such processes is two energetic heavy-flavor jets and missing transverse energy. The number of events that pass our selection for each search process is consistent with the expected standard model background. By comparing our results to the theoretical production cross sections of the supersymmetric top and supersymmetric bottom quarks in the minimal supersymmetric standard model, we exclude, at a 95% confidence level in the frame of that model, a supersymmetric top quark mass up to $132\text{ }\text{ }\mathrm{GeV}/{c}^{2}$ for a neutralino mass of $48\text{ }\text{ }\mathrm{GeV}/{c}^{2}$, and a supersymmetric bottom quark mass up to $193\text{ }\text{ }\mathrm{GeV}/{c}^{2}$ for a neutralino mass of $40\text{ }\text{ }\mathrm{GeV}/{c}^{2}$.

We present a measurement of the mass of the top quark from proton-antiproton collisions recorded at the CDF experiment in Run II of the Fermilab Tevatron. We analyze events from the single lepton plus jets final state (tt-->W(+)bW(-)b-->lnubqq'b). The top-quark mass is extracted using a direct calculation of the probability density that each event corresponds to the tt final state. The probability is a function of both the mass of the top quark and the energy scale of the calorimeter jets, which is constrained in situ by the hadronic W boson mass. Using 167 events observed in 955 pb(-1) of integrated luminosity, we achieve the single most precise measurement of the top-quark mass, 170.8+/-2.2(stat.)+/-1.4(syst.) GeV/c(2).

We present a measurement of the top-quark mass, $M_{\mathrm{top}}$, in the all-hadronic decay channel $t\bar{t} \to W^+b W^- \bar{b} \to q_1\bar{q}_2 b q_3 \bar{q}_4 \bar{b}$. The analysis is performed using 310 pb$^{-1}$ of $\sqrt{s}$=1.96 TeV $p\bar{p}$ collisions collected with the CDF II detector using a multi-jet trigger. The mass measurement is based on an event-by-event likelihood which depends on both the sample purity and the value of the top-quark mass, using 90 possible jet-to-parton assignments in the six-jet final state. The joint likelihood of 290 selected events yields a value of $M_{\mathrm{top}}$=177.1 $\pm$ 4.9 (stat.) $\pm$ 4.7 (syst.) GeV/$c^2$.

Abstract The Compact Muon Solenoid collaboration is designing a new high-granularity endcap calorimeter, HGCAL, to be installed later this decade. As part of this development work, a prototype system was built, with an electromagnetic section consisting of 14 double-sided structures, providing 28 sampling layers. Each sampling layer has an hexagonal module, where a multipad large-area silicon sensor is glued between an electronics circuit board and a metal baseplate. The sensor pads of approximately 1.1 cm 2 are wire-bonded to the circuit board and are readout by custom integrated circuits. The prototype was extensively tested with beams at CERN's Super Proton Synchrotron in 2018. Based on the data collected with beams of positrons, with energies ranging from 20 to 300 GeV, measurements of the energy resolution and linearity, the position and angular resolutions, and the shower shapes are presented and compared to a detailed Geant4 simulation.

The advent of the silicon photomultiplier has allowed the development of highly segmented calorimeters using plastic scintillator as the active media, with photodetectors embedded in the calorimeter, in dimples in the plastic. To reduce the photodetector’s dark current and radiation damage, the high granularity calorimeter designed for the high luminosity upgrade of the CMS detector at CERN’s Large Hadron Collider will be operated at a temperature of about -30° C. Due to flammability considerations, a low oxygen environment is being considered. However, the radiation damage to the plastic scintillator during irradiation in this operating environment needs to be considered. In this paper, we present measurements of the relative decrease of light output during irradiation of small plastic scintillator tiles read out by silicon photomultipliers. The irradiations were performed using a 60Co source both to produce the tiles’ light and as a source of ionizing irradiation at dose rates of 0.3, 1.3, and 1.6 Gy/hr, temperatures of -30, -15, -5, and 0° C, and with several different oxygen concentrations in the surrounding atmosphere. The effect of the material used to wrap the tile was also studied. Substantial temporary damage, which annealed when the sample was warmed, was seen during the low-temperature irradiations, regardless of the oxygen concentration and wrapping material. The relative light loss was largest with 3MTM Enhanced Specular Reflector Film wrapping and smallest with no wrapping, although due to the substantially higher light yield with wrapping, the final light output is largest with wrapping. The light loss was less at warmer temperatures. Damage with 3% oxygen was similar to that in standard atmosphere. Evidence of a plateau in the radical density was seen for the 0° C data.

Plastic scintillators are a versatile and inexpensive option for particle detection, which is why the largest particle physics experiments, CMS and ATLAS, use them extensively in their calorimeters. One of their challenging aspects, however, is their relatively low radiation hardness, which might be inadequate for very high luminosity future projects like the FCC-hh. In this study, results on the effects of ionizing radiation on the optical properties of plastic scintillator samples are presented. The samples are made from two different matrix materials, polystyrene and polyvinyltoluene, and have been irradiated at dose rates ranging from 2.2 Gy/h up to 3.4 kGy/h at room temperature. An internal boundary that separates two regions of different indices of refraction is visible in the samples depending on the dose rate, and it is compatible with the expected oxygen penetration depth during irradiation. The dose rate dependence of the oxygen penetration depth for the two matrix materials suggests that the oxygen penetration coefficient differs for PS and PVT. The values of the refractive index for the internal regions are elevated compared to those of the outer regions, which are compatible with the indices of unirradiated samples.

Results on a search for pair production of second generation scalar leptoquark in $p \bar{p}$ collisions at $\sqrt{s}$=1.96 TeV are reported. The data analyzed were collected by the CDF detector during the 2002-2003 Tevatron Run II and correspond to an integrated luminosity of 198 pb$^{-1}$. Leptoquarks (LQ) are sought through their decay into (charged) leptons and quarks, with final state signatures represented by two muons and jets and one muon, large transverse missing energy and jets. We observe no evidence for $LQ$ production and derive 95% C.L. upper limits on the $LQ$ production cross sections as well as lower limits on their mass as a function of $β$, where $β$ is the branching fraction for $LQ \to μq$.

We present a measurement of the inclusive production cross section for Z bosons decaying to tau leptons in p¯p collisions at √s=1.96 TeV. We use a channel with one hadronically-decaying and one electronically-decaying tau. This measurement is based on 350 pb−1 of CDF Run II data. Using a sample of 504 opposite sign eτ events with a total expected background of 190 events, we obtain σ(p¯p→4Z)⋅B(Z→ττ)=264±23(stat)±14(syst)±15(lumi) pb, in agreement with the next-to-next-to-leading order QCD prediction. This is the first CDF cross section measurement using hadronically-decaying taus in Run II.8 MoreReceived 30 January 2007DOI:https://doi.org/10.1103/PhysRevD.75.092004©2007 American Physical Society

We present a measurement of the fractions ${F}_{0}$ and ${F}_{+}$ of longitudinally polarized and right-handed $W$ bosons in top-quark decays using data collected with the CDF II detector. The data set used in the analysis corresponds to an integrated luminosity of approximately $318\text{ }\text{ }{\mathrm{pb}}^{\ensuremath{-}1}$. We select $t\overline{t}$ candidate events with one lepton, at least four jets, and missing transverse energy. Our helicity measurement uses the decay angle ${\ensuremath{\theta}}^{*}$, which is defined as the angle between the momentum of the charged lepton in the $W$ boson rest frame and the $W$ momentum in the top-quark rest frame. The $\mathrm{cos}{\ensuremath{\theta}}^{*}$ distribution in the data is determined by full kinematic reconstruction of the $t\overline{t}$ candidates. We find ${F}_{0}={0.85}_{\ensuremath{-}0.22}^{+0.15}(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.06(\mathrm{syst})$ and ${F}_{+}={0.05}_{\ensuremath{-}0.05}^{+0.11}(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.03(\mathrm{syst})$, which is consistent with the standard model prediction. We set an upper limit on the fraction of right-handed $W$ bosons of ${F}_{+}&lt;0.26$ at the 95% confidence level.

We measure the branching fraction of the top quark to longitudinally and right-handed polarized $W$ bosons, ${F}_{0}$ and ${F}_{+}$, using approximately $200\text{ }\text{ }{\mathrm{pb}}^{\ensuremath{-}1}$ of $\overline{p}p$ collisions collected by the CDF II detector. We analyze two quantities sensitive to the $W$ helicity: the invariant mass of the charged lepton and the bottom-quark jet in the decay $t\ensuremath{\rightarrow}Wb\ensuremath{\rightarrow}\ensuremath{\ell}\ensuremath{\nu}b$ (where $\ensuremath{\ell}=e$ or $\ensuremath{\mu}$), and the transverse momentum of the charged lepton. Constrained fits yield ${F}_{0}={0.74}_{\ensuremath{-}0.34}^{+0.22}$, and ${F}_{+}&lt;0.27$ at the 95% confidence level. These measurements are consistent with the standard model predictions.

We present the first search for heavy, long-lived particles that decay to photons at a hadron collider. We use a sample of photon+jet+missing transverse energy events in p-pbar collisions at \sqrt{s}=1.96 TeV taken with the CDF II detector. Candidate events are selected based on the arrival time of the photon at the detector. Using an integrated luminosity of 570 pb-1 of collision data, we observe 2 events, consistent with the background estimate of 1.3+-0.7 events. While our search strategy does not rely on model-specific dynamics, we set cross section limits in a supersymmetric model with \tildeχ_1^0-&gt;γ\gravitino and place the world-best 95% C.L. lower limit on the \tildeχ_1^0 mass of 101 GeV/c^2 at τ_{\tildeχ_1^0} = 5 ns.

We report a measurement of the Λ0b lifetime in the exclusive decay Λ0b→J/ψΛ0 in p¯p collisions at √s=1.96 TeV using an integrated luminosity of 1.0 fb−1 of data collected by the CDF II detector at the Fermilab Tevatron. Using fully reconstructed decays, we measure τ(Λ0b)=1.593+0.083−0.078(stat)±0.033(syst) ps. This is the single most precise measurement of τ(Λ0b) and is 3.2σ higher than the current world average.Received 11 September 2006DOI:https://doi.org/10.1103/PhysRevLett.98.122001©2007 American Physical Society

We report an upper limit on the fraction of V+A current, fV+A, in top-quark decays, using approximately 700 pb−1 of p¯p collisions at √s=1.96 TeV acquired by the upgraded Collider Detector at Fermilab. For the decay t→Wb→ℓνb (where ℓ=e or μ), the invariant mass of the charged lepton and the bottom quark jet is sensitive to the polarization of the W boson. We determine fV+A=−0.06±0.25 given a top-quark mass of 175 GeV/c2. We set an upper limit on fV+A of 0.29 at the 95% confidence level, an improvement by a factor of 2 on the previous best direct limit.Received 29 August 2006DOI:https://doi.org/10.1103/PhysRevLett.98.072001©2007 American Physical Society

We have performed a search for new particles which decay to two photons using 1.2/fb of integrated luminosity from p-pbar collisions at sqrt(s) = 1.96 TeV collected using the CDF II Detector at the Fermilab Tevatron. We find the diphoton mass spectrum to be in agreement with the standard model expectation, and set limits on the cross section times branching ratio for the Randall-Sundrum graviton, as a function of diphoton mass. We subsequently derive lower limits for the graviton mass of 230 GeV/c2 and 850 GeV/c2, at the 95% confidence level, for coupling parameters (k/M_Pl) of 0.01 and 0.1 respectively.

Models of maximal flavor violation (MxFV) in elementary particle physics may contain at least one new scalar SU(2) doublet field Phi(FV)=(eta(0),eta(+)) that couples the first and third generation quarks (q_(1), q_(3)) via a Lagrangian term L(FV)=xi(13)Phi(FV)q(1)q(3). These models have a distinctive signature of same-charge top-quark pairs and evade flavor-changing limits from meson mixing measurements. Data corresponding to 2 fb(-1) collected by the Collider Dectector at Fermilab II detector in pp[over ] collisions at sqrt[s]=1.96 TeV are analyzed for evidence of the MxFV signature. For a neutral scalar eta(0) with m_(eta;(0))=200 GeV/c(2) and coupling xi(13)=1, approximately 11 signal events are expected over a background of 2.1+/-1.8 events. Three events are observed in the data, consistent with background expectations, and limits are set on the coupling xi(13) for m(eta(0)=180-300 GeV/c(2).

We report on a search for pair production of first-generation scalar leptoquarks ($LQ$) in $p \bar{p}$ collisions at $\sqrt{s}$=1.96 TeV using an integrated luminosity of 203 $pb^{-1}$ collected at the Fermilab Tevatron collider by the CDF experiment. We observe no evidence for $LQ$ production in the topologies arising from $LQ \bar{LQ} \to eqeq$ and $LQ \bar{LQ} \to eq \nu q$, and derive 95% C.L. upper limits on the $LQ$ production cross section. %as a function of $\beta$, where $\beta$ is the branching fraction for $LQ \to eq$. The results are combined with those obtained from a separately reported CDF search in the topology arising from $LQ\bar{LQ} \to \nu q \nu q$ and 95% C.L. lower limits on the LQ mass as a function of $\beta = BR(LQ \to eq) $ are derived. The limits are 236, 205 and 145 GeV/c$^2$ for $\beta$ = 1, $\beta$ = 0.5 and $\beta$ = 0.1, respectively.

This paper describes a measurement of the top quark mass, Mtop, with the dynamical likelihood method (DLM) using the CDF II detector at the Fermilab Tevatron. The Tevatron produces top/antitop (tt¯) pairs in pp¯ collisions at a center-of-mass energy of 1.96 TeV. The data sample used in this analysis was accumulated from March 2002 through August 2004, which corresponds to an integrated luminosity of 318 pb−1. We use the tt¯ candidates in the “lepton+jets” decay channel, requiring at least one jet identified as a b quark by finding a displaced secondary vertex. The DLM defines a likelihood for each event based on the differential cross section as a function of Mtop per unit phase space volume of the final partons, multiplied by the transfer functions from jet to parton energies. The method takes into account all possible jet combinations in an event, and the likelihood is multiplied event by event to derive the top quark mass by the maximum likelihood method. Using 63 tt¯ candidates observed in the data, with 9.2 events expected from background, we measure the top quark mass to be 173.2+2.6−2.4(stat.)±3.2(syst.) GeV/c2, or 173.2+4.1−4.0 GeV/c2.19 MoreReceived 6 December 2005DOI:https://doi.org/10.1103/PhysRevD.73.092002©2006 American Physical Society

We present the first observation of the baryon decay Lambda b0-->Lambda c+pi- followed by Lambda c+-->pK-pi+ in 106 pb-1 pp collisions at square root s=1.96 TeV in the CDF experiment. In order to reduce systematic error, the measured rate for Lambda b0 decay is normalized to the kinematically similar meson decay B0-->D+pi- followed by D+-->pi+K-pi+. We report the ratio of production cross sections (sigma) times the ratio of branching fractions (B) for the momentum region integrated above pT>6 GeV/c and pseudorapidity range |eta|<1.3: sigma(pp-->Lambda b0X)/sigma(pp-->B0X)xB(Lambda b0-->Lambda c+pi-)/B(B0-->D+pi-)=0.82+/-0.08(stat)+/-0.11(syst)+/-0.22[B(Lambda c+-->pK-pi+)].

We present the results of a search for Wprime boson decaying to electron-neutrino pairs in pbarp collisions at a center-of-mass energy of 1.96 TeV, using a data sample corresponding to 205 pb^-1 of integrated luminosity collected by the CDF II detector at Fermilab. We observe no evidence for this decay mode and set limits on the production cross section times branching fraction, assuming the neutrinos from Wprime boson decays to be light. If we assume the manifest left-right symmetric model, we exclude a Wprime boson with mass less than 788 GeV/c^2 at the 95% confidence level.

We report the first top-quark mass measurement that uses a cross-section constraint to improve the mass determination. This measurement is made with a dilepton t¯t event candidate sample collected with the Collider Detector II at Fermilab. From a data sample corresponding to an integrated luminosity of 1.2 fb−1, we measure a top-quark mass of 170.7+4.2−3.9(stat)±2.6(syst)±2.4(theory) GeV/c2. The measurement without the cross-section constraint is 169.7+5.2−4.9(stat)±3.1(syst) GeV/c2.Received 22 October 2007DOI:https://doi.org/10.1103/PhysRevLett.100.062005©2008 American Physical Society

We search for a third generation vector leptoquark ($VLQ3$) that decays to a $b$ quark and tau lepton using the CDF II detector and $320\text{ }\text{ }{\mathrm{pb}}^{\ensuremath{-}1}$ of integrated luminosity from the Fermilab Tevatron. Observing a number of events in agreement with standard model expectations, we obtain, assuming Yang-Mills (minimal) couplings, the most stringent upper limit on the $VLQ3$ pair production cross section of 344 fb (493 fb) and lower limit on the $VLQ3$ mass of $317\text{ }\text{ }\mathrm{GeV}/{c}^{2}$ ($251\text{ }\text{ }\mathrm{GeV}/{c}^{2}$) at 95% C.L.

We search for the standard model Higgs boson produced in association with an electroweak vector boson in events with no identified charged leptons, large imbalance in transverse momentum, and two jets where at least one contains a secondary vertex consistent with the decay of $b$ hadrons. We use $\ensuremath{\sim}1\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ integrated luminosity of $p\overline{p}$ collisions at $\sqrt{s}=1.96\text{ }\text{ }\mathrm{TeV}$ recorded by the Collider Detector at Fermilab II experiment at the Tevatron. We find 268 (16) single (double) $b$-tagged candidate events, where $248\ifmmode\pm\else\textpm\fi{}43$ ($14.4\ifmmode\pm\else\textpm\fi{}2.7$) are expected from standard model background processes. We observe no significant excess over the expected background and thus set 95% confidence level upper limits on the Higgs boson production cross section for several Higgs boson masses ranging from 110 to $140\text{ }\text{ }\mathrm{GeV}/{c}^{2}$. For a mass of $115\text{ }\text{ }\mathrm{GeV}/{c}^{2}$, the observed (expected) limit is 20.4 (14.2) times the standard model prediction.

We present a measurement of the correlated $b\overline{b}$ production cross section. The data used in this analysis were taken with the upgraded CDF detector (CDF II) at the Fermilab Tevatron collider, and correspond to an integrated luminosity of $742\text{ }\text{ }{\mathrm{pb}}^{\ensuremath{-}1}$. We utilize muon pairs with invariant mass $5\ensuremath{\le}{m}_{\ensuremath{\mu}\ensuremath{\mu}}\ensuremath{\le}80\text{ }\text{ }\mathrm{GeV}/{c}^{2}$ produced by $b\overline{b}$ double semileptonic decays. For muons with ${p}_{T}\ensuremath{\ge}3\text{ }\text{ }\mathrm{GeV}/c$ and $|\ensuremath{\eta}|\ensuremath{\le}0.7$, that are produced by $b$ and $\overline{b}$ quarks with ${p}_{T}\ensuremath{\ge}2\text{ }\text{ }\mathrm{GeV}/c$ and $|y|\ensuremath{\le}1.3$, we measure ${\ensuremath{\sigma}}_{b\ensuremath{\rightarrow}\ensuremath{\mu},\overline{b}\ensuremath{\rightarrow}\ensuremath{\mu}}=1549\ifmmode\pm\else\textpm\fi{}133\text{ }\text{ }\mathrm{pb}$. We compare this result with theoretical predictions and previous measurements. We also report the measurement of ${\ensuremath{\sigma}}_{c\ensuremath{\rightarrow}\ensuremath{\mu},\overline{c}\ensuremath{\rightarrow}\ensuremath{\mu}}$, a by-product of the study of the background to $b\overline{b}$ production.

A measurement of the inclusive bottom jet cross section is presented for events containing a $Z$ boson in $p\bar{p}$ collisions at $\sqrt{s}=1.96$ TeV using the Collider Detector at Fermilab. $Z$ bosons are identified in their electron and muon decay modes, and $b$ jets with $E_T>20$ GeV and $|\eta|<1.5$ are identified by reconstructing a secondary decay vertex. The measurement is based on an integrated luminosity of about 330 ${\rm pb}^{-1}$. A cross section times branching ratio of $\sigma (Z+b {\rm jets}) \times {\cal B}(Z \to \ell^+ \ell^-)= 0.93 \pm 0.36$ pb is found, where ${\cal B}(Z\to \ell^+ \ell^-)$ is the branching ratio of the $Z$ boson or $\gamma^*$ into a single flavor dilepton pair ($e$ or $\mu$) in the mass range between 66 and 116 GeV$/c^2$. The ratio of $b$ jets to the total number of jets of any flavor in the $Z$ sample, within the same kinematic range as the $b$ jets, is $2.36 \pm 0.92%$. Here, the uncertainties are the quadratic sum of statistical and systematic uncertainties. Predictions made with NLO QCD agree, within experimental and theoretical uncertainties, with these measurements.

We report on precision measurements of the masses and widths of the narrow, orbitally excited states ${D}_{1}^{0}$ and ${D}_{2}^{*0}$ using the CDF II detector at the Fermilab Tevatron. Both states (collectively called ${D}^{**}$) are reconstructed in the decay channel ${D}^{**}\ensuremath{\rightarrow}{D}^{*+}{\ensuremath{\pi}}^{\ensuremath{-}}$. The ${D}_{2}^{*0}$ is also reconstructed in the ${D}^{**}\ensuremath{\rightarrow}{D}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$ channel. Using a data set with an integrated luminosity of $210\text{ }\text{ }{\mathrm{pb}}^{\ensuremath{-}1}$, the measured masses and widths for the ${D}_{1}^{0}$ are $2421.7\ifmmode\pm\else\textpm\fi{}0.7\ifmmode\pm\else\textpm\fi{}0.6\text{ }\mathrm{MeV}/{c}^{2}$ and $20.0\ifmmode\pm\else\textpm\fi{}1.7\ifmmode\pm\else\textpm\fi{}1.3\text{ }\mathrm{MeV}/{c}^{2}$ respectively, while for the ${D}_{2}^{*0}$ they are $2463.3\ifmmode\pm\else\textpm\fi{}0.6\ifmmode\pm\else\textpm\fi{}0.8\text{ }\mathrm{MeV}/{c}^{2}$ and $49.2\ifmmode\pm\else\textpm\fi{}2.3\ifmmode\pm\else\textpm\fi{}1.2\text{ }\mathrm{MeV}/{c}^{2}$. These values are currently the single best measurements available.

We present a search for anomalous triple gauge couplings (ATGC) in WW and WZ boson production. The boson pairs are produced in ppbar collisions at sqrt{s}=1.96 TeV, and the data sample corresponds to 350 pb-1 of integrated luminosity collected with the CDF II detector at the Fermilab Tevatron. In this search one W decays to leptons, and the other boson (W or Z) decays hadronically. Combining with a previously published CDF measurement of Wgamma boson production yields ATGC limits of -0.18 < lambda < 0.17 and -0.46 < Delta kappa < 0.39 at the 95% confidence level, using a cut-off scale Lambda=1.5 TeV.

We present the results of a search for standard model Higgs boson production with decay to WW*, identified through the leptonic final states e+ e- nubar nu ,e mu nubar nu and mu+ mu- nubbar nu. This search uses 360 pb-1 of data collected from p pbar collisions at sqrt{s} = 1.96 TeV by the upgraded Collider Detector at Fermilab (CDF II). We observe no signal excess and set 95% confidence level upper limits on the production cross section times branching ratio for the Higgs boson to WW* or any new scalar particle with similar decay products. These upper limits range from 5.5 to 3.2 pb for Higgs boson masses between 120 and 200 GeV/c2.

We report the observation of the exclusive decay Bs0-->Ds-Ds+ at the 7.5 standard deviation level using 355 pb(-1) of data collected by the CDF II detector in pp collisions at sqrt[s]=1.96 TeV at the Fermilab Tevatron. We measure the relative branching ratio B(Bs0-->Ds-Ds+)/B(B0-->D-Ds+)=1.44(-0.44)(+0.48). Using the world average value for B(B0-->D-Ds+), we find B(Bs0-->Ds-Ds+)=(9.4(-4.2)(+4.4))x10(-3). This provides a lower bound DeltaGammasCP/Gammas>or=2B(Bs0-->Ds-Ds+)>1.2x10(-2) at 95% C.L.

We present a measurement of the tt production cross section in pp collisions at square root s = 1.96 TeV which uses events with an inclusive signature of significant missing transverse energy and jets. This is the first measurement which makes no explicit lepton identification requirements, so that sensitivity to W --> tau nu decays is maintained. Heavy flavor jets from top quark decay are identified with a secondary vertex tagging algorithm. From 311 pb(-1) of data collected by the Collider Detector at Fermilab, we measure a production cross section of 5.8 +/- 1.2(stat)(-0.7)(+0.9)(syst) pb for a top quark mass of 178 GeV/c2, in agreement with previous determinations and standard model predictions.

We search for pair production of supersymmetric top quarks (~t_1), followed by R-parity violating decay ~t_1 -> tau b with a branching ratio beta, using 322 pb^-1 of ppbar collisions at sqrt{s}=1.96 TeV collected by the CDF II detector at Fermilab. Two candidate events pass our final selection criteria, consistent with the standard model expectation. We set upper limits on the cross section sigma(~t_1 ~tbar_1)*beta^2 as a function of the stop mass m(~t_1). Assuming beta=1, we set a 95% confidence level limit m(~t_1)>153 GeV/c^2. The limits are also applicable to the case of a third generation scalar leptoquark (LQ_3) decaying LQ_3 -> tau b.

Using $355\text{ }\text{ }{\mathrm{pb}}^{\ensuremath{-}1}$ of data collected by the CDF II detector in $p\overline{p}$ collisions at $\sqrt{s}=1.96\text{ }\text{ }\mathrm{TeV}$ at the Fermilab Tevatron, we study the fully reconstructed hadronic decays ${B}_{(s)}^{0}\ensuremath{\rightarrow}{D}_{(s)}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}$ and ${B}_{(s)}^{0}\ensuremath{\rightarrow}{D}_{(s)}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$. We present the first measurement of the ratio of branching fractions $\mathcal{B}({B}_{s}^{0}\ensuremath{\rightarrow}{D}_{s}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}})/\mathcal{B}({B}^{0}\ensuremath{\rightarrow}{D}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}})=1.05\ifmmode\pm\else\textpm\fi{}0.10(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.22(\mathrm{syst})$. We also update our measurement of $\mathcal{B}({B}_{s}^{0}\ensuremath{\rightarrow}{D}_{s}^{\ensuremath{-}}{\ensuremath{\pi}}^{+})/\mathcal{B}({B}^{0}\ensuremath{\rightarrow}{D}^{\ensuremath{-}}{\ensuremath{\pi}}^{+})$ to $1.13\ifmmode\pm\else\textpm\fi{}0.08(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.23(\mathrm{syst})$, improving the statistical uncertainty by more than a factor of 2. We find $\mathcal{B}({B}_{s}^{0}\ensuremath{\rightarrow}{D}_{s}^{\ensuremath{-}}{\ensuremath{\pi}}^{+})=[3.8\ifmmode\pm\else\textpm\fi{}0.3(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}1.3(\mathrm{syst})]\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}$ and $\mathcal{B}({B}_{s}^{0}\ensuremath{\rightarrow}{D}_{s}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}})=[8.4\ifmmode\pm\else\textpm\fi{}0.8(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}3.2(\mathrm{syst})]\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}$.

We report on the results of a search for standard model Higgs bosons produced in association with W bosons from p-pbar collisions at root s = 1.96 TeV. The search uses a data sample corresponding to approximately 1 fb-1 of integrated luminosity. Events consistent with the W to l-nu and H to b-bbar signature are selected by triggering on a high-pT electron or muon candidate and tagging one or two of the jet candidates as having originated from b quarks. A neural network filter rejects a fraction of tagged charm and light flavor jets, increasing the b-jet purity in the sample and thereby reducing the background to Higgs boson production. We observe no excess l-nu-b-bbar production beyond the background expectation, and we set 95% confidence level upper limits on the production cross section times branching fraction sigma(p-pbar to WH) times Br(H to b-bbar) ranging from 3.9 to 1.3 pb, for specific Higgs boson mass hypotheses in the range 110 to 150 GeV/c2, respectively.

A direct measurement of the total decay width of the W boson G_W is presented using 350 pb-1 of data from ppbar collisions at sqrt(s) = 1.96 TeV collected with the CDF II detector at the Fermilab Tevatron. The width is determined by normalizing predicted signal and background distributions to 230185 W candidates decaying to enu and munu in the transverse-mass region 50 < M_T < 90 GeV and then fitting the predicted shape to 6055 events in the high-M_T region, 90 < M_T < 200 GeV. The result is G_W = 2032 +/- 45 (stat.) +/- 57 (syst.) MeV, consistent with the standard model expectation.