Gülsen Önengüt

A new experimental apparatus, designed principally for a high sensitivity search for νμ → ντ oscillation, has been successlly constructed and made operational by the CHORUS Collaboration for the CERN-WA95 experiment. It consists of a large emulsion target, a scintillating fiber tracker system with optoelectronics read-out, an air-core magnet, a set of trigger hodoscopes, a calorimeter based on the lead/scintillating-fiber technique, and a muon spectrometer. The design, construction and performance of the entire apparatus and of the different detectors are described.

After completion of the data taking for the νμ→ντ oscillation search, the CHORUS lead–scintillator calorimeter was used in the 1998 run as an active target. High-statistics samples of charged-current interactions were collected in the CERN SPS west area neutrino beam. This beam contained predominantly muon (anti-)neutrinos from sign-selected pions and kaons. We measure the flux and energy spectrum of the incident neutrinos and compare them with beam simulations. The neutrino–nucleon and anti-neutrino–nucleon differential cross-sections are measured in the range 0.01<x<0.7, 0.05<y<0.95, 10<Eν<200GeV. We extract the neutrino–nucleon structure functions F2(x,Q2), xF3(x,Q2), and R(x,Q2) and compare these with results from other experiments.

The nuclear emulsion target of the CHORUS detector was exposed to the wide-band neutrino beam of the CERN SPS of 27 GeV average neutrino energy from 1994 to 1997. In total, about 100 000 charged-current (CC) neutrino interactions with at least one identified muon were located in the emulsion target and fully reconstructed, using newly developed automated scanning systems. Charmed particles were searched for by a program recognizing particle decays. The observation of the decay in nuclear emulsion makes it possible to select a sample with very low background and minimal kinematical bias. In all, 2013 CC interactions with a charmed hadron candidate in the final state were selected and confirmed through visual inspection. The charm production rate induced by neutrinos relative to the CC cross-section is measured to be σ(νμN→μ−CX)/σ(CC)=(5.75 ± 0.32(stat)±0.30(syst))%. The charm production cross-section as a function of neutrino energy is also obtained. The results are in good agreement with previous measurements. The charm-quark hadronization produces the following charmed hadrons with relative fractions (in %): fD0=43.7±4.5, fΛc+=19.2±4.2, fD+=25.3±4.2 and fDs+=11.8±4.7.

The final oscillation analysis of the complete set of data collected by CHORUS in the years 1994–1997 is presented. Reconstruction algorithms of data extracted by electronic detectors were improved and the data recorded in the emulsion target were analysed by new automated scanning systems, allowing the use of a new method for event reconstruction in emulsion. CHORUS has applied these new techniques to the sample of 1996–1997 events for which no muons were observed in the electronic detectors. Combining the new sample with the data analysed in previous papers, the overall sensitivity of the experiment to the ντ appearance is thus improved. In a two-neutrino mixing scheme, a 90% C.L. upper limit of sin22θμτ<4.4×10−4 is set for large Δm2, improving by a factor 1.5 the previously published CHORUS result.

We present the results of beam tests with high-energy (8–375 GeV) electrons, pions, protons and muons of a sampling calorimeter based on the detection of Cherenkov light produced by shower particles. The detector, a prototype for the very forward calorimeters in the CMS experiment, consists of thin quartz fibers embedded in a copper matrix. Results are given on the light yield of this device, on its energy resolution for electron and hadron detection, and on the signal uniformity and linearity. The signal generation mechanism gives this type of detector unique properties, especially for the detection of hadron showers: narrow, shallow shower profiles and extremely fast signals. These specific properties were measured in detail. The implications for measurements in the high-rate, high-radiation Large Hadron Collider (LHC) environment are discussed.

CHORUS is an experiment searching for νμ→ντ oscillation in the CERN wide band neutrino beam with a hybrid setup consisting of a nuclear emulsion target followed by electronic detectors. The experiment has been taking data from 1994 through 1997. A subset of the neutrino interactions collected in 1994 and 1995 have been analyzed, looking for ντ charged current interactions where the τ lepton decays to μν̄μντ. In a sample of 31,423 νμ charged current interactions, no ντ candidates were found. For large Δm2μτ values, a limit on the mixing angle of sin22θμτ<3.5×10−3 at 90% C.L. can be set, thus improving the previous best result.

We present a leading order QCD analysis of a sample of neutrino induced charged-current events with two muons in the final state originating in the lead-scintillating fibre calorimeter of the CHORUS detector. The results are based on a sample of 8910 neutrino and 430 antineutrino induced opposite-sign dimuon events collected during the exposure of the detector to the CERN Wide Band Neutrino Beam between 1995 and 1998. % with $E_{\mu 1},E_{\mu 2} > 5$ GeV and $Q^2 > 3$ GeV$^2$ collected %between 1995 and 1998. The analysis yields a value of the charm quark mass of $\mc = (1.26\pm 0.16 \pm 0.09) \GeVcc $ and a value of the ratio of the strange to non-strange sea in the nucleon of $\kappa = 0.33 \pm 0.05 \pm 0.05$, improving the results obtained in similar analyses by previous experiments.

We present performance studies of a full-length prototype for the CASTOR quartz-tungsten sampling calorimeter, installed in the very forward region of the CMS experiment at the LHC. The response linearity and energy resolution, the uniformity, as well as the showers’ spatial properties in the prototype have been studied with electrons, pions and muons of various energies. A special study was also carried out for testing the light-output with a 90-degree cut of the quartz plates of the calorimeter. The data were taken during the CASTOR test beam at CERN/SPS in 2007.

Part of the neutrino events collected in 1994-1995 by the CHORUS experiment has been analysed. A search was performed for ντ charged current interactions followed by the τ lepton decay into a single charged negative hadron, a possible indication for νμ→ντ oscillation. A sample of 6844 events without an identified muon has been located in the emulsion target. Within the selection criteria, no τ− candidate has been found. Combining this result with the one from the search for ντ interactions using the muonic decay mode (36 182 events with an identified muon), a 90% C.L. limit on the mixing angle sin22θμτ<1.8·10−3 (at large Δm2) has been derived.

We present the results of experimental studies of hadron showers in a copper/quartz-fiber calorimeter, based on the detection of Cherenkov light. These studies show that there are very significant differences between the signals from protons and pions at the same energies. In the energy range between 200 and 375 GeV, where these studies were performed, the calorimeter's response to protons was typically 10% smaller than the response to pions. On the other hand, the energy resolution was about 25% better for protons. In addition, the protons had a Gaussian line shape, whereas the pion response curve was asymmetric. These differences can be understood from the requirements of baryon number conservation in the shower development. They are expected to be present in any non-compensating calorimeter, to a degree determined by the e/h value.

We investigated the darkening of nine high OH− fibre types irradiated with 500MeV electrons from the Linac Injector of LEP (LIL) at CERN. The transmission of Xe light was measured in situ in the 350–800nm range. The induced attenuation at 450nm is typically 1.52±0.15dB/m for a 100Mrad absorbed dose. Two-parameter fits for darkening and recovery are presented. After irradiation the tensile strength remains essentially unchanged. For Polymicro quartz core fibres the tensile strength is typically 4.6±0.4GPa.

From 1994 to 1997, the emulsion target of the CHORUS detector was exposed to the wideband neutrino beam of the CERN SPS. In total about 100 000 charged-current neutrino interactions were located in the nuclear emulsion target and fully reconstructed. From this sample of events based on the data acquired by new automatic scanning systems, 2013 charm-decay events were selected by a pattern recognition program. They were confirmed as decays through visual inspection. Based on these events, the effective branching ratio of charmed particles into muons was determined to be B¯μ=[7.3±0.8(stat)±0.2(syst)]×10−2. In addition, the muonic branching ratios are presented for dominating charm-decay topologies. Normalization of the muonic decays to charged-current interactions provides σμ−μ+/σcc=[3.16±0.34(stat)±0.09(syst)]×10−3. Selecting only events with visible energy greater than 30 GeV gives a value of B¯μ that is less affected by the charm production threshold and quasi-elastic Λc+ production. Combining this value with the current average of B¯μ×|Vcd|2 at the leading order yields the value of |Vcd|LO=0.236±0.016.

During the years 1994–1997, the emulsion target of the CHORUS detector was exposed to the Wide Band Neutrino Beam from the CERN-SPS. About 170 000 neutrino interactions were successfully located in the emulsion. Improvements in the automatic emulsion scanning systems and application of different criteria allowed the sample of located events to be used for studies of charm production. We present a measurement of the production rate of D0 mesons based on a sample of 25 693 located νμ charged-current (CC) interactions analysed so far. After reconstruction of the event topology in the vertex region, 283 D0 decays were observed with an estimated background of 9.2 K0 and Λ decays. The ratio of cross-section of D0 production and νμ CC interactions is found to be (1.99±0.13(stat.)±0.17(syst.))×10−2 at 27 GeV average νμ energy.

During the years 1994–1997, the emulsion target of the CHORUS detector was exposed to the wide-band neutrino beam of the CERN SPS of 27 GeV average neutrino energy. In total about 100 000 charged-current neutrino interactions were located in the nuclear emulsion target and fully reconstructed. From this sample of events which was based on the data acquired by new automatic scanning systems, 1048 charged-current interactions with a D0 in the final state were selected by a pattern recognition program and confirmed as neutral-particle decays through visual inspection. The ratio of decay branching fractions of the D0 into four charged particles to two charged particles was measured to be B(D0→V4)/B(D0→V2)=0.207±0.016±0.004. The inclusive measurement of the observed production rate of the D0 with a decay into four charged prongs in combination with external measurements of this topological branching ratio was used to determine the total D0 production rate by neutrinos without additional assumption on the branching fractions. The value of this rate relative to the charged-current cross-section was found to be σ(D0)/σ(CC)=0.0269±0.0018±0.0013. In addition, the same normalization method was used to deduce the inclusive topological decay rate into final states with neutral particles only. A value of 0.218±0.049±0.036 was found for this branching fraction. From an observed number of three charged six-prong events the branching ratio into six charged particles was determined to be (1.2−0.9+1.3±0.2)×10−3. A measurement of the energy dependence of the D0 production by neutrinos relative to the total charged-current cross-section is also reported. This measurement was used to deduce for mc, the effective charm-quark mass, a value of (1.42±0.08)GeV/c2.

A measurement of Λc+ production in neutrino nucleon charged-current interactions is presented. In a subsample of about 50 000 interactions located in the emulsion target of the CHORUS detector, exposed to the wide band neutrino beam of the CERN SPS, candidates for decays of short-lived particles were identified using new automatic scanning systems and later confirmed through visual inspection. Criteria based on the flight length allowed a statistical separation among the different charm species thus enabling a sample particularly rich in Λc+ to be defined. At an average neutrino energy of 27 GeV, the product σ(Λc+)/σ(CC)×BR(Λc+→3p) was measured to be (0.37±0.10(stat)±0.02(syst))×10−2, while the values of (1.54±0.35(stat)±0.18(syst))×10−2 and of 0.24±0.07(stat)±0.04(syst) were obtained for σ(Λc+)/σ(CC) and BR(Λc+→3p), respectively.

The $\overline{p}p$ annihilation cross section has been measured over the mass range 1925-1960 MeV with a rms resolution of \ifmmode\pm\else\textpm\fi{}2.5 MeV. This search yields no evidence for narrow enhancements in this mass interval. Using an $A+\frac{B}{p}$ parameterization of the background, a 2-standard-deviation upper limit of 16 mb MeV is set for the integrated area of any resonance with mass between 1936 and 1942 MeV and width \ensuremath{\lesssim}4 MeV.

We report on a search for associated charm production in neutrino charged-current interactions in the CHORUS experiment, based on the visual observation of charmed-particle decays. The search differs from those carried out so far in which the production of cc̄ has been inferred from measurements of events with two or three muons in the final state, resulting from the decay of charmed hadrons. One event with a double charm-decay topology has been found and a corresponding background of 0.04 events has been evaluated.

A study of quasi-elastic production of charmed baryons in charged-current interactions of neutrinos with the nuclear emulsion target of CHORUS is presented. In a sample of about 46 000 interactions located in the emulsion, candidates for decays of short-lived particles were identified by using new automatic scanning systems and later confirmed through visual inspection. Criteria based both on the topological and kinematical characteristics of quasi-elastic charm production allowed a clear separation between events of this type and those in which charm is produced in deep inelastic processes. A final sample containing 13 candidates consistent with quasi-elastic production of a charmed baryon with an estimated background of 1.7 events was obtained. At the average neutrino energy of 27 GeV the cross-section for the total quasi-elastic production of charmed baryons relative to the νN charged-current cross-section was measured to be σ(QE)/σ(CC)=(0.23+0.12−0.06(stat)+0.02−0.03(syst))×10−2. Through an analysis of the topology at the production and decay vertices the relative cross-sections were measured separately for singly (Λc+,Σc+,Σc+∗) and doubly (Σc++,Σc++∗) charged baryons.

We report on the first direct observation of a neutrino induced charged-current interaction with two subsequent decays of short-lived particles close to the interaction vertex. This rare double-kink signature in the CHORUS emulsion target is interpreted as a Ds∗+ production followed by the decay chain Ds∗+→Ds+γ,Ds+→τ+ντ,τ+→μ+νμντ̄. The event is characterised by small Q2 and small four-momentum transfer squared t to the target nucleon, which indicates a diffractive production mechanism. A complete analysis of the event is presented.

During the years 1994–1997, the emulsion target of the CHORUS detector was exposed to the CERN-SPS Wide Band Neutrino Beam. The improvements of the past few years in the automatic emulsion scanning systems allowed a sample of events located in emulsion to be used for studies of charm production. Based on a sample of 56172νμ charged-current interactions analysed so far, we find a value of Bμ=0.093±0.009(stat.)±0.009(syst.) for the semi-leptonic branching fraction of charm hadrons. The result for events with visible energy larger than 30 GeV, Bμ=0.102±0.016(stat.)±0.010(syst.), can be combined with the existing measurements of the dimuon rate to yield a value of 0.219±0.022 for the magnitude of the Cabibbo–Kobayashi–Maskawa matrix element |Vcd|.

During the years 1994–1997, the emulsion target of the CHORUS detector was exposed to the wide-band neutrino beam of the CERN SPS. In total about 100 000 charged-current neutrino interactions were located in the nuclear emulsion target and fully reconstructed. From this sample of events which was based on the data acquired by new automatic scanning systems, 1048 D0 events were selected by a pattern recognition program. They were confirmed as neutral-particle decays through visual inspection. Fragmentation properties of deep-inelastic charm production were measured using these events. Distributions of the D0 momentum, Feynman x (xF), z and tanθout, the transverse angle out of the leptonic plane defined by the muon and the neutrino, are presented. The mean value of z was measured to be 〈z〉=0.63±0.03(stat)±0.01(syst). From fits to the z distribution, values for the Peterson parameter εP=0.108±0.017(stat)±0.013(syst) and the Collins–Spiller parameter εCS=0.21−0.04+0.05(stat)±0.04(syst) are found. For the average value of xF we find 〈xF〉=0.38±0.04(stat)±0.03(syst) and for the forward–backward asymmetry A=0.79±0.14(stat)±0.05(syst). The distribution of tanθout was measured with an average value 〈tanθout〉=0.030±0.002.

In this paper a search for associated charm production both in neutral and charged current $\nu$-nucleus interactions is presented. The improvement of automatic scanning systems in the {CHORUS} experiment allows an efficient search to be performed in emulsion for short-lived particles. Hence a search for rare processes, like the associated charm production, becomes possible through the observation of the double charm-decay topology with a very low background. About 130,000 $\nu$ interactions located in the emulsion target have been analysed. Three events with two charm decays have been observed in the neutral-current sample with an estimated background of 0.18$\pm$0.05. The relative rate of the associated charm cross-section in deep inelastic $\nu$ interactions, $\sigma(c\bar{c}\nu)/\sigma_\mathrm{NC}^\mathrm{DIS}= (3.62^{+2.95}_{-2.42}({stat})\pm 0.54({syst}))\times 10^{-3}$ has been measured. One event with two charm decays has been observed in charged-current $\nu_\mu$ interactions with an estimated background of 0.18$\pm$0.06 and the upper limit on associated charm production in charged-current interactions at 90% C.L. has been found to be $\sigma (c\bar{c} \mu^-)/\sigma_\mathrm{CC} < 9.69 \times 10^{-4}$.

The CHORUS experiment, designed to search for νμ→ντ oscillations, consists of a nuclear emulsion target and electronic detectors. In this paper, results on the production of charged particles in a small sample of charged-current neutrino– and anti-neutrino–nucleus interactions at high energy are presented. For each event, the emission angle and the ionization features of the charged particles produced in the interaction are recorded, while the standard kinematic variables are reconstructed using the electronic detectors. The average multiplicities for charged tracks, the pseudo-rapidity distributions, the dispersion in the multiplicity of charged particles and the KNO scaling are studied in different kinematical regions. A study of quasi-elastic topologies performed for the first time in nuclear emulsions is also reported. The results are presented in a form suitable for use in the validation of Monte Carlo generators of neutrino–nucleus interactions.

Observation of J/ψ production by neutrinos in the calorimeter of the CHORUS detector exposed to the CERN SPS wide-band νμ beam is reported. A spectrum-averaged cross section σJ/ψ=(6.3±3.0)×10−41 cm2 is obtained for 20 GeV ⩽Eν⩽ 200 GeV. The data are compared with the theoretical model based on the QCD Z-gluon fusion mechanism.

During the years 1994–1997, the emulsion target of the CHORUS detector was exposed to the wide-band neutrino beam of the CERN SPS of 27 GeV average neutrino energy. In total about 100 000 charged-current neutrino interactions were located in the nuclear emulsion target and fully reconstructed. A high-statistics sample of neutrino interactions with a D0 in the final state was collected. Using the decay mode D*+→D0π+ a production cross-section measurement of the D*+ in neutrino–nucleon charged-current interactions was performed. The low Q-value of the decay was used to isolate a sample of candidate events containing a positive hadron with a small pT with respect to the D0 direction. A signal of 22.1±5.5D*+ events was obtained. The D*+ production cross-section relative to the D0 production cross-section, σ(D*+)/σ(D0), was estimated to be 0.38±0.09(stat)±0.05(syst). From this result, the fraction of D0's produced via the decay of a D* was deduced to be 0.63±0.17. The D*+ production cross-section relative to the νμ charged-current interaction, σ(D*+)/σ(CC), was estimated to be [1.02±0.25(stat)±0.15(syst)]%.

Abstract During the years 1994–1997, the emulsion target of the CHORUS detector was exposed to the wide-band neutrino beam of the CERN SPS collecting about 106 neutrino interactions. A measurement of ν ¯ μ -induced charm production is performed by using the presence of a 5% ν ¯ μ component in the ν μ beam. The measurement takes advantage of the capability to observe the decay topology in the emulsion. The analysis is based on a sample of charged-current interactions with at least one identified muon. About 100 000 were located in the emulsion target and fully reconstructed. By requiring a positive muon charge as determined by the CHORUS muon spectrometer, 32 ν ¯ μ -induced charm events were observed with an estimated background of 3.2 events. At an average antineutrino energy in the neutrino beam of 18 GeV, the charm production rate induced by antineutrinos is measured to be σ ( ν ¯ μ N → μ + c ¯ X ) / σ ( ν ¯ μ N → μ + X ) = ( 5.0 −0.9 +1.4 ( stat ) ± 0.7 ( syst ) ) % . The ratio between neutral and charged charm production rates in this process is ( 2.6 −1.0 +1.7 ( stat ) ± 0.8 ( syst ) ) . The charm production rate as a function of the antineutrino energy is found to be in good agreement with previous results derived from di-lepton data.

This Letter reports on a study of trimuon events induced by neutrino interactions in the CHORUS calorimeter exposed to the CERN SPS wide-band νμ beam. Among the multimuon events produced in the calorimeter, 42 μ−μ−μ+ events were selected and their kinematical properties investigated. In the past, several groups collected a sample of about one hundred events of this type but their source was largely unknown. Taking advantage of experimental data presently available on the production and muonic branching ratios of light neutral mesons and resonances, we make absolute predictions for the expected rates in our experiment. Detailed Monte Carlo simulations described in this article show that more than half of the trimuon events can be attributed to this source. Muons from π− and K− decays in charm dimuon events are responsible for an additional ≈25% contribution to the total μ−μ−μ+ rate. The remaining 25% of events are likely to come from the internal bremsstrahlung of virtual photons into a muon pair. Associated-charm production with subsequent decays of both charmed particles into muons is a negligible source of trimuon events.

Narrow (Γ ≲ 20 MeV) gamma lines have been sought with a magnetic pair spectrometer at the BNL AGS, attaining a sensitivity of order ΓγΓ ∼ 3 × 10−3. The 129 MeV Panofsky line is seen from secondary π−; in addition a narrow anomaly of 3.3σ significance appears at Eγ = 105 ± 3 MeV. If this is in fact a gamma line, its features suggest a mixed qq + NN model.

The first pre-production-prototype (PPP-I) of the quartz fibre calorimeter of the CMS detector has been tested at CERN. The calorimeter consists of quartz fibres embedded in an iron matrix. Results are presented on the energy resolution and on the signal uniformity of the prototype for electrons and pions and the signal uniformity and linearity.

The experiments at the Large Hadron Collider (LHC) will have to deal with unprecedented radiation levels. In the large-rapidity regions, close to the beam pipe, these levels reach megagrays per year. The detectors to be installed in these regions, the HF Calorimeters, are designed to operate under these conditions. In this paper, we describe the results of studies in which a prototype calorimeter was exposed to radiation of the type and intensity expected at the LHC. These studies made it possible to estimate the effects of this radiation on the response and the resolution of the calorimeter as a function of time during LHC operation.

The solutions of static axially symmetric Einstein-Maxwell equations corresponding to the series of stationary axially symmetric solutions for gravitational fields of spinning masses obtained by Tomimatsu and Sato are considered. This class of two-parameter solutions representing a system with mass and electric or magnetic dipole are extended through Kinnersley’s method of generating stationary Einstein-Maxwell fields. It is shown that all the solutions thus extended have the same behaviour in the distant region and describe a source with mass, electric charge, magnetic dipole, higher multipoles of all three kinds and angular momentum.

The $\ensuremath{\gamma}$-to-charge multiplicity ratio $\frac{〈{M}_{\ensuremath{\gamma}}〉}{〈{M}_{\mathrm{ch}}〉}$ in $\overline{N}N$ annihilations is restricted by $I$-spin conservation. In deuterium, the ratio is constrained by $I$-spin conservation to be equal to 1, while an experiment reported a value of 1.24\ifmmode\pm\else\textpm\fi{}0.03; this measurement was based on missing and $\ensuremath{\gamma}$ energies. The experiment reported in this paper measures the rate of conversion of $\ensuremath{\gamma}'\mathrm{s}$ as a function of converter thickness and obtains $\frac{〈{M}_{\ensuremath{\gamma}}〉}{〈{M}_{\mathrm{ch}}〉}=1.26\ifmmode\pm\else\textpm\fi{}0.03$ for $\overline{p}p$ annihilations, which is in agreement with the large $\ensuremath{\gamma}$ excess observed in deuterium. Statistical models which ignore $I$-spin conservation predict such a $\ensuremath{\gamma}$ excess, while those taking into account $I$-spin conservation predict values near 1.

CMS very forward calorimeter is based on a quartz fibre technology. The calorimeter prototype composed of two longitudinal segments was tested at CERN in 1996. We present the test beam data analysis of this prototype. It was shown that the mean values of responses for pions and electrons of the same energy could be equalised using the appropriate ratio of calibration constants for longitudinal segments. The beam test data were used to simulate the calorimeter response to hadron jets.

A systematic search for superfragments (charmed nuclei) has been performed in 22 200 neutrino–emulsion interactions obtained with the CHORUS experiment making use of automatic off-line image analysis. The absence of candidates provides an upper limit for the superfragment production rate of 1.9×10−4 (90% C.L.) relative to neutrino charged-current interactions at an average neutrino energy of 27 GeV. In the same analysis 28 hyperfragment decays were found. For the first time, a production rate of hyperfragments in neutrino–emulsion interactions was obtained. The value of the hyperfragment production rate relative to the neutrino charged-current cross-section was found to be (2.0±0.4(stat)±0.3(syst))×10−3.

We present test-beam data analysis of a quartzfibre calorimeter prototype composed of a single active section with a passive absorber in front of it. The partial suppression of the electromagnetic showers leads to the equalization of the response to electrons and pions for a given depth of this passive section. Results are compared with the Monte-Carlo expectations.

The Chorus experiment, which aims at a search for vμ → vτ oscillations using the neutrino beam of the CERN-SPS, has successfully taken data in 1994 and 1995. The detection technique will be discussed and the performances of the apparatus as well as a status report will be given.

The WA95/CHORUS experiment at CERN is a dedicated vμ−vτ oscillation search experiment. Using the wide band neutrino beam of the CERN-SPS accelerator, with an exposure of 2.4 × 1019 protons on the target, this experiment will explore the domain of small mixing angles down to sin22θμτ ≈ 3 × 10−4 for mass differences Δm2 > 1 eV2, more than one order of magnitude better than the current limits. The conceptual design of the CHORUS experiment and data on the detector performances are reported.

Centauro and Strange Object Research (CASTOR) which is a tungsten/quartz Cerenkov sampling calorimeter, is installed in the very forward region of the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC). It will cover the pseudo rapidity range 5.1<eta <6.6 and will be placed 14.38 m away from the interaction point. In order to test the performance of the CASTOR Calorimeter, CASTOR prototype IV was tested at CERN/SPS H2 beam line in 2008. In my analysis X-surface scan is studied using E=50 GeV pions and E=100 GeV electrons. Hadronic Calorimeter (HCAL) which is a subsystem of the CMS experiment at the LHC, consists of four subdetectors, Hadronic Barrel (HB), Hadronic Endcap (HE), Hadronic Outer (HO) and Hadronic Forward (HF). In HCAL, pedestal is important to determine the muon energy deposits and for quality of calibration of HCAL. Also in my analysis, I studied pedestal stability of all subdetectors of HCAL by using data taken during CRAFT (Cosmic Ray at Four Tesla) runs.

The CMS‐CASTOR calorimeter is designed to study the very forward, baryon‐rich region in heavy ion collisions. Together with ZDC, it will make possible the covering of almost the whole angular region for CMS. CASTOR consists of quartz plates in a heavy metal matrix. Cherenkov light produced in the quartz plates will be detected by Hamamatsu R5380 Photomultiplier Tubes (PMTs). All the PMTs which will be used in the calorimeter have to be verified for gain and timing characterisation to have the performance required by CMS‐CASTOR Group before their installation into the calorimeter. We established a testing station at Cukurova University for this purpose. In the present paper we are going to give the anode dark current and gain measurements of these PMTs.

We investigate the generalized form of Duffin–Kemmer–Petiau (DKP) equation in the presence of both a position-dependent electrical field and curved spacetime for the 2-dimensional anti-de Sitter spacetime. Moreover, we derive both the asymptotic wave function and construct energy quantization with the help of the properties of gamma function. All thermodynamic quantities of the system have been calculated with the help of the Euler–MacLaurin formula in the final state.

The Mueller (1) method has led to an analysis of the inclusive reactions in the context of the Regge-pole model. A number ~f papers have discussed the problem of early scaling as properties of the exoticity of certain channels (3). Although there is no unique way of approaching thc problem of early scaling, the method of CHA~ et al. (3) which assumes ab~ exotic for an early sealing of the reaction a + b-~ c + X in the fragmentat ion region has played an important role in explaining the present data. On the other hand, in a recent paper (3) it has been shown that the algebra of vertex strcngths of CABIBBO, HO~WlTZ and NE'E~.N (4) (CHN) leads to interesting relations for the inclusive reactions in the target fragmentation region. Application of the CHN algebra to the processes in the central region predicts well-satisfied relations (5). In this paper we show that the present one-particle inclusive data are compatible with the paremetrization of ref. (3) and using these data we make predictions for the two-particle inclusive reactions in the fragmentation region. The single-particle inclusive process in the fragmentation region can be regarded as the im~tginary part of the forward elastic scattering of a particle a or b on a pseudopartielc state (b~) or (a~) respectively, as shown in Fig. 1. The CHN algebra determines the relativc strengths of various particle-reggeon couplings. The evenand odd-signature trajectories couple to the scalar current

We have calculated the energy dependence of pion asymmetry relative to the direction of hyperon polarization in the three-body radiative decays of polarized hyperons, using the inner bremsstrahlung model. We find that in the low pion energy region, the pion asymmetry in the radiative decay relative to the non-radiative decay is kinematically enhanced. For certain decays, this effect could be exploited experimentally to obtain additional information about the properties of the hyperons.