33 research outputs found
A detector for the study of neutrino-electron scattering
No full textThe CHARM II Collaboration has built a massive, fine-grained and low-density detector for the study of muon-neutrino and muon-antineutrino scattering on electrons. The detector consists of a target calorimeter of 692 t of glass followed by a magnetic spectrometer. The calorimeter is used to detect the different types of neutrino interactions, and to measure the energy and direction of the produced particle showers; the spectrometer permits the determination of the momentum of muons produced in charged-current reactions on nuclei. The calorimeter is composed of 441 detector planes having a total of 154 560 plastic streamer tubes with digital readout of the wires and of 73920 cathode pickup strips grouped in 9240 channels with analog readout. It is further instrumented with 1540 scintillators. A complete description of the detector and some results of its performance with cosmic-ray muons are presented. © 1989.0SCOPUS: ar.jinfo:eu-repo/semantics/publishe
Calibration and performance of the CHARM-II detector
No full textThe neutrino detector CHARM-II at CERN, consisting of a large target calorimeter equipped with streamer tubes and a muon spectrometer, has been exposed to a test beam of electrons, pions and muons with momenta between 2 and 60 GeV/c in order to study the digital response of the streamer tubes, the analog response of the pickup strips and the momentum resolution of the. © 1993.0SCOPUS: ar.jinfo:eu-repo/semantics/publishe
NEUTRAL CURRENT COUPLING-CONSTANTS FROM NEUTRINO-ELECTRON AND ANTINEUTRINO-ELECTRON SCATTERING
No full textWe are reporting on a determination of neutral current coupling constants from a study of differential cross sections of muon- (anti)neutrino-electron scattering. The results were obtained with the CHARM-II detector which was exposed to the CERN wide band neutrino beam in the years 1987-1990. A total of about 2100 ve and 2200 v ̄e scattering events were observed. From a comparison between the data and predicted event distributions, the effective vector and axial-vector neutral current coupling constants of the electron were determined to be ge_v=-0.025+/-0.019 and ge_A=-0.503+/-0.018
Neutral current coupling constants from neutrino and antineutrino-electron scattering
No full textWe are reporting on a determination of neutral current coupling constants from a study of differential cross sections of muon- (anti)neutrino-electron scattering. The results were obtained with the CHARM-II detector which was exposed to the CERN wide band neutrino beam in the years 1987-1990. A total of about 2100 ve and 2200 v̄e scattering events were observed. From a comparison between the data and predicted event distributions, the effective vector and axial-vector neutral current coupling constants of the electron were determined to be gev=-0.025±0.019 and geA=-0.503±0.018. © 1992.0SCOPUS: ar.jinfo:eu-repo/semantics/publishe
A new determination of the electroweak mixing angle from muon-neutrino-electron scattering
No full textWe are reporting on a new determination of sin2θ{symbol}w from the ratio of vμe to ve scattering cross sections. A new detector designed for this purpose was exposed tothe Wide Band Neutrino Beamof the 450 GeV (CERN SPS. An analysis of data taken in 1987 and 1988 is presented based on 762 vμe and 1017 ve events. From the ratio of σ(vμe) to σ(vμe) we determined sin2θ{symbol}w=0.233±0.012 (stat) ± 0.008 (syst) without radiative correction. With radiative correction for mt=mH=100 GeV we find sin2θ{symbol}w=0.232±0.012(stat) ±0.008(syst). © 1989.0SCOPUS: ar.jinfo:eu-repo/semantics/publishe
A Precise Measurement of the Cross-section of the Inverse Muon Decay Nu(mu)+e(-)-]mu(-)+nu(e)
No full textWe report our final results from the analysis of the full high statistics sample of events of the reaction nu(mu) + e(-) --> mu(-) + nu(e) collected with the CHARM II detector in the CERN wide-band neutrino beam during the years 1988 to 1991. From a signal of 15 758 +/- 324 inverse muon decay events we derived, in the Born approximation, a value of (16.51 +/- 0.93) x 10(-42) cm(2) GeV-1 for the asymptotic cross section slope sigma/E(n)u, in good agreement with the Standard Model prediction of 17.23 x 10(-42) cm(2) GeV-1. The result constrains the scalar coupling of the electron and the muon to \g(LL)(S)\(2) < 0.475 at 90% CL
Coherent single charged pion production by neutrinos
No full textWe report on a measurement of coherent single charged pion production in neutrino-nucleus scattering. The analysis is based on data taken with the CHARM II detector in beams of muon-neutrinos and -antineutrinos. The event numbers amount to N(μ-π) = 748 and N(μ+π) = 631. Cross sections and their dependence on the neutrino energy are determined. The results are in agreement with the predictions of models based on the PCAC hypothesis
Neutral-current Coupling-constants From Nu-mu-e- and (nu)bar-mu-e- Scattering
No full textWe report on determinations of the neutral current coupling constants of the electron from the study of muon neutrino and antineutrino scattering off electrons. The results were obtained with the CHARM II detector which was exposed to the CERN wide band neutrino beam during the years 1987 to 1991. We present the determination of g V and g A from the measurement of νμ e and ν̄μ e cross sections with 80% of the data and a preliminary result for sin2θ w from the ratio of νμ e and v̄μ e cross sections, using the full data sample. We furthermore give results from the comparison of neutrino electron scattering with inverse muon decay and present the first measurement of the y‐distributions for νμ e and ν̄μ e scattering. The agreement between our results and those from the measurements at LEP demonstrates the validity of the Standard Model over a range in momentum transfer which spans six orders of magnitude
Neutral current coupling constants from neutrino-electron scattering
No full textWe are reporting on a determination of neutral current coupling constants from a study of differential cross sections of muon-(anti)neutrino electron scattering. The results were obtained with the CHARM-II detector which was exposed to the CERN wide band neutrino beam in the years 1987 to 1991. A total of about 3000 nue and 3000 nueBAR scattering events were observed. We present a preliminary value of sin2 theta(W) determined with the ratio of neutrino and antineutrino electron scattering cross-sections, based on the full data sample, and we give a determination of the effective vector and axial-vector neutral current coupling constants and the first measurement of the shape of the y-distributions based on 80% of the total statistics
New results on inverse muon decay and low multiplicity reactions
No full textNew results on inverse muon decay and coherent charged pion production by neutrinos are presented. The data come from the CHARM-II neutrino detector operated at the CERN wide-band neutrino beam. High-statistics data samples of 14500 inverse muon decay events and 3500 nu(mu)e elastic scattering events allow the determination of the electroweak parameters from the ratio of the cross-sections of neutral-to-charged-current neutrino electron scattering. The best fit values of the electroweak mixing angle sin2 theta(W) and the relative coupling strength rho of neutral and charged current are: sin2 theta(W) = 0.237 +/- 0.014 and rho = 0.987 +/- 0.042. In the second topic, coherent single charged pion production was measured in neutrino and antineutrino beams. The measured cross-sections, averaged over the wide-band beam spectra and the glass target nuclei composition, are: sigma(nu(mu)A --> mu-pi+A) = (51 +/- 10) X 10(-40) cm2 nucleus and sigma(nu(mu)ABAR --> mu+pi-A) = (43 +/- 9) x 10(-40) cm2 nucleus. The energy dependence shows the expected flattering of the cross-sections at high energy
