24,934 research outputs found
Neutrino production of opposite sign dimuons in the NOMAD experiment
No full textThe NOMAD Collaboration presents a study of opposite sign dimuon events in the framework of Leading Order QCD. A
total of 2714 neutrino(mu) and 115 antineutrino(mu) induced opposite sign dimuon events are observed in the Front-Calorimeter of NOMAD during the 1995 and 1996 runs
Limit on νe → ντ oscillations from the NOMAD experiment
No full textIn the context of a two-flavour approximation we reinterpret the published NOMAD limit on neutrino(mu) to neutrino(tau) oscillations in terms of neutrino(e) to neutrino(tau) oscillations. At 90% C.L. we obtain sin22u - 5.2=10y2 for large Dm2, while for sin22u s1 the e t et et confidence region includes Dm2-11 eV2rc4
Search for νμ → νe oscillations in the NOMAD experiment
No full textWe present the results of a search for νμ →νe oscillations in the NOMAD experiment at CERN. The experiment looked
for the appearance of νe in a predominantly νμ wide-band neutrino beam at the CERN SPS. No evidence for oscillations was
found. The 90% confidence limits obtained are m2 < 0.4 eV2 for maximal mixing and sin2(2θ)<1.4×10−3 for large m2.
This result excludes the LSND allowed region of oscillation parameters with m2 10 eV2
Measurement of the Λ polarization in νμ charged currents interactions in the NOMAD experiment
No full textThe Lamda polarization in neutrino(mu) charged current interactions has been measured in the NOMAD experiment.
The event sample (8087 reconstructed events) is more than an order of magnitude larger than that of previous bubble chamber experiments, while the quality of event reconstruction is
comparable. We observe negative polarization along the W-boson direction
Measurement of the antiΛ polarization in νμ charged currents interactions in the NOMAD experiment
No full textWe present a measurement of the polarization of antiLamda hyperons produced in νμ charged current
interactions. The full data sample from the NOMAD experiment has been analyzed using the
same V0 identification procedure and analysis method reported in a previous paper for the case of Lamda hyperons. The antiLamda polarization hasbeen measured for the first time in a neutrino experiment. The polarization vector is found to be
compatible with zero
Study of D*+ production in νμ charged current interactions in the NOMAD experiment
No full textA search was made among νμ charged current events collected in the NOMAD experiment for the reaction:
νμ +N →μ− +D+ + hadrons
→D0 + π+
→K− + π+.
A high purity D+ sample composed of 35 events was extracted. The D+ yield in νμ charged current interactions was
measured to be T = (0.79 ± 0.17(stat.) ± 0.10(syst.))%. The mean fraction of the hadronic jet energy taken by the D+ is
0.67 ± 0.02(stat.) ± 0.02(syst.). The distributions of the fragmentation variables z, PT
2 and xF for D+ are also presented
A study of strange particle production in νμ charged current interactions in the NOMAD experiment
No full textA study of strange particle production in νμ charged current interactions has been performed using the data from the NOMAD experiment. Yields of neutral strange particles (K0s,, ̄ ) have
been measured. Mean multiplicities are reported as a function of the event kinematic variables Eν ,W2 and Q2 as well as of the variables describing particle behaviour within a hadronic jet: xF , z
and p2T. Decays of resonances and heavy hyperons with identified K0sand in the final state have been analyzed. Clear signals corresponding to K±, ±, − and 0 have been observed
Final NOMAD results from on νμ → ντ and νe → ντ oscillations including a new search for ντ appearance using hadronic τ decays
No full textResults from the ντ appearance search in a neutrino beam using the full NOMAD data sample
are reported. A new analysis unifies all the hadronic τ decays, significantly improving the overall
sensitivity of the experiment to oscillations. The “blind analysis” of all topologies yields no evidence
for an oscillation signal. In the two-family oscillation scenario, this sets a 90% CL allowed region
in the sin2 2θμτ –_m2 plane which includes sin2 2θμτ < 3.3 × 10−4 at large _m2 and _m2 <
0.7 eV2/c4 at sin2 2θμτ = 1. The corresponding contour in the νe →ντ oscillation hypothesis results
in sin2 2θeτ < 1.5 × 10−2 at large _m2 and _m2 < 5.9 eV2/c4 at sin2 2θeτ = 1. We also derive
limits on effective couplings of the τ lepton to νμ or νe
Updated results from the nu(tau) appearance search in NOMAD
No full textUpdated results from the appearance searches for neutrino(mu) to neutrino(tau) and neutrino(e) to neutrino(tau) oscillations in the full NOMAD data sample are reported. The increased data and the use of more refined kinematic schemes for the neutrino CC selection allow a significant improvement of the overall sensitivity. The ‘‘blind analysis’’ of both the deep-inelastic and the low multiplicity samples yields no evidence for an oscillation signal
A study of quasi-elastic muon neutrino and antineutrino scattering in the NOMAD experiment
No full textWe have studied the muon neutrino and antineutrino quasi-elastic (QEL) scattering reactions using a set of experimental data collected by the NOMAD Collaboration. We have performed measurements of the cross-section of these processes on a nuclear target (mainly carbon).The axial mass parameter M was extracted from the measured quasi-elastic neutrino cross section. The corresponding result is M =1.05±0.02(stat)±0.06(syst) GeV. Our measured M is found to be in good agreement with the world average value obtained in previous deuterium filled bubble chamber experiments. The NOMAD measurement of M is lower than those recently published by K2K and MiniBooNE Collaborations. However, within the large errors quoted by these experiments on M, these results are compatible with the more precise NOMAD value
- …
