O. M. Kuznetsov

Limits on neutral light scalar and pseudoscalar particles in a proton beam dump experiment

A search has been performed for weakly interacting neutral light scalar and pseudoscalar particles in a proton beam dump experiment. No positive signal is observed. Limits on the mass and life-time of these particles are set in the frame of the Standard Model and its minimal supersymmetric extension. The Higgs particle of theSU2L×U1 Standard Theory is excluded for masses in the range 1 MeV<mH<80 MeV at 95%CL. Limits on the Peccei-Quinn like axions are derived.

Neutrino production of charmed particles in a hybrid experiment E-564

AbstractCryogenically sensitive nuclear emulsion was placed inside the 15-foot bubble chamber of FNAL and exposed to a wide-band energy (up to 200 GeV) neutrino beam. 194 charged-current neutrino interactions and 13 decays of charmed particles were registered. Using the nuclear emulsion as a vertex detector with the good spectrometric properties of the 15-foot bubble chamber has allowed the decays of charmed particles to be effectively analysed. Attentions is focussed on the new physical results. Λc+ baryon andDs+ meson decay channels, production of charmed ∑c baryons and Λc+ via ∑c. For the first time an event interpreted as production of the excited (c

Production and decay of F+(2030) observed in νμ interactions in emulsion

\overline s

Mass limits on a light Higgs boson from π-, K-, η′ -meson decays in the 70 GeV proton beam-dump experiment

)-state with mass ∼2790 MeV/c2 has been registered.

Backward emitted protons in interactions of neutrinos with nuclei in photoemulsion

A search has been performed for weakly interacting neutral light scalar and pseudoscalar particles in a proton-iron beam dump experiment via the Bethe-Heitler process. No positive signal was observed. Limits are derived on the masses of these particles in the framework of the Standard Model and its minimal supersymmetric extension (MSSM) comparing the experimental results with expectations for Bethe-Heitler e+e− and μ+μ− pair production. The Higgs particle of the SU2L×U1 Standard Theory is excluded for masses in the range mH<0.9 MeV at 95% CL. Limits on light Higgs particles of the MSSM and Peccei-Quinn like axions are derived.

Estimation ofvμ→vτ oscillation parameters in the E-564 hybrid experiment

Abstract An event representing the production and decay of the charmed F+ meson has been identified by means of a 3-constraint fit to decay hypothesis F+ → π+π+π−π0, in which both γ-rays from the π0 converted. The event was produced by a charged current νμ interaction in an emulsion stack located inside the Fermilab 15-foot bubble chamber. The F+ traveled 50 μm, corresponding to a proper time of 1.4 × 10−13 seconds, before decaying in flight. Its mass was determined to be 2017 ± 25MeV.

Observation of charmed F+ meson produced by neutrino interaction in emulsion

Abstract The production of prompt and ordinary ( ν ) e was investigated in a proton beam dump experiment at the 70 GeV Serpukhov accelerator measuring their interactions in the IHEP-JINR neutrino detector. An upper limit of σ charm μ b/nucleon at 90% CL was obtained near the production threshold.

Measurement of xf3, f2 structure functions and Gross-Llewellyn-Smith sum rule with IHEP-JINR neutrino detector

Abstract Data from a 70 GeV proton-iron beam-dump experiment and the theoretical predictions of light Higgs production from the decays π ± →e ± V (∼) e H, K ± →e ± V (∼) e H, K ± →π ± H, K 0 L →π 0 H, η′→η′H were used to establish limits on the mass of a scalar Higgs boson in the context of the standard model. The mass range 1 m H c 2 was excluded at 95% CL.