arXiv subjects

V. Leontiev

Publications and source records attributed to V. Leontiev.

12 recordsLinked to original sources

arXiv2026

Production of {\Lambda} hyperons in 4.0A GeV and 4.5A GeV carbon-nucleus interactions at the Nuclotron

The BM@N experiment (Baryonic Matter at the Nuclotron) is the first fixed-target experiment at the JINR NICA accelerator complex. In this work, data on the interactions of a carbon-ion beam with kinetic energies of 4.0A~GeV and 4.5A~GeV with C, Al, Cu, and Pb targets are used to measure transverse momentum spectra and rapidity distributions of $\Lambda$ hyperon yields. The results are compared with the predictions of DCM-SMM, UrQMD, and PHSD transport models and with the $\Lambda$ yield measurements in other experiments at similar collision energies.

hep-ex↗

arXiv2025

Production of protons, deuterons and tritons in argon-nucleus interactions at 3.2 AGeV

Results of the BM@N experiment at the Nuclotron/NICA complex on the production of protons, deuterons and tritons in interactions of an argon beam of 3.2 AGeV with fixed targets of C, Al, Cu, Sn and Pb are presented. Transverse mass spectra, rapidity distributions and multiplicities of protons, deuterons and tritons are measured. The results are treated within a coalescence approach and compared with predictions of theoretical models and with other measurements

hep-ex↗

arXiv2024

The BM@N spectrometer at the NICA accelerator complex

BM@N (Baryonic Matter at Nuclotron) is the first experiment operating and taking data at the Nuclotron/NICA ion-accelerating complex.The aim of the BM@N experiment is to study interactions of relativistic heavy-ion beams with fixed targets. We present a technical description of the BM@N spectrometer including all its subsystems.

hep-ex↗

arXiv2023

Production of $π^+$ and $K^+$ mesons in argon-nucleus interactions at 3.2 AGeV

First physics results of the BM@N experiment at the Nuclotron/NICA complex are presented on π+ and K+ meson production in interactions of an argon beam with fixed targets of C, Al, Cu, Sn and Pb at 3.2 AGeV. Transverse momentum distributions, rapidity spectra and multiplicities of $π^+$ and $K^+$ mesons are measured. The results are compared with predictions of theoretical models and with other measurements at lower energies.

hep-ex↗

arXiv2010

Observation of the destructive interference in the radiative kaon decay K- --> mu-nugamma

Using data collected with the ISTRA+ spectrometer at U70 proton synchrotron of IHEP, we report the first measurement of the destructive interference in the radiative kaon cecay K- -->mu-nugamma. We find the difference of the vector and axial form factors Fv-Fa=0.126+/-0.027+/-0.043. The measured value is two standard deviations above the O(p**4) ChPT prediction equal to 0.055. Inclusion of exotic tensor interaction gives Fv-Fa=0.144+/-0.044+/-0.035 and Ft=-0.0079+/-0.0113+/-0.0073, i.e. -0.03<Ft<0.01 at 90% CL,consistent both with zero and with recent theoretical prediction equal to |Ft|=0.022.

hep-ex↗

arXiv2005

The SPHINX spectrometer

The paper describes the SPHINX facility which includes a wide-aperture magnetic spectrometer with scintillation counters and hodoscopes, proportional chambers and drift tubes, multichannel electromagnetic and hadron calorimeters, a guard system, a RICH velocity spectrometer and a hodoscopical threshold Cherenkov detector for the identification of charged secondary particles. The SPHINX spectrometer, in its last modification, had the possibility to record 3000-4000 trigger events per an accelerator burst. The spectrometer was used during the last decade in experiments with the 70GeV proton beam of the IHEP accelerator U-70.

physics.ins-det↗

arXiv2005

Observation of the radiative kaon decay K- --> mu-pi0gammanu

Using data collected with the ISTRA+ spectrometer during the 2001 run of the U-70 proton synchrotron in Protvino, we report the first observation of the radiative kaon decay K- -->mu-pi0gammanu. We find Br(Kmu3g)/Br(Kmu3) for two regions 5<Eg<30 and 30<Eg<60 MeV consistent with theoretical predictions. The measured angular distribution asymmetry for the first region, 0.093+/-0.141, is two standard deviations away from the theoretical prediction of 0.354. The measured asymmetry in the T-odd variable is -0.03+/-0.13.

hep-ex↗

arXiv2004

Search for light pseudoscalar sgoldstino in K- decays

A search for the light pseudoscalar sgoldstino production in the three body K- decay K-->pipi0P has been performed with the ISTRA+ detector exposed to the 25 GeV negative secondary beam of the U70 proton synchrotron. No signal is seen. An upper limit for the branching ratio Br(K->pipi0P), at 90% confidence level, is found to be around 9*10**-6 in the effective mass m(P) range from 0 till 200 MeV, excluding the region near m(pi0) where it degrades to 3.5*10**-5.

hep-ex↗

arXiv2002

Precision Measurement of Energy and Position Resolutions of the BTeV Electromagnetic Calorimeter Prototype

The energy dependence of the energy and position resolutions of the electromagnetic calorimeter prototype made of lead tungstate crystals produced in Bogoroditsk (Russia) and Shanghai (China) is presented. These measurementswere carried out at the Protvino accelerator using a 1 to 45 GeV electron beam. The crystals were coupled to photomultiplier tubes. The dependence of energy and position resolutions on different factors as well as the measured electromagnetic shower lateral profile are presented.

hep-ex↗

arXiv2002

Study of Radiation Damage in Lead Tungstate Crystals Using Intense High Energy Beams

We report on the effects of radiation on the light output of lead tungstate crystals. The crystals were irradiated by pure, intense high energy electron and hadron beams as well as by a mixture of hadrons, neutrons and gammas. The crystals were manufactured in Bogoroditsk, Apatity (both Russia), and Shanghai (China). These studies were carried out at the 70-GeV proton accelerator in Protvino.

hep-ex↗

arXiv2002

Study of the K- -> mu- nu pi0 decay

The decay $K^{-} \to μ^{-} \barν π^{0}$ has been studied using in-flight decays detected with ``ISTRA+'' setup operating in the 25 GeV negative secondary beam of the U-70 PS. About 112K events were used for the analysis. The $λ_{+}$ and $λ_{0}$ slope parameters of the decay formfactors $f_{+}(t)$, $f_{0}(t)$ have been measured : $λ_{+}= 0.0321 \pm 0.004$(stat) $\pm 0.002$(syst) $λ_{0}= 0.0209 \pm 0.004$(stat) $\pm 0.002$(syst); the correlation $d λ_{0}/d λ_{+}=-0.46$ The limits on the possible tensor and scalar couplings have been derived: $f_{T}/f_{+}(0)=-0.021 \pm 0.028$(stat) $\pm 0.014$(theory); $f_{S}/f_{+}(0)=0.004 \pm 0.005$(stat) $\pm 0.005$(theory)

hep-ph↗

arXiv2001

Study of the K- -> pi0 e- nu decay

The decay K- -> pi0 e- nu has been studied using in-flight decays detected with "ISTRA+" setup operating at the 25 GeV negative secondary beam of the U-70 PS. About 130K events were used for the analysis. The lambda_+ parameter of the vector formfactor has been measured: lambda_+ = 0.0293 +- 0.0015(stat) +- 0.002(syst). The limits on the possible tensor and scalar couplings have been derived: f_T/f_+(0)=-0.044 +0.059 -0.057 (stat) f_S/f_+(0)=-0.020 +0.025 -0.016 (stat)

hep-ex↗