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M. Zavertyaev

Publications and source records attributed to M. Zavertyaev.

5 recordsLinked to original sources
arXiv2012

Empirical parameterization of the high energy behaviour of average charged particle multiplicities in e+e-, ep and pp collisions

A simple fit of existing data for center-of-mass energies above the b-threshold shows that the average charged particle multiplicities in pp_bar and pp interactions can be parameterized by a simple power law N_ch = N_0*(s/s_0)^(gamma) with gamma close to 1/5. Choosing s_0=m_p^2, where m_p is a proton mass, one finds N_0=2.32. The average charged particle multiplicities in e+e- and e(+/-)p interactions follows the same power law with an offset of +/- 1 unit in N_0. The observed trend leads to the conclusion that in LHC experiments at energy of 7TeV one should expect the average charge multiplicity in the region of N_ch close to 80.

hep-ex↗
arXiv2004

Strangeness Production at the HERA-B Experiment

HERA-B is a fixed target experiment at the 920 GeV HERA proton beam at DESY which uses a variety of nuclear targets. During the last data taking period from Nov. 2002 to Feb. 2003, 200 million minimum bias events were recorded. A large sample of V^0(K_zero, Lambda_zero, Lambda_zero_bar), approximately 20000 cascade hyperons Xi^(-/+) and 1200 Omega^(-/+) over low background were reconstructed using these data. About 1 million K^*(892) --> K pi and 60,000 phi(1020) --> K^+K^- decays in central production $(-0.15 < x_F < 0.1, 0.5 < p_t^2 < 12.1 (GeV/c)^2 were analyzed. Preliminary results for differential p_t^2 spectra, atomic numeber dependence and anti-particle to particle ratios are presented.

hep-ex↗
arXiv2004

Search for Theta^+ and Xi^{--}_{3/2} pentaquarks in HERA-B

A search for Theta^+(1540) and Xi^{--}_{3/2}(1862) pentaquark candidates has been performed in proton-induced reactions on C, Ti and W targets at sqrt(s) = 41.6 GeV studying the pK_s resp. Xi^-pi^- and Xi^-pi^+ (and charge conjugated) decay channels at mid-rapidity. With sensitivities of (Br)x(dsigma/dx_F) < 5 to 25 microbarn/nucleon, we find no evidence for narrow pentaquark peaks in any of the studied final states. Preliminary values for the upper limit of relative yield ratios at mid-rapidity are (Theta^+(1540)) / (Lambda(1520)) < 0.02, (Br)x(Xi^{--}_{3/2}(1862)) / (Xi(1530)^0) < 0.077, and (Br)x(Xi_bar^{++}_{3/2}(1862)) / (Xi_bar(1530)^0) < 0.058 at 95% CL.

hep-ex↗