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S. R. Slabospitsky

Publications and source records attributed to S. R. Slabospitsky.

At least 19 recordsLinked to original sources
arXiv2026

A search for the dark photon in the OKA experiment

A search for the massless dark photon in the decay $K^{+}\to π^{+}π^{0}\overline{{} γ}$ is performed with the OKA detector exposed to 17.7 GeV/c RF separated secondary beam of the U70 Proton Synchrotron. A high-statistics data sample of the $K^{+}$ decays is used for a missing mass search of the stable massless invisible dark photon ($\overlineγ$) in the final state. In the absence of a statistically valuable signal the upper limit on the branching ratio of the decay $Br<2.0\times10^{-6}$ is obtained with a 90% confidence level based on a realistic matrix element of the process. Currently, it is the best upper limit for this hypothetical decay channel.

hep-ex↗
arXiv2008

Simulation of the Polarized Fermion Decay

In this paper the modification of the method conventionally used for the modeling of the massive fermions production and decays is proposed. The step by step algorithm is presented. Under the strict conditions the proposed method of modeling allow distinctly raise the efficiency of the computations.

hep-ph↗
arXiv2007

New Polarization Program at U70 (SPASCHARM Project)

The new polarization program SPASCHARM is being prepared in Protvino. The program has two stages. The first stage is dedicated to single-spin asymmetries in the production of miscellaneous light resonances with the use of 34 GeV $π^-$-beam. Inclusive and exclusive reactions will be studied simultaneously. The second stage is dedicated to single-spin and double-spin asymmetries in charmonium production with the use of 70 GeV polarized proton beam which will allow us to understand charmonium hadronic production mechanism and make gluon polarization $Δg(x)$ extraction at large $x$.

hep-ex↗
arXiv2006

A standard format for Les Houches Event Files

A standard file format is proposed to store process and event information, primarily output from parton-level event generators for further use by general-purpose ones. The information content is identical with what was already defined by the Les Houches Accord five years ago, but then in terms of Fortran commonblocks. This information is embedded in a minimal XML-style structure, for clarity and to simplify parsing.

hep-ph↗
arXiv2005

Spin physics program in the U70 polarized proton beam

A possibility to accelerate a high intensity polarized proton beam up to 70 GeV at the IHEP accelerator, extract it from the main ring and deliver to several experimental setups is being studied now. We propose to study a wealth of single- and double-spin observables in various reactions using longitudinally and transverserly polarized proton beams at U70. The proposed measurements can be done at the existing detectors as well as require to create a few new experimental setups at U70.

hep-ex↗
arXiv2002

Study of s-channel Charged Higgs Production in CMS

CMS potential for study of the s-channel $H^{\pm}$-boson production via light quark annihilation is investigated for large values of $\tanβ$ ($=20÷50$) and relatively light charge Higgs boson ($M_H = 200 ÷400$ GeV). An appropriate parameterisation for $M_{\top}(j, \ETM)$-distributions of the signal and background events is proposed, which provides the determination of the charged Higgs mass and $\tanβ$ parameter.

hep-ph↗
arXiv2002

TopReX generator (version~3.25). Short manual

This is the manual of the specialized event generator TopReX 3.25. The generator provides the simulation of several important processes in pp and p pbar collisions, not implemented in PYTHIA (yet). Some of these processes include t-quarks whose spin polarizations are taken into account in the subsequent decay of the t-quarks. Several non-SM top quark decay channels are included, too. All calculated subprocesses can be accessed from PYTHIA as external processes. In addition, TopReX can be used as stand alone event generator, providing partonic final states before showering. In this mode the control of the event generation is taken by TopReX itself. A few simple examples of main routines, which show how to use TopReX in the different modes are discussed.

hep-ph↗
arXiv2000

Charged Higgs Contribution into (t b_bar)-pair Production in Hadronic Collisions

We investigate the charged Higgs boson contribution into $t\bar b$-pair production in pp-collisions at LHC. It is shown that due to the $\cz$-boson exchange the total yield of $t\bar b$ is modified significantly for small and large values of $\tanβ$. However, for the small values of $\tanβ$ one should expect also the production of right-polarized top quark contrary to pure left-polarized t-quark production through $W^{\pm}$-boson exchange only. This fact provides a possibility to separate $H^{\pm}$ and $W^{\pm}$ contributions by means of the investigations of angular distributions of top decay products. The detailed simulation of the signal and relevant background processes is performed.

hep-ph↗
arXiv2000

Asymmetry in Charmed Particles Production in $Σ^{-}$ beam

We present the calculation of the inclusive $x_F$-distributions of charmed hadrons, produced in high-energy $Σ^-$-beam. The calculation is based on the modified mechanism of charmed quarks fragmentation as well as on the mechanism of $c$-quark recombination with the valence quarks from initial hadrons. We predict the additional asymmetry in the production of charmed hadrons due to the different distributions of the valence s and d quarks in $Σ^-$-beam.

hep-ph↗
arXiv2000

Charmed hadrons production in high-energy $Σ^-$ beam

We present the calculation of the inclusive x_F-distributions of charmed hadrons, produced in high-energy $Σ^-$-beam. Our calculation is based on the modified mechanism of charmed quarks fragmentation as well as on the mechanism of c-quark recombination with the valence quarks from initial hadrons.

hep-ph↗
arXiv1998

Double Top Production at Hadronic Colliders

We calculate the contribution of anomalous top-quark interaction with a gluon, photon, and $Z$-boson (FCNC) to $t \bar t$ pair production in hadronic collisions. Using the current data from Run~1 of the Tevatron we evaluate the upper limit on the the anomalous coupling of $t$-quark with gluon, $|κ_g/Λ| \le 0.52$ TeV$^{-1}$. We examine the production of double top ($t t$ or $\bar t \bar t$) at hadronic colliders as a result of FCNC interactions of the top quark. It is shown that the study of such reactions at LHC collider makes possible to obtain the constraint on strength of coupling at the level of $|κ_g /Λ| \le 0.09$ TeV$^{-1}$.

hep-ph↗
arXiv1998

Search for Anomalous Top--Quark Interaction at LEP-2 Collider

We show that a search for $e^+ e^- \to t \bar q$ $(\bar q = \bar c, \bar u)$ events at LEP--2 collider provide a possibility to improve significantly the modern constraints on coupling constants of anomalous $t$--quark interaction via flavor--changing neutral currents.

hep-ph↗
arXiv1997

On Mechanism of Charmed c-Quarks Fragmentation in Hadronic Collisions

We propose a modification of the mechanism of charmed quarks fragmentation into $D$ mesons in hadronic collisions. It is shown that the distinction in valence quark distributions in the initial $π^{\pm}$ and $K^{\pm}$ mesons leads to different inclusive spectra of $D$ and $D_s$ mesons produced in $π^{\pm}$ and $K^{\pm}$ beams.

hep-ph↗
arXiv1997

The Contribution of Bc Mesons to the Search for B->tau nu Decays at LEP

We study the contribution of B_c mesons to the search for B->tau nu decays. We find that at LEP the contributions from B_u and B_c mesons can be comparable. This observation can have a relevant impact on the extraction of constraints on new physics (such as charged-Higgs contributions) from current LEP limits on B->tau nu final states. Inclusion of the B_c contribution can reduce the current L3 limit on Tan(beta)/M_H from 0.38/GeV (90%CL) down to 0.27/GeV (90%CL).

hep-ph↗
arXiv1995

CORE 2.1 (COmpendium of RElations, Version 2.1)

The present CORE 2.1 (COmpendium of RElations, Version 2.1) contains various formulas and relations used in the practical calculations in the Standard Model. The properties of the Pauli, Dirac, Gell--Mann matrices, wave functions of free fermions and gauge bosons are considered. We present the full Lagrangian of the Standard Model and the corresponding Feynman rules. The method of the evaluation of the Feynman (loop) integrals and calculations in non-covariant gauges is considered. We discuss in brief the relativistic kinematic and present a large number of the matrix elements of the various processes in the Standard Model.

hep-ph↗