arXiv subjects

V. T. Kim

Publications and source records attributed to V. T. Kim.

13 recordsLinked to original sources

arXiv2022

Conceptual design of the Spin Physics Detector

The Spin Physics Detector, a universal facility for studying the nucleon spin structure and other spin-related phenomena with polarized proton and deuteron beams, is proposed to be placed in one of the two interaction points of the NICA collider that is under construction at the Joint Institute for Nuclear Research (Dubna, Russia). At the heart of the project there is huge experience with polarized beams at JINR. The main objective of the proposed experiment is the comprehensive study of the unpolarized and polarized gluon content of the nucleon. Spin measurements at the Spin Physics Detector at the NICA collider have bright perspectives to make a unique contribution and challenge our understanding of the spin structure of the nucleon. In this document the Conceptual Design of the Spin Physics Detector is presented.

hep-ex↗

arXiv2021

Possible studies at the first stage of the NICA collider operation with polarized and unpolarized proton and deuteron beams

This paper contains suggestions for experiments with usage of the Spin Physics Detector (SPD) at the first stage of the SPD NICA Programme developing at JINR. Double polarized pp-, dd- and pd- collisions at c.m.s. NN energies of 3.4-10 GeV, which will be accessible at the initial stage of experiments, allow one to study spin dependence of the NN interaction, search for multiquark states at double strangeness, charm and beauty thresholds, study the short-range structure of the deuteron. Double polarized pd scattering offer a possibility to test the Standard Model through the search for T-invariance violation.

hep-ph↗

arXiv2015

The transverse momentum dependence of charged kaon Bose-Einstein correlations in the SELEX experiment

We report on the measurement of the one-dimensional charged kaon correlation functions using 600~GeV/{\it c} $Σ^-$, $π^-$ and 540~GeV/{\it c} $p$ beams from the SELEX~(E781) experiment at the Fermilab Tevatron. $K^{\pm}K^{\pm}$ correlation functions are studied for three transverse pair momentum, $k_T$, ranges and parameterized by a Gaussian form. The emission source radii, $R$, and the correlation strength, $λ$, are extracted. The analysis shows a decrease of the source radii with increasing kaon transverse pair momentum for all beam types.

hep-ex↗

arXiv2010

Peculiar features of the relations between pole and running heavy quark masses and estimates of the O(α_s^4) contributions

Perturbative relations between pole and running heavy quark masses, defined in the Minkowski regions, are considered. Special attention is paid to the appearance of the kinematic $π^2$-effects, which exist in the coefficients of these series. The estimates of order $O(α_s^4)$ QCD corrections are presented.

hep-ph↗

arXiv2009

Uncertainties of QCD predictions for Higgs boson decay into bottom quarks at NNLO and beyond

An importance of the detailed studies of the theoretical QCD predictions for the decay width of Standard Model Higgs boson into bottom quarks, in the case when $\rm{M_H\leq 2M_W}$, is emphasized. The effects of higher order perturbative QCD corrections up to order $α_s^4$-terms are considered. The resummations of the $π^2$ terms resulting from analytical continuation, typical of Minkowskian quantities, is undertaken for the $Γ(H\to\bar{b}b)$ decay width. The uncertainties in the calculation of this decay width are analyzed.

hep-ph↗

arXiv2009

Higgs boson decay into bottom quarks and uncertainties of perturbative QCD predictions

Different methods for treating the results of higher-order perturbative QCD calculations of the decay width of the Standard Model Higgs boson into bottom quarks are discusssed. Special attention is paid to the analysis of the $M_H$ dependence of the decay width $Γ(H\to \bar{b}b})$ in the cases when the mass of b-quark is defined as the running parameter in the $\bar{MS}$-scheme and as the quark pole mass. The relation between running and pole masses is taken into account in the order $α_s^4$-approximation. Some special features of applications of Analytical Perturbation Theory (APT) are commented.

hep-ph↗

arXiv2009

Asymptotic effects in jet production at high energies

Monte Carlo event simulation with BFKL evolution is discussed. We report current status of a Monte Carlo event generator ULYSSES with BFKL evolution implemented. The ULYSSES, based on Pythia Monte Carlo generator, would help to reveal BFKL effects at LHC energies. In particular, such an observable as dijet K-factor can serve as a source of BFKL dynamics at the LHC, and it would also help to search for new physics.

hep-ph↗

arXiv2007

Higgs Decay To \bar{b}b: Different Approaches To Resummation Of QCD Effects

The comparison between parameterisations of the perturbation results for the decay width of the Standard Model Higgs boson to \bar{b}b-quarks pairs, based on application of \bar{MS}-scheme running quark mass and pole b-quark mass, are presented. In the case of the latter parameterisation taking into account of order O(α_s^3) term is rather important. It is minimising deviations of the results obtained at the O(α_s^2) level from the results, which follow from the running quark mass approach

hep-ph↗

arXiv2005

Initial-state nuclear effects in proton-nucleus collisions

Two important initial-state nuclear effects in hadron-nucleus collisions are considered. The ratios of inclusive differential cross sections for Drell-Yan dimuon production are calculated. The calculated results are compared to the E866 data. It is shown that consideration of multiple soft rescatterings of incident quarks in nuclei and initial-state quark energy loss effects allow to get a good agreement between the calculated results and the experimental data.

hep-ph↗

arXiv2003

Phase Transition in Light-Front $ϕ^4_{1+1}$

We reproduce Chang's duality condition in a regularized $ϕ^4_{1+1}$ theory quantized on a light front. The regularization involves higher derivatives in the Lagrangian, renders the model finite in the ultraviolet, and does not require introduction of a finite size of the system. It is demonstrated that the light-front quantization is a natural way to treat systems with higher derivatives. The phase transition is related to the presence of tachyons in the regularized theory. Prospects for computing the critical coupling in this formulation are briefly discussed.

hep-th↗

arXiv2002

High-Energy QCD Asymptotics of Photon-Photon Collisions

The high-energy behaviour of the total cross section for highly virtual photons, as predicted by the BFKL equation at next-to-leading order (NLO) in QCD, is discussed. The NLO BFKL predictions, improved by the BLM optimal scale setting, are in good agreement with recent OPAL and L3 data at CERN LEP2. NLO BFKL predictions for future linear colliders are presented.

hep-ph↗

arXiv2002

The BFKL Pomeron within Physical Renormalization Schemes and Scales

In this lecture the next-to-leading order (NLO) corrections to the QCD Pomeron intercept obtained from the Balitsky-Fadin-Kuraev-Lipatov (BFKL) equation are discussed. It is shown that the BFKL Pomeron intercept when evaluated in non-Abelian physical renormalization schemes with Brodsky-Lepage-Mackenzie (BLM) optimal scale setting does not exhibit the serious problems encountered in the modified minimal subtraction (bar{MS}) scheme. The results obtained provide an opportunity for applications of the NLO BFKL resummation to high-energy phenomenology. One of such applications for virtual gamma-gamma total cross section shows a good agreement with preliminary data at CERN LEP.

hep-ph↗

arXiv1993

The Effects of the Massless O(alpha_s^2), O(αα_s), O(α^2) QCD and QED Corrections and of the Massive Contributions to Gamma(H^0\rightarrow b\overline{b})

We consider in detail various theoretical uncertainties of the perturbative predictions for the decay width of $H^0\rightarrow b\overline{b}$ process in the region $50\ GeV< M_H\leq 2M_W$. We calculate the order $O(α_s^2)$-contributions to the expression for $Γ_{Hb\overline{b}}$ through the pole quark mass and demonstrate that they are important for the elimination of the numerical difference between the corresponding expression and the one through the running $b$-quark mass. The order $O(αα_s)$ and $O(α^2)$ massless and order $O(m_b^2/M_H^2)$ massive corrections to $Γ_{Hb\overline{b}}$ are also calculated. The importance of the latter contributions for modeling of the threshold effects is demonstrated. The troubles with identifying of the 4 recent L3 events $e^+e^-\rightarrow l^+l^-γγ$ with the decay of a Standard Higgs boson are discussed.

hep-ph↗