arXiv subjects

Yu. Kalinovsky

Publications and source records attributed to Yu. Kalinovsky.

10 recordsLinked to original sources

arXiv2025

Temperature Dependence of the Masses of Various Meson States: A Comparative Study in SU(3) and SU(4) extended Linear-Sigma Model

In the extended Linear-Sigma Model (eLSM), the chiral phase structure of meson states, including pseudoscalars ($J^{pc}=0^{-+}$), scalars ($J^{pc}=0^{++}$), vectors ($J^{pc}=1^{--}$), and axial-vectors ($J^{pc}=1^{++}$), is investigated with the mean-field approximation. A systematic comparison between SU(3) and SU(4) configurations is provided. It has been found that the estimations of meson masses derived from SU(4) eLSM are more congruent with experimental values than those derived from SU(3) eLSM. Consequently, we conclude that an increase in quark degrees of freedom significantly enhances the accuracy of meson mass simulations. We investigate the effect of temperature on the masses of various meson states calculated in the SU(3) and SU(4) eLSM. After establishing all the fitting parameters, the temperature dependence of meson masses shows that although various meson states exhibit unique patterns in their mass changes with temperature, they all seem to share a similar range of dissolution temperatures. This means that the critical temperature that marks the phase transition from hadrons to quarks appears to vary slightly depending on the meson states. In this regard, we find that the quarkonium states, formed by a quark and its antiquark, are largely unaffected by variations in the temperature.

hep-ph↗

arXiv2025

Mesons in nonlocal model with four-dimensional separable kernel

In this work we study the meson properties in the framework of an effective quark model. We start from the Bethe-Salpeter equation choosing the interaction kernel in nonlocal form with the Gaussian meson vertex function, characterized by a meson size parameter $\Lambda_H$. We demonstrate the model's predictive power by applying it to both light and heavy systems. Key results include a calculation of the $\pi^0\to\gamma\gamma$ decay width and the pion transition form factor $F_{\pi\gamma}(Q^2)$, which reproduces experimental data from low to high $Q^2$. We further predict the electromagnetic properties of heavy quarkonia, obtaining the two-photon decay widths of $\eta_c$ and $\eta_b$ and the radiative decay widths of $J/\psi$ and $\Upsilon$, all of which show consistency with available data and other theoretical approaches. The model provides a computationally efficient and unified framework for describing mesons from the light to heavy quark sectors.

hep-ph↗

arXiv2022

Pion damping width and pion spectral function in hot pion gas

The temperature behaviour of the pion width in the hadronic phase is investigated in the framework of the NJL model. The contribution to the width from the pion-pion collision is considered with a scalar sigma-meson as an intermediate state. It is shown that the pion width significantly broadens at $T>0.1$ GeV. Using the two-step iteration method, suggested by Kadanoff and Baym, the pion spectral function in a hot pion gas is calculated at different temperatures.

hep-ph↗

arXiv2019

Using the Beth-Uhlenbeck approach to describe the kaon to pion ratio in a 2+1 flavor PNJL model

The kaon to pion ratios are discussed in the framework of a 2+1 flavor PNJL model. In order to interpret the behaviour of bound states in medium the Beth-Uhlenbeck approach is used. It is shown that in terms of phase shifts in the K+ channel an additional low-energy mode could appear as a bound state in medium since the masses of the quark constituents are different. The comparison with experimental data for the ratios is performed and the influence of the anomalous mode to the "horn" effect in the K+/pi+ ratio is discussed.

hep-ph↗

arXiv2008

$η$ and $η'$ mesons in the Dyson-Schwinger approach using a generalization of the Witten-Veneziano relation

The description of the $η$ and $η^\prime$ mesons in the Dyson-Schwinger approach has relied on the Witten-Veneziano relation. The present paper explores the consequences of using instead its generalization recently proposed by Shore. On the examples of three different model interactions, we find that irrespective of the concrete model dynamics, our Dyson-Schwinger approach is phenomenologically more successful in conjunction with the standard Witten-Veneziano relation than with the proposed generalization valid in all orders in the $1/N_c$ expansion.

hep-ph↗

arXiv2002

Mott Effect and J/Psi Dissociation at the Quark-Hadron Phase Transition

We investigate the in-medium modification of pseudoscalar and vector mesons in a QCD motivated chiral quark model by solving the Dyson-Schwinger equations for quarks and mesons at finite temperature for a wide mass range of meson masses, from light (pi, rho) to open-charm (D, D*) states. At the chiral / deconfinement phase transition, the quark-antiquark bound states enter the continuum of unbound states and become broad resonances (the hadronic Mott effect). We calculate the in-medium cross sections for charmonium dissociation due to collisions with light hadrons in a chiral Lagrangian approach, and show that the D and D* meson spectral broadening lowers the threshold for charmonium dissociation by pi and rho meson impact. This leads to a step-like enhancement in the reaction rate. We suggest that this mechanism for enhanced charmonium dissociation may be the physical mechanism underlying the anomalous J/Psi suppression observed by NA50.

nucl-th↗

arXiv2002

Hadronic Spectral Function and Charm Meson Production

At the chiral restoration/deconfinement transition, most hadrons undergo a Mott transition from being bound states in the confined phase to resonances in the deconfined phase. We investigate the consequences of this qualitative change in the hadron spectrum on final state interactions of charmonium in hot and dense matter, and show that the Mott effect for D-mesons leads to a critical enhancement of the J/Psi dissociation rate. Anomalous J/Psi suppression in the NA50 experiment is discussed as well as the role of the Mott effect for the heavy flavor kinetics in future experiments at the LHC. The status of our calculations of hadron-hadron cross sections using the quark interchange and chiral Lagrangian approaches is reviewed, and an Ansatz for a unification of these schemes is given.

hep-ph↗

arXiv2002

Heavy Quarks on the Lattice

I review the basic ideas behind lattice QCD calculations that involve charm and bottom quarks. I report on the progress in getting the correct hyperfine splitting in charmonium from lattice QCD. Some of the basic technology behind numerical lattice QCD calculations is explained by studying some specific examples: computation of the charm quark mass, and the calculation of fB.

hep-lat↗

arXiv2001

Heavy flavor kinetics at the hadronization transition

We investigate the in-medium modification of the charmonium breakup processes due to the Mott effect for light (pi, rho) and open-charm (D, D*) quark-antiquark bound states at the chiral/deconfinement phase transition. The Mott effect for the D-mesons effectively reduces the threshold for charmonium breakup cross sections, which is suggested as an explanation of the anomalous J/psi suppression phenomenon in the NA50 experiment. Further implications of finite-temperature mesonic correlations for the hadronization of heavy flavors in heavy-ion collisions are discussed.

hep-ph↗

arXiv1996

K_{l 3} and π_{e 3} transition form factors

$K_{\ell 3}$ and $π_{e 3}$ transition form factors are calculated as an application of Dyson-Schwinger equations. The role of nonanalytic contributions to the quark--W-boson vertex is elucidated. A one-parameter model for this vertex provides a uniformly good description of these transitions, including the value of the scalar form factor of the kaon at the Callan-Treiman point. The $K_{\ell 3}$ form factors, $f_\pm^K$, are approximately linear on $t\in [m_e^2,m_μ^2]$ and have approximately the same slope. $f_-^K(0)$ is a measure of the Euclidean constituent-quark mass ratio: $M^E_s/M^E_u$. In the isospin symmetric limit: $-f_+^π(0)= F_π(t)$, the electromagnetic pion form factor, and $f_-^π(t)\equiv 0$.

nucl-th↗