We investigate the dissociation of a heavy meson in the medium composed of light quarks and gluons. In the quark-gluon plasma, the dissociation length of the heavy meson becomes short as the temperature or quark chemical potential increases. On the contrary, in the hadronic phase the dissociation length becomes large as the chemical potential increases, due to the different dissociation mechanism with one used in the quark-gluon plasma.
We study the dissociation of heavy vector mesons in a thermal medium from the point of view of the configurational entropy. Bottomonium and charmonium vector mesons in a plasma are represented using a holographic AdS/QCD model. The quasinormal modes, describing the quasiparticle states, are determined for a representative range of temperature and the corresponding CE is then computed. The main result indicates that the CE is an important contrivance to investigate the stability of the heavy mesons against dissociation in the thermal medium.
K*-charmonium dissociation reactions in hadronic matter are studied in the Born approximation, in the quark-interchange mechanism, and with a temperature-dependent quark potential. We obtain the temperature dependence of unpolarized cross sections for K*-charmonium dissociation reactions which produce charmed mesons and charmed strange mesons. We use the cross sections for charmonium dissociation in collisions with pion, rho meson, kaon, vector kaon, and eta meson to calculate dissociation rates of charmonium with the five types of mesons. Because of the temperature dependence of the meson mas…
We calculate distributions of different vector mesons in purely exclusive ($p p \to p p V$) and semi-exclusive ($p p \to p X V$) processes with electromagnetic dissociation of a proton. The cross section for the electromagnetic dissociation is expressed through electromagnetic structure functions of the proton. We include the transverse momentum distribution of initial photons in the associated flux. Contributions of the exclusive and semi-exclusive processes are compared for different vector mesons ($V = ϕ, J/ψ, Υ$). We discuss how the relative contribution of the semi-exclusive processes dep…
The in-medium behavior of ground-state $q\bar{q}$ mesons, where $q \in \{u,d,s,c\}$, in vector and axial-vector channels is studied based on the spectral analysis for mesonic correlators at finite temperature and zero chemical potential. We first compute the correlators by solving the quark gap equations and the inhomogeneous Bethe-Salpeter equations in the rainbow-ladder approximation. Using a phenomenological ansatz, the spectral functions are extracted by fitting the correlators. By analyzing the evolution of the spectral functions with the temperature, we obtain the dissociation temperatur…
We calculate the cross sections for both electromagnetic and diffractive dissociation of protons for semiexclusive production of $J/ψ$ mesons in proton-proton collisions at the LHC. Several differential distributions in missing mass ($M_X$), or single-particle variables related exclusively to the $J/ψ$ meson are calculated for $\sqrt{s}$ = 7 TeV as an example. The cross sections and distributions are compared to the cross section of the purely exclusive reaction $p p \to p p J/ψ$. We show the corresponding ratio as a function of $J/ψ$ meson rapidity. We compare the distributions for purely ele…
We investigate the effect of the electromagnetic field generated in relativistic heavy-ion collisions on the dissociation of $Υ$ mesons. The electromagnetic field is calculated using a simple model which characterizes the emerging quark-gluon plasma (QGP) by its conductivity only. A numerical estimate of the field strength experienced by $Υ$ mesons embedded in the expanding QGP and its consequences on the $Υ$ dissociation is made. The electromagnetic field effects prove to be negligible compared to the established strong-interaction suppression mechanisms.
We study kaon-charmonium and eta-charmonium dissociation reactions. The K-charmonium dissociation and the eta-charmonium dissociation include 27 reactions. Cross sections for the reactions are calculated in the Born approximation, in the quark-interchange mechanism and with a temperature-dependent quark potential. The temperature dependence of peak cross sections of endothermic reactions is linked to the temperature dependence of quark-antiquark relative-motion wave functions, meson masses and the quark potential. Although the eta meson and kaon have similar masses, the energy and temperature …
We present the results of a holographic model for heavy vector mesons inside a plasma at finite temperature and density. The spectral function shows a nice description of the dissociation of the mesons in the medium, corresponding to the decrease in the height of the peaks as the temperature and (or) the density increase. We consider the case of bottomonium states at finite temperature and also the case of charmonium dissociation at zero temperature but finite chemical potential.
The fraction of heavy vector mesons detected after a heavy ion collision provides information about the possible formation of a plasma state. An interesting framework for estimating the degree of dissociation of heavy mesons in a plasma is the holographic approach. It has been recently shown that a consistent picture for the thermal behavior of charmonium and bottomonium states in a thermal medium emerges from holographic bottom up models. A crucial ingredient in this new approach is the appropriate description of decay constants, since they are related to the heights of the quasiparticle peak…
By solving two body Dirac equations with potentials at finite temperature, we calculated the dissociation temperature T_d of B_c mesons in the quark-gluon plasma. It is found that the T_d becomes higher with the relativistic correction than the T_d from the Schroedinger equation. Both the short range interaction and the constant term of the potential at the long-range scale have a contribution to the shift of T_d, while the spin interaction is negligible.
We present a holographic bottom up model for the thermal behavior of $ c \bar c$ vector mesons in a finite temperature and density plasma. There is a clear physical interpretation for the three imput energy parameters of the model. Two of them are related to the mass spectrum of the heavy meson. Namely the quark mass and the string tension of the quark anti-quark interaction. The third parameter is a large energy scale associated with the non-hadronic meson decay. In such a process the heavy meson is transformed into a much lighter state by electroweak processes. The corresponding transition a…
We present a holographic description of the thermal behavior of $ b \bar b$ heavy vector mesons inside a plasma at finite temperature and density. The meson dissociation in the medium is represented by the decrease in the height of the spectral function peaks. In order to find a description for the evolution of the quasi-states with temperature and chemical potential it is crucial to use a model that is consistent with the decay constant behavior. The reason is that the height of a spectral function peak is related to the value of the zero temperature decay constant of the corresponding partic…
Momenta of charmonia created in Pb-Pb collisions at the Large Hadron Collider are so large that three or more mesons may be produced when the charmonia collide with light mesons in hadronic matter. We study the meson-charmonium collision in a mechanism where the collision produces two quarks and two antiquarks, the charm quark then fragmenting into charmed mesons, and the other three constituents as well as quarks and antiquarks created from vacuum give rise to two or more mesons. The absolute square of the transition amplitude for the production of two quarks and two antiquarks is derived fro…
We investigate the in-medium modification of the charmonium breakup processes due to the Mott-effect for D-mesons at the chiral phase transition. A model calculation for the process J/Psi+pi --> D+D^*+ h.c. is presented which demonstrates that threshold effects in the thermal averaged breakup cross section can be explained as a Mott transition where final state quark-antiquark bound states enter the continuum of resonant states at the QCD phase transition. Applications to heavy-ion collisions within a modified Glauber model scenario and the phenomenon of anomalous J/$ψ$ suppression in the CERN…
We have computed the masses and decay constants of isotriplet $π_2(1670)$, the isoscalar $η_2(1645)$ and $η_2(1870)$ states as the ground-state nonet of $1^1D_2$ case within the Thermal QCD sum rules framework. This method is applied to the spectral changes of pseudotensor mesons at high temperatures including quark, gluon, and mixed condensates up to the five dimensions. We found that their masses and decay constants are insensitive to temperature in low-temperature regions. At the near-critical temperature, we observed an exponential decrease of the masses of $π_2$, $η_2(1645)$, and $η_2(187…
At forward rapidities and high energies we expect to probe the non-linear regime of Quantum Chromodynamics (QCD). One of the most promising observables to constrain the QCD dynamics in this regime is exclusive vector meson photoproduction (EVMP). We study the EVMP in association with a leading baryon (product of the proton dissociation) in photon-hadron interactions that take place in $pp$ and $p$Pb collisions at large impact parameters. We present the rapidity distributions for $ρ$ and $J/ψ$ photoproduction in association with a leading baryon (neutron and delta states) at LHC run 2 energies.…
Magneto-rotational dissociation is the decay, by the way of tunneling, of a rotating bound state in the magnetic field. The corresponding probability was recently computed in the quasi-classical approximation using the Imaginary Time Method and was shown to increase with the angular velocity and decrease with the magnetic field strength \cite{Tuchin:2021lxl}. This letter reports the calculation of the quantum correction to the dissociation probability associated with the spin of the tunneling particle. The quasi-classical motion of spin is described by the Bargmann--Michel--Telegdi equation in…
In this paper, quarkonium dissociation is investigated in an anisotropic plasma in the hot and dense media. For that purpose, the multidimensional Schrodinger equation is solved analytically by Nikiforov-Uvarov (NU) method for the real part of the potential in an anisotropic medium. The binding energy and dissociation temperature are calculated. In comparison with an isotropic medium, the binding energy of quarkonium is enhanced in the presence of an anisotropic medium. The present results show that the dissociation temperature increases with increasing anisotropic parameter for 1S state of th…
There are strong indications that ultra-relativistic heavy ion collisions, produced in accelarators, lead to the formation of a new state of matter: the quark gluon plasma (QGP). This deconfined QCD matter is expected to exist just for very short times after the collision. All the information one can get about the plasma is obtained from the particles that reach the detectors. Among them, heavy vector mesons are particularly important. The abundance of $ c {\bar c}$ and $b {\bar b}$ states produced in a heavy ion collision is a source of information about the plasma. In contrast to the light m…
The analytical exact iteration method (AEIM) have been used to calculate the N-dimensional radial schrodinger equation with the real part of complex-valued potential and it is generalized to the finite value of anisotropy (ξ), temperature and baryonic chemical potential. In N-dimensional space the energy eigen values have been calculated for any states (n,l). The present results have been used to study the properties of quarkonium states (i.e, the binding energy and mass spectra in the N-dimensional space). The influences of anisotropy (ξ) on the dissociation temperature(TD) has been also calc…
We compute and analyze correlation functions in the isovector vector channel at vanishing spatial momentum across the deconfinement phase transition in lattice QCD. The simulations are carried out at temperatures $T/T_c=0.156, 0.8, 1.0, 1.25$ and $1.67$ with $T_c\simeq203$MeV for two flavors of Wilson-Clover fermions with a zero-temperature pion mass of $\simeq270$MeV. Exploiting exact sum rules and applying a phenomenologically motivated ansatz allows us to determine the spectral function $ρ(ω,T)$ via a fit to the lattice correlation function data. From these results we estimate the electrica…
We study the energy dispersions of holographic light mesons and their decay constants on dense nuclear medium. As the spatial momenta of mesons along the boundary direction increase, both observables of the mesons not only increase but also split according to the isospin charges. The decay constant of the negative meson is more large than that of the positive meson of the same type due to the chemical potentials of the background nucleons.
We study heavy flavor properties at finite temperature in the framework of a relativistic potential model. With an improved method to solve the three-body Dirac equation, we determine a universal set of model parameters for both mesons and baryons by fitting heavy flavor masses in vacuum. Taking heavy quark potential from lattice QCD simulations in hot medium, we systematically calculate heavy flavor binding energies and averaged sizes as functions of temperature. The meson and baryons are separately sequentially dissociated in the quark-gluon plasma, and the mesons can survive at higher tempe…
A collision of a light meson and a charmonium produces quarks and antiquarks first, then the charm quark fragments into a charmed hadron, and finally three or more mesons are produced. This is the mechanism that we consider and propose to understand the prompt-J/psi nuclear modification factor in the range of J/psi transverse momentum from 10 GeV/c to 18 GeV/c, as measured by the CMS Collaboration and the ATLAS Collaboration. Unpolarized cross sections are derived and calculated for the reactions pion+charmonium ->H_c+X with H_c being a charmed meson. Numerical cross sections are parametrized …
We describe the Mott dissociation of pions and kaons within a Beth-Uhlenbeck approach based on the PNJL model, which allows for a unified description of bound, resonant and scattering states. Within this model we evaluate the temperature and chemical potential dependent modification of the phase shifts both in the pseudoscalar and scalar isovector meson channels for $N_f=2+1$ quark flavors. We show that the character change of the pseudoscalar bound states to resonances in the continuum at the Mott transition temperature is signaled by a jump of the phase shift at the threshold from $π$ to zer…
We study the charmonium dissociation in the hot medium with finite baryon chemical potential $μ_B$. Charmonium bound states are dissociated in the medium by the color screening effect and the random scatterings with thermal partons, which are included in the real and imaginary parts of the potential respectively. $J/ψ$ fraction in the $c\bar c$ pair defined to be the quantum overlap between the wave package and the wave function of $J/ψ$ eigenstate decreases with time due to the complex potentials. When $μ_B$ is large compared with the medium temperature, the Deybe mass is increased evidently.…
