We have studied the dissociation of quarkonia states in a deconfined medium of quarks and gluons at the large baryon chemical potential and small temperature region. The aim of this study is to probe the dense baryonic medium expected to be produced at the Facility for Anti-proton and Ion Research(FAIR), GSI Darmstadt. This is done by correcting both the short- and long-distance terms of the Cornell potential by a dielectric function, embodying the effects of deconfined quarks and gluons, at finite baryon chemical potential and temperature. It is found that $J/ψ$ is dissociated approximately at 1.4$μ_c$ in the temperature range 20-50 $MeV$, which can indirectly help to locate the point on the QCD phase diagram at the large chemical potential and low-temperature zone.
The probability of tunnel decay of quarkonium (bond state of a heavy quark and a heavy antiquark) into free quarks in a strong electric field is estimated.
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…
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…
For weakly bound quarkonia, we rederive the next-to-leading order cross sections of quarkonium dissociation by partons that include the hard thermal loop (HTL) resummation. Our results calculated with an effective vertex from the Bethe-Salpeter amplitude reduce to those obtained by potential nonrelativistic QCD (pNRQCD) in the relevant kinematical limit, and they can be used in a wide temperature range applicable to heavy quark systems in heavy ion collisions. Based on the lattice computation of the temperature-dependent binding energy, our numerical analysis on $Υ(1S)$ indicates that at high …
We consider the quarkonium diffusion, dissociation and recombination inside quark-gluon plasma. We compute scattering amplitudes in potential nonrelativistic QCD for relevant processes. These processes include the gluon absorption/emission at the order $gr$, inelastic scattering at the order $g^2r$ and elastic scattering with medium constituents at the order $g^2r^2$. We show these amplitudes satisfy the Ward identity. We also consider one-loop corrections. The dipole interaction between the color singlet and octet is not running at the one-loop level. Interference between the tree-level gluon…
Medium-Induced Quarkonium Dissociation at Finite Chemical Potential and Weak Magnetic Field
Discipline of Natural Sciences, PDPM IIITDM（PDPM印度理工学院德里曼德拉技术学院自然学系）；Department of Physics, Lords Institute of Engineering and Technology（洛兹工程技术学院物理系）；Key Laboratory of Quark and Lepton Physics (MOE) & Institute of Particle Physics, Central China Normal University（华中师范大学夸克与轻子物理教育部重点实验室及粒子物理研究所）；Department of Physics, Integral University（Integral大学物理系）；Department of Physics, Institute of Science, Banaras Hindu University (BHU)（贝拿勒斯印度教大学科学研究所物理系）
By the use of the gauge/gravity duality, we calculate the imaginary part of heavy quarkonium potential and thermal width with the effect of gluon condensate which is absent in AdS$_{5}$ background. Our results show that the dropping gluon condensate reduces the absolute value of imaginary potential and therefore decreases the thermal width both in "exact" and "approximate" approach implying that the heavy quarkonium has a weaker bound with the increase of gluon condensate. In addition, the thermal width will disappear at a critical condensate value, which indicates the dissociation of quarkoni…
Using the chromo-electric dipole coupling Hamiltonian from QCD multipole expansion, we derive the dissociation cross sections of heavy quarkonia by thermal gluons at next-to-leading order (NLO, also known as inelastic parton scattering dissociation) in the Quark-Gluon Plasma (QGP) in the framework of second order quantum mechanical perturbation theory. While suffering divergence (infrared and soft-collinear divergences) in vacuum, the cross sections thus derived become finite in the QGP as rendered by the finite thermal gluon masses. In contrast to the leading order (LO, also known as gluo-dis…
Holographic entropy and real-time dynamics of quarkonium dissociation in non-Abelian plasma
在格点量子色动力学中观察到的解除禁闭跃迁处的重夸克对熵峰值表明，该跃迁是由束缚态熵的增加有效驱动的。熵随夸克间距的增大而增大，导致熵力的突现，引起夸克偶素态的离解。由于跃迁点附近的夸克-胶子等离子体是一个强耦合系统，我们利用规范-引力对偶性研究了重夸克偶素的熵及其离解的实时动力学。特别地，我们采用改进的全息QCD模型作为大$N_c$ Yang Mills理论的对偶描述。研究边界上夸克之间的基本弦的动力学，我们发现熵在跃迁点处达到峰值。我们还研究了系统的实时动力学，考虑全息字符串下降的黑洞视界，它平衡。在附近的解除禁闭过渡，解离时间被发现是小于费米，这表明熵破坏是在这个温度区域的主要解离机制。
In this paper, we critically examine hierarchies between energy scales that determine quarkonium dynamics in the quark gluon plasma. A particularly important role is played by the ratio of the binding energy of species ($E_b$) and the medium scales; temperature ($T$) and Debye mass ($m_D$). It is well known that if these ratios are much larger than one then the dominant process governing quarkonium evolution is dissociation by thermal gluons (gluo-dissociation). On the other hand, if this ratio is much smaller than one then quarkonium dynamics is dominated by screening and Landau damping of th…
We calculate the transition between a quarkonium state and an unbound heavy quark-antiquark pair through gluo-dissociation and inelastic parton scattering using a partonic picture that interpolates between the formal limits based on potential nonrelativistic QCD (pNRQCD) at different temperatures. While the thermal width increases with momentum and temperature, the quarkonium regeneration is affected by the heavy quark distribution function which depends on the diffusion constant. By solving the Boltzmann equation with the dissociation and regeneration terms, we investigate the medium modifica…
We continue the study of a recently constructed holographic QCD model supplemented with magnetic field. We consider the holographic dual of a quark, anti-quark pair and investigate its entropy beyond the deconfinement phase transition in terms of interquark distance, temperature and magnetic field. We obtain a clear magnetic field dependence in the strongly decreasing entropy near deconfinement and in the entropy variation for growing interquark separation. We uncover various supporting evidences for inverse magnetic catalysis. The emergent entropic force is found to become stronger with magne…
We generalize known results for heavy quarkonium in a thermal bath to the case of a finite baryonic density, and provide a number of formulas for the energy shift and decay width that hold at weak coupling for sufficiently large temperature and/or chemical potential. We find that a non-vanishing decay width requires a temperature larger than the typical binding energy, no matter how large the chemical potential is. This implies that at zero temperature the dissociation mechanism of heavy quarkonium is due entirely to screening, unlike in the finite temperature case. We use several effective th…
By coupling the Boltzmann transport equations of both quarkonium and open heavy quarks, we investigate their dynamical evolution inside the quark-gluon plasma and study quarkonium production in heavy ion collisions. The Boltzmann transport equation of quarkonium is derived from the open quantum system formalism and effective field theory of QCD by assuming quarkonium interacts weakly with the plasma. The dissociation and recombination terms in the Boltzmann equation are calculated in potential nonrelativistic QCD. It is shown that the combination of quarkonium dissociation, recombination, open…
We investigate the real-time evolution of quarkonium bound states in a quark-gluon plasma in one dimension using an improved QCD based stochastic potential model. This model describes the quarkonium dynamics in terms of a Schrödinger equation with an in-medium potential and two noise terms encoding the residual interactions between the heavy quarks and the medium. The probabilities of bound states in a static medium and in a boost-invariantly expanding quark-gluon plasma are discussed. We draw two conclusions from our results: One is that the outcome of the stochastic potential model is qualit…
