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Indrani Nilima

Publications and source records attributed to Indrani Nilima.

9 recordsLinked to original sources

Medium-Induced Quarkonium Dissociation at Finite Chemical Potential and Weak Magnetic Field

We investigate the in-medium modification and dissociation of heavy quarkonium in a hot QCD medium at finite quark chemical potential and in the weak magnetic-field regime. Starting from the one-loop resummed gluon propagator in the imaginary-time formalism, and incorporating non-perturbative effects through a phenomenological correction to the HTL description, we compute the real and imaginary parts of the dielectric permittivity. This, in turn, leads to a complex heavy-quark potential: the real part is used to determine binding energies by solving the nonrelativistic Schr\"odinger equation, while the imaginary part generates thermal decay widths, dominated by Landau damping. Within the explored parameter range, temperature has the greatest control over Debye screening, potential modification, and quarkonium stability, whereas finite density and weak magnetic fields introduce comparatively smaller quantitative changes. As the temperature increases, binding energies decrease and thermal widths grow, giving rise to the expected hierarchy between ground and excited states and a sequential suppression pattern in the dissociation temperatures. Overall, our results indicate that while finite chemical potential and weak magnetic fields can shift quarkonium properties in a measurable way, thermal effects remain the primary driver of dissociation, with direct relevance for heavy-ion collision phenomenology.

hep-ph

Quarkonia dissociation at finite magnetic field in the presence of momentum anisotropy

In this study, we investigate the potential of heavy quarkonia within a magnetized hot QGP medium having finite momentum anisotropy. The phenomenon of inverse magnetic catalysis is introduced into the system, influencing the magnetic field-modified Debye mass and thereby altering the effective quark masses. Concurrently, the impact of momentum anisotropy in the medium is considered that influence the particle distribution in the medium. The thermal decay width and dissociation temperature of quarkonium states, specifically the 1S and 2S states of charmonium and bottomonium, are computed. Our results reveal that both momentum anisotropy and the inverse magnetic catalysis effects play a significant role in modifying the thermal decay width and dissociation temperature of these heavy quarkonia states.

hep-ph

Energy loss of heavy quarks in the presence of magnetic field

We study the heavy quark energy loss in the presence of a background magnetic field. The analysis considers the high magnetic field generated by spectators from initial hard collisions that were incorporated using the medium-modified Debye mass, determined from quark condensates at finite temperature and magnetic field via recent lattice quantum chromodynamics (LQCD) calculations. We analyse the impact of medium polarization on the heavy quark propagation in a quark-gluon plasma formed in relativistic heavy-ion colliders like RHIC and LHC. For simplification, we considered the static medium with constant temperature and magnetic field values. Then, we explore the nuclear modification factor ($R_{AA}$) at different magnitudes of magnetic field strengths at fixed temperatures. The energy loss of heavy quarks significantly increases, leading to $R_{AA}$ suppression at higher magnetic field values

hep-ph

Anisotropic tomography of heavy quark dissociation by using general propagator structure at finite magnetic field

In this work we have explored the imaginary part of the Heavy Quark (HQ) potential and subsequently the dissociation of heavy quarkonia at finite temperature and magnetic field. With respect to earlier investigations on this topic, present work contain three new ingredients. First one is considering all Landau level summation, for which present work can be applicable in entire magnetic field domain - from weak to strong. Second one is the general structure of the gauge boson propagator in a hot magnetized medium, which is used here in heavy quark potential problem first time. Third one is a rich anisotropic structure of the complex heavy quark potential, which explicitly depends on the longitudinal and transverse distance. By comparing with earlier references, we have attempted to display our new contributions by plotting heavy quark potential tomography and dissociation probability at finite temperature and magnetic field.

hep-ph

Heavy quark potential and LQCD based quark condensate at finite magnetic field

In the present work, we have studied heavy quarkonia potential in hot and magnetized quark gluon plasma. Inverse magnetic catalysis (IMC) effect is incorporated within the system through the magnetic field modified Debye mass by modifying the effective quark masses. We have obtained the real and imaginary part of the heavy quark potential in this new scenario. After the evaluation of the binding energy and the decay width we comment about the dissociation temperatures of the heavy quarkonia in presence of magnetic field.

hep-ph

Equation of states and charmonium suppression in Heavy ion collisions

The present article is the follow-up of our work Bottomonium suppression in quasi-particle model, where we have extended the study for charmonium states using quasi-particle model in terms of quasi-gluons and quasi quarks/antiquarks as a equation of state. By employing medium modification to a heavy quark potential thermodynamic observables {\em viz.} pressure, energy density, speed of sound etc. have been calculated which nicely fit with the lattice equation of state for gluon, massless and as well {\em massive} flavored plasma. For obtaining the thermodynamic observables we employed the debye mass in the quasi particle picture. We extended the quasi-particle model to calculate charmonium suppression in an expanding, dissipative strongly interacting QGP medium (SIQGP). We obtained the suppression pattern for charmonium states with respect to the number of participants at mid-rapidity and compared it with the experimental data (CMS JHEP) and (CMS PAS) at LHC energy (Pb+Pb collisions, $\sqrt{s_{NN}}$= $2.76$ TeV).

hep-ph

Dissociation of heavy quarkonia in an anisotropic hot QCD medium in a Quasi-Particle Model

The present article is the follow up work of, Phys.\ Rev.\ D {\bf 94}, 094006 (2016), where we have extended the study of quarkonia dissociation in (momentum) anisotropic hot QCD medium. As evident by the experimentally observed collective flow at RHIC and LHC, the momentum anisotropy is present at almost all the stages after the collision and therefore, it is important to include its effects in the analysis. Employing the in-medium (corrected) potential while considering the anisotropy (both oblate and prolate cases) in the medium, the thermal widths and the binding energies of the heavy quarkonia states (s-wave charmonia and s-wave bottomonia specifically, for radial quantum numbers n = 1 and 2) have been determined. The hot QCD medium effects have been included employing a quasi-particle description. The presence of anisotropy has modified the potential and then the thermal widths and the binding energies of these states in a significant manner. The results show a quite visible shift in the values of dissociation temperatures as compared to the isotropic case. Further, the hot QCD medium interaction effects suppress the dissociation temperature as compared to the case where we consider the medium as a non-interacting ultra-relativistic gas of quarks (anti-quarks) and gluons.

nucl-th

Bottomonium suppression in nucleus-nucleus collisions using effective fugacity quasi-particle model

In the present article, we have studied the equation of state and dissociation temperature of bottomonium state by correcting the full Cornell potential in isotropic medium by employing the effective fugacity quasi-particle Debye mass. We had also calculated the bottomonium suppression in an expanding, dissipative strongly interacting QGP medium produced in relativistic heavy-ion collisions. Finally we compared our results with experimental data from RHIC 200GeV/nucleon Au-Au collisions, LHC 2.76 TeV/nucleon Pb-Pb, and LHC 5.02 TeV/nucleon Pb-Pb collisions as a function of number of participants

hep-ph

Dissociation of heavy quarkonium in hot QCD medium in a quasi-particle model

Following a recent work on the effective description of the equations of state for hot QCD obtained from a Hard thermal loop expression for the gluon self-energy, in terms of the quasi-gluons and quasi- quark/anti-quarks with respective effective fugacities, the dissociation process of heavy quarkonium in hot QCD medium has been investigated. This has been done by investigating the medium modification to a heavy quark potential. The medium modified potential has a quite different form (a long range Coulomb tail in addition to the usual Yukawa term) in contrast to the usual picture of Debye screening. The flavor dependence of the binding energies of the heavy quarkonia states and the dissociation temperature have been obtained by employing the debye mass for pure gluonic and full QCD case computed employing the quasi-particle picture. Thus estimated dissociation patterns of the charmonium and bottomonium states, considering Debye mass from different approaches in pure gluonic case and full QCD, have shown good agreement with the other potential model studies.

nucl-th