arXiv subjects

Prasanta Murmu

Publications and source records attributed to Prasanta Murmu.

3 recordsLinked to original sources

arXiv2026

Towards compressed baryonic matter densities: thermodynamics and transport coefficients

We study the thermodynamic and transport properties of hot and dense quantum chromodynamic matter expected to be produced in low-energy heavy-ion collisions, using three different effective quantum chromodynamic frameworks: the Nambu--Jona-Lasinio model, the chiral effective model, and the hadron resonance gas model. We briefly outline the theoretical formulation of thermodynamic quantities and transport coefficients within these approaches, where quarks are treated with effective masses in the Nambu--Jona-Lasinio and chiral effective models, and hadronic degrees of freedom are employed in the hadron resonance gas model. The transport coefficients are evaluated using the Boltzmann transport equation in the relaxation-time approximation. Following the theoretical overview, we present a comprehensive analysis of the behavior of these quantities as functions of the baryon chemical potential or net baryon density. The Lorenz ratio $κ/(σT)$ is found to increase rapidly-indicating a strong violation of the Wiedemann-Franz law in the low-$μ_{B}$ regime--while approaching the universal value at higher baryon chemical potentials or densities. The shear-viscosity-to-entropy-density ratio $η/s$ remains nearly constant at low $μ_{B}$ but exhibits a gradual increase as $μ_{B}$ grows. We also discuss the qualitative similarities of these trends with those observed in the electron-hole plasma of graphene, an emergent quasi-relativistic system characterized by massless energy-momentum dispersion.

nucl-th↗

arXiv2025

Numerically studying Pesticide diffusion in air using Langevin formalism

The use of pesticides for enhancing crop yield and preventing infestations is a widespread agricultural practice. However, in recent years, there has been a growing shift toward traditional chemical-free organic farming. Regulatory frameworks impose specific distance requirements between organic farms and neighboring lands where chemical pesticides are used to minimize cross-contamination. In this work, we numerically analyze the spread of pesticide droplets to adjacent fields under varying weather conditions, providing a systematic analysis that highlights conditions where existing guidelines might require reassessment. We employ the formalism of the Langevin equations to model the diffusion of pesticide particles and their transport due to wind and other environmental factors. Assuming a non-relativistic, classical diffusion framework, we track the dispersion of commonly used pesticides to assess their potential contamination range. We present our key findings, discuss their implications, and, toward the end, outline possible directions for future research.

physics.app-ph↗

arXiv2020

Shear viscosity and electrical conductivity of relativistic fluid in presence of magnetic field: a massless case

We have explored the shear viscosity and electrical conductivity calculations for bosonic and fermionic medium, which goes from without to with magnetic field picture and then their simplified massless expressions. In presence of magnetic field, 5 independent velocity gradient tensors can be designed, so their corresponding proportional coefficients, connected with the viscous stress tensor provide us 5 shear viscosity coefficients. In existing litterateurs, two sets of tensors are available. Starting from them, present work has obtained two sets of expressions for 5 shear viscosity coefficients, which can be ultimately classified into three basic components: parallel, perpendicular and Hall components as one get same for electrical conductivity at finite magnetic field. Our calculations are based on kinetic theory approach in relaxation time approximation. Repeating same mathematical steps for finite magnetic field picture, which traditionally practiced for without field case, we have obtained 2 sets of 5 shear viscosity components, whose final expressions are in well agreements with earlier references, although a difference in methodology or steps can be clearly noticed. Realizing the massless results of viscosity and conductivity for Maxwell-Boltzmann, Fermi-Dirac and Bose-Einstein distribution function, we have applied them for massless quark gluon plasma and hadronic matter phases, which can provide us a rough order of strength, within which actual results will vary during quark-hadron phase transition. Present work also indicates that magnetic field might have some role for building perfect fluid nature in RHIC or LHC matter. The lower bound expectation of shear viscosity to entropy density ratio is also discussed.

hep-ph↗