arXiv subjects

Ke-Ming Shen

Publications and source records attributed to Ke-Ming Shen.

8 recordsLinked to original sources

arXiv2025

Study of the EEC discrimination power on quark and gluon jet quenching effects in heavy-ion collisions at $\sqrt{s}=5.02$ TeV

We present a systematic investigation of flavor-dependent jet quenching using energy-energy correlators (EEC) in $\sqrt{\rm s}=5.02$ TeV Pb+Pb collisions. Employing the improved SHELL model, which incorporates collisional and radiative energy loss, as well as medium response, we quantify distinct quenching signatures for quark and gluon jets. Key findings include: (1) Pure quark jets exhibit strong EEC enhancement at large angular scales, while gluon jets show a bimodal enhancement pattern at both small and large scales; (2) Dual-shift decomposition in the EEC ratio reveals shifts toward large primarily driven by energy loss, while small-$R_{L}$~shifts extend beyond selection bias and indicate intrinsic enhancement of the gluon-initiated jets; (3) Quark jets experience global suppression of averaged energy weight $\langle\mathrm{weight}\rangle(R_{L})$, whereas gluon jets exhibit concentration toward small $R_{L}$; (4) Mechanism decomposition identifies elastic energy loss concentrating $\langle\mathrm{weight}\rangle(R_{L})$ toward small $R_{L}$, radiative loss dominating quark jet modification, and medium response amplifying large $R_{L}$ ~enhancement via soft hadrons. The observed flavor dependence in EEC modifications is dominantly driven by intrinsic jet structure differences rather than medium-induced mechanisms. We propose photon-tagged jets as quark proxies and inclusive charged-hadron jets as gluon proxies, finding they reproduce the respective flavor-specific quenching patterns. Our work establishes the EEC as a precision probe of color-charge-dependent jet-medium interactions, providing new constraints for the detailed $\hat{q}$ extraction and QGP tomography, while highlighting the critical role of pre-quenching flavor asymmetries.

nucl-th↗

arXiv2024

Unraveling the Energy-Energy Correlators for Heavy Flavor Tagged Jets in pp, p+Pb and Pb+Pb Collisions

In this study, energy-energy correlator (EEC) distributions for the $\rm D^0$, $\rm B^0$-tagged, inclusive, and the PYTHIA generated pure quark jets are computed in pp, p+Pb, and Pb+Pb collisions at \sqrts =5.02 TeV for a same jet transverse momentum interval 15-30 GeV. We find the number of particles per jet determines the height of the EEC distribution in pp baseline. The averaged energy weight distribution resulted in a shift of the originally larger angular distributed particle distribution to a smaller RL, thereby obtaining an EEC distribution. The EEC distributions for all quark-tagged jets in A+A exhibit a noticeable shift towards larger RL region, suggesting that the jets will be more widely distributed compared to those in pp collisions. The jet quenching effect will cause the pair angular distribution to shift towards larger values and increase the number of particles per jet. This redistribution of energy within the jets suggests that the already reduced jet energy is redistributed among a larger number of particles, leading to a reduced energy weight per pair. The enhancement of the number of particles per jet and the reduced averaged energy weight interplay with each other to form the medium modification of EEC.

hep-ph↗

arXiv2024

Impact of (magneto-)thermoelectric effect on diffusion of conserved charges in hot and dense hadronic matter

We investigate the thermoelectric effect, which describes the generation of an electric field induced by temperature and conserved charge chemical potential gradients, in the hot and dense hadronic matter created in heavy-ion collisions. Utilizing the Boltzmann kinetic theory within the repulsive mean-field hadron resonance gas model, we evaluate both the diffusion thermopower matrix and diffusion coefficient matrix for the baryon number ($B$), electric charge ($Q$), and strangeness ($S$). The Landau-Lifshitz choice for the rest frame of the fluid is enforced in the derivation. We find that the thermoelectric effect hinders the diffusion processes of multiple conserved charges, particularly reducing the coupling between electric charge and baryon number (strangeness) in baryon (strangeness) diffusion. Given that the repulsive mean-field interactions between hadrons have a significant effect on the diffusion thermopower matrix and diffusion coefficient matrix in the baryon-rich region, we extend the investigation to include the impact of magnetic fields, analyzing the magneto-thermoelectric effect on both the diffusion coefficient matrix and the Hall-like diffusion coefficient matrix. The sensitivities of the magnetic field-dependent diffusion thermopower matrix and magneto-thermoelectric modified diffusion coefficient matrix to the choices of various transverse conditions are also studied.

nucl-th↗

arXiv2023

A note on the connection between non-additive entropy and $h$-derivative

In order to study as a whole a wide part of entropy measures, we introduce a two-parameter non-extensive entropic form with respect to the $h$-derivative, which generalizes the conventional Newton--Leibniz calculus. This new entropy, $S_{h,h'}$, is proved to describe the non-extensive systems and recover several types of well-known non-extensive entropic expressions, such as the Tsallis entropy, the Abe entropy, the Shafee entropy, the Kaniadakis entropy and even the classical Boltzmann--Gibbs one. As a generalized entropy, its corresponding properties are also analyzed.

cond-mat.stat-mech↗

arXiv2023

a q-EW-TOPSIS model of grey correlation for supply capacity evaluation

The paper describes a new supply capacity evaluation model based on the non-extensive statistical entropy. The traditional EW-TOPSIS model is selected as baseline and the GRA method is used to modify it. The correction results in the non-extensive parameter q which leads to the so-called q-EW-TOPSIS model. This new model has advantages over the traditional EW-TOPSIS model, including the ability to accurately evaluate indicator weights with smaller sample sizes and weaker rules, and a more stable and closer-to-complete structure due to the use of entropy evaluation and mutual restriction between indicators. This study provides a more reliable and universal modified EW model. It is proved to be a more compatible model with systems and own greater credibility.

stat.AP↗

arXiv2019

Analysis on hadron spectra in heavy-ion collisions with a new non-extensive approach

The transverse momentum spectra of identified charged hadrons stemming from high energy collisions at different beam energies are described by a new non-extensive distribution, the Kaniadakis $κ$-distribution, with respect to the constraints in non-extensive quantum statistics. All fittings are also compared with the Tsallis distributions as well as the usual Boltzmann-Gibbs one. $χ^2/ndf$ is also used to test the fitting goodness of all functions. Our results show that these different non-extensive approaches can be well applied in high energy collisions rather than the classical one. The Kaniadakis statistics is typically better applied into such systems with both positive and negative particles considered. This provides an alternative non-extensive view to study high energy physics. Analysis on the fitting parameters are present as well. The similar relationships of all functions remind us of the further understanding of the non-extensivity.

hep-ph↗

arXiv2017

Chiral phase transition in linear sigma model with non-extensive statistical mechanics

From the non-extensive statistical mechanics, we investigate the chiral phase transition at finite temperature $T$ and baryon chemical potential $μ_B$ in the framework of the linear sigma model. The corresponding non-extensive distribution, based on Tsallis' statistics, is characterized by a dimensionless non-extensive parameter, $q$, and the results in the usual Boltzmann-Gibbs case are recovered when $q\to 1$. The thermodynamics of the linear sigma model and its correspodning phase diagram are analysed. At high temperature region, the critical temperature $T_c$ is shown to decrease with increasing $q$ from the phase diagram in the $(T,~μ)$ plane. However, larger values of $q$ causes the rise of $T_c$ at low temperature but high chemical potential. Moreover, it is found that $μ$ different from zero corresponds to a first-order phase transition while $μ=0$ to a crossover one. The critical endpoint (CEP) carries higher chemical potential but lower temperature with $q$ increasing due to the non-extensive effects.

nucl-th↗

arXiv2017

Generalized Ensemble Theory with Non-extensive Statistics

The non-extensive canonical ensemble theory is reconsidered with the method of Lagrange multipliers by maximizing Tsallis entropy, with the constraint that the normalized term of Tsallis' $q-$average of physical quantities, the sum $\sum p_j^q$, is independent of the probability $p_i$ for Tsallis parameter $q$. The self-referential problem in the deduced probability and thermal quantities in non-extensive statistics is thus avoided, and thermodynamical relationships are obtained in a consistent and natural way. We also extend the study to the non-extensive grand canonical ensemble theory and obtain the $q$-deformed Bose-Einstein distribution as well as the $q$-deformed Fermi-Dirac distribution. The theory is further applied to the generalized Planck law to demonstrate the distinct behaviors of the various generalized $q$-distribution functions discussed in literature.

cond-mat.stat-mech↗