arXiv subjects

Prottoy Das

Publications and source records attributed to Prottoy Das.

5 recordsLinked to original sources

arXiv2023

Measurement of leading charged-particle jet properties in p--Pb collisions at $\sqrt{s_{\rm NN}}$ = 5.02 TeV with ALICE

Jets are collimated sprays of particles produced from the fragmentation and hadronization of hard-scattered partons in high energy hadronic and nuclear collisions. Jet properties are sensitive to details of parton showering processes and are expected to be modified in the presence of a dense partonic medium. Measurement of intra-jet properties in p--Pb collisions will help to investigate cold nuclear matter effects and enrich our current understanding of particle production in such collision systems. In this work, we present the measurement of leading charged-particle jet properties, namely the mean charged-particle multiplicity and the fragmentation functions, in the range of jet $p_{\rm T}$ 10 -- 100 GeV/c at midrapidity in minimum bias p--Pb collisions at $\sqrt{s_{\rm NN}}$ = 5.02 TeV with ALICE. Results are compared with theoretical model predictions.

nucl-ex↗

arXiv2022

Jet modification in absence of QGP-medium: the role of multiparton interactions and color reconnection

Recent studies of high-multiplicity events in small collision systems (proton-proton and proton-lead) have drawn research interest towards the possibility of the formation of partonic medium in such systems. One of the important consequences of the formation of dense partonic medium is quenching of high-momentum final-state particles resulting in several experimental observations such as suppression in nuclear modification factor $R_{\rm AA}$, modification of jet shape observable $\rho(r)$ and jet fragmentation ($z^{\rm ch}$) distributions, etc. In this work, we study $\rho(r)$ and $z^{\rm ch}$ for inclusive charged-particle jets in proton-proton (pp) collisions at $\sqrt{s}$~=~13~TeV using PYTHIA~8 Monash~2013 Monte Carlo simulation. We show that the color reconnection (CR) and multiparton interaction (MPI) mechanisms in PYTHIA~8 can lead to an increased rate of jet production. We also find that the mechanisms of MPI and CR and change in the gluonic contribution in high-multiplicity events result in significant modification of $\rho(r)$ and $z^{\rm ch}$ compared to those in minimum bias events for 10~$<p_{\rm T,\,jet}^{\rm ch}<$~20~GeV/$c$. We notice a direct connection of $\langle N_{\rm MPI}\rangle$ and gluonic contribution with the amount of modification in $\rho(r)$ -- the larger the number of MPIs and/or gluonic contribution, the larger the amount of modification of $\rho(r)$.

hep-ph↗

arXiv2022

Dynamics of Hot QCD Matter -- Current Status and Developments

The discovery and characterization of hot and dense QCD matter, known as Quark Gluon Plasma (QGP), remains the most international collaborative effort and synergy between theorists and experimentalists in modern nuclear physics to date. The experimentalists around the world not only collect an unprecedented amount of data in heavy-ion collisions, at Relativistic Heavy Ion Collider (RHIC), at Brookhaven National Laboratory (BNL) in New York, USA, and the Large Hadron Collider (LHC), at CERN in Geneva, Switzerland but also analyze these data to unravel the mystery of this new phase of matter that filled a few microseconds old universe, just after the Big Bang. In the meantime, advancements in theoretical works and computing capability extend our wisdom about the hot-dense QCD matter and its dynamics through mathematical equations. The exchange of ideas between experimentalists and theoreticians is crucial for the progress of our knowledge. The motivation of this first conference named "HOT QCD Matter 2022" is to bring the community together to have a discourse on this topic. In this article, there are 36 sections discussing various topics in the field of relativistic heavy-ion collisions and related phenomena that cover a snapshot of the current experimental observations and theoretical progress. This article begins with the theoretical overview of relativistic spin-hydrodynamics in the presence of the external magnetic field, followed by the Lattice QCD results on heavy quarks in QGP, and finally, it ends with an overview of experiment results.

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arXiv2022

Measurement of charged-particle jet properties in p--Pb collisions at $\sqrt{s_{\rm NN}} = 5.02$ TeV with ALICE

We present the measurement of charged-particle jet properties in minimum bias p--Pb collisions at $\sqrt{s_{\rm NN}}$ = 5.02 TeV in ALICE. Jets are reconstructed from charged particles at midrapidity using the anti-$k_{\rm T}$ jet finding algorithm with jet resolution parameter $R$ = 0.4. The mean charged particle multiplicity and jet fragmentation function for leading charged-particle jets in the $p_{\rm T}$ interval 10 $< p_{\rm T, jet}^{\rm ch} <$ 100 GeV/$c$ are measured and compared with theoretical model predictions.

nucl-ex↗

arXiv2021

Effect of magnetic field on jet transport coefficient $\hat{q}$

We report the estimation of jet transport coefficient, $\hat{q}$ for quark- and gluon-initiated jets using a simple quasi-particle model in absence and presence of magnetic field. This model introduces a temperature and magnetic field-dependent degeneracy factor of partons, which is tuned by fitting the entropy density of lattice quantum chromodynamics data. At a finite magnetic field, $\hat{q}$ for quark jets splits into parallel and perpendicular components whose magnetic field dependence comes from two sources: the field-dependent degeneracy factor and the phase space part guided from the shear viscosity to entropy density ratio. Due to the electrically neutral nature of gluons, the estimation of $\hat{q}$ for gluon jets is affected only by the field-dependent degeneracy factor. In presence of a finite magnetic field, we find a significant enhancement in $\hat{q}$ for both quark- and gluon-initiated jets at low temperature, which gradually decreases towards high temperature. We compare the obtained results with the earlier calculations based on the anti-de Sitter/conformal field theory correspondence, and a qualitatively similar trend is observed. The change in $\hat{q}$ in presence of magnetic field is, however, quantitatively different for quark- and gluon-initiated jets. This is an interesting observation which can be explored experimentally to verify the effect of magnetic field on $\hat{q}$.

hep-ph↗