Amit Kumar
A5000824634- Particle physics theoretical and experimental studies
- High-Energy Particle Collisions Research
- Quantum Chromodynamics and Particle Interactions
- Particle Detector Development and Performance
- Computational Fluid Dynamics and Aerodynamics
- Thermography and Photoacoustic Techniques
- Gamma-ray bursts and supernovae
- Thermal properties of materials
- Fluid Dynamics and Turbulent Flows
- Numerical methods in inverse problems
- Radiation Detection and Scintillator Technologies
- Advanced X-ray and CT Imaging
- Gas Dynamics and Kinetic Theory
- Advanced NMR Techniques and Applications
- Metastasis and carcinoma case studies
- Pulsars and Gravitational Waves Research
- Plasma and Flow Control in Aerodynamics
- Nuclear Physics and Applications
- Markov Chains and Monte Carlo Methods
- Extraction and Separation Processes
- Particle Accelerators and Free-Electron Lasers
- Radio Frequency Integrated Circuit Design
- Wave and Wind Energy Systems
- Nuclear physics research studies
- Advanced Chemical Physics Studies
Wayne State University
2017-2024
University of Cagliari
2022-2024
University of Regina
2024
McGill University
2020-2024
Humboldt-Universität zu Berlin
2024
Seascape Consultants (United Kingdom)
2022-2023
Bhabha Atomic Research Centre
2011-2020
Nagoya University
2019
Michigan State University
2019
Indian Institute of Technology Indore
2018
We study the properties of strongly-coupled quark-gluon plasma with a multistage model heavy ion collisions that combines T$_\mathrm{R}$ENTo initial condition ansatz, free-streaming, viscous relativistic hydrodynamics, and hadronic transport. A model-to-data comparison Bayesian inference is performed, revisiting assumptions made in previous studies. The role parameter priors studied light their importance towards interpretation results. emphasize use closure tests to perform extensive...
Using combined data from the Relativistic Heavy Ion and Large Hadron Colliders, we constrain shear bulk viscosities of quark-gluon plasma (QGP) at temperatures ∼150–350 MeV. We use Bayesian inference to translate experimental theoretical uncertainties into probabilistic constraints for viscosities. With model averaging propagate an estimate uncertainty generated by transition hydrodynamics hadron transport in plasma's final evolution stage, providing most reliable phenomenological date on...
We report a new determination of $\stackrel{\ifmmode \hat{}\else \^{}\fi{}}{q}$, the jet transport coefficient quark-gluon plasma. use JETSCAPE framework, which incorporates novel multistage theoretical approach to in-medium evolution and Bayesian inference for parameter extraction. The calculations, based on Matter Lbt quenching models, are compared experimental measurements inclusive hadron suppression in $\mathrm{Au}+\mathrm{Au}$ collisions at BNL Relativistic Heavy Ion Collider (RHIC)...
We present a new study of jet interactions in the quark-gluon plasma created high-energy heavy-ion collisions, using multistage event generator within jetscape framework. focus on medium-induced modifications rate inclusive jets and high transverse momentum (high-${p}_{\mathrm{T}}$) hadrons. Scattering-induced energy loss is calculated two stages: virtuality stage based matter model, which scattering highly virtual partons modifies vacuum radiation pattern, second at lower lbt leading gain...
The modification of hard jets in an extended static medium held at a fixed temperature is studied using three different Monte Carlo event generators: linear Boltzmann transport (LBT), modular all twist transverse-scattering elastic-drag and radiation (MATTER), algorithm for relativistic treatment heavy-ion interactions (MARTINI). Each generator contains set assumptions regarding the energy virtuality partons within jet versus scale and, hence, applies to epoch space-time history evolution....
We study parton energy-momentum exchange with the quark gluon plasma (QGP) within a multistage approach composed of in-medium Dokshitzer-Gribov-Lipatov-Altarelli-Parisi evolution at high virtuality, and (linearized) Boltzmann transport formalism lower virtuality. This simulation is then calibrated in comparison high-<a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:msub><a:mi>p</a:mi><a:mi>T</a:mi></a:msub></a:math> charged hadrons, <b:math...
The JETSCAPE simulation framework is an overarching computational envelope for developing complete event generators heavy-ion collisions. It allows modular incorporation of a wide variety existing and future software that simulates different aspects collision. default package contains both the framework, entire set indigenous third party routines can be used to directly compare with experimental data. In this article, we outline algorithmic design define interfaces describe modules required...
The JETSCAPE framework is a modular and versatile Monte Carlo software package for the simulation of high energy nuclear collisions. In this work we present new tune JETSCAPE, called PP19, validate it by comparison to jet-based measurements in $p+p$ collisions, including inclusive single jet cross sections, shape observables, fragmentation functions, charged hadron dijet mass sections. These observables collisions provide baseline their counterparts Quantifying level agreement results with...
We present an attempt to probe the underlying structure of quark-gluon plasma (QGP) at high resolution, based on extracted jet transport coefficient $\stackrel{\ifmmode \hat{}\else \^{}\fi{}}{q}$. argue that exchanged momentum $k$ between hard parton and medium varies over a range scales, for $k\ensuremath{\ge}1\phantom{\rule{0.28em}{0ex}}\mathrm{GeV},\phantom{\rule{0.28em}{0ex}}\stackrel{\ifmmode \^{}\fi{}}{q}$ can be expressed in terms distribution function (PDF). Because mass QGP...
We present a study of the transverse size parton showers and their diminishing interaction with medium in high virtuality stage jet evolution. consider process hard quark produced deep inelastic scattering off large nucleus. Single gluon radiation from this quark, absence scattering, is re-derived using wave-packets. This allows for derivation quantum uncertainty at point splitting. then incorporated within Monte-Carlo shower routine yielding sizes noticeably larger than classical antenna...
In this work, real photon production scattering rates from jet-medium interactions in the quark-gluon plasma (QGP) is perturbatively calculated using higher-twist (HT) formalism. Focus given towards off of highly virtual (and energetic) quarks, taking into account heavy quark mass scales [Phys. Rev. C 94, 054902 (2016)], fermion-boson conversion processes [Nucl. Phys. A 793, 128-170 (2007)], as well coherence effects 105, 024908 (2022)]. generalized factorization procedure, such used $e$-$A$...
Understanding the modification of jets and high-$p_T$ probes in small systems requires integration soft hard physics. We present recent developments extending JETSCAPE framework to build an event generator, which includes correlations between partons, study jet observables systems. The multi-scale physics collision is separated into different stages. Hard scatterings are first sampled at binary positions provided by Glauber geometry. They then propagated backward space-time following...
How does nature hold together protons and neutrons to form the wide variety of complex nuclei in Universe? Describing many-nucleon systems from fundamental theory quantum chromodynamics has been greatest challenge answering this question. The chiral effective field description nuclear force now makes possible but requires certain parameters that are not uniquely determined. Defining needs identification observables sensitive different parametrizations. From a measurement proton elastic...
We present the first calculation of jet transport coefficient $\stackrel{^}{q}$ in quenched and ($2+1$)-flavor QCD on a 4D Euclidean lattice. The lightlike propagation an energetic parton is factorized from mean square gain momentum transverse to direction propagation, which expressed terms thermal field-strength correlator. leading-twist term its operator product expansion calculated Continuum extrapolated results, full estimates based unrenormalized lattice data, over multiple sizes, are...
We present predictions and postdictions for a wide variety of hard jet-substructure observables using multistage model within the framework. The details various parameter choices are described in []. A novel feature this is presence two stages jet modification: high-virtuality phase [modeled modular all twist transverse-scattering elastic-drag radiation ()], where modified coherence effects diminish medium-induced radiation, lower virtuality linear Boltzmann transport parton splits fully...
We present the first attempt to extract "$x$" dependence of parton distribution function (PDF) quark gluon plasma (QGP). In absence knowledge regarding mass a QGP constituent, we define new variable $x_N$, nucleonic momentum fraction, which represents ratio that self-contained section has nucleon. Calculations are compared data for single hadron suppression in terms nuclear modification factor $R_{AA}$ and azimuthal anisotropy parameter $v_{2}$, as transverse $p_{T}$, centrality energy...
Parton energy-momentum exchange with the quark gluon plasma (QGP) is a multi-scale problem. In this work, we calculate interaction of charm quarks QGP within higher twist formalism at high virtuality and energy using MATTER model, while low portion treated via (linearized) Boltzmann Transport (LBT) formalism. Coherence effect that reduces medium-induced emission rate in model also taken into account. The interplay between these two formalisms studied detail used to produce good description...
In this talk we review jet production in a large variety of collision systems using the JETSCAPE event generator and Hybrid Hadronization. Hadronization combines quark recombination, applicable when distances between partons phase space are small, string fragmentation appropriate for dilute parton systems. It can therefore smoothly describe transition from very like $e^++𝑒^−$ to full $𝐴 + 𝐴$ collisions. We test picture by generate jets various Comparison experimental data $𝑝 𝑝$ collisions...
We present here a possible resolution of the jet quenching parameter $\hat{q}$ puzzle by exploring momentum fraction $x$ and scale $Q^2$ dependence $\hat{q}$, in addition to temperature dependence. explore broadening due Glauber gluon exchange with quark-gluon plasma (QGP). This has led us define for partons QGP. also show here, first time, forms parton distribution function (PDF) The QGP-PDF as input been used fit PHENIX CMS data simultaneously. observe that evolution energy are missing...
The jet transport coefficient $\hat{q}$ is the leading that controls modification of hard jets produced in heavy-ion collisions. This inherently non-perturbative, and hence, challenging to compute from first principles. In this report, we present a perturbative quantum chromodynamics (pQCD) lattice gauge theory based formulation study $\hat{q}$. We formulate within 4-dimensional (4D) quenched SU(3) lattice. consider order diagram for parton passing through quark-gluon plasma....
We present the first calculation of jet transport coefficient $\hat{q}$ in quenched and (2+1)-flavor QCD on a 4-D Euclidean lattice. The light-like propagation an energetic parton is factorized from mean square gain momentum transverse to direction propagation, which expressed terms thermal field-strength correlator. leading-twist term its operator product expansion calculated Continuum extrapolated results, full estimates based un-renormalized lattice data, over multiple sizes, are compared...
Considerable information about the early-stage dynamics of heavy-ion collisions is encoded in rapidity dependence measurements. To leverage large amount experimental data, we perform a systematic analysis using three-dimensional hydrodynamic simulations multiple collision systems -- and small, symmetric asymmetric. Specifically, fully 3D multi-stage initialized by parameterized model for rapidity-dependent energy deposition, which calibrate on hadron multiplicity anisotropic flow...