1,804 research outputs found
Effect of magnetic field on the optical and thermodynamic properties of a high-temperature hadron resonance gas with van der Waals interactions
We study the behavior of a hadronic matter in the presence of an external
magnetic field within the van der Waals hadron resonance gas (VDWHRG) model,
considering both attractive and repulsive interactions among the hadrons.
Various thermodynamic quantities like pressure (), energy density
(), magnetization (), entropy density (), squared
speed of sound (), specific heat capacity at constant volume
() are calculated as functions of temperature () and static finite
magnetic field (). We also consider the effect of baryochemical potential
() on the above-mentioned thermodynamic observables in the presence of
a magnetic field. Further, we estimate the magnetic susceptibility (), relative permeability (), and electrical susceptibility
() which can help us to understand the system better. With
the information of and dielectric constant (), we
enumerate the refractive index () of the system under consideration.
Through this model, we quantify a liquid-gas phase transition in the
T-eB- phase space.Comment: 18 pages and 5-captioned figures. Submitted for publicatio
Proton number cumulants in a modified van der Waals hadron resonance gas
An estimate of the proton number cumulants in the hadronic matter is
presented considering a van der Waals-type interaction between the constituent
particles. We argue that the attractive and repulsive parameters in the VDW
hadron resonance gas (VDWHRG) model change as functions of baryochemical
potential () and temperature (). This, in turn, affects the
estimation of thermodynamic properties and, consequently, the conserved charge
fluctuations. We employ a simple parametrization to bring in the center-of-mass
energy () dependence on temperature and baryochemical
potential and then estimate the proton number cumulants with the modified
approach. The modified van der Waals hadron resonance gas model (MVDWHRG)
explains the existing experimental data very well.Comment: 9-pages and 6-captioned figures, Submitted for publicatio
Thermodynamics of a rotating hadron resonance gas with van der Waals interaction
Studying the thermodynamics of the systems produced in ultra-relativistic
heavy-ion collisions is crucial in understanding the QCD phase diagram.
Recently, a new avenue has opened regarding the implications of large initial
angular momentum and subsequent vorticity in the medium evolution in
high-energy collisions. This adds a new type of chemical potential into the
partonic and hadronic systems, called the rotational chemical potential. We
study the thermodynamics of an interacting hadronic matter under rotation,
formed in an ultra-relativistic collision. We introduce attractive and
repulsive interactions through the van der Waals equation of state.
Thermodynamic properties like the pressure (), energy density
(), entropy density (), trace anomaly (), specific heat () and squared speed of sound () are studied as functions of temperature () for zero and finite
rotation chemical potential. The charge fluctuations, which can be quantified
by their respective susceptibilities, are also studied. The rotational (spin)
density corresponding to the rotational chemical potential is explored. In
addition, we explore the possible liquid-gas phase transition in the hadron gas
with van der Waals interaction in the -- phase space.Comment: 11 pages and 6 captioned figures. Submitted for publicatio
Diffusion and fluctuations of open charmed hadrons in an interacting hadronic medium
Heavy quarks are excellent probes to understand the hot and dense medium
formed in ultra-relativistic collisions. In a hadronic medium, studying the
transport properties, e.g. the drag (), momentum diffusion (),
and spatial diffusion () coefficients of open charmed hadrons can
provide useful information about the medium. Moreover, the fluctuations of
charmed hadrons can help us to locate the onset of their deconfinement. In this
work, we incorporate attractive and repulsive interactions in the
well-established van der Waals hadron resonance gas model (VDWHRG) and study
the diffusion and fluctuations of charmed hadrons. This study helps us
understand the importance of interactions in the system, which significantly
affect both the diffusion and fluctuations of charmed hadrons.Comment: 11 pages and 8 captioned figures. Submitted for publicatio
Role of chemical potential at kinetic freeze-out using Tsallis non-extensive statistics in proton-proton collisions at the Large Hadron Collider
The charged-particle transverse momentum spectra (-spectra)
measured by the ALICE collaboration for collisions at 7 and
13 TeV have been studied using a thermodynamically consistent form of Tsallis
non-extensive statistics. The Tsallis distribution function is fitted to the
-spectra and the results are analyzed as a function of final state
charged-particle multiplicity for various light flavor and strange particles,
such as . At the LHC energies, particles and
antiparticles are produced in equal numbers. However, the equality of particle
and antiparticle yields at the kinetic freeze-out may imply that they have the
same but opposite chemical potential which is not necessarily zero. We use an
alternative procedure that makes use of parameter redundancy, by introducing a
finite chemical potential at the kinetic freeze-out stage. This article
emphasizes the importance of the chemical potential of the system produced in
collisions at the LHC energies using the Tsallis distribution function
which brings the system to a single freeze-out scenario.Comment: Same as the published version in EPJ
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.Comment: Compilation of the contributions (148 pages) as presented in the `Hot
QCD Matter 2022 conference', held from May 12 to 14, 2022, jointly organized
by IIT Goa & Goa University, Goa, Indi
Predisposition to Cancer Caused by Genetic and Functional Defects of Mammalian Atad5
ATAD5, the human ortholog of yeast Elg1, plays a role in PCNA deubiquitination. Since PCNA modification is important to regulate DNA damage bypass, ATAD5 may be important for suppression of genomic instability in mammals in vivo. To test this hypothesis, we generated heterozygous (Atad5+/m) mice that were haploinsuffficient for Atad5. Atad5+/m mice displayed high levels of genomic instability in vivo, and Atad5+/m mouse embryonic fibroblasts (MEFs) exhibited molecular defects in PCNA deubiquitination in response to DNA damage, as well as DNA damage hypersensitivity and high levels of genomic instability, apoptosis, and aneuploidy. Importantly, 90% of haploinsufficient Atad5+/m mice developed tumors, including sarcomas, carcinomas, and adenocarcinomas, between 11 and 20 months of age. High levels of genomic alterations were evident in tumors that arose in the Atad5+/m mice. Consistent with a role for Atad5 in suppressing tumorigenesis, we also identified somatic mutations of ATAD5 in 4.6% of sporadic human endometrial tumors, including two nonsense mutations that resulted in loss of proper ATAD5 function. Taken together, our findings indicate that loss-of-function mutations in mammalian Atad5 are sufficient to cause genomic instability and tumorigenesis
MUSiC : a model-unspecific search for new physics in proton-proton collisions at root s=13TeV
Results of the Model Unspecific Search in CMS (MUSiC), using proton-proton collision data recorded at the LHC at a centre-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 35.9 fb(-1), are presented. The MUSiC analysis searches for anomalies that could be signatures of physics beyond the standard model. The analysis is based on the comparison of observed data with the standard model prediction, as determined from simulation, in several hundred final states and multiple kinematic distributions. Events containing at least one electron or muon are classified based on their final state topology, and an automated search algorithm surveys the observed data for deviations from the prediction. The sensitivity of the search is validated using multiple methods. No significant deviations from the predictions have been observed. For a wide range of final state topologies, agreement is found between the data and the standard model simulation. This analysis complements dedicated search analyses by significantly expanding the range of final states covered using a model independent approach with the largest data set to date to probe phase space regions beyond the reach of previous general searches.Peer reviewe
Search for new particles in events with energetic jets and large missing transverse momentum in proton-proton collisions at root s=13 TeV
A search is presented for new particles produced at the LHC in proton-proton collisions at root s = 13 TeV, using events with energetic jets and large missing transverse momentum. The analysis is based on a data sample corresponding to an integrated luminosity of 101 fb(-1), collected in 2017-2018 with the CMS detector. Machine learning techniques are used to define separate categories for events with narrow jets from initial-state radiation and events with large-radius jets consistent with a hadronic decay of a W or Z boson. A statistical combination is made with an earlier search based on a data sample of 36 fb(-1), collected in 2016. No significant excess of events is observed with respect to the standard model background expectation determined from control samples in data. The results are interpreted in terms of limits on the branching fraction of an invisible decay of the Higgs boson, as well as constraints on simplified models of dark matter, on first-generation scalar leptoquarks decaying to quarks and neutrinos, and on models with large extra dimensions. Several of the new limits, specifically for spin-1 dark matter mediators, pseudoscalar mediators, colored mediators, and leptoquarks, are the most restrictive to date.Peer reviewe
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