scholarly journals DSMesons in Asymmetric Hot and Dense Hadronic Matter

2015 ◽  
Vol 2015 ◽  
pp. 1-16 ◽  
Author(s):  
Divakar Pathak ◽  
Amruta Mishra
Keyword(s):  
Heavy Ion ◽  
Mass Splitting ◽  
Hadronic Matter ◽  
Isospin Asymmetry ◽  
Baryonic Density ◽  
Significant Difference ◽  
Strangeness Content ◽  
Mass Degeneracy ◽  
The Masses ◽  
Ion Collision

The in-medium properties ofDSmesons are investigated within the framework of an effective hadronic model, which is a generalization of a chiralSU(3)model, toSU(4), in order to study the interactions of the charmed hadrons. In the present work, theDSmesons are observed to experience net attractive interactions in a dense hadronic medium, hence reducing the masses of theDS+andDS-mesons from the vacuum values. While this conclusion holds in both nuclear and hyperonic media, the magnitude of the mass drop is observed to intensify with the inclusion of strangeness in the medium. Additionally, in hyperonic medium, the mass degeneracy of theDSmesons is observed to be broken, due to opposite signs of the Weinberg-Tomozawa interaction term in the Lagrangian density. Along with the magnitude of the mass drops, the mass splitting betweenDS+andDS-mesons is also observed to grow with an increase in baryonic density and strangeness content of the medium. However, all medium effects analyzed are found to be weakly dependent on isospin asymmetry and temperature. We discuss the possible implications emanating from this analysis, which are all expected to make a significant difference to observables in heavy ion collision experiments, especially the upcoming Compressed Baryonic Matter (CBM) experiment at the future Facility for Antiproton and Ion Research (FAIR), GSI, where matter at high baryonic densities is planned to be produced.

scholarly journals Bottom-strange mesons in hyperonic matter

2014 ◽  
Vol 23 (11) ◽  
pp. 1450073 ◽  
Author(s):  
Divakar Pathak ◽  
Amruta Mishra
Keyword(s):  
Heavy Quark ◽  
Quark Sector ◽  
Baryonic Density ◽  
Pseudoscalar Mesons ◽  
Medium Mass ◽  
Strangeness Content ◽  
Medium Modifications ◽  
Mass Degeneracy ◽  
Charmed Strange Mesons ◽  
Quark Content

The in-medium behavior of bottom-strange pseudoscalar mesons in hot, isospin asymmetric and dense hadronic environment is studied using a chiral effective model. The same was recently generalized to the heavy quark sector and employed to study the behavior of open-charm and open-bottom mesons. The heavy quark (anti-quark) is treated as frozen and all medium modifications of these bottom-strange mesons are due to their strange anti-quark (quark) content. We observe a pronounced dependence of their medium mass on baryonic density and strangeness content of the medium. Certain aspects of these in-medium interactions are similar to those observed for the strange-charmed mesons in a preceding investigation, such as the lifting of mass-degeneracy of [Formula: see text] and [Formula: see text] mesons in hyperonic matter, while the same is respected in vacuum as well as in nuclear matter. In general, however, there is a remarkable distinction between the two species, even though the formalism predicts a completely analogous in-medium interaction Lagrangian density. We discuss in detail the reason for different in-medium behavior of these bottom-strange mesons as compared to charmed-strange mesons, despite the dynamics of the heavy quark being treated as frozen in both cases.

scholarly journals Universal descriptions of chemical freeze-out based on pressure and specific heat

2018 ◽  
Vol 27 (06) ◽  
pp. 1850047 ◽  
Author(s):  
Subhasis Samanta
Keyword(s):  
Specific Heat ◽  
Heavy Ion ◽  
Hadronic Matter ◽  
Repulsive Interaction ◽  
Heavy Ion Collision ◽  
Radius Parameter ◽  
Ion Collision ◽  
Best Fit ◽  
Chemical Freeze ◽  
Freeze Out

The lattice QCD data of pressure and the energy density have been used to extract the hadronic radius parameter of the excluded volume hadron resonance gas (EVHRG) model. The equation of state can be described well with the extracted radius parameter [Formula: see text] fm. Specific heat is also calculated in the EVHRG model. Further, two new universal descriptions of chemical freeze-out parameters have been introduced based on pressure and specific heat, respectively. It is shown that the chemical freeze-out parameters obtained at various [Formula: see text] in ideal hadron resonance gas (HRG) model approximately correspond to [Formula: see text] and [Formula: see text], respectively. These two quantities are important to describe the thermodynamic properties of the hadronic matter created in heavy-ion collision experiment. The sensitivity of universal chemical freeze-out lines on repulsive interaction is also studied. It has been observed that the behaviors of chemical freeze-out lines for [Formula: see text] and [Formula: see text] in EVHRG model remain similar to ideal HRG model for the best fit value of hadronic radii.

scholarly journals Electroweak SU(2)L × U(1)Y model with strong spontaneously fermion-mass-generating gauge dynamics

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Petr Beneš ◽  
Jiří Hošek ◽  
Adam Smetana
Keyword(s):  
Chiral Symmetry Breaking ◽  
Axial Vector ◽  
Higgs Sector ◽  
Dyson Equation ◽  
Mass Splitting ◽  
Fermion Mass ◽  
Goldstone Bosons ◽  
The Standard Model ◽  
Exploratory Stage ◽  
The Masses

Abstract Higgs sector of the Standard model (SM) is replaced by quantum flavor dynamics (QFD), the gauged flavor SU(3)f symmetry with scale Λ. Anomaly freedom requires addition of three νR. The approximate QFD Schwinger-Dyson equation for the Euclidean infrared fermion self-energies Σf(p2) has the spontaneous-chiral-symmetry-breaking solutions ideal for seesaw: (1) Σf(p2) = $$ {M}_{fR}^2/p $$ M fR 2 / p where three Majorana masses MfR of νfR are of order Λ. (2) Σf(p2) = $$ {m}_f^2/p $$ m f 2 / p where three Dirac masses mf = m(0)1 + m(3)λ3 + m(8)λ8 of SM fermions are exponentially suppressed w.r.t. Λ, and degenerate for all SM fermions in f. (1) MfR break SU(3)f symmetry completely; m(3), m(8) superimpose the tiny breaking to U(1) × U(1). All flavor gluons thus acquire self-consistently the masses ∼ Λ. (2) All mf break the electroweak SU(2)L × U(1)Y to U(1)em. Symmetry partners of the composite Nambu-Goldstone bosons are the genuine Higgs particles: (1) three νR-composed Higgses χi with masses ∼ Λ. (2) Two new SM-fermion-composed Higgses h3, h8 with masses ∼ m(3), m(8), respectively. (3) The SM-like SM-fermion-composed Higgs h with mass ∼ m(0), the effective Fermi scale. Σf(p2)-dependent vertices in the electroweak Ward-Takahashi identities imply: the axial-vector ones give rise to the W and Z masses at Fermi scale. The polar-vector ones give rise to the fermion mass splitting in f. At the present exploratory stage the splitting comes out unrealistic.

Collision geometry and particle production in high energy heavy ion collision experiments

2008 ◽  
Vol 32 (4) ◽  
pp. 308-328
Author(s):  
Wang Ya-Ping ◽  
Zhou Dai-Mei ◽  
Huang Rui-Dian ◽  
Cai Xu
Keyword(s):  
Particle Production ◽  
Heavy Ion ◽  
High Energy ◽  
Heavy Ion Collision ◽  
Ion Collision

Dynamical model for neck formation in the entrance channel of a heavy ion collision

1982 ◽  
Vol 306 (4) ◽  
pp. 307-313 ◽  
Author(s):  
S. K. Samaddar ◽  
B. C. Samanta ◽  
D. Sperber ◽  
M. Zielińska-Pfabé
Keyword(s):  
Heavy Ion ◽  
Entrance Channel ◽  
Dynamical Model ◽  
Heavy Ion Collision ◽  
Neck Formation ◽  
Ion Collision

Study and Investigation of Hard Photons Emission in Heavy Ion Collisions

2021 ◽  
Vol 19 (2) ◽  
pp. 61-65
Author(s):  
Taghreed A. Younis ◽  
Hadi J.M. Al-Agealy
Keyword(s):  
Critical Temperature ◽  
Quark Gluon Plasma ◽  
Heavy Ion Collisions ◽  
Heavy Ion ◽  
Gluon Plasma ◽  
Heavy Ion Collision ◽  
Hard Photon ◽  
Ion Collisions ◽  
Strength Models ◽  
Ion Collision

This work involves hard photon rate production from quark -gluon plasma QGP interaction in heavy ion collision. Using a quantum chromodynamic model to investigate and calculation of photons rate in 𝑐𝑔 → 𝑠𝑔𝛾 system due to strength coupling, photons rate, temperature of system, flavor number and critical. The photons rate production computed using the perturbative strength models for QGP interactions. The strength coupling was function of temperature of system, flavor number and critical temperature. Its influenced by force with temperature of system, its increased with decreased the temperature and vice versa. The strength coupling has used to examine the confinement and deconfinement of quarks in QGP properties and influence on the photon rate production. In our approach, we calculate the photons rate depending on the strength coupling, photons rate and temperature of system with other factors. The results plotted as a function of the photons energy. The photons rate was decreased with increased temperature and increased with decreased with strength coupling.

scholarly journals Hadron Resonance Gas EoS and the Fluidity of Matter Produced in HIC

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Guruprasad Kadam ◽  
Swapnali Pawar
Keyword(s):  
Mass Spectrum ◽  
Chemical Potential ◽  
Heavy Ion ◽  
Baryon Chemical Potential ◽  
Hadron Mass ◽  
Lattice Quantum ◽  
Hadron Gas ◽  
Ion Collision ◽  
Discrete Mass ◽  
The Ideal

We study the equation of state (EoS) of hot and dense hadron gas by incorporating the excluded volume corrections into the ideal hadron resonance gas (HRG) model. The total hadron mass spectrum of the model is the sum of the discrete mass spectrum consisting of all the experimentally known hadrons and the exponentially rising continuous Hagedorn states. We confront the EoS of the model with lattice quantum chromodynamics (LQCD) results at finite baryon chemical potential. We find that this modified HRG model reproduces the LQCD results up to T=160 MeV at zero as well as finite baryon chemical potential. We further estimate the shear viscosity within the ambit of this model in the context of heavy-ion collision experiments.

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