nucl-th digest · Apr 4, 2022

[Submitted on 1 Apr 2022]

Production and anisotropic flow of thermal photons in collision of $α$ -clustered carbon with heavy nuclei at relativistic energies

Pingal Dasgupta🇨🇳 · Rupa Chatterjee🇮🇳 · Guo-Liang Ma🇨🇳

The presence of $α$ -clustered structure in the light nuclei produces different exotic shapes in nuclear structure studies at low energies. Recent phenomenological studies suggest that collision of heavy nuclei with $α$ -clustered carbon ( $^{12}$ C) at relativistic energies can lead to large initial state anisotropies. This is expected to impact the final momentum anisotropies of the produced particles significantly. The emission of electromagnetic radiations is considered to be more sensitive to the initial state compared to hadronic observables and thus photon observables are expected to be affected by the initial clustered structure profoundly. In this work we estimate the production and anisotropic flow of photons from most-central collisions of triangular $α$ -clustered carbon and gold at $s_{NN} = 200$ GeV using an event-by-event hydrodynamic framework and compare the results with those obtained from unclustered carbon and gold collisions. We show that the thermal photon $v_{3}$ for most central collisions is significantly large for the clustered case compared to the case with unclustered carbon, whereas the elliptic flow parameter does not show much difference for the two cases. In addition, the ratio of anisotropic flow coefficients is found to be a potential observable to constrain the initial state produced in relativistic heavy-ion collisions and also to know more about the $α$ -clustered structure in carbon nucleus.

Comments:: 8 pages, 7 figures, final published version
Subjects:: Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:: 2204.00235 [pdf]

PRC(2023)·10 citations

Zero-temperature thermodynamics of dense asymmetric strong-interaction matter

Employing constraints derived from the microscopic theory of the strong interaction, we estimate the zero-temperature phase structure of dense isospin-asymmetric matter with two quark flavors. We find indications that strong-interaction matter along trajectories relevant for astrophysical applications undergoes a first-order phase transition from a color-superconducting phase to an ungapped quark-matter phase when the density is increased. Such a phase transition is found to be absent in isospin-symmetric matter. Moreover, by taking into account constraints from

β

-equilibrium, charge neutrality, and color neutrality, we provide an estimate for the speed of sound in neutron-star matter. Notably, we observe that the speed of sound in neutron-star matter exceeds the asymptotic value associated with the noninteracting quark gas and even increases towards lower densities across a wide range, in agreement with recent results for isospin-symmetric matter. Considering results from studies based on chiral effective field theory at low densities, our findings suggest the existence of a maximum in the speed of sound for

n / n_{0} ≲ 10

, where

n_{0}

is the nuclear saturation density.

Comments:: 18 pages, 9 figures; v2: comments and references added, one appendix added
Subjects:: Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
arXiv:: 2204.00358 [pdf]

PRD(2022)·37 citations

Monday·April 4, 2022

Production and anisotropic flow of thermal photons in collision of $α$ -clustered carbon with heavy nuclei at relativistic energies

Zero-temperature thermodynamics of dense asymmetric strong-interaction matter

Affiliations

Production and anisotropic flow of thermal photons in collision of α-clustered carbon with heavy nuclei at relativistic energies

Zero-temperature thermodynamics of dense asymmetric strong-interaction matter

Affiliations

Production and anisotropic flow of thermal photons in collision of $α$ -clustered carbon with heavy nuclei at relativistic energies