Astrophysical aspects of neutrino dynamics in ultra-degenerate quark gluon plasma

The cardinal focus of the present review is to explore the role of neutrinos originating from the ultra-dense core of neutron stars composed of quark gluon plasma in the astrophysical scenario. The collective excitations of the quarks involving the neutrinos through the different kinematical processes have been studied. The cooling of the neutron stars as well as pulsar kicks due to asymmetric neutrino emission have been discussed in detail. Results involving calculation of relevant physical quantities like neutrino mean free path and emissivity have been presented in the framework of non-Fermi liquid behavior as applicable to ultra-degenerate plasma.Comment: 10 pages, 9 figures, Accepted for publication as Review Article in Advances of High Energy Physics. arXiv admin note: text overlap with arXiv:1204.2684; text overlap with arXiv:0706.4381 by other author

Role of magnetic interactions in neutron stars

In this work, we present a calculation of the non-Fermi liquid correction to the specific heat of magnetized degenerate quark matter present at the core of the neutron star. The role of non-Fermi liquid corrections to the neutrino emissivity has been calculated beyond leading order. We extend our result to the evaluation of the pulsar kick velocity and cooling of the star due to such anomalous corrections and present a comparison with the simple Fermi liquid case.Comment: 6 pages, Proceedings of the 3rd International Conference on New Frontiers in Physics, Kolymbari, Crete, Greece (matches published version

Dissociation of heavy quarkonium states in rapidly varying strong magnetic field

In a transient magnetic field, heavy quarkonium bound states evolve non adiabatically. In presence of a strong magnetic field, $J/\Psi$ and $\Upsilon(1S)$ become more tightly bound than we expected earlier for a pure thermal medium. We have shown that in a time varying magnetic field, there is a possibility of moderate suppression of $J/\Psi$ through the non adiabatic transition to continuum where as the $\Upsilon(1S)$ is so tightly bound that can not be dissociated through this process. We have calculated the dissociation probabilities up to the first order in the time dependent perturbation theory for different values of initial magnetic field intensity.Comment: 4 pages, 2 figure

Next to leading order non Fermi liquid corrections to the neutrino emissivity and cooling of the neutron star

In this work we derive the expressions of the neutrino mean free path(MFP) and emissivity with non Fermi liquid corrections up to next to leading order(NLO) in degenerate quark matter. The calculation has been performed both for the absorption and scattering processes. Subsequently the role of these NLO corrections on the cooling of the neutron star has been demonstrated. The cooling curve shows moderate enhancement compared to the leading order(LO) non-Fermi liquid result. Although the overall correction to the MFP and emissivity are larger compared to the free Fermi gas, the cooling behavior does not alter significantly.Comment: 8 pages, 8 figures, references added, matches published versio

Dynamically screened strongly quantized electron transport in binary neutron-star merger

We examine electron-transport coefficients in magnetized hot and dense electron-ion plasma relevant in binary neutron star merger simulation. We calculate electrical and thermal conductivities in low density, high temperature, highly magnetized plasma of binary neutron star mergers where quantum oscillatory behavior of electrons emerge. For pronounced thermodynamic effects, we consider zeroth Landau level population of electrons for the calculation of conductivity. We solve Boltzmann equation in presence of magnetic field to obtain the dissipative components of electrical and thermal conductivities. The dissipative coefficients are formulated considering frequency dependent dynamical screening in the quantized electron-ion scattering rate. Numerical estimations show that the effect of dynamical screening of photon propagator on electrical and thermal conductivities is pronounced. We observe that dynamical screening reduces the maxima of both the electrical and thermal conductivities by factors of thirty one and twenty respectively leading to a reduction in the corresponding time scales of these coefficients. The common scaling factor between electrical and thermal conductivity is also observed to follow cubic relationship with temperature violating Wiedemann-Franz law.Comment: Accepted in The European Physical Journal C. arXiv admin note: substantial text overlap with arXiv:2108.1187

Role of magnetic interactions in neutron stars

In this work, we present a calculation of the non-Fermi liquid correction to the specific heat of magnetized degenerate quark matter present at the core of the neutron star. The role of non-Fermi liquid corrections to the neutrino emissivity has been calculated beyond leading order. We extend our result to the evaluation of the pulsar kick velocity and cooling of the star due to such anomalous corrections and present a comparison with the simple Fermi liquid case

Multi-partonic medium induced cascades in expanding media

Going beyond the simplified gluonic cascades, we introduce both gluon and quark degrees of freedom for partonic cascades inside the medium. We then solve the set of coupled evolution equations numerically with splitting kernels calculated for static, exponential, and Bjorken expanding media to arrive at medium-modified parton spectra for quark and gluon initiated jets. Using these, we calculate the inclusive jet RAA where the phenomenologically driven combinations of quark and gluon jet fractions are included. Then, the rapidity dependence of the jet RAA is examined. We also study the path-length dependence of jet quenching for different types of expanding media by calculating the jet v2 . Additionally, we study the sensitivity of observables on effects from nuclear modification of parton distribution functions, vacuum-like emissions in the plasma, and the time of the onset of the quenching. All calculations are compared with recently measured data.publishedVersio

Non-Fermi liquid correction to the neutrino mean free path and emissivity in neutron star beyond the leading order

In this work we have derived the expressions of the mean free path (MFP) and emissivity of the neutrinos by incorporating non-Fermi liquid (NFL) corrections upto next to leading order (NLO). We have shown how such corrections affect the cooling of the neutron star composed of quark matter core.Comment: Published in the Proceedings of the International Conference on Recent Trends in Nuclear Physics-2012, Indi

Medium-induced cascade in expanding media

Detailed insight into the interplay between parton energy loss and the way deconfined medium created in heavy-ion collisions expands is of great importance for improving the understanding of the jet quenching phenomenon. In this paper we study the impact of the expansion of deconfined medium on the single-gluon emission spectrum, its resummation and the jet suppression factor (QAA) within the BDMPS-Z formalism. We calculate these quantities for three types of expansion scenarios, namely static, exponentially decaying and Bjorken expanding media. The distribution of medium-induced gluons is calculated using an evolution equation with splitting kernels derived from the gluon emission spectra. A universal behavior of splitting kernels is derived in the regime of soft gluon emissions when evaluated at a common effective evolution time τeff. Novel scaling features of the resulting gluon distribution and jet QAA are discussed. For realistic spectra valid beyond the soft-gluon emission limit, where the results are obtained by a numerical solution of the evolution equation, these features are partially replaced by a scaling expected from considering an averaged jet quenching parameter along the trajectory of propagation. Further we show that differences arising from different types of the medium expansion can be to a large extent scaled out by appropriate choice of the quenching parameter. Sizable differences among the values of the quenching parameter for different types of medium expansion point to the importance of the medium expansion for precise modeling of the jet quenching phenomenon.publishedVersio