arXiv subjects

Sabiar Shaikh

Publications and source records attributed to Sabiar Shaikh.

4 recordsLinked to original sources

arXiv2026

Heavy hadron spectrum from 2+1+1 flavor MILC lattices

We study the mass spectra and various mass differences of heavy hadrons containing one or more bottom quarks using MILC's $N_f = 2+1+1$ HISQ gauge ensembles at three lattice spacings. For the valence quarks, we employ a combination of lattice actions: the NRQCD action is used for bottom quarks, the anisotropic Clover action for charm quarks, and the $O(a)$-improved Wilson--Clover action for strange and lighter (up/down) quarks. Heavy hadron operators with at least one bottom quark are constructed by considering all possible combinations with charm, strange, and light quarks corresponding to various quantum numbers.

hep-lat↗

arXiv2022

Confinement-deconfinement transition in $SU(3)$-Higgs theory

We study lattice cutoff effects on the confinement-deconfinement transition and the $Z_3$ symmetry in $SU(3)$-Higgs theory in $3+1$ dimensions. The Higgs in this study is a complex triplet with vanishing bare mass and quartic coupling. The lattice cutoff is regulated by varying the number of temporal lattice sites, $N_\tau$. Our results show that the nature of the confinement-deconfinement transition depends on $N_\tau$. For $N_\tau=2$ the transition is found to be the end point of a first-order transition and is first order for $N_\tau \ge 3$. The distributions of the Polyakov loop and other observables, sensitive to the $Z_3$ symmetry, show that the strength of $Z_3$ explicit breaking decreases with $N_\tau$. Up to $T\simeq 2T_c$, the free energy difference between $Z_3$ states decreases with $N_\tau$, suggesting the realization of $Z_3$ symmetry in the continuum limit.

hep-lat↗

arXiv2021

$Z_N$ symmetry in $SU(N)$ gauge theories

We study $Z_N$ symmetry in $SU(N)$ gauge theories in the presence of matter fields in the fundamental representation, by restricting the lattice partition function integration to matter fields which are uniform in spatial directions and gauge fields with vanishing spatial components. In this approximation the gauge matter field interaction effectively reduces to a 1-dimensional gauged chain. This makes analytical calculations of the matter field contribution to the Polyakov loop free energy possible. We show that in the limit of large number of temporal sites the explicit breaking of $Z_N$ symmetry in this free energy vanishes, driven by dominance of the density of states. We argue that the spatial links as well as the spatial modes of the matter fields determine the boundaries separating regions where $Z_N$ symmetry is realised from rest of the phase diagram.

hep-lat↗

arXiv2021

Confinement-Deconfinement transition and $Z_2$ symmetry in $Z_2+$Higgs theory

We study the Polyakov loop and the $Z_2$ symmetry in the lattice $Z_2+$Higgs theory in 4D Euclidean space using Monte Carlo simulations. The results show that this symmetry is realised in the Higgs symmetric phase for large number of temporal lattice sites. To understand the dependence on the number of temporal sites, we consider a one dimensional model by keeping terms of the original action corresponding to a single spatial site. In this approximation the partition function can be calculated exactly as a function of the Polyakov loop. The resulting free energy is found to have the $Z_2$ symmetry in the limit of large temporal sites. We argue that this is due to $Z_2$ invariance as well as dominance of the distribution or density of states corresponding to the action.

hep-lat↗