Diquark interactions in quark–gluon plasma and their role in diquark stars

Abstract

Within the framework of the constituent quark model and a generalized Pauli principle, the diquark interaction energies in quark–gluon plasma are explicitly calculated. In particular, two-diquark interaction energies are computed using ϕ4-terms in the effective Lagrangian in the spirit of the Donoghue and Sateesh model (1988 Phys. Rev. D 38 360). We also account for the extended character of the diquark. These results are used to determine the coupling strengths for a variety of colour–spin two-diquark states. Equations of state for the diquark matter for a variety of cases are derived and subsequently the Tolman–Oppenheimer–Volkoff equations for the masses and radii of diquark stars are solved. In this work, we restrict ourselves to the study of only the non-strange version of diquarks.

Isospin breaking from diquark clustering

“…The range of the correlation r corr = √ 12/β is 0.867 fm for β = 4 fm −1 , 0.433 fm for β = 8 fm −1 and 0.289 fm for β = 12 fm −1 compared with 0.27 fm from Bloch et al [7], 0.32 fm from Carlson, Kogut and Pandharipande [9], 0.21 fm from Sisodiya et al [144], and 0.24 fm from Keiner [28].…”

Introduction to Quark-Gluon plasma

“…Apart from QGP the diquark systems are also very important in study of neutron stars and quark stars. Recently Sisodiya, Kaushal, Parashar, and Bhasin [86] have calculated the diquark interaction energies for all color-spin state configurations in the so called diquark gluon plasma within the framework of the constituent quark model and a generalized Pauli principle. In this work, they have restricted to the study of only the non-strange version of diquarks.…”

Strange diquark stars within the framework of an effective phi4theory

“…Also, this shows that strange quarks and antiquarks produced by pair of gluons in the plasma, in fact, lead to the formation of a relatively large number of composite particles containing one or more strange quarks during the subsequent hadronization process. In the context of non-strange hadronic matter, a possibility of the existence of an intermediate phase consisting of quarks, diquarks and gluons, has been the subject of the study of several authors [34][35][36][37][38][39][40] in the recent past. In particular, a preliminary investigation to find out the range of densities in which quark matter could exist in the form of diquark-clusters as primary constituent was carried out by Donoghue and Sateesh (DS) [34].…”

“…In particular, a preliminary investigation to find out the range of densities in which quark matter could exist in the form of diquark-clusters as primary constituent was carried out by Donoghue and Sateesh (DS) [34]. The study was later pursued by Kastor and Traschen (KT) [35] and followed by several other authors [36][37][38][39][40]. The approach suggested by DS, although inspired by the P-matrix method of Jaffe and Low [41], is essentially based on an effective φ 4 theory for diquarks.…”

“…In the present work, in addition to SQM and SQGP, we shall explore the possibility of existence of strange diquark matter and an intermediate phase consisting of strange diquark-quark-gluon plasma. Recently, within the framework suggested by DS, we have studied [39,40] the diquark-diquark (dq-dq) interaction energies in a very general manner using the constituent quark model and a generalized Pauli principle. In this work, we account for all the possible colour-spin states {C, S} of the diquark such as { 3, 0}, { 3, 1}, {6, 0} and {6, 1}, rather than restricting merely to the { 3, 0} diquark state as considered by DS [34].…”