Chiral symmetry breaking, color superconductivity and color neutral quark matter: a variational approach

We investigate the vacuum realignment for chiral symmetry breaking and color superconductivity at finite density in Nambu-Jona-Lasinio model in a variational method. The treatment allows us to investigate simultaneous formation of condensates in quark antiquark as well as in diquark channels. The methodology involves an explicit construction of a variational ground state and minimisation of the thermodynamic potential. Color and electric charge neutrality conditions are imposed through introduction of appropriate chemical potentials. Color and flavor dependent condensate functions are determined through minimisation of the thermodynamic potential. The equation of state is calculated. Simultaneous existence of a mass gap and superconducting gap is seen in a small window of quark chemical potential within the model when charge neutrality conditions are not imposed. Enforcing color and electric charge neutrality conditions gives rise to existence of gapless superconducting modes depending upon the magnitude of the gap and the difference of the chemical potentials of the condensing quarks.Comment: 13 pages, 6 figures,to appear in Phys. Rev.

Whole-genome sequencing reveals host factors underlying critical COVID-19

Critical COVID-19 is caused by immune-mediated inflammatory lung injury. Host genetic variation influences the development of illness requiring critical care1 or hospitalization2,3,4 after infection with SARS-CoV-2. The GenOMICC (Genetics of Mortality in Critical Care) study enables the comparison of genomes from individuals who are critically ill with those of population controls to find underlying disease mechanisms. Here we use whole-genome sequencing in 7,491 critically ill individuals compared with 48,400 controls to discover and replicate 23 independent variants that significantly predispose to critical COVID-19. We identify 16 new independent associations, including variants within genes that are involved in interferon signalling (IL10RB and PLSCR1), leucocyte differentiation (BCL11A) and blood-type antigen secretor status (FUT2). Using transcriptome-wide association and colocalization to infer the effect of gene expression on disease severity, we find evidence that implicates multiple genes—including reduced expression of a membrane flippase (ATP11A), and increased expression of a mucin (MUC1)—in critical disease. Mendelian randomization provides evidence in support of causal roles for myeloid cell adhesion molecules (SELE, ICAM5 and CD209) and the coagulation factor F8, all of which are potentially druggable targets. Our results are broadly consistent with a multi-component model of COVID-19 pathophysiology, in which at least two distinct mechanisms can predispose to life-threatening disease: failure to control viral replication; or an enhanced tendency towards pulmonary inflammation and intravascular coagulation. We show that comparison between cases of critical illness and population controls is highly efficient for the detection of therapeutically relevant mechanisms of disease

Non-perturbative methods in quantum field theory

SIGLEAvailable from British Library Document Supply Centre- DSC:D60833 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Renormalization of the supersymmetric O(N) non-linear sigma model A superfield approach

SIGLEAvailable from British Library Document Supply Centre- DSC:9106.16(DAMTP--88/20) / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Chiral realisation in the chiral Gross-Neveu model

SIGLEAvailable from British Library Document Supply Centre- DSC:9106.16(DAMTP--88/23) / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Mass generation and renormalization of supersymmetric sigma models and some other two-dimensional theories

SIGLEAvailable from British Library Document Supply Centre- DSC:9106.16(DAMTP--87/26) / BLDSC - British Library Document Supply CentreGBUnited Kingdo