Possibility of formation of a disoriented chiral condensate in $pp$ collisions at energies available at the CERN Large Hadron Collider via the reaction-diffusion equation

Possibility of formation of a disoriented chiral condensate in $p p$ collisions at energies available at the CERN Large Hadron Collider via the reaction-diffusion equation

Partha Bagchi, Arpan Das, Srikumar Sengupta, and Ajit M. Srivastava

Phys. Rev. C 93, 024914 – Published 24 February 2016

Abstract

There are indications of formation of a thermalized medium in high multiplicity $p p$ collisions at energies available at the CERN Large Hadron Collider. It is possible that such a medium may reach high enough energy density and temperature that a transient stage of quark-gluon plasma, where chiral symmetry is restored, may be achieved. Due to rapid three-dimensional expansion, the system will quickly cool, undergoing a spontaneous chiral symmetry breaking transition. We study the dynamics of the chiral field, after the symmetry breaking transition, for such an event using a reaction-diffusion equation approach which we have recently applied for studying QCD transitions in relativistic heavy-ion collisions. We show that the interior of such a rapidly expanding system is likely to lead to the formation of a single large domain of disoriented chiral condensate (DCC), which has been a subject of intensive search in earlier experiments. We argue that large multiplicity $p p$ collisions naturally give rise to required boundary conditions for the existence of slowly propagating front solutions of the reaction-diffusion equation with resulting dynamics of the chiral field leading to the formation of a large DCC domain.