Event topology and multiplicity dependence of K*(892)± meson production in Proton+Proton collisions with ALICE at the LHC and exploring the possibility of a thermalized medium formation in small systems

Abstract

The main goal of ultra-relativistic heavy-ion collisions is to create and char acterize quark-gluon plasma (QGP). It is a deconfined state of quarks and gluons that can be realized at high density and temperature. The existence of QGP was predicted by quantum chromodynamics. Such a state of matter is expected to exist microseconds after the Big Bang. Thus the study of its properties and evo lution could give a better understanding of the existence of matter in the present universe. In the laboratory, QGP is expected to be formed by the collisions of heavy ions using particle colliders. Relativistic Heavy Ion Collider (RHIC) and Large Hadron Collider (LHC) are the dedicated state-of-the-art experimental fa cilities to this end and are focussed on understanding the properties of QGP. In central heavy-ion collisions, a large number of particles are produced through the multiple interactions of participants in the overlap region. Although most of the observed particles produced in such collisions are results of the fragmentations of pieces of the colliding nuclei, a considerable amount of particle creation occurs by high incident energies (⇡ TeV). While the particles created are mostly pions, the production of relatively heavy particles than pions and heavy flavor (strange and charm) quark matter also takes place. However, in pp collisions, it was expected that the final state particles are only the result of the fragmentations of pieces of the two protons. And hence, historically, the proton on proton (pp) collisions were considered a baseline for forming QGP in heavy-ion collisions due to their significantly smaller size compared to the studying later. Recent observation of heavy-ion-like features in a small systems like pp collisions from the experiment at the LHC has generated considerable interest in the scientific community. For example, the discovery of collective-like phenomena, strangeness enhancement are a few among them. These developments have significant consequences on the results obtained from heavy-ion collisions, as pp collisions have been used as a benchmark for heavy-ion collisions to understand a possible medium formation.