Insight into particle production mechanisms via angular correlations of identified particles measured with ALICE in pp collisions at $\mathbf{\sqrt{\textit s}}=7$ TeV

Abstract

Two-particle correlations as a function of $Δη$ and $Δφ$ are used in all collision systems to study a wide range of physical phenomena. Examples include the collective behavior of the quark-gluon plasma medium, jets, quantum statistics or Coulomb effects, conservation laws, and resonance decays. In this work, measurements of the correlations of identified particles and their antiparticles (for $π$, K, p, $Λ$) are reported in pp collisions at $\sqrt{s}=7$ TeV at low transverse momenta. The analysis reveals differences in particle production between baryons and mesons. The correlation functions for mesons exhibit the expected peak dominated by effects of mini-jet fragmentation and are reproduced well by general purpose Monte Carlo generators. For baryon pairs where both particles have the same baryon number, a near-side anti-correlation structure is observed instead of a peak; our experimental observation present a challenge to the contemporary models (PYTHIA, PHOJET). This effect is further interpreted in the context of baryon production mechanisms in the fragmentation processes.