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Insight into particle production mechanisms via angular correlations of identified particles in pp collisions at \(\sqrt{\mathrm{s}}=7\) TeV

An Erratum to this article was published on 10 December 2019

This article has been updated

A preprint version of the article is available at arXiv.


Two-particle angular correlations were measured in pp collisions at \(\sqrt{s} = 7\) TeV for pions, kaons, protons, and lambdas, for all particle/anti-particle combinations in the pair. Data for mesons exhibit an expected peak dominated by effects associated with mini-jets and are well reproduced by general purpose Monte Carlo generators. However, for baryon–baryon and anti-baryon–anti-baryon pairs, where both particles have the same baryon number, a near-side anti-correlation structure is observed instead of a peak. This effect is interpreted in the context of baryon production mechanisms in the fragmentation process. It currently presents a challenge to Monte Carlo models and its origin remains an open question.


Ultrarelativistic proton–proton collisions at the Large Hadron Collider (LHC) provide a unique opportunity to study Quantum Chromodynamics (QCD) at new energy scales. Two-particle angular correlations [