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

Abstract

Two-particle angular correlations were measured in pp collisions at √ 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 anticorrelation 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.

p−p, p−Λ , and Λ−Λ correlations studied via femtoscopy in <

“…PYTHIA also shows the same nonfemtoscopic correlation for larger k * but fails to reproduce quantitatively the behavior shown in Fig. 2, as already observed for the angular correlation of baryon-baryon and antibaryon-antibaryon pairs [58].…”

“…To enhance the number of protons produced at the primary vertex, a selection is imposed on the distance of closest approach (DCA) in both beam (z) and transverse (xy) directions. In order to minimize the fraction of protons originating from the interaction of primary particles with the detector material, a low transverse momentum cutoff is applied [58]. At high p T a cutoff is introduced to ensure the purity of the proton sample, as the purity drops below 80% for larger p T due to the decreasing separation power of the combined TPC and TOF particle identification.…”

Simulation studies of R2(Δη,Δφ) and P2(Sahoo1, Nandi2, Pujahari3 et al. 2019Phys. Rev. C6040View full textAdd to dashboardCite

“…Two-and multi-particle azimuthal correlations functions have provided evidence for the existence of anisotropic flow in A-A collisions [1][2][3][4][5][6][7], quark scaling (approximate) of flow coefficients in A-A collisions at RHIC and LHC [8][9][10][11]. They were also used to investigate the presence of flow in smaller systems (e.g., p-A and high multiplicity pp collisions) [12][13][14][15][16][17]. Differential two-particle (number) correlation functions additionally enabled the discovery of jet quenching at RHIC [18,19] and its detailed characterization in A-A collisions at both RHIC and LHC [20].…”

A femtoscopic correlation analysis tool using the Schrödinger equation (CATS)

“…The production of such pairs is enhanced due to the intrinsic baryon number conservation and therefore shows a strong kinematic correlation which overlaps to the true femtoscopic signal in the final correlation function. Since these mini-jets are not present in the correlation function of B-B/B-B [17], those systems are well suited to study the final state interaction. The femtoscopic formalism includes the computation of the correlation function for a given source function and interaction potential [2] C(k) = S(r) | ψ k (r) | 2 d 3 r,…”