Exploring potential jet modification in small collision systems with two particle correlations at PHENIX

Abstract Systematic studies of charge-dependent two- and three-particle correlations in Pb-Pb collisions at $$ \sqrt{s_{\mathrm{NN}}} $$ s NN = 2.76 and 5.02 TeV used to probe the Chiral Magnetic Effect (CME) are presented. These measurements are performed for charged particles in the pseudorapidity (η) and transverse momentum (pT) ranges |η| < 0.8 and 0.2 < pT< 5 GeV/c. A significant charge-dependent signal that becomes more pronounced for peripheral collisions is reported for the CME-sensitive correlators γ1, 1 = 〈cos(φα + φβ − 2Ψ2)〉 and γ1, − 3 = 〈cos(φα − 3φβ + 2Ψ2)〉. The results are used to estimate the contribution of background effects, associated with local charge conservation coupled to anisotropic flow modulations, to measurements of the CME. A blast-wave parametrisation that incorporates local charge conservation tuned to reproduce the centrality dependent background effects is not able to fully describe the measured γ1,1. Finally, the charge and centrality dependence of mixed-harmonics three-particle correlations, of the form γ1, 2 = 〈cos(φα + 2φβ − 3Ψ3)〉, which are insensitive to the CME signal, verify again that background contributions dominate the measurement of γ1,1.

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Pair-correlation ansatz for the ground state of interacting bosons in an arbitrary one-dimensional potential

Scientific Reports ◽

10.1038/s41598-021-92556-7 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Przemysław Kościk ◽

Arkadiusz Kuroś ◽

Adam Pieprzycki ◽

Tomasz Sowiński

Keyword(s):

Boundary Conditions ◽

Ground State ◽

Pair Correlation ◽

Contact Interactions ◽

One Dimensional ◽

Particle Correlations ◽

Variational Scheme ◽

Full Control ◽

Arbitrary Shapes

AbstractWe derive and describe a very accurate variational scheme for the ground state of the system of a few ultra-cold bosons confined in one-dimensional traps of arbitrary shapes. It is based on assumption that all inter-particle correlations have two-body nature. By construction, the proposed ansatz is exact in the noninteracting limit, exactly encodes boundary conditions forced by contact interactions, and gives full control on accuracy in the limit of infinite repulsions. We show its efficiency in a whole range of intermediate interactions for different external potentials. Our results manifest that for generic non-parabolic potentials mutual correlations forced by interactions cannot be captured by distance-dependent functions.

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PROBING AWAY SIDE JET MODIFICATION WITH THREE PARTICLE CORRELATIONS

International Journal of Modern Physics E ◽

10.1142/s0218301307007337 ◽

2007 ◽

Vol 16 (07n08) ◽

pp. 1982-1987

Author(s):

◽

N. N. AJITANAND

Keyword(s):

Spatial Distribution ◽

Correlation Functions ◽

Theoretical Models ◽

The Other ◽

Experimental Investigations ◽

Powerful Method ◽

Particle Correlation ◽

Low Viscosity ◽

Jet Modification ◽

Rhic Data

Recent experimental investigations have focussed on the abnormal spatial distribution of away side jet fragments as signals of significant medium induced effects. A variety of theoretical models including recent string-theory based efforts have supported the notion of Mach Cone like effects in the low viscosity QGP fluid. However, the presence of significant flow fields may deflect the fragmentation direction producing a significantly differing type of jet topology from that of the Mach cone. Three particle correlation functions constitute a powerful method whereby the predominance of one or the other type of mechanism can be differentiated. In this work the use of such an approach will be demonstrated via simulations and the results of its application to RHIC data will be presented.

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