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Márton I. Nagy

Publications and source records attributed to Márton I. Nagy.

2 recordsLinked to original sources

A self-consistent calculation of non-spherical Bose-Einstein correlation functions with Coulomb final-state interaction

Particle correlations and femtoscopy are a rich subfield of high-energy physics. As the experimental data become more precise, there is an increasing need for the theoretical calculations to provide better and more general descriptions of the measurements. One of the important new directions is the investigation of the precise shape of the Bose-Einstein correlation functions utilizing Lévy-stable distributions. This work is a direct follow-up to our previous study, in which we developed a novel method for calculating Bose-Einstein correlation functions including the Coulomb final-state interaction. In this paper, we present a self-consistent generalization of the previous approach to non-spherical source functions and investigate the validity of the previously applied approximations assuming spherical symmetry. We present a software package that includes the calculation of a fully three-dimensional correlation function including the Coulomb interaction.

nucl-th↗

Multi-dimensional investigation of the pion pair-source in heavy-ion collisions with EPOS

The purpose of femtoscopy is to unveil the space-time characteristics of heavy-ion collisions as mirrored in the correlation function of identical particles. We aim to augment such research by investigating the source function of particle creation based on a modern event generator, the EPOS package. It simulates high energy nuclear collisions and is proven to reliably reproduce the characteristics of real collisions. The source function has been almost always assumed to be Gaussian, but lately it is experimentally found that Lévy-stable distributions provide a much more acceptable description. This paper focuses on the source shape that is reconstructed in a femtoscopic measurement, in particular, the event-by-event geometry as well as the deviation from spherical symmetry of the source in the EPOS simulation. Such an investigation tests some scenarios of the appearance of non-Gaussian source functions. We find that in such a realistic simulation, non-Gaussian sources indeed appear, even in a three-dimensional setting and without event averaging. However, our reconstructed Lévy exponent (responsible for the long-range behavior of the source) is systematically larger than that observed in experiment; a discrepancy that might hint at further significance of this exponent.

hep-ph↗