Neutral pion number fluctuations

TL;DR

This paper reports measurements of neutral pion number fluctuations in proton interactions, revealing a sharp increase in fluctuations at high multiplicities that may indicate Bose-Einstein condensate formation.

Contribution

First measurement of neutral pion fluctuations in proton interactions at U-70, including corrections and analysis of multiplicity distributions.

Findings

Sharp growth of fluctuations at multiplicities > 22

Potential indication of Bose-Einstein condensate formation

Use of electromagnetic calorimeter for $b1^0$ reconstruction

Abstract

Neutral pion number fluctuations have been measured in proton interactions at U-70 accelerator (IHEP, Protvino). The experiment is carried out on the SVD-2 setup. Charged and neutral particles are registered simultaneously. The reconstruction of $\pi ^0$-mesons is fulfilled by means of observed gamma quanta at the electromagnetic calorimeter. The corrections on the setup acceptance, triggering, efficiencies of detectors and the reconstruction algorithm are included. The multiplicity distributions of the neutral pions have permitted to define the scaled variance, $\omega $, for $\pi ^0$-mesons. The revealed sharp growth of fluctuations of the neutral pion number at total meson multiplicities more than 22 can indicate the Bose-Einstein condensate formation.