Multiplicity fluctuation analysis of target residues in nucleus-emulsion collisions at a few hundred MeV/nucleon

TL;DR

This study investigates target residue multiplicity fluctuations in nucleus-emulsion collisions at hundreds of MeV/nucleon using scaled factorial moments, finding no evidence of non-statistical fluctuations and attributing observed variations to density distribution effects.

Contribution

It applies scaled factorial moment analysis in both normal and cumulative spaces to identify the nature of multiplicity fluctuations in nucleus-emulsion collisions.

Findings

No evidence of non-statistical multiplicity fluctuations.

Fluctuations are caused by non-uniformity of single-particle density.

Normal space analysis shows linear increase of ln<Fq> with lnM at low q.

Abstract

Multiplicity fluctuation of the target evaporated fragments emitted in 290 A MeV 12C-AgBr, 400 A MeV 12C-AgBr, 400 A MeV 20Ne-AgBr and 500 A MeV 56Fe-AgBr interactions is investigated using scaled factorial moment method in two-dimensional normal phase space and cumulative variable space, respectively. It is found that in normal phase space the scaled factorial moment (ln<Fq>) increases linearly with increase of the divided number of phase space (lnM) for lower q-value and increases linearly with the increase of lnM and then becomes saturated or decreased for higher q-value, in cumulative variable space ln<Fq> decreases linearly with increase of lnM, which indicates that no evidence of non-statistical multiplicity fluctuation is observed in our data sets. So any fluctuation indicated in the results of normal variable space analysis is totally caused by non-uniformity of single-particle density distribution.