Detecting quantum fluctuations of multiplicity

TL;DR

The paper addresses detecting quantum fluctuations of multiplicity in hadron collisions at finite energies, arguing that two sources—impact-parameter fluctuations and intrinsic quantum fluctuations at fixed $b$—compete, with reflective scattering increasingly amplifying the quantum component. It proposes a decomposition $\delta n = \delta_b n + \delta_q n$ and shows that in the reflective regime $\delta_b n$ vanishes asymptotically, leaving $\delta_q n$ as the dominant contribution; it relates $P_n(s)$ to $P_n(s,b)$ via $P_n(s) \approx P_n(s,b)|_{b=R(s)}$ where $R(s) \approx \ln s$. For experimental access, the work suggests measuring the forward-backward multiplicity difference $\Delta = n_F - n_B$ through the distribution $P_{\Delta}(s)$ and combining centrality-resolved multiplicity data with unitarity-based relations, drawing parallels to quantum-optics-inspired distributions and constraining the nature of quantum fluctuations in multiparticle production.

Abstract

Transition to the reflective scattering mode results in the increasing role of the multiplicity fluctuations of quantum origin and its asymptotic dominance. We note here the feasibility to experimentally detect presence of quantum fluctuations of multiplicity at finite energies.