Generalized scaling of the transverse mass spectrum at the Relativistic Heavy-Ion Collider
Jurgen Schaffner-Bielich, Dmitri Kharzeev, Larry McLerran, Raju Venugopalan
TL;DR
The paper提出s a generalized $m_t$-scaling for identified hadron spectra in AuAu collisions at RHIC, grounded in Color Glass Condensate and gluon saturation concepts. It introduces a universal function f(m_t/p_s) modulated by species-dependent factors and shows that spectra across centralities collapse onto a common curve when scaled by $p_s$ and σ, with $p_s$ and σ themselves scaling with centrality in a manner consistent with CGC expectations. The work connects the scaling of transverse mass spectra to multiplicity and centrality, providing quantitative fits to RHIC data and offering a framework to interpret mean $p_t$ growth and centrality trends through saturation physics. It also discusses potential deviations due to radial flow, especially near threshold, and situates the findings within broader SPS and Tevatron observations.
Abstract
We argue that the transverse mass spectra of identified hadrons as measured in gold-gold collisions at BNL's Relativistic Heavy-Ion Collider (RHIC) follows a generalized scaling law. Such a scaling behavior is motivated by the idea of a Color Glass Condensate, or more generally, saturation of the gluon density. In particular, we describe the shapes of transverse mass spectra as a function of centrality. This scaling of the transverse mass spectrum is shown to be consistent with previously observed scaling of multiplicity with centrality.