Conservation Laws and the Multiplicity Evolution of Spectra at the Relativistic Heavy Ion Collider

Abstract

Transverse momentum distributions in ultra-relativistic heavy ion collisions carry considerable information about the dynamics of the hot system produced. Direct comparison with the same spectra from $p+p$ collisions has proven invaluable to identify novel features associated with the larger system, in particular, the "jet quenching" at high momentum and apparently much stronger collective flow dominating the spectral shape at low momentum. We point out possible hazards of ignoring conservation laws in the comparison of high- and low-multiplicity final states. We argue that the effects of energy and momentum conservation actually dominate many of the observed systematics, and that $p+p$ collisions may be much more similar to heavy ion collisions than generally thought.

15 pages, 14 figures, submitted to PRC; Figures 2,4,5,6,12 updated, Tables 1 and 3 added, typo in Tab.V fixed, appendix B partially rephrased, minor typo in Eq.B1 fixed, minor wording; references added

References in corpus (8)

• Hydrodynamic Models for Heavy Ion Collisions
• Recent results in relativistic heavy ion collisions: from ``a new state of matter'' to "the perfect fluid"
• The multiplicity dependence of inclusive $p_t$ spectra from p-p collisions at $\sqrt{s}$ = 200 GeV
• What Do Electromagnetic Plasmas Tell Us about Quark-Gluon Plasma?
• Global Conservation Laws and Femtoscopy of Small Systems
• The microcanonical ensemble of the ideal relativistic quantum gas with angular momentum conservation
• Momentum conservation and correlation analyses in heavy-ion collisions at ultrarelativistic energies
• Canonical suppression in microscopic transport models

Cited by in corpus (8)

• Azimuthal correlations from transverse momentum conservation and possible local parity violation
• Elliptic flow in proton-proton collisions at 7 TeV
• Rapid hydrodynamic expansion in relativistic heavy-ion collisions
• Interplay of the emission from thermal and direct sources in relativistic heavy ion collisions
• Elliptic flow coefficients from transverse momentum conservation
• Utilizing maximum likelihood estimator for flow analysis
• Multiparticle azimuthal cumulants from transverse momentum conservation and collective flow
• Effect of transverse momentum conservation and flow on symmetric cumulants $s{c}_{2,3}\left\{4\right\}$ and $s{c}_{2,3,4}\left\{6\right\}$