Corrections to the Smoothness and On-Shell Approximations in Femtoscopy and Coalescence

Abstract

Relativistic heavy-ion collisions produce femtometer-scale sources whose space-time structure can be constrained using two-particle femtoscopic correlations. Standard implementations rely on the smoothness and on-shell approximations, which effectively remove the relative momentum dependence of the particle emission function. We explore the validity of these approximations by deriving model-independent expansions that quantify the leading corrections for femtoscopy and coalescence with arbitrary sources and final-state interactions. The resulting first- and second-order correction terms can be evaluated with essentially the same numerical complexity as the usual Koonin-Pratt expressions; for angle-averaged correlations the first-order contributions vanish by symmetry. We illustrate the framework with explicit calculations in a blast-wave source model; for blast-wave parameter sets representative of pp and PbPb fits at LHC energies, the corrections are at or below the percent level for pp correlations and deuteron coalescence. These corrections are potentially subdominant compared to other effects, for example, corrections to the equal time approximation.

arXiv comment3 figures

References in corpus (27)

• An accurate nucleon-nucleon potential with charge-independence breaking
• Heavy Ion Collisions: The Big Picture, and the Big Questions
• What RHIC Experiments and Theory tell us about Properties of Quark-Gluon Plasma ?
• Femtoscopy in Relativistic Heavy Ion Collisions: Two Decades of Progress
• Particle Interferometry for Relativistic Heavy-Ion Collisions
• Coalescence and flow in ultra-relativistic heavy ion collisions
• Production of charged pions, kaons and (anti-)protons in Pb-Pb and inelastic pp collisions at $\sqrt{s_{\mathrm{NN}}}$ = 5.02 TeV
• Production of light nuclei and anti-nuclei in pp and Pb-Pb collisions at LHC energies
• Two-Particle Correlations in Relativistic Heavy-Ion Collisions
• Pion, kaon, and proton production in central Pb-Pb Collisions at $\sqrt{s_{NN}}=2.76$ TeV
• Unveiling the strong interaction among hadrons at the LHC
• Study of the $\Lambda$-$\Lambda$ interaction with femtoscopy correlations in pp and p-Pb collisions at the LHC
• Search for a common baryon source in high-multiplicity pp collisions at the LHC
• Cosmic rays, anti-helium, and an old navy spotlight
• A femtoscopic Correlation Analysis Tool using the Schrödinger equation (CATS)
• Finite-size effect on two-particle production in continuous and discrete spectrum
• Model Independent Features of the Two-Particle Correlation Function
• Production of light nuclei in the thermal and coalescence models
• HBT Correlators -- Current Formalism vs. Wigner Function Formulation
• Nuclear coalescence from correlation functions
• On coalescence as the origin of nuclei in hadronic collisions
• Final state interactions in two-particle interferometry
• Towards the understanding of the genuine three-body interaction for p$-$p$-$p and p$-$p$-\Lambda$
• Femtoscopy with Lévy sources from SPS through RHIC to LHC
• Can one extract source radii from transport theories?
• An Inconsistency in the Simulation of Bose-Einstein Correlations
• Can the strong interactions between hadrons be determined using femtoscopy?