Year: 2024
Type: article
Abstract: It has been traditionally hypothesized that the heavy quark (charm c and bottom b ) fragmentation is universal across different collision systems, based on the notion that hadronization as a soft process should occur at the characteristic nonperturbative quantum chromodynamics (QCD) scale, Λ Q C D . However, this universality hypothesis has recently been challenged by the observation that the c - and b -baryon production relative to their meson counterparts in minimum bias proton-proton ( p p ) collisions at the CERN Large Hadron Collider (LHC) energies is significantly enhanced as compared to the electron-positron ( e + e − ) collisions. The conception of nonuniversality is unambiguously reinforced by the latest measurement of the charged-particle multiplicity dependence of the b -baryon–to–meson yield ratio, Λ b / B , by the LHCb experiment in s = 13 TeV p p collisions at the LHC, evolving continuously from the saturation value in minimum bias p p collisions toward the small value in e + e − collisions as the system size gradually reduces. We address the multiplicity dependence of b -baryon production in the canonical statistical hadronization model with input b -hadron spectrum augmented with many hitherto unobserved states from quark model predictions. We demonstrate that the decreasing trend of the Λ b / B toward low multiplicities can be quantitatively understood from the canonical suppression on the yield of Λ b , as caused by the requirement of strict conservation of baryon number in sufficiently small systems. We have therefore proposed a plausible scenario for understanding the origin of the nonuniversality of heavy quark fragmentation in elementary collisions. Published by the American Physical Society 2024
Source: Physical Review C
Authors: Yuxuan Dai, Shouxing Zhao, Min He
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: hybrid
Awards: G3030300266, G6827809544
OpenAlex ID: W4402361770