English

Constituent quarks and systematic errors in mid-rapidity charged multiplicity $dN_{\rm ch}/d\eta$ distributions

Nuclear Experiment 2018-01-19 v1

Abstract

Centrality definition in A++A collisions at colliders such as RHIC and LHC suffers from a correlated systematic uncertainty caused by the efficiency of detecting a p++p collision (50±5%50\pm 5\% for PHENIX at RHIC). In A++A collisions where centrality is measured by the number of nucleon collisions, NcollN_{\rm coll}, or the number of nucleon participants, NpartN_{\rm part}, or the number of constituent quark participants, NqpN_{\rm qp}, the error in the efficiency of the primary interaction trigger (Beam-Beam Counters) for a p++p collision leads to a correlated systematic uncertainty in NpartN_{\rm part}, NcollN_{\rm coll} or NqpN_{\rm qp} which reduces binomially as the A++A collisions become more central. If this is not correctly accounted for in projections of A++A to p++p collisions, then mistaken conclusions can result. A recent example is presented in whether the mid-rapidity charged multiplicity per constituent quark participant (dNch/dη)/Nqp({dN_{\rm ch}/d\eta})/{N_{\rm qp}} in Au++Au at RHIC was the same as the value in p++p collisions.

Keywords

Cite

@article{arxiv.1801.06063,
  title  = {Constituent quarks and systematic errors in mid-rapidity charged multiplicity $dN_{\rm ch}/d\eta$ distributions},
  author = {M. J. Tannenbaum},
  journal= {arXiv preprint arXiv:1801.06063},
  year   = {2018}
}

Comments

12 pages, 10 figures. arXiv admin note: text overlap with arXiv:1705.07925

R2 v1 2026-06-22T23:48:53.020Z