English

Sequential Y(nS) suppression in high-multiplicity pp collisions: the experimental case for an early, globally correlated medium

High Energy Physics - Phenomenology 2026-04-24 v2 High Energy Physics - Experiment

Abstract

The multiplicity-dependent suppression of Υ(nS)\Upsilon(n\mathrm{S}) states measured by CMS in pppp at s=7\sqrt s=7\,TeV \cite{CMS2020}, and of ψ(2S)/J/ψ\psi(2S)\big/J/\psi measured by LHCb at s=13\sqrt s=13\,TeV \cite{LHCb2024}, is subjected to four multi-differential tests: \emph{cone isolation}, \emph{azimuthal sectors}, \emph{transverse sphericity}, and \emph{prompt vs. non-prompt}. Cone and sphericity close a \emph{scissors constraint}: the local reading of the Comover Interaction Model is in tension with the cone data, its global reading with the sphericity data. The non-prompt flatness forces the mechanism to act at early proper times. None of the considered hadronic or string-based frameworks -- CIM local or global, PYTHIA 8 MPI \cite{Sjostrand2015}, rope hadronisation \cite{Bierlich2015}, CGC \cite{Ma2015}, Trainor TCM \cite{Trainor2008} -- naturally satisfies the four constraints simultaneously in its published form. The surviving class is an early, globally correlated medium consistent with partonic degrees of freedom, co-occurring with the ALICE strangeness enhancement \cite{ALICE_SE}, the long-range ridge \cite{CMS_ridge}, and below the threshold of the partonic baryon-meson v2v_2 \cite{ALICE_v2}, in a density window compatible with the Campanini \& Ferri equation of state \cite{Campanini2011}.

Keywords

Cite

@article{arxiv.2604.17657,
  title  = {Sequential Y(nS) suppression in high-multiplicity pp collisions: the experimental case for an early, globally correlated medium},
  author = {Renato Campanini},
  journal= {arXiv preprint arXiv:2604.17657},
  year   = {2026}
}

Comments

18 pages,8 figures.v2: significance values in the sphericity section replaced , Bjorken energy-density section replaced by a model-independent ; azimuthal-sector discussion extended to highlight the transverse sector as the most diagnostic; cone-isolation argument restated in model-independent form without Cornell radii. Physics arguments and experimental results unchanged