Sequential Y(nS) suppression in high-multiplicity pp collisions: the experimental case for an early, globally correlated medium
Abstract
The multiplicity-dependent suppression of states measured by CMS in at TeV \cite{CMS2020}, and of measured by LHCb at 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 \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