CERN Accelerating science

Preprint
Report number	arXiv:2402.05995 ; CERN-TH-2024-021
Title	The unexpected uses of a bowling pin: exploiting $^{20}$Ne isotopes for precision characterizations of collectivity in small systems
Author(s)	Giacalone, Giuliano (U. Heidelberg, ITP) ; Bally, Benjamin (IRFU, Saclay) ; Nijs, Govert (CERN) ; Shen, Shihang (IAS, Julich) ; Duguet, Thomas (IRFU, Saclay ; Leuven U.) ; Ebran, Jean-Paul (CEA DAM ; U. Paris-Saclay) ; Elhatisari, Serdar (Gaziantep U. ; Bonn U., HISKP ; U. Bonn, Phys. Inst., BCTP) ; Frosini, Mikael (CEA Cadarache) ; Lähde, Timo A. (IAS, Julich ; JCHP, Julich ; Unlisted, DE) ; Lee, Dean (Michigan State U.) ; Lu, Bing-Nan (GSCAEP, Beijing) ; Ma, Yuan-Zhuo (Michigan State U.) ; Meißner, Ulf-G. (Bonn U., HISKP ; U. Bonn, Phys. Inst., BCTP ; IAS, Julich ; JCHP, Julich ; Tbilisi State U.) ; Noronha-Hostler, Jacquelyn (Illinois U., Urbana) ; Plumberg, Christopher (Pepperdine U.) ; Rodríguez, Tomás R. (UCM, Madrid, Dept. Phys.) ; Roth, Robert (Darmstadt, Tech. U. ; Darmstadt, GSI) ; van der Schee, Wilke (CERN ; Utrecht U. (main) ; Nikhef, Amsterdam) ; Somà, Vittorio (IRFU, Saclay)
Imprint	2024-02-08
Number of pages	17
Note	17 pages, 14 figures. The Trajectum code can be found at https://sites.google.com/view/govertnijs/trajectum and plotting routines can be found at http://wilkevanderschee.nl/trajectum
Subject category	nucl-ex ; Nuclear Physics - Experiment ; hep-ph ; Particle Physics - Phenomenology ; nucl-th ; Nuclear Physics - Theory
Abstract	Whether or not femto-scale droplets of quark-gluon plasma (QGP) are formed in so-called small systems at high-energy colliders is a pressing question in the phenomenology of the strong interaction. For proton-proton or proton-nucleus collisions the answer is inconclusive due to the large theoretical uncertainties plaguing the description of these processes. While upcoming data on collisions of $^{16}$O nuclei may mitigate these uncertainties in the near future, here we demonstrate the unique possibilities offered by complementing $^{16}$O$^{16}$O data with collisions of $^{20}$Ne ions. We couple both NLEFT and PGCM ab initio descriptions of the structure of $^{20}$Ne and $^{16}$O to hydrodynamic simulations of $^{16}$O$^{16}$O and $^{20}$Ne$^{20}$Ne collisions at high energy. We isolate the imprints of the bowling-pin shape of $^{20}$Ne on the collective flow of hadrons, which can be used to perform quantitative tests of the hydrodynamic QGP paradigm. In particular, we predict that the elliptic flow of $^{20}$Ne$^{20}$Ne collisions is enhanced by as much as 1.170(8)$_{\rm stat.}$(30)$_{\rm syst.}$ for NLEFT and 1.139(6)$_{\rm stat.}$(39)$_{\rm syst.}$ for PGCM relative to $^{16}$O$^{16}$O collisions for the 1% most central events. At the same time, theoretical uncertainties largely cancel when studying relative variations of observables between two systems. This demonstrates a method based on experiments with two light-ion species for precision characterizations of the collective dynamics and its emergence in a small system.
Other source	Inspire
Copyright/License	preprint: (License: CC BY 4.0)