Enhanced production of charged over neutral kaons in Ar+Sc collisions measured by NA61/SHINE at CERN SPS

2025/10/30 by T. Matulewicz, Matulewicz, Tomasz
Physics and Astronomy · #FOS: Physical sciences #High-Energy Particle Collisions Research #Nuclear Experiment (nucl-ex) #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions

paper · pdf · doi:10.48550/arxiv.2510.26846

openalex publication_date 2025/10/30 · openalex created_date 2025/11/05 · openalex updated_date 2026/07/28

Abstract

The isospin symmetry, originating from similar masses of u and d quarks, if exact would result in equal numbers of charged (K⁺ and K^-) and neutral (K⁰ and K⁰) mesons produced in collisions of isospin-symmetric atomic nuclei. The charged and neutral K meson production in Ar+Sc collisions at a center-of-mass energy of 11.9 GeV per nucleon pair was measured by the NA61/SHINE Collaboration. The production of charged K mesons at mid-rapidity is (18.4±6.1)% higher than that of the neutral K mesons.The models of hadron production, including known isospin-symmetry breaking effects, cannot explain the measurements.

Citations

• Evidence of isospin-symmetry violation in high-energy collisions of atomic nuclei

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