Speaker
Description
On behalf of the HADES and CBM collaborations.
Hyperons, baryons containing at least one strange quark, are pivotal to advancing our understanding of matter under extreme conditions. They are hypothesized to play a crucial role in the dense cores of neutron stars, where their emergence is expected at densities exceeding nuclear saturation. Among hyperons, Λ hyperons are of particular interest as they have been shown to significantly soften the equation of state (EoS) under the absence of strong repulsive two or three-body forces. This softening leads to pronounced effects on the maximum mass and radius of neutron stars, introducing discrepancies between observational data and theoretical predictions [1]. The so-called ”hyperon puzzle” is therefore a key topic in nuclear astrophysics. A deeper comprehension of QCD driven hyperon-hyperon interactions in extreme astrophysical environments is essential to address these challenges.
The study presented in this talk focuses on the production and interaction of Λ-Λ pairs, in the reaction channel pp → ΛΛK+K+, a doubly strange baryonic system, in proton-proton collisions at √s = 3.46 GeV at the High Acceptance Di-Electron Spectrometer (HADES) at GSI. As a foundational step, the near-threshold (at 0.24 GeV above the threshold in the CoM) production cross-section is determined. In this talk, I will detail the experimental methods, analysis procedure and preliminary results on the production cross-section.
Additionally, I will present recent studies on ΛΛ interaction signatures such as cusp formation based on simulation data from the Compressed Baryonic Matter (CBM) experiment at FAIR [2]. These complementary results offer valuable comparative insights into multi-strange baryon dynamics across different experimental platforms.
References
[1] D. Logoteta, I. Vidana, and I. Bombaci, “Impact of chiral hyperonic three-body forces on neutron stars,” The European Physical Journal A, vol. 55, no. 11, p. 207, 2019.
[2] X.-K. Dong, F.-K. Guo, B.-S. Zou, “Explaining the many threshold structures in the heavy-quark hadron spectrum”, Phys. Rev. Lett. 126 (15) (2021) 152001
