Measurement of the mass difference and the binding energy of the hypertriton and antihypertriton

0523917 - ÚJF 2021 RIV GB eng J - Journal Article
Adam, J. - Adamczyk, L. - Adams, J. R. - Adkins, J. K. - Agakishiev, G. - Bielčík, J. - Bielčíková, Jana - Chaloupka, P. - Federič, Pavol - Holub, L. - Kocan, M. - Kosarzewski, L. K. - Kramárik, L. - Líčeník, Robert - Moravcová, Z. - Rusňák, Jan - Šimko, Miroslav - Šumbera, Michal - Vaněk, Jan … Total 358 authors
Measurement of the mass difference and the binding energy of the hypertriton and antihypertriton.
Nature Physics. Roč. 16, č. 4 (2020), s. 409-412. ISSN 1745-2473. E-ISSN 1745-2481
R&D Projects: GA MŠMT LTT18002
Research Infrastructure: BNL-CZ II - 90109
Institutional support: RVO:61389005
Keywords : STAR collaboration * heavy ion experiments
OECD category: Nuclear physics
Impact factor: 20.034, year: 2020
Method of publishing: Limited access
https://doi.org/10.1038/s41567-020-0799-7

According to the CPT theorem, which states that the combined operation of charge conjugation, parity transformation and time reversal must be conserved, particles and their antiparticles should have the same mass and lifetime but opposite charge and magnetic moment. Here, we test CPT symmetry in a nucleus containing a strange quark, more specifically in the hypertriton. This hypernucleus is the lightest one yet discovered and consists of a proton, a neutron and a Lambda hyperon. With data recorded by the STAR detector at the Relativistic Heavy Ion Collider, we measure the Lambda hyperon binding energy B Lambda for the hypertriton, and find that it differs from the widely used value and from predictions, where the hypertriton is treated as a weakly bound system. Our results place stringent constraints on the hyperon-nucleon interaction and have implications for understanding neutron star interiors, where strange matter may be present. A precise comparison of the masses of the hypertriton and the antihypertriton allows us to test CPT symmetry in a nucleus with strangeness, and we observe no deviation from the expected exact symmetry.
Permanent Link: http://hdl.handle.net/11104/0308207