Correlated pion-proton pair emission off hot and dense QCD matter

0544737 - ÚJF 2022 RIV NL eng J - Journal Article
Adamczewski-Musch, J. - Arnold, O. - Behnke, C. - Belounnas, A. - Belyaev, A. - Berger-Chen, J. C. - Blanco, A. - Blume, C. - Chlad, Lukáš - Kugler, Andrej - Rodriguez Ramos, Pablo - Sobolev, Yuri, G. - Svoboda, Ondřej - Tlustý, Pavel - Wagner, Vladimír … Total 122 authors
Correlated pion-proton pair emission off hot and dense QCD matter.
Physics Letters. B. Roč. 819, AUG (2021), č. článku 136421. ISSN 0370-2693. E-ISSN 1873-2445
R&D Projects: GA MŠMT EF18_046/0016066; GA MŠMT LTT17003
Research Infrastructure: FAIR-CZ II - 90112
Institutional support: RVO:61389005
Keywords : HADES * Baryonic resonances * heavy-ion reactions
OECD category: Particles and field physics
Impact factor: 4.950, year: 2021
Method of publishing: Open access
https://doi.org/10.1016/j.physletb.2021.136421

In this letter we report the first multi-differential measurement of correlated pion-proton pairs from 2 billion Au+Au collisions at root(S)(NN) = 2.42 GeV collected with HADES. In this energy regime the population of Delta(1232) resonances plays an important role in the way energy is distributed between intrinsic excitation energy and kinetic energy of the hadrons in the fireball. The triple differential d(3)N/dM(pi +/- p)dp(T)dy distributions of correlated pi(+/-)p pairs have been determined by subtracting the pi p combinatorial background using an iterative method. The invariant-mass distributions in the Delta(1232) mass region show strong deviations from a Breit-Wigner function with vacuum width and mass. The yield of correlated pion-proton pairs exhibits a complex isospin, rapidity and transverse-momentum dependence. In the invariant mass range 1.1 < M-inv(GeV/c(2)) < 1.4, the yield is found to be similar for pi(+)p and pi(-)p pairs, and to follow a power law (A(part))(alpha), where (A(part)) is the mean number of participating nucleons. The exponent alpha depends strongly on the pair transverse momentum (p(T)) while its p(T)-integrated and charge-averaged value is alpha = 1.5 +/- 0.08(st) +/- 0.2(sy).
Permanent Link: http://hdl.handle.net/11104/0321560