Observation of Directed Flow of Hypernuclei Λ3H and Λ4H in √sNN=3 GeV Au + Au Collisions at RHIC

作者：Aboona, B. E.; Adam, J.; Adams, J. R.; Agakishiev, G.; Aggarwal, I.; Aggarwal, M. M.; Ahammed, Z.; Aitbaev, A.; Alekseev, I.; Anderson, D. M.; Aparin, A.; Atchison, J.; Averichev, G. S.; Bairathi, V.; Baker, W.; Cap, J. G. Ball; Barish, K.; Bhagat, P.; Bhasin, A.; Bhatta, S.; Bordyuzhin, I. G.; Brandenburg, J. D.; Brandin, A. V.; Cai, X. Z.; Caines, H.; Sanchez, M. Calderon de la Barca; Cebra, D.; Ceska, J.; Chakaberia, I.; Chan, B. K.; Chang, Z.; Chen, D.; Chen, J.; Chen, J. H.; Chen, Z.

来源：Physical Review Letters, 2023, 130(21): 212301.

DOI：10.1103/PhysRevLett.130.212301

• BEAM-ENERGY DEPENDENCE
• AZIMUTHAL ANISOTROPY
• COLLISIONS
• LAMBDA

We report here the first observation of directed flow (v(1)) of the hypernuclei H-3(Lambda) and H-3(Lambda) in mid-central Au + Au collisions at root s(NN) 1/4 3 GeV at RHIC. These data are taken as part of the beam energy sNN scan program carried out by the STAR experiment. From 165 x 10(6) events in 5%-40% centrality, about 8400 H-3(Lambda) and 5200 H-4(Lambda) candidates are reconstructed through two- and three-body decay channels. We observe that these hypernuclei exhibit significant directed flow. Comparing to that of light nuclei, it is found that the midrapidity v(1) slopes of H-3(Lambda) and (4)(Lambda)AH follow baryon number scaling, implying that the coalescence is the dominant mechanism for these hypernuclei production in the 3 GeV Au + Au collisions.