TY - JOUR
T1 - First Observation of an Attractive Interaction between a Proton and a Cascade Baryon
AU - Acharya, S.
AU - Adamova, D.
AU - Adhya, SP
AU - Adler, A.
AU - Adolfsson, J
AU - Aggarwal, MM.
AU - Rinella, G.A.
AU - Agnello, Maria
AU - Agrawal, N.
AU - Ahammed, Z.
AU - Bearden, Ian
AU - Bilandzic, Ante
AU - Bourjau, Christian Alexander
AU - rtc312, rtc312
AU - Pacik, Vojtech
AU - Gaardhøje, Jens Jørgen
AU - bsm989, bsm989
AU - Nielsen, Børge Svane
AU - Gajdosova, Katarina
AU - Zhou, You
AU - Thoresen, Freja
AU - Vislavicius, Vytautas
AU - Schukraft, Jürgen
AU - Pierre, Richert
AU - Alice Collaboration
PY - 2019/9/13
Y1 - 2019/9/13
N2 - This Letter presents the first experimental observation of the attractive strong interaction between a proton and a multistrange baryon (hyperon) Ξ-. The result is extracted from two-particle correlations of combined p-Ξ-S.p-Ξ+ pairs measured in p-Pb collisions at sNN=5.02 TeV at the LHC with ALICE. The measured correlation function is compared with the prediction obtained assuming only an attractive Coulomb interaction and a standard deviation in the range [3.6, 5.3] is found. Since the measured p-Ξ-S.p-Ξ+ correlation is significantly enhanced with respect to the Coulomb prediction, the presence of an additional, strong, attractive interaction is evident. The data are compatible with recent lattice calculations by the HAL-QCD Collaboration, with a standard deviation in the range [1.8, 3.7]. The lattice potential predicts a shallow repulsive Ξ-interaction within pure neutron matter and this implies stiffer equations of state for neutron-rich matter including hyperons. Implications of the strong interaction for the modeling of neutron stars are discussed.
AB - This Letter presents the first experimental observation of the attractive strong interaction between a proton and a multistrange baryon (hyperon) Ξ-. The result is extracted from two-particle correlations of combined p-Ξ-S.p-Ξ+ pairs measured in p-Pb collisions at sNN=5.02 TeV at the LHC with ALICE. The measured correlation function is compared with the prediction obtained assuming only an attractive Coulomb interaction and a standard deviation in the range [3.6, 5.3] is found. Since the measured p-Ξ-S.p-Ξ+ correlation is significantly enhanced with respect to the Coulomb prediction, the presence of an additional, strong, attractive interaction is evident. The data are compatible with recent lattice calculations by the HAL-QCD Collaboration, with a standard deviation in the range [1.8, 3.7]. The lattice potential predicts a shallow repulsive Ξ-interaction within pure neutron matter and this implies stiffer equations of state for neutron-rich matter including hyperons. Implications of the strong interaction for the modeling of neutron stars are discussed.
U2 - 10.1103/PhysRevLett.123.112002
DO - 10.1103/PhysRevLett.123.112002
M3 - Journal article
C2 - 31573229
SN - 0031-9007
VL - 123
JO - Physical Review Letters
JF - Physical Review Letters
IS - 11
M1 - 112002
ER -