Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Acharya, U. A.*; 長谷川 勝一; 今井 憲一*; 佐甲 博之; 佐藤 進; 谷田 聖; PHENIX Collaboration*; 他365名*
Physical Review C, 106(1), p.014908_1 - 014908_13, 2022/07
被引用回数:6 パーセンタイル:65.93(Physics, Nuclear)Small nuclear collisions are mainly sensitive to cold-nuclear-matter effects; however, the collective behavior observed in these collisions shows a hint of hot-nuclear-matter effects. The identified-particle spectra, especially the mesons which contain strange and antistrange quarks and have a relatively small hadronic-interaction cross section, are a good tool to study these effects. The PHENIX experiment has measured
mesons in a specific set of small collision systems
Al,
Au, and
He
Au, as well as
Au, at
GeV. The transverse-momentum spectra and nuclear-modification factors are presented and compared to theoretical-model predictions. The comparisons with different calculations suggest that quark-gluon plasma may be formed in these small collision systems at
GeV. However, the volume and the lifetime of the produced medium may be insufficient for observing strangeness-enhancement and jet-quenching effects. Comparison with calculations suggests that the main production mechanisms of
mesons at midrapidity may be different in
Al versus
He
Au collisions at
GeV. While thermal quark recombination seems to dominate in
He
Au collisions, fragmentation seems to be the main production mechanism in
Al collisions.
橋本 直*; 谷田 聖; J-PARC E15 Collaboration*; 他65名*
Progress of Theoretical and Experimental Physics (Internet), 2015(6), p.061D01_1 - 061D01_11, 2015/06
被引用回数:35 パーセンタイル:83.22(Physics, Multidisciplinary)An experiment to search for the bound state was performed via the in-flight
reaction using
kaons at 1 GeV/
at the J-PARC hadron experimental facility. In the semi-inclusive neutron missing-mass spectrum at
, no significant peak was observed in the region corresponding to
binding energy larger than 80 MeV, where a bump structure has been reported in the
final state in different reactions. Assuming the state to be isotropically decaying into
, mass-dependent upper limits on the production cross section were determined to be 30-180, 70-250, and 100-270
b/sr, for the natural widths of 20, 60, and 100 MeV, respectively, at 95% confidence level.