Angular decay coefficients of mesons at forward rapidity from collisions at GeV

Adare, A.*; 長谷川 勝一; 今井 憲一; 永宮 正治; 佐甲 博之; 佐藤 進; 谷田 聖; PHENIX Collaboration*; 他389名*

Physical Review D, 95(9), p.092003_1 - 092003_13, 2017/05

AA2017-0100.pdf:0.69MB

https://doi.org/10.1103/PhysRevD.95.092003

We report the first measurement of the full angular distribution for inclusive decays in collisions at GeV. The measurements are made for transverse momentum GeV/ and rapidity in the Helicity, Collins-Soper, and Gottfried-Jackson reference frames. In all frames the polar coefficient is strongly negative at low and becomes close to zero at high , while the azimuthal coefficient is close to zero at low , and becomes slightly negative at higher . The frame-independent coefficient is strongly negative at all in all frames. The data are compared to the theoretical predictions provided by nonrelativistic quantum chromodynamics models.