Measurements of at forward rapidity in collisions at GeV

Aidala, C.*; 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425名*

Physical Review D, 95(9), p.092002_1 - 092002_18, 2017/05

AA2017-0101.pdf:1.49MB

https://doi.org/10.1103/PhysRevD.95.092002

We report the first measurement of the fraction of mesons coming from -meson decay () in collisions at GeV. The measurement is performed using the forward silicon vertex detector and central vertex detector at PHENIX, which provide precise tracking and distance-of-closest-approach determinations, enabling the statistical separation of due to -meson decays from prompt . The measured value of is for with transverse momenta GeV/ and rapidity . The measured fraction at PHENIX is compared to values measured by other experiments at higher center of mass energies and to fixed-order-next-to-leading-logarithm and color-evaporation-model predictions. The cross section per unit rapidity extracted from the obtained and the PHENIX inclusive cross section measured at 200 GeV scaled with color-evaporation-model calculations, at the mean hadron rapidity in 510 GeV collisions, is b. It is consistent with the fixed-order-next-to-leading-logarithm calculations.