Single electron yields from semileptonic charm and bottom hadron decays in Au + Au collisions at = 200 GeV

=200GeVでの金-金衝突におけるチャームとボトムのセミレプトニック崩壊からくる電子の測定

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426名*

Adare, A.*; Hasegawa, Shoichi; Imai, Kenichi; Nagamiya, Shoji; Sako, Hiroyuki; Sato, Susumu; Tanida, Kiyoshi; PHENIX Collaboration*; 426 of others*

The PHENIX Collaboration at the Relativistic Heavy Ion Collider has measured open heavy flavor production in minimum bias Au + Au collisions at = 200 GeV via the yields of electrons from semileptonic decays of charm and bottom hadrons. Previous heavy flavor electron measurements indicated substantial modification in the momentum distribution of the parent heavy quarks owing to the quark-gluon plasma created in these collisions. For the first time, using the PHENIX silicon vertex detector to measure precision displaced tracking, the relative contributions from charm and bottom hadrons to these electrons as a function of transverse momentum are measured in Au + Au collisions. We compare the fraction of electrons from bottom hadrons to previously published results extracted from electron-hadron correlations in collisions at = 200 GeV and find the fractions to be similar within the large uncertainties on both measurements for 4 GeV/. We use the bottom electron fractions in Au + Au and along with the previously measured heavy flavor electron to calculate the for electrons from charm and bottom hadron decays separately. We find that electrons from bottom hadron decays are less suppressed than those from charm for the region 3 4 GeV/.