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تسجيل مستخدم جديدCharm and beauty isolation from heavy flavor decay electrons in Au+Au collisions at $sqrt{s_{rm NN}}$ = 200 GeV at RHIC
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We present a study of charm and beauty isolation based on a data-driven method with recent measurements on heavy flavor hadrons and their decay electrons in Au+Au collisions at $sqrt{s_{rm NN}}$ = 200 GeV at RHIC. The individual electron $p_{rm T}$ spectra, $R_{rm AA}$ and $v_2$ distributions from charmed and beauty hadron decays are obtained. We find that the electron $R_{rm AA}$ from beauty hadron decays ($R_{rm AA}^{rm brightarrow e}$) is suppressed in minimum bias Au+Au collisions but less suppressed compared with that from charmed hadron decays at $p_{rm T}$ $>$ 3.5 GeV/$c$, which indicates that beauty quark interacts with the hot-dense medium with depositing its energy and is consistent with the mass-dependent energy loss scenario. For the first time, the non-zero electron $v_2$ from beauty hadron decays ($v_2^{rm brightarrow e}$) at $p_{rm T}$ $>$ 3.0 GeV/$c$ is observed and shows smaller elliptic flow compared with that from charmed hadron decays at $p_{rm T}$ $<$ 4.0 GeV/$c$. At 2.5 GeV/$c$ $<$ $p_{rm T}$ $<$ 4.5 GeV/$c$, $v_2^{rm brightarrow e}$ is smaller than a number-of-constituent-quark (NCQ) scaling hypothesis. This suggests that beauty quark is unlikely thermalized and too heavy to be moved in a partonic collectivity in heavy-ion collisions at the RHIC energy.
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