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تسجيل مستخدم جديدThe $phi (1020)rightarrow e^{+}e^{-}$ meson decay measured with the STAR experiment in Au+Au collisions at $sqrt{s_{_{NN}}}$ = 200 GeV
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We report the measurement of the leptonic ($e^{+}e^{-}$) decay channel of the $phi$(1020) meson in Au+Au collisions at $sqrt{s_{_{NN}}}$ = 200 GeV by the STAR experiment. The transverse momentum ($p_{rm T}$) spectrum is measured for 0.1 $le p_{rm T} le 2.5$ GeV/$c$ at mid-rapidity ($|y|le1$). We obtain the $p_{rm T}$-integrated $phi$(1020) mass $M_{phi}=1017.7pm0.8 (rm {stat.}) pm0.9 (rm {sys.})$ MeV/$c^{2}$ and width $Gamma_{phi} = 8.0pm 2.5(rm {stat.}) pm 2.3(rm {sys.}) textrm{MeV/}c^{2}$, which are within 1.5,$sigma$ and 1.1,$sigma$ of the vacuum values, respectively. No significant difference is observed in the measured $p_{rm T}$ spectrum, $dN/dy$, or $left<p_{rm T}right>$ of the $phi$(1020) meson between the $e^{+}e^{-}$ and hadronic ($K^{+}K^{-}$) decay channels as measured by the same experiment. The experimental results are compared to a theoretical model including medium-modified $phi$(1020).
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