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arXiv · 1503.04217

The $\phi (1020)\rightarrow e^{+}e^{-}$ meson decay measured with the STAR experiment in Au+Au collisions at $\sqrt{s_{_{NN}}}$ = 200 GeV

STAR Collaboration·L. Adamczyk·J. K. Adkins·G. Agakishiev·M. M. Aggarwal·Z. Ahammed·I. Alekseev·A. Aparin·D. Arkhipkin·E. C. Aschenauer·M. U. Ashraf·A. Attri·G. S. Averichev·X. Bai·V. Bairathi·R. Bellwied·A. Bhasin·A. K. Bhati·P. Bhattarai·J. Bielcik·J. Bielcikova·L. C. Bland·I. G. Bordyuzhin·J. Bouchet·J. D. Brandenburg·A. V. Brandin·I. Bunzarov·J. Butterworth·H. Caines·M. Calderón de la Barca Sánchez·J. M. Campbell·D. Cebra·I. Chakaberia·P. Chaloupka·Z. Chang·A. Chatterjee·S. Chattopadhyay·X. Chen·J. H. Chen·J. Cheng·M. Cherney·W. Christie·G. Contin·H. J. Crawford·S. Das·L. C. De Silva·R. R. Debbe·T. G. Dedovich·J. Deng·A. A. Derevschikov·B. di Ruzza·L. Didenko·C. Dilks·X. Dong·J. L. Drachenberg·J. E. Draper·C. M. Du·L. E. Dunkelberger·J. C. Dunlop·L. G. Efimov·J. Engelage·G. Eppley·R. Esha·O. Evdokimov·O. Eyser·R. Fatemi·S. Fazio·P. Federic·J. Fedorisin·Z. Feng·P. Filip·Y. Fisyak·C. E. Flores·L. Fulek·C. A. Gagliardi·D. Garand·F. Geurts·A. Gibson·M. Girard·L. Greiner·D. Grosnick·D. S. Gunarathne·Y. Guo·A. Gupta·S. Gupta·W. Guryn·A. I. Hamad·A. Hamed·R. Haque·J. W. Harris·L. He·S. Heppelmann·A. Hirsch·G. W. Hoffmann·S. Horvat·X. Huang·H. Z. Huang·T. Huang·B. Huang·P. Huck
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Abstract

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 $M_{\phi}=1017.7\pm0.8 (\rm {stat.}) \pm0.9 (\rm {sys.})$ MeV/$c^{2}$ and width $\Gamma_{\phi} = 8.0\pm 2.5(\rm {stat.}) \pm 2.3(\rm {sys.}) \textrm{MeV/}c^{2}$, 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 $ 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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STAR Collaboration, L. Adamczyk, J. K. Adkins, G. Agakishiev, M. M. Aggarwal, Z. Ahammed, I. Alekseev, A. Aparin, D. Arkhipkin, E. C. Aschenauer, M. U. Ashraf, A. Attri, G. S. Averichev, X. Bai, V. Bairathi, R. Bellwied, A. Bhasin, A. K. Bhati, P. Bhattarai, J. Bielcik, J. Bielcikova, L. C. Bland, I. G. Bordyuzhin, J. Bouchet, J. D. Brandenburg, A. V. Brandin, I. Bunzarov, J. Butterworth, H. Caines, M. Calderón de la Barca Sánchez, J. M. Campbell, D. Cebra, I. Chakaberia, P. Chaloupka, Z. Chang, A. Chatterjee, S. Chattopadhyay, X. Chen, J. H. Chen, J. Cheng, M. Cherney, W. Christie, G. Contin, H. J. Crawford, S. Das, L. C. De Silva, R. R. Debbe, T. G. Dedovich, J. Deng, A. A. Derevschikov, B. di Ruzza, L. Didenko, C. Dilks, X. Dong, J. L. Drachenberg, J. E. Draper, C. M. Du, L. E. Dunkelberger, J. C. Dunlop, L. G. Efimov, J. Engelage, G. Eppley, R. Esha, O. Evdokimov, O. Eyser, R. Fatemi, S. Fazio, P. Federic, J. Fedorisin, Z. Feng, P. Filip, Y. Fisyak, C. E. Flores, L. Fulek, C. A. Gagliardi, D. Garand, F. Geurts, A. Gibson, M. Girard, L. Greiner, D. Grosnick, D. S. Gunarathne, Y. Guo, A. Gupta, S. Gupta, W. Guryn, A. I. Hamad, A. Hamed, R. Haque, J. W. Harris, L. He, S. Heppelmann, A. Hirsch, G. W. Hoffmann, S. Horvat, X. Huang, H. Z. Huang, T. Huang, B. Huang, P. Huck. 2015-03-13. The $\phi (1020)\rightarrow e^{+}e^{-}$ meson decay measured with the STAR experiment in Au+Au collisions at $\sqrt{s_{_{NN}}}$ = 200 GeV. https://arxiv.org/abs/1503.04217

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