Energy dependence of acceptance-corrected dielectron excess mass spectrum at mid-rapidity in Au+Au collisions at √sNN=19.6 and 200 GeV

STAR Collaboration

doi:10.1016/j.physletb.2015.08.044

Energy dependence of acceptance-corrected dielectron excess mass spectrum at mid-rapidity in Au+Au collisions at √sNN=19.6 and 200 GeV

STAR Collaboration

Research output: Contribution to journal › Article › peer-review

38 Scopus citations

Abstract

The acceptance-corrected dielectron excess mass spectra, where the known hadronic sources have been subtracted from the inclusive dielectron mass spectra, are reported for the first time at mid-rapidity |yee|<1 in minimum-bias Au+Au collisions at √sNN=19.6 and 200 GeV. The excess mass spectra are consistently described by a model calculation with a broadened ρ spectral function for Mee<1.1 GeV/c2. The integrated dielectron excess yield at √sNN=19.6 GeV for 0.4<Mee<0.75 GeV/c2, normalized to the charged particle multiplicity at mid-rapidity, has a value similar to that in In+In collisions at √sNN=17.3 GeV. For √sNN=200 GeV, the normalized excess yield in central collisions is higher than that at √sNN=17.3 GeV and increases from peripheral to central collisions. These measurements indicate that the lifetime of the hot, dense medium created in central Au+Au collisions at √sNN=200 GeV is longer than those in peripheral collisions and at lower energies.

Original language	English
Pages (from-to)	64-71
Number of pages	8
Journal	Physics Letters B
Volume	750
DOIs	https://doi.org/10.1016/j.physletb.2015.08.044
State	Published - Nov 12 2015
Externally published	Yes

Funding

We thank the RHIC Operations Group and RCF at BNL , the NERSC Center at LBNL, the KISTI Center in Korea, and the Open Science Grid consortium for providing resources and support. This work was supported in part by the Offices of NP and HEP within the U.S. DOE Office of Science , the U.S. NSF , CNRS/IN2P3 , FAPESP CNPq of Brazil, the Ministry of Education and Science of the Russian Federation , NNSFC , CAS , MoST and MoE of China, the Korean Research Foundation , GA and MSMT of the Czech Republic, FIAS of Germany, DAE , DST , and CSIR of India, the National Science Centre of Poland, National Research Foundation ( NRF-2012004024 ), the Ministry of Science, Education and Sports of the Republic of Croatia, and RosAtom of Russia.

Funders	Funder number
FAPESP CNPq
MOE of China
RosAtom of Russia
National Science Foundation	1206009, CNRS/IN2P3, 1067907, 1505716
Office of Science
National Research Foundation	NRF-2012004024
Department of Science and Technology, Ministry of Science and Technology, India
Council of Scientific and Industrial Research, India
Department of Atomic Energy, Government of India
National Natural Science Foundation of China
Ministerstvo Školství, Mládeže a Tělovýchovy
Chinese Academy of Sciences
Ministarstvo Obrazovanja, Znanosti i Sporta
Ministry of Education and Science of the Russian Federation
Narodowe Centrum Nauki
Ministry of Science and Technology, Taiwan

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10.1016/j.physletb.2015.08.044

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@article{5d2fcc4521fd4bb6be9ee7a3752a2011,

title = "Energy dependence of acceptance-corrected dielectron excess mass spectrum at mid-rapidity in Au+Au collisions at √sNN=19.6 and 200 GeV",

abstract = "The acceptance-corrected dielectron excess mass spectra, where the known hadronic sources have been subtracted from the inclusive dielectron mass spectra, are reported for the first time at mid-rapidity |yee|<1 in minimum-bias Au+Au collisions at √sNN=19.6 and 200 GeV. The excess mass spectra are consistently described by a model calculation with a broadened ρ spectral function for Mee<1.1 GeV/c2. The integrated dielectron excess yield at √sNN=19.6 GeV for 0.4",

author = "{STAR Collaboration} and L. Adamczyk and Adkins, {J. K.} and G. Agakishiev and Aggarwal, {M. M.} and Z. Ahammed and I. Alekseev and J. Alford and A. Aparin and D. Arkhipkin and Aschenauer, {E. C.} and Averichev, {G. S.} and A. Banerjee and R. Bellwied and A. Bhasin and Bhati, {A. K.} and P. Bhattarai and J. Bielcik and J. Bielcikova and Bland, {L. C.} and Bordyuzhin, {I. G.} and J. Bouchet and Brandin, {A. V.} and I. Bunzarov and Burton, {T. P.} and J. Butterworth and H. Caines and {Calder'on de la Barca S'anchez}, M. and Campbell, {J. M.} and D. Cebra and Cervantes, {M. C.} and I. Chakaberia and P. Chaloupka and Z. Chang and S. Chattopadhyay and Chen, {J. H.} and X. Chen and J. Cheng and M. Cherney and W. Christie and Codrington, {M. J.M.} and G. Contin and Crawford, {H. J.} and S. Das and {De Silva}, {L. C.} and Debbe, {R. R.} and Dedovich, {T. G.} and J. Deng and Derevschikov, {A. A.} and {di Ruzza}, B. and J. Schambach",

note = "Publisher Copyright: {\textcopyright} 2015 The Authors.",

year = "2015",

month = nov,

day = "12",

doi = "10.1016/j.physletb.2015.08.044",

language = "English",

volume = "750",

pages = "64--71",

journal = "Physics Letters B",

issn = "0370-2693",

publisher = "Elsevier",

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TY - JOUR

T1 - Energy dependence of acceptance-corrected dielectron excess mass spectrum at mid-rapidity in Au+Au collisions at √sNN=19.6 and 200 GeV

AU - STAR Collaboration

AU - Adamczyk, L.

AU - Adkins, J. K.

AU - Agakishiev, G.

AU - Aggarwal, M. M.

AU - Ahammed, Z.

AU - Alekseev, I.

AU - Alford, J.

AU - Aparin, A.

AU - Arkhipkin, D.

AU - Aschenauer, E. C.

AU - Averichev, G. S.

AU - Banerjee, A.

AU - Bellwied, R.

AU - Bhasin, A.

AU - Bhati, A. K.

AU - Bhattarai, P.

AU - Bielcik, J.

AU - Bielcikova, J.

AU - Bland, L. C.

AU - Bordyuzhin, I. G.

AU - Bouchet, J.

AU - Brandin, A. V.

AU - Bunzarov, I.

AU - Burton, T. P.

AU - Butterworth, J.

AU - Caines, H.

AU - Calder'on de la Barca S'anchez, M.

AU - Campbell, J. M.

AU - Cebra, D.

AU - Cervantes, M. C.

AU - Chakaberia, I.

AU - Chaloupka, P.

AU - Chang, Z.

AU - Chattopadhyay, S.

AU - Chen, J. H.

AU - Chen, X.

AU - Cheng, J.

AU - Cherney, M.

AU - Christie, W.

AU - Codrington, M. J.M.

AU - Contin, G.

AU - Crawford, H. J.

AU - Das, S.

AU - De Silva, L. C.

AU - Debbe, R. R.

AU - Dedovich, T. G.

AU - Deng, J.

AU - Derevschikov, A. A.

AU - di Ruzza, B.

AU - Schambach, J.

PY - 2015/11/12

Y1 - 2015/11/12

N2 - The acceptance-corrected dielectron excess mass spectra, where the known hadronic sources have been subtracted from the inclusive dielectron mass spectra, are reported for the first time at mid-rapidity |yee|<1 in minimum-bias Au+Au collisions at √sNN=19.6 and 200 GeV. The excess mass spectra are consistently described by a model calculation with a broadened ρ spectral function for Mee<1.1 GeV/c2. The integrated dielectron excess yield at √sNN=19.6 GeV for 0.4

AB - The acceptance-corrected dielectron excess mass spectra, where the known hadronic sources have been subtracted from the inclusive dielectron mass spectra, are reported for the first time at mid-rapidity |yee|<1 in minimum-bias Au+Au collisions at √sNN=19.6 and 200 GeV. The excess mass spectra are consistently described by a model calculation with a broadened ρ spectral function for Mee<1.1 GeV/c2. The integrated dielectron excess yield at √sNN=19.6 GeV for 0.4

UR - http://www.scopus.com/inward/record.url?scp=84940398947&partnerID=8YFLogxK

U2 - 10.1016/j.physletb.2015.08.044

DO - 10.1016/j.physletb.2015.08.044

M3 - Article

AN - SCOPUS:84940398947

SN - 0370-2693

VL - 750

SP - 64

EP - 71

JO - Physics Letters B

JF - Physics Letters B

ER -

Energy dependence of acceptance-corrected dielectron excess mass spectrum at mid-rapidity in Au+Au collisions at √sNN=19.6 and 200 GeV

Abstract

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