L. Adamczyk, AGH University of Science and Technology, Poland
James K. Adkins, University of KentuckyFollow
G. Agakishiev, Joint Institute for Nuclear Research, Russia
M. M. Aggarwal, Panjab University, India
Z. Ahammed, Variable Energy Cyclotron Centre, India
I. Alekseev, Alikhanov Institute for Theoretical and Experimental Physics, Russia
J. Alford, Kent State University
A. Aparin, Joint Institute for Nuclear Research, Russia
D. Arkhipkin, Brookhaven National Laboratory
E. C. Aschenauer, Brookhaven National Laboratory
G. S. Averichev, Joint Institute for Nuclear Research, Russia
A. Banerjee, Variable Energy Cyclotron Centre, India
R. Bellwied, University of Houston
A. Bhasin, University of Jammu, India
A. K. Bhati, Panjab University, India
P. Bhattarai, University of Texas at Austin
J. Bielcik, Czech Technical University in Prague, Czech Republic
J. Bielcikova, Nuclear Physics Institute AS CR, Czech Republic
L. C. Bland, Brookhaven National Laboratory
I. G. Bordyuzhin, Alikhanov Institute for Theoretical and Experimental Physics, Russia
J. Bouchet, Kent State University
A. V. Brandin, Moscow Engineering Physics Institute, Russia
I. Bunzarov, Joint Institute for Nuclear Research, Russia
T. P. Burton, Brookhaven National Laboratory
J. Butterworth, Rice University
H. Caines, Yale University
M. Calderón de la Barca Sánchez, University of California - Davis
J. M. Campbell, Ohio State University
D. Cebra, University of California - Davis
M. C. Cervantes, Texas A & M University - College Station
Renee H. Fatemi, University of KentuckyFollow
Suvarna Ramachandran, University of KentuckyFollow


Balance functions have been measured in terms of relative pseudorapidity (Δη) for charged particle pairs at the BNL Relativistic Heavy Ion Collider from Au + Au collisions at √sNN = 7.7GeV to 200 GeV using the STAR detector. These results are compared with balance functions measured at the CERN Large Hadron Collider from Pb + Pb collisions at √sNN = 2.76 TeV by the ALICE Collaboration. The width of the balance function decreases as the collisions become more central and as the beam energy is increased. In contrast, the widths of the balance functions calculated using shuffled events show little dependence on centrality or beam energy and are larger than the observed widths. Balance function widths calculated using events generated by UrQMD are wider than the measured widths in central collisions and show little centrality dependence. The measured widths of the balance functions in central collisions are consistent with the delayed hadronization of a deconfined quark gluon plasma (QGP). The narrowing of the balance function in central collisions at √sNN = 7.7 GeV implies that a QGP is still being created at this relatively low energy.

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Published in Physical Review C, v. 94, issue 2, 024909, p. 1-7.

©2016 American Physical Society

The copyright holder has granted permission for posting the article here.

Due to the large number of authors, only the first 30 and the authors affiliated with the University of Kentucky are listed in the author section above. For the complete list of authors, please download this article.

The authors of this article are collectively known as STAR Collaboration.

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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.

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