Speaker
Prof.
Sergei Voloshin
(Wayne State University)
Description
Recently, the STAR Collaboration has reported a strong dependence of
the elliptic flow of positive and negative pions on the net charge
density [1]. This measurement attracted a lot of community attention,
as the signal appeared to be of the magnitude and the sign of that
predicted by the theory of the Chiral Magnetic Wave [2]. At the same
time the interpretation of the results and further detailed study of
the effect is rather difficult as the observable itself, the slope of
elliptic flow value on the observed charge asymmetry in the STAR TPC
acceptance, depends on the tracking efficiency and detector
acceptance. In this talk we show how one can first make the observable
robust (efficiency independent) and then make it suitable for many
differential studies, not possible before. We use this observable, a
three-particle correlator, in our model calculations to show the
sensitivity of the signal to several background effects, such as local
charge conservation, and propose experimental tests for further
identification of the effects responsible for the observed signal.
[1] G.~Wang [STAR Collaboration], ``Search for Chiral Magnetic Effects
in High-Energy Nuclear Collisions,'' Nucl.\ Phys.\ A904-905 {\bf
2013}, 248c (2013).
[2] Y.~Burnier, D.~E.~Kharzeev, J.~Liao and H.~-U.~Yee, ``Chiral
magnetic wave at finite baryon density and the electric quadrupole
moment of quark-gluon plasma in heavy ion collisions,''
Phys.\ Rev.\ Lett.\ {\bf 107}, 052303 (2011).
Primary authors
Ron Belmont
(Wayne State University (US))
Prof.
Sergei Voloshin
(Wayne State University)
