Transverse spherocity classifies heavy-ion collision events to suppress backgrounds in chiral magnetic effect searches, with AMPT simulations showing higher scaled signals in isotropic events.
Adamczyket al.(STAR), Measurement of charge mul- tiplicity asymmetry correlations in high-energy nucleus- nucleus collisions at √sN N = 200 GeV, Phys
2 Pith papers cite this work. Polarity classification is still indexing.
abstract
A study is reported of the same- and opposite-sign charge-dependent azimuthal correlations with respect to the event plane in Au+Au collisions at 200 GeV. The charge multiplicity asymmetries between the up/down and left/right hemispheres relative to the event plane are utilized. The contributions from statistical fluctuations and detector effects were subtracted from the (co-)variance of the observed charge multiplicity asymmetries. In the mid- to most-central collisions, the same- (opposite-) sign pairs are preferentially emitted in back-to-back (aligned on the same-side) directions. The charge separation across the event plane, measured by the difference, $\Delta$, between the like- and unlike-sign up/down $-$ left/right correlations, is largest near the event plane. The difference is found to be proportional to the event-by-event final-state particle ellipticity (via the observed second-order harmonic $v^{\rm obs}_{2}$), where $\Delta=(1.3\pm1.4({\rm stat})^{+4.0}_{-1.0}({\rm syst}))\times10^{-5}+(3.2\pm0.2({\rm stat})^{+0.4}_{-0.3}({\rm syst}))\times10^{-3}v^{\rm obs}_{2}$ for 20-40% Au+Au collisions. The implications for the proposed chiral magnetic effect are discussed.
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background 1representative citing papers
The hexadecapole component of Δγ(φ_pair) is proposed as a CME-sensitive and background-insensitive observable based on magnetic field fluctuations in heavy-ion collision models.
citing papers explorer
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Probing the chiral magnetic effect via transverse spherocity event classification in relativistic heavy-ion collisions
Transverse spherocity classifies heavy-ion collision events to suppress backgrounds in chiral magnetic effect searches, with AMPT simulations showing higher scaled signals in isotropic events.
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A higher-harmonic observable for the chiral magnetic effect in heavy-ion collisions
The hexadecapole component of Δγ(φ_pair) is proposed as a CME-sensitive and background-insensitive observable based on magnetic field fluctuations in heavy-ion collision models.