Measurements of the chiral magnetic effect with background isolation in 200 GeV Au+Au collisions at STAR

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61389005%3A_____%2F19%3A00502950" target="_blank" >RIV/61389005:_____/19:00502950 - isvavai.cz</a>

Result on the web

<a href="https://doi.org/10.1016/j.nuclphysa.2018.08.035" target="_blank" >https://doi.org/10.1016/j.nuclphysa.2018.08.035</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.nuclphysa.2018.08.035" target="_blank" >10.1016/j.nuclphysa.2018.08.035</a>

Result language

angličtina

Original language name

Measurements of the chiral magnetic effect with background isolation in 200 GeV Au+Au collisions at STAR

Original language description

Using two novel methods, pair invariant mass (m(inv)) and comparative measurements with respect to reaction plane (Psi(RP)) and participant plane (Psi(PP)), we isolate the possible chiral magnetic effect (CME) from backgrounds in 200 GeV Au+Au collisions at STAR. The invariant mass method identifies the resonance background contributions, coupled with the elliptic flow (v(2)), to the charge correlator CME observable (Delta gamma). At high mass (m(inv) > 1.5 GeV/c(2)) where resonance contribution is small, we obtain the average Delta gamma magnitude. In the low mass region (m(inv) < 1.5 GeV/c(2)), resonance peaks are observed in Delta gamma(m(inv)). An event shape engineering (ESE) method is used to model the background shape in m(inv) to extract the potential CME signal at low m(inv). In the comparative method, the Psi(RP) is assessed by spectator neutrons measured by the ZDCs, and the Psi(PP) by the 2nd-harmonic event plane measured by the TPC. The v(2) is stronger along Psi(PP) and weaker along Psi(RP), in contrast, the magnetic field, mainly from spectator protons, is weaker along Psi(PP) and stronger along Psi(RP). As a result, the Delta gamma measured with respect to Psi(RP) and Psi(PP) contain different amounts of CME and background, and can thus determine these two contributions. It is found that the possible CME signals with background isolation by these two novel methods are small, on the order of a few percent of the inclusive Delta gamma measurements.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

10304 - Nuclear physics

Project

—

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2019

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Nuclear Physics. A

ISSN

0375-9474

e-ISSN

—

Volume of the periodical

982

Issue of the periodical within the volume

2

Country of publishing house

NL - THE KINGDOM OF THE NETHERLANDS

Number of pages

4

Pages from-to

535-538

UT code for WoS article

000457515500119

EID of the result in the Scopus database

2-s2.0-85060123771