Azimuthally fluctuating magnetic field and its impacts on observables in heavy-ion collisions

Abstract

The heavy-ion collisions can produce extremely strong transient magnetic and electric fields. We study the azimuthal fluctuation of these fields and their correlations with the also fluctuating matter geometry (characterized by the participant plane harmonics) using event-by-event simulations. A sizable suppression of the angular correlations between the magnetic field and the 2nd and 4th harmonic participant planes is found in very central and very peripheral collisions, while the magnitudes of these correlations peak around impact parameter b ∼ 8 − 10fm for RHIC collisions. This can lead to notable impacts on a number of observables related to various magnetic field induced effects, and our finding suggests that the optimal event class for measuring them should be that corresponding to b ∼ 8 − 10 fm.

Electromagnetic fields and anomalous transports in heavy-ion collisions—a pedagogical review

“…Recent numerical simulations found that the magnitude of the magnetic field in RHIC Au + Au collisions at √ s = 200 GeV can be at the order of 10 18 − 10 19 Gauss 1 and in LHC Pb + Pb collisions at √ s = 2.76 TeV can reach the order of 10 20 Gauss [2][3][4][5][6][7][8][9][10][11]. The electric filed can also be generated owing to event-by-event fluctuations [5,[7][8][9] (we will explain the physical meaning of such fluctuations in Sec. II) or in asymmetric collisions like Cu + Au collision [12][13][14], and its strength is roughly of the same order as the magnetic field.…”

Covariant chiral kinetic equation in the Wigner function approach

“…In non-central heavy-ion collisions at high energies very strong magnetic fields [4,[19][20][21][22][23][24][25][26][27] and huge global angular momenta [28][29][30][31][32] are produced. The CME, CVE and some other effects such as chiral magnetic wave [33,34] have been extensively studied in heavy-ion collisions.…”

“…(36) with dx µ /dτ and dp µ /dτ given by Eq. (22). We work in the co-moving frame with u µ = (1, 0).…”

Pseudoscalar condensation induced by chiral anomaly and vorticity for massive fermions

“…The CME, CVE and other related effects such as chiral magnetic wave [15,16] have been extensively studied in the quark-gluon plasma produced in high-energy heavy-ion collisions in which very strong magnetic fields [5,[17][18][19][20][21][22][23][24][25] and huge global angular momenta [26][27][28][29] are produced in non-central collisions. The charge separation effect observed in STAR [30,31] and ALICE [32] experiments are consistent to the CME prediction.…”

“…(20) In this appendix, we give a detailed derivation of Eq. (20). From the definition of the Wigner function (3) and that of the axial vector component, we obtain…”