Quarkonium dissociation in quark-gluon plasma via ionization in a magnetic field

Abstract

We study the impact of a magnetic field, generated in collisions of relativistic heavy ions, on the decay probability of a quarkonium produced in the central rapidity region. The quark and antiquark components are subject to mutually orthogonal electric and magnetic fields in the quarkonium comoving frame. In the presence of an electric field, the quarkonium has a finite dissociation probability.We use theWKB approximation to derive the dissociation probability. We find that the quarkonium dissociation energy, i.e., the binding energy at which the dissociation probability is of order unity, increases with the magnetic field strength. It also increases with quarkonium momentum in the laboratory frame owing to the Lorentz boost of the electric field in the comoving frame. We argue that J/ψ's produced in heavy-ion collisions at the Large Hadron Collider with P⊥ > 9 GeV would dissociate even in vacuum. In plasma, the J/ψ dissociation in a magnetic field is much stronger because of the decrease of its binding energy with temperature.We discuss phenomenological implications of our results. Disciplines Astrophysics and Astronomy | Physics CommentsThis article is from Physical Review C 84 (2011) We study the impact of a magnetic field, generated in collisions of relativistic heavy ions, on the decay probability of a quarkonium produced in the central rapidity region. The quark and antiquark components are subject to mutually orthogonal electric and magnetic fields in the quarkonium comoving frame. In the presence of an electric field, the quarkonium has a finite dissociation probability. We use the WKB approximation to derive the dissociation probability. We find that the quarkonium dissociation energy, i.e., the binding energy at which the dissociation probability is of order unity, increases with the magnetic field strength. It also increases with quarkonium momentum in the laboratory frame owing to the Lorentz boost of the electric field in the comoving frame. We argue that J/ψ's produced in heavy-ion collisions at the Large Hadron Collider with P ⊥ > 9 GeV would dissociate even in vacuum. In plasma, the J/ψ dissociation in a magnetic field is much stronger because of the decrease of its binding energy with temperature. We discuss phenomenological implications of our results.

Electromagnetic radiation by quark-gluon plasma in a magnetic field

“…In particular, when j = k, ω s,jk = 0, i.e. no photon is emitted, which is also evident in (10). The reason is clearly seen in the frame where p = 0: since ε j ≥ ε k , constraints (2) and (3) hold only if ω = 0.…”

“…It contributes to enhancement of dilepton production at low invariant masses [7] and enhances the azimuthal anisotropy of the quark-gluon plasma (QGP) [8,9]. It causes dissociation of the bound states, particularly charmonia, via ionization [10,11]. Additionally, magnetic field may drive the Chiral Magnetic Effect (CME) [1,12], which is the generation of an electric field parallel to the magnetic one via the axial anomaly in the hot nuclear matter.…”

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

“…possible ρ meson condensation in strong magnetic field [50][51][52][53][54], the neutral pion condensation in vaccum [55], the anisotropic viscosities in hydrodynamic equations [56][57][58][59][60], and the early-stage phenomena in heavy-ion collisions like the EM-field induced particle production [26,[61][62][63][64][65][66] and the dissociation of heavy-flavor mesons [67][68][69][70][71]. These topics will not be the main focus of this article.…”

Charmonium spectroscopy in strong magnetic fields by QCD sum rules:S-wave ground states

“…Motivated by formation of strong electromagnetic fields in neutron stars/magnetars [3,4] and ultrarelativistic heavy-ion collisions at the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC) [5][6][7][8], a number of lattice QCD simulations and analytic calculations have shown that strong magnetic fields modify properties of QCD vacuum such as quark condensates [5,[9][10][11][12][13][14][15][16][17][18] and gluon condensates [19,20], and consequently modify even phase structures [15,19,[21][22][23] and hadron properties [5,9,[24][25][26][27][28][29][30][31][32][33][34][35]. One of the remarkable findings is a discrepancy between meson spectra obtained from a hadronic effective model calculation and a lattice QCD simulation in strong magnetic fields [26,27].…”