Hadronic Paschen–Back effect

Sachio Iwasaki,Makoto Oka,Kei Suzuki,Tetsuya Yoshida

doi:10.1016/j.physletb.2018.10.024

Abstract

We find a novel phenomenon induced by the interplay between a strong magnetic field and finite orbital angular momenta in hadronic systems, which is analogous to the Paschen–Back effect observed in the field of atomic physics. This effect allows the wave functions to drastically deform. We discuss anisotropic decay from the deformation as a possibility to measure the strength of the magnetic field in high-energy heavy-ion collisions, which has not been measured experimentally. As an example we investigate charmonia with a finite orbital angular momentum in a strong magnetic field. We calculate the mass spectra and mixing ratios. To obtain anisotropic wave functions, we apply the cylindrical Gaussian expansion method. There we use different extension parameters for the parallel and transverse directions to the magnetic field.

Highlights

The Paschen-Back effect (PBE) for a quantum system under a strong magnetic field is well-known in the field of atomic physics [1]
In this work we have focused on Hadronic Paschen-Back effect (HPBE) in a simplified situation with only a static and homogeneous magnetic field
To consider more realistic situations in heavy-ion collisions, we examine the influence of (i) finite temperature, (ii) time evolution of magnetic field, (iii) finite vorticity, on HPBE for the P-wave charmonia

Summary

Introduction

The Paschen-Back effect (PBE) for a quantum system under a strong magnetic field is well-known in the field of atomic physics [1]. It is theoretically predicted that the strongest magnetic field in the present universe can be created at the Relativistic Heavy Ion Collider, RHIC (|eB| ∼ 0.1 GeV2 at most), and the Large Hadron Collider, LHC (|eB| ∼ 1.0 GeV2 at most) [2,3,4,5,6,7,8,9,10,11,12,13] They are comparable to the typical scale of quantum chromodynamics (QCD), Λ ∼ 0.3 GeV. One of the reasons of difficulties in measuring a magnetic field

Formulation of HPBE

Numerical setup

Numerical results

Measurements of HPBE

Discussion and conclusion