Chiral Magnetic Effect and Negative Magnetoresistance across the phase diagram of finite-density SU(2) gauge theory

@misc{buividovich2026chiral,
  title = {{Chiral Magnetic Effect and Negative Magnetoresistance across the phase diagram of finite-density SU(2) gauge theory}},
  author = {P. V. Buividovich and L. von Smekal and D. Smith},
  howpublished = {arXiv},
  year = {2026},
  month = sep,
  doi = {10.48550/arxiv.2605.04743},
  eprint = {2605.04743},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2605.04743},
}

TY  - UNPB
TI  - Chiral Magnetic Effect and Negative Magnetoresistance across the phase diagram of finite-density SU(2) gauge theory
AU  - P. V. Buividovich
AU  - L. von Smekal
AU  - D. Smith
PY  - 2026
DA  - 2026/09/11
PB  - arXiv
DO  - 10.48550/arxiv.2605.04743
UR  - https://arxiv.org/abs/2605.04743
AB  - We study the signatures of the Chiral Magnetic Effect (CME) in SU(2) gauge theory with N_f = 2 flavours of dynamical fermions at finite temperature T, quark chemical potential μ and a weak external magnetic field $e B$. We consider both the correlator of the axial density and the vector current, which gives direct access to the out-of-equilibrium CME, and the correlator of two vector currents, which probes the CME indirectly via the enhancement of the longitudinal electric conductivity (Negative Magnetoresistance, NMR). We find that the CME response extracted from the vector-axial correlator exhibits a rather weak dependence on temperature and density in the quark-gluon plasma regime, and is very close to the universal value for free massless quarks. The CME appears to be mildly suppressed at low temperatures in the hadronic phase. In contrast, the NMR behaves in a qualitatively different way across the phase diagram, and is strongly suppressed at either large densities or temperatures. The magnitude of the NMR response appears to be considerably smaller than the prediction based on the lowest Landau level calculation for free quarks. Our findings suggest that for relatively small magnetic field strengths e B ≲ m_π^2 the relation between the CME and NMR might not be as direct as expected. We also do not find statistically significant indications for an enhancement of the CME or NMR strength in the vicinity of the crossover or second-order phase transition lines in the $(μ, T)$ phase diagram.
ER  -