Reliability of finite-density pseudocritical-temperature estimators

Determine whether the peak positions of the thermal-derivative observables derived from the baryon number susceptibility, denoted by χ_T and χ_C, provide equally reliable estimators of the QCD pseudocritical temperature at finite baryon chemical potential.

Background

The paper defines two finite-density pseudocritical-temperature estimators from the peak positions of the thermal derivatives χ_T and χ_C of the baryon number susceptibility χ_2B. At zero baryon chemical potential, these observables have well-defined peaks and yield consistent pseudocritical temperatures.

For nonzero baryon chemical potential, however, the authors use the peak positions only as operational estimators when fitting the pseudocritical line. Their reliability has not been established through the underlying universal scaling behavior, leaving unresolved whether the two estimators are comparably trustworthy at finite density. Resolving this issue is important for obtaining a more precise and theoretically controlled determination of the QCD crossover curvature from the pseudocritical line.

References

At finite $$, it is not yet established whether the peak positions of $_T$ and $_C$ provide equally reliable estimators of the pseudocritical temperature.

— The QCD crossover temperature and curvature coefficient from unbiased exponential resummation at physical quark masses in (2+1)-flavor lattice QCD  (2608.19330 - Mitra, 19 Aug 2026) in Section “Curvature coefficient,” paragraph beginning “Next, we estimate”