Universal critical behavior of generalized susceptibilities of net-baryon number at small quark mass

In the limit of small quark masses, the angle between the temperature axis and the applied magnetic field direction in the three-dimensional Ising model vanishes as [Formula: see text] when mapped onto the QCD [Formula: see text] phase plane. By selecting two distinct small angles and projecting the Ising model results onto QCD, we have investigated the universal critical behavior of the sixth-, eighth- and tenth-order susceptibilities of the net-baryon number. When considering only the leading critical contribution, the negative dip in the [Formula: see text]-dependence of the generalized susceptibilities along the freeze-out curve below the phase transition line is not universal, in contrast to the observation in the case where the angle is [Formula: see text]. Its existence depends on the mapping parameters and the distance to the phase transition line. After incorporating the sub-leading critical contribution, the negative dip is enhanced to some extent but remains a nonrobust feature. On the other hand, along a line situated above and parallel to the phase transition line, the negative dip in the [Formula: see text]-dependence of the susceptibilities is not consistently prominent. In contrast, the positive peak structure persists pronounced in all cases and represents a robust characteristic of generalized susceptibilities of the net-baryon number near the critical point.