On the large doping side of the transition ρc(T) is metallic, while on the low-doping side ρc(T) changes from metallic to semi-conducting behavior with decreasing T. As a function of doping, the jump in ρc across the first-order transition evolves into a sharp crossover at higher temperatures. This crossover coincides with the pseudogap temperature T* in the single-particle density of states, the spin susceptibility and other observables. Such coincidence in crossovers is expected along the continuation of the first-order transition into the supercritical regime, called the Widom line. This implies that not only the dynamic and the thermodynamic properties but also the DC transport in the normal state are governed by the hidden first-order transition.
Refs: G. Sordi et al, PRB 87, 041101(R) (2013); G. Sordi et al, Sci. Rep. 2, 547 (2012); G. Sordi et al, PRL 108, 216401 (2012); G. Sordi et al, PRB 84, 075161 (2011); G. Sordi et al, PRL 104, 226402 (2010).