Critical phase of a magnetic hard hexagon model on triangular lattice
  We introduce a magnetic hard hexagon model with two-body restrictions for configurations of hard hexagons and investigate its critical behavior by using Monte Carlo simulations and a finite size scaling method for discreate values of activity. It turns out that the restrictions bring about a critical phase which the usual hard hexagon model does not have. An upper and a lower critical value of the discrete activity for the critical phase of the newly proposed model are estimated as 4 and 6, respectively. 
Yasushi Honda and Tsuyoshi Horiguchi (Department of Computer and   Mathematical Sciences, Tohoku University, Sendai, Japan)