The Variational-Cumulant Expansion method is applied to investigate the phase structure and the critical behavior of lattice φ4 theory at two different temperatures. The phase diagrams, the external current J as a function of the expectation value of the field operator 〈φL〉 are calculated to the third order analytically. The critical behaviors of the expectation value 〈φL〉, the renormalized mass mR and mR/〈φL〉 are given and compared with the mean-field scaling laws with logarithmic scaling corrections. It is shown that, at a fixed bare coupling, the broken phase at a lower temperature might be restored at a higher temperature and a bound on the Higgs-boson mass at definite temperature can exist.
|Original language||English (US)|
|Number of pages||6|
|Journal||Zeitschrift fur Physik C-Particles and Fields|
|State||Published - Mar 1997|
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)