arXiv subjects

Lee Lin

Publications and source records attributed to Lee Lin.

3 recordsLinked to original sources

arXiv1995

Mass Bounds in Mirror-Fermion Models

Numerical simulations are performed on different lattice sizes of chiral U(1) and SU(2) scalar-fermion models with explicit mirror pairs of fermions in the broken symmetry phase. Relevance of these models to the electroweak theory is discussed. Shift symmetry of the action is exploited to decouple the unwanted mirror-fermion. Upper and lower bounds on the renormalized scalar mass as a function of the renormalized fermion mass are obtained in the SU(2) version of the model. Our numerical data are found to be in qualitative agreement with one-loop results. No evidence for a nontrivial fixed point has been observed. The mirror-fermion models are likely to be trivial in the continuum limit. Our Monte Carlo data show that with a $180\, GeV$ top quark, the Standard Model Higgs boson should have a mass between $100$ and $800\, GeV$.

hep-ph↗

arXiv1995

Study of the Decoupling of Heavy Fermions in a Z_2 Scalar-Fermion Model

According to one-loop perturbation theory, fermions whose masses are totally generated from Yukawa couplings do not decouple in the heavy mass limit. We investigate this issue nonperturbatively in a 4-dimensional $Z_2$ scalar-fermion model with staggered fermions. Our data at intermediate and stronger Yukawa couplings on $8^4$ and $12^4$ lattices suggest the nondecoupling of heavy fermions as predicted from one-loop calculation. However, at the strongest Yukawa coupling where a possible multi-critical point may come into play, we cannot be conclusive.

hep-lat↗

arXiv1994

Nondecoupling of Heavy Mirror-Fermion

According to one-loop perturbation theory, fermions whose masses are totally generated from Yukawa couplings do not decouple in the heavy mass limit. We investigate this issue nonperturbatively in the strong coupling regime of the chiral $U(1)$ mirror-fermion model in four dimensions. Our numerical results, obtained on $6^3\cdot 16$, $6^3\cdot 24$ and $8^3\cdot 16$ lattices, indicate nondecoupling of heavy fermion and mirror-fermion, thus supporting the one-loop picture.

hep-lat↗