相关论文: Bounds on the New Generations
We derive bounds on vector leptoquarks coupling to the first generation, using data from low energy experiments as well as from high energy accelerators. Similarly to the case of scalar leptoquarks, we find that the strongest indirect…
Without assuming that Higgs masses have the same values as other scalar masses at the input GUT scale, we combine constraints on the minimal supersymmetric extension of the Standard Model (MSSM) coming from the cold dark matter density with…
We consider the standard model in the formulationo of non-commutative geometry, for a Euclidean space-time consisting of two copies. The electroweak scale is set by the vacuum expectation value of a scalar field and is undetermined at the…
The existing bounds from CDF on the masses of the fourth generation quarks, t' and b', are reexamined. The bound of 256 GeV on the t' mass assumes that the primary decay of the t' is into q+W, which is not the case for a substantial region…
The agreement of electroweak measurements with theory places limits on the masses of the top quark and the $W$ boson. It is shown how these limits arise and what constraints various measurements (particularly a top quark mass determination)…
It has been shown in a recent paper that the Higgs quartic and Yukawa sectors of the Standard Model (SM) with a heavy fourth generation exhibit at a two-loop level a quasi fixed point structure instead of the one-loop Landau singularity and…
The constraint on the mass of the charged Higgs boson from the recent measurement of the inclusive $b \rightarrow s \gamma$ decay is studied in a framework of the minimal supergravity. It is shown that the lower bound for the charged Higgs…
The usually considered vacuum of the two-Higgs-doublet model (2HDM) could be unstable if it locates at a local but not global minimum (GM) of the scalar potential. By requiring the vacuum to be a GM, we obtain an additional constraint,…
Recent developments on the four dimensional (4d) lattice studies of the finite temperature electroweak phase transition (EWPT) are summarized. The phase diagram is given in the continuum limit. The finite temperature SU(2)-Higgs phase…
The LHC is already putting bounds on the Higgs mass. In this paper we use those bounds to put constrains on the MSSM parameter space coming from the fact that, in supersymmetry, the Higgs mass is a function of the masses of sparticles, and…
No-scale structure of the Kahler potential is obtained in many types of supersymmetric models. In this paper, phenomenological aspects of these models are investigated with special attention to the current Higgs mass bound at LEP and b \to…
We speculate about the possible interpretations of the recently observed excess in the $h \to \tau \mu$ decay. We derive a robust lower bound on the Higgs boson coupling strength to a tau and a muon, even in presence of the most general new…
Depending on the Higgs-boson and top-quark masses, $M_H$ and $M_t$, the effective potential of the Standard Model at finite (and zero) temperature can have a deep and unphysical stable minimum $\langle \phi(T)\rangle$ at values of the field…
A model for composite electroweak bosons is re-examined to establish approximate ranges for the initial predictions of the top and Higgs masses. Higher order corrections to this $4$-fermion theory at a high mass scale where the theory is…
An updated global analysis within the Standard Model (SM) of all relevant electroweak precision and Higgs boson search data is presented with special emphasis on the implications for the Higgs boson mass, M_H. Included are, in particular,…
We discuss a minimal extension to the standard model in which there are two Higgs bosons and, in addition to the usual fermion content, two fermion doublets and one fermion singlet. The little hierachy problem is solved by the vanishing of…
After the Higgs discovery, the question of whether particles beyond those of the Standard Model exist is more pressing than ever. In this context, the scalar sector is particularly promising, since it lies at the core of the internal…
Particle physics model building within the context of string theory suggests that further copies of the Higgs boson sector may be expected. Concerns regarding tree-level flavor changing neutral currents are easiest to allay if little or no…
Lattice work, exploring the Higgs mass triviality bound, seems to indicate that a strongly interacting scalar sector in the minimal standard model cannot exist while low energy QCD phenomenology seems to indicate that it could. We attack…
Combining the constraints coming from the ~$M_W$ ~measurements and the unsuccesful search for the Higgs boson at LEP we determine in the framework of MSSM the allowed mass regions for the lighter scalar partner of the top quark. For a heavy…