137,029 research outputs found
Non-Gaussian statistics, maxwellian derivation and stellar polytropes
In this letter we discuss the Non-gaussian statistics considering two
aspects. In the first, we show that the Maxwell's first derivation of the
stationary distribution function for a dilute gas can be extended in the
context of Kaniadakis statistics. The second one, by investigating the stellar
system, we study the Kaniadakis analytical relation between the entropic
parameter and stellar polytrope index . We compare also the
Kaniadakis relation with proposed in the Tsallis
framework.Comment: 10 pages, 1 figur
Tree-level metastability bounds for the most general two Higgs doublet model
Within two Higgs doublet models, it is possible that the current vacuum is
not the global minimum, in which case it could possibly decay at a later stage.
We discuss the tree-level conditions which must be obeyed by the most general
scalar potential in order to preclude that possibility. We propose a new
procedure which is not only more general but also easier to implement than the
previously published one, including CP conserving as well as CP violating
scalar sectors. We illustrate these conditions within the context of the Z2
model, softly broken by a complex, CP violating parameter.Comment: RevTex, 13 pages, 3 figure
Generalized CP Invariance and the Yukawa sector of Two-Higgs Models
We analyze generalized CP symmetries of two-Higgs doublet models, extending
them from the scalar to the fermion sector of the theory. We show that, with a
single exception, those symmetries imply massless fermions. The single model
which accommodates a fermionic mass spectrum compatible with experimental data
possesses a remarkable feature. It displays a new type of spontaneous CP
violation, which occurs not in the scalar sector responsible for the symmetry
breaking mechanism but, rather, in the fermion sector.Comment: RevTex, 4 pages, no figures Version2: Remarkable additional
conclusion => title & text changes; section adde
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