Zeros of the inverted neutrino mass matrix

I investigate viable textures with two texture zeros for the inverted neutrino mass matrix, and present the predictions of those textures for the neutrino masses and for lepton mixing. By using an Abelian symmetry and one or two heavy scalar singlets, I construct realizations of those textures in the context of seesaw models.Comment: 7 pages, LaTe

Complete On-Shell Renormalization Scheme for the Minimal Supersymmetric Higgs Sector

Systematic on-shell renormalization programme is carried out for the Higgs and gauge boson sectors of the Minimal Supersymmetric Standard Model. Complete 1-loop results for the 2- and 3-point Green's functions are explicitly given. The Higgs boson masses and the cross sections for the neutral scalar production in the $e^+e^-$ colliders are calculated.Comment: 64 pages, 10 figures (not included, availaible on request in PostScript format), LaTeX, preprint no MPI-Ph/92-117 and DFPD 93/TH/1

Low energy threshold corrections to neutrino masses and mixing angles

We compute the low energy threshold corrections to neutrino masses and mixing in the Standard Model (SM) and its minimal supersymmetric version, using the effective theory technique. We demonstrate that they stabilize the renormalization group (RG) running with respect to the choice of the scale to which the RG equation is integrated. This confirms the correctness of the recent re-derivation of the RGE for the SM in hep-ph/0108005. The explicit formulae for the low energy threshold corrections corrections can be applied to specific models of neutrino masses and mixing.Comment: 20 pages, 2 postscript figure

Neutrino Mass Matrix Running for Non-Degenerate See-Saw Scales

We consider the running of the neutrino mass matrix in the Standard Model and the Minimal Supersymmetric Standard Model, extended by heavy singlet Majorana neutrinos. Unlike previous studies, we do not assume that all of the heavy mass eigenvalues are degenerate. This leads to various effective theories when the heavy degrees of freedom are integrated out successively. We calculate the Renormalization Group Equations that govern the evolution of the neutrino mass matrix in these effective theories. We show that an appropriate treatment of the singlet mass scales can yield a substantially different result compared to integrating out the singlets at a common intermediate scale.Comment: 12 pages, 9 figure

The decay h0→A0A0h^0 \to A^0A^0: a complete 1-loop calculation in the MSSM

In the minimal supersymmetric standard model the decay $h^0 \to A^0A^0$ of the light neutral scalar $h^0$ is kinematically allowed for low values of $\tan\beta$ when radiative corrections to the neutral Higgs masses are taken into account. The width of this decay mode is revisited on the basis of a complete 1-loop diagrammatic calculation. We give the analytical expressions and numerical results and compare them with the corresponding ones from the simpler and compact approximations of the effective potential method and the renormalization group approach.Comment: 25 pages, LaTex, 10 figures included. Complete ps-file also available via WWW at http://itpaxp1.physik.uni-karlsruhe.de/prep/prep.htm

Diminishing "charginos nearly degenerate with the lightest neutralino" slit using precision data

Though LEP II direct searches still cannot exclude a chargino nearly degenerate with the lightest neutralino if their mass is only slightly above half of the Z boson mass, it can be excluded indirectly analyzing precision data. In this particular limit simple analytical formulas for oblique electroweak radiative corrections are presented.Comment: 6 pages, latex, 2 figures included; published on PLB. Bounds on chargino mass are improved; two references are adde