264 research outputs found
The Messenger Sector of SUSY Flavour Models and Radiative Breaking of Flavour Universality
The flavour messenger sectors and their impact on the soft SUSY breaking
terms are investigated in SUSY flavour models. In the case when the flavour
scale M is below the SUSY breaking mediation scale M_S, the universality of
soft terms, even if assumed at M_S, is radiatively broken. We estimate this
effect in a broad class of models. In the CKM basis that effect gives flavour
off-diagonal soft masses comparable to the tree-level estimate based on the
flavour symmetry.Comment: 24 pages, 3 figures. v3: minor changes in the text, typos corrected,
version accepted for publication in JHE
FCNC and CP Violation Observables in a SU(3)-flavoured MSSM
A non-Abelian flavour symmetry in a minimal supersymmetric standard model can
explain the flavour structures in the Yukawa couplings and simultaneously solve
the SUSY flavour problem. Similarly the SUSY CP problem can be solved if CP is
spontaneously broken in the flavour sector. In this work, we present an
explicit example of these statements with a SU(3) flavour symmetry and
spontaneous CP violation. In addition, we show that it is still possible to
find some significant deviation from the SM expectations as far as FCNC and CP
violation are concerned. We find that large contributions can be expected in
lepton flavour violating decays, as and , electric dipole moments, and and kaon CP violating
processes as . Thus, these flavoured MSSM realizations are
phenomenologically sensitive to the experimental searches in the realm of
flavor and CP vioation physics.Comment: 56 pages, 12 figures; included new NLO contributions to nEDM from
charged Higgs, relevant figures updated, and analysis of O(1) coefficients;
added appendices and reference
Electric dipole moments from spontaneous CP violation in SU(3)-flavoured SUSY
The SUSY flavour problem is deeply related to the origin of flavour and hence
to the origin of the SM Yukawa couplings themselves. Since all CP-violation in
the SM is restricted to the flavour sector, it is possible that the SUSY CP
problem is related to the origin of flavour as well. In this work, we present
three variations of an SU(3) flavour model with spontaneous CP violation. Such
models explain the hierarchy in the fermion masses and mixings, and predict the
structure of the flavoured soft SUSY breaking terms. In such a situation, both
SUSY flavour and CP problems do not exist. We use electric dipole moments and
lepton flavour violation processes to distinguish between these models, and
place constraints on the SUSY parameter space.Comment: 8 pages, 2 Figures, to appear in the DISCRETE'08 proceeding
B anomalies and muon g - 2 from Dark Matter
Motivated by the result of the Muon g-2 experiment and the long-standing anomalies in semileptonic í” meson decays, we systematically build a class of minimal models that can address both experimental results thanks to the contributions of a set of new fields that include a thermal Dark Matter candidate. This talk is mainly based on Refs
Lepton Flavour Violation from SUSY--GUTs: Where do we stand for MEG, PRISM/PRIME and a Super Flavour factory
We analyse the complementarity between Lepton Flavour Violation (LFV) and LHC experiments in probing the Supersymmetric (SUSY) Grand Unified Theories (GUT) when neutrinos got a mass via the see--saw mechanism. Our analysis is performed in an SO(10) framework, where at least one neutrino Yukawa coupling is necessarily as large as the top Yukawa coupling. Our study thoroughly takes into account the whole RG running, including the GUT and the right handed neutrino mass scales, as well as the running of the observable neutrino spectrum. We find that the upcoming (MEG, SuperKEKB) and future (PRISM/PRIME, Super Flavour factory) LFV experiments will be able to test such SUSY framework for SUSY masses to be explored at the LHC and, in some cases, even beyond the LHC sensitivity reach
Muon and electron and lepton masses in flavor models
The stringent experimental bound on is compatible
with a simultaneous and sizable new physics contribution to the electron and
muon anomalous magnetic moments (), only if we
assume a non-trivial flavor structure of the dipole operator coefficients. We
propose a mechanism in which the realization of the correction is
manifestly related to the mass generation through a flavor symmetry. A
radiative flavon correction to the fermion mass gives a contribution to the
anomalous magnetic moment. In this framework, we introduce a chiral enhancement
from a non-trivial quartic coupling of the scalar potential.
We show that the muon and electron anomalies can be simultaneously explained in
a vast region of the parameter space with predicted vector-like mediators of
masses as large as ~TeV.Comment: 18 pages, 3 figures, 2 table
SUSY-GUTs, SUSY-Seesaw and the Neutralino Dark Matter
We will consider a SUSY-SU(5) with one right-handed neutrino with a large top
like Yukawa coupling. Assuming universal soft masses at high scale we compute
the low-energy spectrum and subsequently the neutralino LSP relic density
taking also into consideration SU(5) as well as the see-saw running effects
above the gauge coupling unification scale. We found that there exists no
viable region in parameter space for \tan\beta \ler ~35. The
coannihilation process starts becoming efficient for \tan\beta \ger 35-40.
However, this process is significantly constrained by the limited range in
which the stau is lighter than the neutralino. In fact, for a given
we find that there exists an upper bound on the lightest neutralino mass
() in this region. The A-pole funnel region appears at very large
, while the focus-point region does not make an
appearance till large (), namely a few TeV. Large terms at
high scale can lead to extended regions consistent with WMAP constraints and
remove the upper bounds in the stau coannihilation regions.Comment: 18 pages, 7 figures; references added, figure added, improved
discussions in text, to appear in JHE
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