Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userSuppressed flavor violation in Lepton Flavored Dark Matter from an extra dimension
108
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
Phenomenological studies of Flavored Dark Matter (FDM) models often have to assume a near-diagonal flavor structure in the coupling matrix in order to remain consistent with bounds from flavor violating processes. In this paper we show that for Lepton FDM, such a structure can naturally arise from an extra dimensional setup. The extra dimension is taken to be flat, with the dark matter and mediator fields confined to a brane on one end of the extra dimension, and the Higgs field to a brane on the other end. The Standard Model fermion and gauge fields are the zero modes of corresponding bulk fields with appropriate boundary conditions. Global flavor symmetries exist in the bulk and on the FDM brane, while they are broken on the Higgs brane. Flavor violating processes arise due to the misalignment of bases for which the interactions on the two branes are diagonalized, and their size can be controlled by a choice of the lepton profiles along the extra dimension. By studying the parameter space for the model, we show that when relic abundance and indirect detection constraints are satisfied, the rates for flavor violating processes such as $muto egamma$ remain far below the experimental limits.
rate research
Read More
We analyze the flavor violation in warped extra dimension due to radion mediation. We show that Delta S=2 and Delta B=2 flavor violating processes impose stringent constraints on radion mass, m_phi and the scale Lambda_phi. In particular, for Lambda_phi ~ O(1) TeV, B_d^0-bar{B}^0_d implies that m_phi ~ 65 GeV. We also study radion contributions to lepton flavor violating processes: tau -> (e,mu) phi, tau -> emu^+mu^- and B -> l_i l_j. We show that BR(B_s -> mu^+ mu^-) can be of order 10^{-8}, which is reachable at the LHCb. The radion search at LHC, through the flavor violation decays into tau mu or top-charm quarks, is also considered.
In this paper we analyze a dark matter model inspired by theories with extra dimensions. The dark matter candidate corresponds to the first Kaluza-Klein mode of a real scalar added to the Standard Model. The tower of new particles enriches the calculation of the relic abundance. For large mass splitting, the model converges to the predictions of the inert singlet dark matter model. For nearly degenerate mass spectrum, coannihilations increase the cross-sections used for direct and indirect dark matter searches. Moreover, the Kaluza-Klein zero mode can mix with the SM higgs and further constraints can be applied.
We consider the minimal supersymmetric standard model within a scenario of large $tanbeta$ and heavy squarks and gluinos, with masses of the heavy neutral Higgs bosons below the TeV scale. We allow for the presence of a large, model independent, source of lepton flavor violation (LFV) in the slepton mass matrix in the $tau-mu$ sector by the mass insertion approximation. We constrain the parameter space using the $tau$ LFV decays together with the $B$-mesons physics observables, the anomalous magnetic moment of the muon and the dark matter relic density. We further impose the exclusion limit on spin-independent neutralino-nucleon scattering from CDMS and the recent CDF limit from direct search of the heavy neutral Higgs at the TEVATRON. We re-examine the prospects for the detection of Higgs mediated LFV at LHC, at a photon collider and in LFV decays of the $tau$ such as $tautomueta$, $tautomugamma$. We find rates probably too small to be observed at future experiments if models have to accommodate for the relic density measured by WMAP and explain the $(g-2)_{mu}$ anomaly: better prospects are found if these two constraints are applied only as upper bounds. The spin-independent neutralino-nucleon cross section in the studied constrained parameter space is just below the present CDMS limit and the running XENON100 experiment will cover the region of the parameter space where the lightest neutralino has large gaugino-higgsino mixing.
We investigate a model on an extra dimension $S^1$ where plenty of effective boundary points described by point interactions (zero-thickness branes) are arranged. After suitably selecting the conditions on these points for each type of five-dimensional fields, we realize the tiny active neutrino masses, the charged lepton mass hierarchy, and lepton mixings with a CP-violating phase, simultaneously. Not only the quarks but also the leptons configurations are generated in a unified way with acceptable accuracy, with neither the see-saw mechanism nor symmetries in Yukawa couplings, by suitably setting the model parameters, even though their flavor structures are dissimilar each other. One remarkable point is that a complex vacuum expectation value of the five-dimensional Higgs doublet in this model becomes the common origin of the CP violation in both quark and lepton sectors. The model can be consistent with the results of the precision electroweak measurements and Large Hadron Collider experiments.
Flavor symmetric model is one of the attractive Beyond Standard Models (BSMs) to reveal the flavor structure of the Standard Model (SM). A lot of efforts have been put into the model building and we find many kinds of flavor symmetries and setups are able to explain the observed fermion mass matrices. In this paper, we look for common predictions of physical observables among the ones in flavor symmetric models, and try to understand how to test flavor symmetry in experiments. Especially, we focus on the BSMs for leptons with extra Higgs $SU(2)_L$ doublets charged under flavor symmetry. In many flavor models for leptons, remnant symmetry is partially respected after the flavor symmetry breaking, and it controls well the Flavor Changing Neutral Currents (FCNCs) and suggests some crucial predictions against the flavor changing process, although the remnant symmetry is not respected in the full lagrangian. In fact, we see that $tau^- to e^+ mu^- mu^-$ $( mu^+ e^- e^-)$ and $e^+ e^- to tau^+tau^-$ $(mu^-mu^+)$ processes are the most important in the flavor models that the extra Higgs doublets belong to triplet representation of flavor symmetry. For instance, the stringent constraint from the $mu to e gamma$ process could be evaded according to the partial remnant symmetry. We also investigate the breaking effect of the remnant symmetry mediated by the Higgs scalars, and investigate the constraints from the flavor physics: the flavor violating $tau$ and $mu$ decays, the electric dipole moments, and the muon anomalous magnetic moment. We also discuss the correlation between FCNCs and nonzero $theta_{13}$, and point out the physical observables in the charged lepton sector to test the BSMs for the neutrino mixing.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
