Search results for "FLAVOR"
showing 10 items of 360 documents
η–η′ mixing in the flavor basis and large N
2010
Abstract The mass matrix for η – η ′ is derived in the flavor basis at O ( p 4 ) of the chiral Lagrangian using the large N approximation. Under certain assumptions, the mixing angle ϕ = 41.4 ° and the decay constants ratio f K / f π = 1.15 are calculated in agreement with the data. It appears that the FKS scheme arises as a special limit of the chiral Lagrangian. Their mass matrix is obtained without the hypothesis on the mixing pattern of the decay constants.
Search for the rare decay Bs 0→μ+μ-
2010
We present the results of a search for the flavor changing neutral current decay B-s(0) -> mu(+)mu(-) using 6.1 fb(-1) of p (p) over bar collisions at root s = 1.96 TeV collected by the D0 experiment at the Fermilab Tevatron Collider. The observed number of B-s(0) candidates is consistent with background expectations. The resulting upper limit on the branching fraction is B(B-s(0) -> mu(+)mu(-)) < 5.1 x 10(-8) at the 95% C.L. This limit is a factor of 2.4 better than that of the previous DO analysis and the best limit to date. Published by Elsevier B.V.
Lepton Flavor Violation and non-unitarity Lepton Mixing in Low-Scale Type-I Seesaw
2011
Within low-scale seesaw mechanisms, such as the inverse and linear seesaw, one expects (i) potentially large lepton flavor violation (LFV) and (ii) sizeable non-standard neutrino interactions (NSI). We consider the interplay between the magnitude of non-unitarity effects in the lepton mixing matrix, and the constraints that follow from LFV searches in the laboratory. We find that NSI parameters can be sizeable, up to percent level in some cases, while LFV rates, such as that for \mu -> e \gamma, lie within current limits, including the recent one set by the MEG collaboration. As a result the upcoming long baseline neutrino experiments offer a window of opportunity for complementary LFV and …
Testing a lepton quarticity flavor theory of neutrino oscillations with the DUNE experiment
2018
Oscillation studies play a central role in elucidating at least some aspects of the flavor problem. Here we examine the status of the predictions of a lepton quarticity flavor theory of neutrino oscillations against the existing global sample of oscillation data. By performing quantitative simulations we also determine the potential of the upcoming DUNE experiment in narrowing down the currently ill-measured oscillation parameters $\theta_{23}$ and $\delta_{\text{CP}}$. We present the expected improved sensitivity on these parameters for different assumptions.
General flavor blind minimal supersymmetric standard model andCPviolation
2001
We study the implications on flavor changing neutral current and $\mathrm{CP}$ violating processes in the context of supersymmetric theories without a new flavor structure (flavor blind supersymmetry). The low-energy parameters are determined by the running of the soft breaking terms from the grand unified scale with supersymmetric (SUSY) phases consistent with the electric dipole moment constraints. We find that the $\mathrm{CP}$ asymmetry in $\stackrel{\ensuremath{\rightarrow}}{b}s\ensuremath{\gamma}$ can reach large values potentially measurable at B factories, especially in the low $BR(\stackrel{\ensuremath{\rightarrow}}{b}s\ensuremath{\gamma})$ region, while the contributions to electr…
Restricted flavor structure of soft SUSY breaking trilinear couplings
2000
We analyze the flavor structure of the trilinear couplings in the different theoretical models of SUSY breaking. We generically obtain A_{ij}= A^L_i + A^R_j in all the models examined. In fact, this is the rigorous form when SUSY breaking effects appear through the Kahler metric of chiral fields or through wave-function renormalization. Indeed, the low-energy phenomenological requirements from the absence of charge and color breaking minima and the measurements in flavor changing neutral current (FCNC) observables strongly favor this restricted form of the trilinear matrices. As a straightforward consequence, the number of unknown parameters associated with the trilinear couplings is decrea…
Status and implications of neutrino masses: a brief panorama
2015
15 pages.- 10 figures
Flavor changing neutral currents in the dualized standard model
1998
The Dualized Standard Model which gives explanations for both fermion generations and Higgs fields has already been used to calculate fermion mass and mixing parameters with success. In this paper, we extend its application to low energy FCNC effects deriving bounds for various processes in terms of one single mass scale. Using then experimental information from K_L - K_S mass difference and air showers beyond the GZK cut-off, these bounds are converted into rough, order-of-magnitude predictions. In particular, the estimates for the decay K_L \to e^\pm \mu^\mp and for the mass difference between the neutral D-mesons seem accessible to experiment in the near future.
Absolute neutrino mass scale from flavor symmetries
2013
Abstract The 2012 has been an important year for neutrino physics, current data are reviewed and compared with 2011 global fit. Models based on discrete flavor symmetries predict neutrino mass mass sum-rule (MSR), which is useful to reduce the number of independent model parameters. We found that only four classes of MSR are possible. Such neutrino MSRs constrain the absolute neutrino mass scale. We study the implications of these mass relations for the lightest neutrino mass and for the lower bound of the effective mass m e e of the neutrinoless double beta decay.
Is charged lepton flavor violation a high energy phenomenon?
2013
Searches for rare processes such as mu --> e gamma put stringent limits on lepton flavour violation expected in many Beyond the Standard Model physics scenarios. This usually precludes the observation of flavour violation at high energy colliders such as the LHC. We here discuss a scenario where right-handed neutrinos are produced via a Z' portal but which can only decay via small flavour violating couplings. Consequently, the process rate is unsuppressed by the small couplings and can be visible despite unobservably small mu --> e gamma rates.