相关论文: Double beta decay of sigma^- hyperons
Neutrinoless double beta decay is the most powerful tool to probe not only for Majorana neutrino masses but for lepton number violating physics in general. We discuss relations between lepton number violation, double beta decay and neutrino…
There is a general consensus that detection of a double-beta decay without any neutrino involved would mark physics beyond the Standard Model. This is because in such decay modes lepton number conservation would be violated and the neutrino…
The semileptonic decays $\bar{B}\to D(D^*)\pi\ell\bar{\nu}$ are analyzed by heavy quark and chiral symmetries. The branching ratio is of order of a few percent for $\dpi$, but it is much smaller for $\dstar$, of order $10^{-4}-10^{-5}$. The…
The differential branching ratio, forward-backward asymmetry, CP asymmetry and lepton polarization for a B-meson to decay to strange hadronic final states and a $\tau^+\tau^-$ pair in a CP softly broken two Higgs doublet model are computed.…
The rare hyperon decay $\Sigma^+ \to p \ell^+ \ell^-$ is a flavour-changing neutral current process mediated by an $s \to d$ transition that occurs only at loop level within the Standard Model. Consequently, this decay is highly suppressed,…
By analyzing existing data on pseudoscalar charmonium decays, we obtain the ratio of the branching fractions of $\eta_c(2S)$ and $\eta_c$ decays into ten different final states with light hadrons. For the first time, we test the two…
Double beta decay has been proven to be a powerful tool to constrain $B-L$ violating physics beyond the standard model. We present a representation for the long-range part of the general $0\nu\beta\beta$ decay rate allowed by…
In this letter we present the study of the eightfold degeneracy in the $(\theta_{13},\delta)$ measurement including both appearance and disappearance channels. We analyse, for definiteness, the case of a standard low-$\gamma$ $\beta$-Beam…
Tau lepton emission in two-nucleon disappearance reactions from within nuclei which conserve baryon number minus lepton number (B-L) is considered. It is shown that some existing limits on proton decay channels and two-nucleon disappearance…
We explore the semileptonic and nonleptonic decays of doubly heavy baryons $(\Omega_{cc}^ {(*) +}, \Omega_{bb}^ {(*)0}, \Omega_{bc}^ {(*) -}, \Omega_{bc}^ {\prime 0}) $ induced by the $s\to u$ transition. Hadronic form factors are…
Branching fractions of B^0s decays into specific CP eigenstates are presented, and these and other results are combined in world averages to evaluate implications on the width difference between mass or CP eigenstates, \Delta\Gamma_s. New…
In the Minimal Supersymmetric Standard Model, neutralinos lighter than 50 GeV are compatible with all accelerator, precision, and cosmological bounds. Such neutralinos might constitute a relevant decay channel for the Higgs boson, modifying…
CMS has reported indications (2.4\sigma) of the decay of the Higgs boson into \mu\tau. The simplest explanation for such a decay would be a general Two Higgs Doublet Model (2HDM). In this case, one would expect the heavy neutral Higgs…
The $\Delta S = 2$ transition $b \to s s \bar d$ is extremely small in the standard model, proceeding only via box diagrams. Such decays are thus an appropriate ground for searching new physics. We present a study of several two-body and…
We make a comparative study of the neutrinoless double beta decay constraints on heavy sterile neutrinos versus other direct and indirect constraints from both lepton number conserving and violating processes, as a sensitive probe of the…
The MEGA experiment, which searched for the muon- and electron-number violating decay \mu -> e + \gamma, is described. The spectrometer system, the calibrations, the data taking procedures, the data analysis, and the sensitivity of the…
A measurement of neutrinoless double beta decay in one isotope does not allow to determine the underlying physics mechanism. We discuss the discrimination of mechanisms for neutrinoless double beta decay by comparing ratios of half life…
Main theoretical approaches to weak radiative hyperon decays are briefly reviewed. It is emphasized that only approaches with great predictive power should be seriously considered when seeking a resolution of the puzzle presented by…
We report the first evidence for the decay Sigma+ -> p mu+ mu- from data taken by the HyperCP experiment(E871) at Fermilab. Based on three observed events, the branching ratio is B(Sigma+ -> p,mu+,mu-) = [8.6 +6.6,-5.4(stat) +/-5.5(syst)] x…
The search for neutrinoless double beta decay and WIMP dark matter has a broad potential to test particle physics beyond the standard model. During the last years, the analysis of various contributions to the double beta decay rate by the…