相关论文: $\Delta L=2$ hyperon semileptonic decays
Searches for $\Delta L=2$ decays are crucial to disentangle the Dirac vs Majorana nature of neutrinos. While neutrinoless nuclear double beta decays are the most promising tool to look for di-electron signals of $\Delta L=2$, searches of…
Using data collected on the Upsilon(4S) resonance and the nearby continuum by the CLEO detector at the Cornell Electron Storage Ring, we have searched for the semileptonic decay of B mesons to electron-antiproton inclusive final states. We…
The Majorana nature of neutrinos can be experimentally verified only via {\it lepton-number} violating processes involving charged leptons. We study 36 lepton-number violating ($\lv$) processes from the decays of tau leptons and…
Recently, several hints of lepton non-universality have been observed in the semileptonic B meson decays in terms of both in the neutral current ($b\to s l \bar{l}$) and charged current ($b\to c l \bar{\nu_{l}}$) transitions. Motivated by…
A search for heavy Majorana neutrinos produced in the $B^- \to \pi^+\mu^-\mu^-$ decay mode is performed using 3 fb$^{-1}$ of integrated luminosity collected with the LHCb detector in $pp$ collisions at center-of-mass energies of 7 TeV and 8…
We investigate the possible contribution of Majorana neutrinos to $B$ meson decays in an effective interaction formalism, in the mass range $0.5$ GeV $<m_N<5 $ GeV. We study the decay of the $B^-$ meson via $B^- \to \mu^- \mu^- \pi^+$ at…
Recently, several indications of lepton non-universality observables have been perceived in semileptonic $B$ meson decay processes, both in the neutral-current ($b \to s ll $) and charged-current ($b \to c l \bar \nu_l$) transitions.…
We explore the possibility of CP violation in baryonic $\Lambda_b\to(\Lambda_c^+, p^+)\pi^+\mu^-\mu^-$ decays which are mediated by two Majorana sterile neutrino and are $|\Delta L|=2$ lepton number violating processes. Appreciable CP…
We study lepton number violating decays of charged K, D, D_s, B and B_c mesons of the form M^+\to {M'}^-\ell^+\ell^+, induced by the existence of Majorana neutrinos. These processes provide information complementary to neutrinoless double…
We consider four lepton-number violating (\lv) processes: (a) neutrinoless double-beta decay (0\nu\beta\beta), (b) Delta L = 2 tau decays, (c) Delta L = 2 rare meson decays and (d) nuclear muon-positron conversion. In the absence of exotic…
The experimental observation of lepton-number violating processes would unambiguously indicate the Majorana nature of neutrinos. Various $\Delta L$ = 2 processes for pseudoscalar meson $M_1$ decays to another pseudoscalar meson $M_2$ and…
Using data collected by the CLEO II detector at the center-of-mass energy on or near the Upsilon(4S) resonance, we have determined the 90% confidence level upper limit B(Bbar --> Lambda_c^+ e- X)/B(Bbar --> Lambda_c^+ X, Lambdabar_c^- X) <…
Ratios of charmed meson and baryon semileptonic decay rates appear to be satisfactorily described by considering only the lowest-lying (S-wave) hadronic final states and assuming the kinematic factor describing phase space suppression is…
We have obtained the differential decay rate and calculated the branching ratios of the exclusive semileptonic decays $B(D) \to Xl\nu$, where $X$ is a p-wave meson, using the nonrelativistic ISGW quark model. Our results are compared with…
The effect of Majorana neutrinos in the MeV mass range on the double beta decay of various isotopes is studied on pure phenomenological arguments. By using only experimental half life data, limits on the mixing parameter $U_{eh}^2$ of the…
In the minimal extension of the standard electroweak theory with ultra massive Majorana neutrinos, the process e- + e- -> mu- + mu- could be observable, in sharp contrast with the reaction e- + e- -> W- + W- which is entirely controlled by…
Motivated by the excess events that have recently been found near the endpoints of the double beta decay spectra of several elements, we re-examine models in which double beta decay can proceed through the neutrinoless emission of massless…
The width for the mu decay is calculated in the V-A theory leaving open the possibility of non zero neutrino masses. It is shown that not only the agreement with the experimental data is kept, but the smallness of the experimental error…
The Belle experiment at the KEKB asymmetric energy e+e- collider recorded large data sets of both, B and Bs decays. Semileptonic decays B(s) -> X l nu (l = electron or muon) constitute approximately one fifth of the total decay width of…
Semileptonic decays of the $\Xi_b$ baryon are studied in the framework of the relativistic quark-diquark model based on the quasipotential approach. The weak decay form factors are calculated with the comprehensive account of all…