相关论文: Lepton Number Violation in Top-Color Assisted Tech…
In the context of topcolor-assisted techicolor(TC2) models, we study the contributions of the neutral top-pion $\pi^{0}_{t}$ to the lepton flavor violating(LFV) processes $l_{i}\to l_{j}\gamma$ and $l_{i}\to l_{j}l_{k}l_{l}$. We find that…
Topcolor--assisted technicolor provides a dynamical explanation for electroweak and flavor symmetry breaking and for the large mass of the top quark without unnatural fine tuning. A major challenge is to generate the observed mixing between…
Recent study on the charged top-pion correction to R_b shows that it is negative and large, so that the precision experimental value of R_b gives rise to a severe constraint on the topcolor-assisted technicolor models such that the top-pion…
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…
Processes $\tau\rightarrow l\gamma$, $\tau\rightarrow lll$ with $l= e,\mu$ and $\mu(\tau) \to e (\mu) \gamma$ are evaluated in the framework of a model based on the extended symmetry gauge $SU(3)_c \otimes SU(3)_L \otimes U(1)_Y$ with a…
A lepton-flavor violating (LFV) Z' boson may mimic some of the phenomena usually attributed to supersymmetric theories. Using a conservative model of LFV Z' bosons, the recent BNL E821 muon g-2 deviation allows for a LFV Z' interpretation…
An upper bound on the total cross-section of s-wave electroweak instanton/sphaleron induced baryon plus lepton number violating processes is presented. It is obtained by exploiting a recently reported lower bound on the corresponding…
A search for new high-mass resonances in proton-proton collisions having final states with an electron or muon and missing transverse momentum is presented. The analysis uses proton-proton collision data collected in 2016 with the CMS…
Proton decay experiments typically constrain baryon number violation to the scale of grand unified theories. From a phenomenological point of view, this makes direct probing of the associated new resonances, such as the X and Y bosons, out…
We study pseudo-Goldstone boson corrections to top quark pair production rates in technicolor models with and without topcolor at the E=0.5 teV and 1.5 TeV photon colliders. We find that, for reasonable ranges of the parameters, the…
Lepton number violation (LNV) can be induced by Majorana neutrinos in four-body decays of the neutral B meson and the top quark. We study the effects of Majorana neutrinos in these |\Delta L|=2 decays in an scenario where a single heavy…
We study the Lepton number violating like-sign dilepton processes $h_1 h_2 \to l^\pm l^{\prime \pm} jj X$ and $h_1 h_2 \to l^\pm l^{\prime \pm} W^\pm X$, mediated by heavy GeV scale Majorana neutrinos. We focus on the resonantly enhanced…
A search for heavy resonances that decay to tau lepton pairs is performed using proton-proton collisions at sqrt(s) = 13 TeV. The data were collected with the CMS detector at the CERN LHC and correspond to an integrated luminosity of 2.2…
The new particles predicted by the topcolor-assisted technicolor ($TC2$) model and the littlest Higgs model with T-parity (called $LHT$ model) can induce the lepton flavor violation ($LFV$) couplings at tree level or one loop level, which…
After discussion of mechanisms of lepton number violation, we consider meson decays $K^+ \to\pi^ - \ell ^ + \ell '^ +$ and $D^ + \to K^ - \ell ^ + \ell '^ +$ ($\ell,\ell ' = e,\mu $) with $\Delta L= 2$ in the Standard Model extended by…
The search for lepton flavor violation (LFV) is a powerful probe to look for new physics beyond the Standard Model. We explored the possibility of searches for LFV $Z$ boson couplings to electron and muon pairs at the upcoming…
Lepton family number violation is tested by searching for $\mu^+\to e^+X^0$ decays among the 5.8$\times 10^8$ positive muon decay events analyzed by the TWIST collaboration. Limits are set on the production of both massless and massive…
A deep inerastic scattering process \mutau is discussed to study lepton flavor violation between muons and tau leptons. In supersymmetric models, the Higgs boson mediated diagrams could be important for this reaction. We find that at a muon…
We search for lepton flavor and lepton number violating tau decays into a lepton (ell = electron or muon) and two charged mesons (h,h' = pi^\pm or K^\pm), tau- -> ell-h+h'- and tau- -> ell+h-h'-, using 671 fb^{-1} of data collected with the…
We construct a new gauged $U(1)_\ell$ lepton number model which is anomaly-free for each SM generation. The active neutrino masses are radiatively generated with a minimal scalar sector. The phenomenology and collider signals are studied.…