1,892 research outputs found

    Scotogenic A4A_4 Neutrino Model for Nonzero θ13\theta_{13} and Large δCP\delta_{CP}

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    Assuming that neutrinos acquire radiative seesaw Majorana masses through their interactions with dark matter, i.e. scotogenic from the Greek 'scotos' meaning darkness, and using the non-Abelian discrete symmetry A4A_4, we propose a model of neutrino masses and mixing with nonzero θ13\theta_{13} and necessarily large leptonic CP violation, allowing both the normal and inverted hierarchies of neutrino masses, as well as quasi-degenerate solutions.Comment: 12 pages, 12 figure

    Nonstandard interactions of tau neutrino via charged Higgs and WW' contribution

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    We consider charged Higgs and WW' gauge boson contributions to the quasielastic scattering ντ+nτ+p\nu_{\tau}+ n \rightarrow \tau^- + p and νˉτ+pτ++n\bar{\nu}_{\tau}+ p \rightarrow \tau^+ + n . These effects modify the standard model cross section for these processes and thus impact the extraction of the neutrino mixing angles θ23\theta_{23} and θ13\theta_{13} . We include form factor effects in our calculations and find the deviation of the actual mixing angle from the measured one, assuming the standard model cross section, can be significant and can depend on the energy of the neutrino.Comment: 23 pages, 19 figure

    Probing lepton non-universality in tau neutrino Scattering

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    Recently hints of lepton flavor non-universality emerged in the BaBar and LHCb experiments. In this paper we propose tests of lepton universality in ντ\nu_{\tau} scattering. To parametrize the new physics we adopt an effective Lagrangian approach and consider the neutrino deep inelastic scattering processes ντ+Nτ+X\nu_{\tau}+ N \to \tau + X and νμ+Nμ+X\nu_{\mu}+ N \to \mu + X where we assume the largest new physics effects are in the τ\tau sector. We also consider an explicit leptoquark model in our calculations. In order to make comparison with the standard model and also in order to cancel out the uncertainties of the parton distribution functions, we consider the ratio of total and differential cross sections of tau-neutrino to muon-neutrino scattering. We find new physics effects that can possibly be observed at the proposed Search for Hidden Particles (SHiP) experiment at CERN.Comment: 29 pages, 29 figures. Typos correcte

    Model based system engineering approach of a lightweight embedded TCP/IP

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    The use of embedded software is growing very rapidly. Accessing the internet is a necessary service which has large range of applications in many fields. The Internet is based on TCP/IP which is a very important stack. Although TCP/IP is very important there is not a software engineering model describing it. The common method in modeling and describing TCP/IP is RFCs which is not sufficient for software engineer and developers. Therefore there is a need for software engineering approach to help engineers and developers to customize their own web based applications for embedded systems. This research presents a model based system engineering approach of lightweight TCP/IP. The model contains the necessary phases for developing a lightweight TCP/IP for embedded systems. The proposed model is based on SysML as a model based system engineering language

    Phenomenology of ΛbΛcτνˉτ\Lambda_b \to \Lambda_c \tau \bar{\nu}_{\tau} using lattice QCD calculations

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    In a recent paper we studied the effect of new-physics operators with different Lorentz structures on the semileptonic ΛbΛcτνˉτ\Lambda_b \to \Lambda_c \tau \bar{\nu}_{\tau} decay. This decay is of interest in light of the R(D())R({D^{(*)}}) puzzle in the semileptonic BˉD()τνˉτ\bar{B} \to D^{(*)} \tau {\bar\nu}_\tau decays. In this work we add tensor operators to extend our previous results and consider both model-independent new physics (NP) and specific classes of models proposed to address the R(D())R({D^{(*)}}) puzzle. We show that a measurement of R(Λc)=B[ΛbΛcτνˉτ]/B[ΛbΛcνˉ]R(\Lambda_c) = {\cal B}[\Lambda_b \to \Lambda_c \tau \bar{\nu}_{\tau}] / {\cal B}[\Lambda_b \to \Lambda_c \ell \bar{\nu}_{\ell}] can strongly constrain the NP parameters of models discussed for the R(D())R({D^{(*)}}) puzzle. We use form factors from lattice QCD to calculate all ΛbΛcτνˉτ\Lambda_b \to \Lambda_c \tau \bar{\nu}_{\tau} observables. The ΛbΛc\Lambda_b \to \Lambda_c tensor form factors had not previously been determined in lattice QCD, and we present new lattice results for these form factors here.Comment: 44 pages, 105 figure

    Radiative Scaling Neutrino Mass with A4A_4 Symmetry

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    A new idea for neutrino mass was proposed recently, where its smallness is not due to the seesaw mechanism, i.e. not inversely proportional to some large mass scale. It comes from a one-loop mechanism with dark matter in the loop consisting of singlet Majorana fermions NiN_i with masses of order 10 keV and neutrino masses are scaled down from them by factors of about 10510^{-5}. We discuss how this model may be implemented with the non-Abelian discrete symmetry A4A_4 for neutrino mixing, and consider the phenomenology of NiN_i as well as the extra scalar doublet (η+,η0)(\eta^+,\eta^0).Comment: 11 pages, 1 figur

    The charged lepton mass matrix and non-zero θ13\theta_{13} with TeV scale New Physics

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    We provide an explicit structure of the charged lepton mass matrix which is 2-3 symmetric except for a single breaking of this symmetry by the muon mass. We identify a flavor symmetric limit for the mass matrices where the first generation is decoupled from the other two in the charged lepton sector while in the neutrino sector the third generation is decoupled from the first two generations. The leptonic mixing in the symmetric limit can be, among other structures, the bi-maximal (BM) or the tri-bimaximal (TBM) mixing. Symmetry breaking effects are included both in the charged lepton and the neutrino sector to produce corrections to the leptonic mixing and explain the recent θ13\theta_{13} measurements. A model that extends the SM by three right handed neutrinos, an extra Higgs doublet, and two singlet scalars is introduced to generate the leptonic mixing.Comment: 28 pages, 24 figures. arXiv admin note: substantial text overlap with arXiv:1111.307
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