1,229 research outputs found

    Effects of physics beyond the standard model on the neutrino charge radius: an effective Lagrangian approach

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    In this work, we look for possible new physics effects on the electromagnetic charge and anapole form factors, fQ(q2)f_Q(q^2) and fA(q2)f_A(q^2), for a massless Dirac neutrino, when these quantities are calculated in the context of an effective electroweak Yang-Mills theory, which induces the most general SUL(2)SU_L(2)--invariant Lorentz tensor structure of nonrenormalizable type for the WWγWW\gamma vertex. It is found that in this context, besides the standard model contribution, the additional contribution to fQ(q2)f_{Q}(q^2) and fA(q2)f_{A}(q^2) (fQOW(q2)f_{Q}^{O_W}(q^2) and fAOW(q2)f_{A}^{O_W}(q^2), respectively) are gauge independent and finite functions of q2q^2 after adopting a renormalization scheme. These form factors, fQOW(q2)f_{Q}^{O_W}(q^2) and fAOW(q2)f_{A}^{O_W}(q^2), get contribution at the one loop level only from the proper neutrino electromagnetic vertex. Besides, the relation fQeff(q2)=q2fAeff(q2)f_{Q}^{eff}(q^2)=q^2f_{A}^{eff}(q^2) (fQeff(q2)=fQSM(q2)+fQOW(q2)f_{Q}^{eff}(q^2)=f_{Q}^{SM}(q^2)+f_{Q}^{O_W}(q^2), fAeff(q2)=fASM(q2)+fAOW(q2)f_{A}^{eff}(q^2)=f_{A}^{SM}(q^2)+f_{A}^{O_W}(q^2)) is still fulfilled and hence the relation aνeff=eff/6a_{\nu}^{eff} = ^{eff} /6 (aνeff=aνSM+aνOWa_{\nu}^{eff} = a_{\nu}^{SM}+ a_{\nu}^{O_W}, eff=SM+<rν2>OW ^{eff} = ^{SM}+< r^2_{\nu} > ^{O_W})is gotten, just as in the SM. Using the experimental constraint on the anomalous WWγWW\gamma vertex, a value for the additional contribution to the charge radius of |^{O_W}| \lsim 10^{-34} cm^2 is obtained, which is one order of magnitude lower than the SM value.Comment: 9 pages, 3 figure

    T-violation in Kμ3K_{\mu3} decay in a general two-Higgs doublet model

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    We calculate the transverse muon polarization in the Kμ3+K^+_{\mu3} process arising from the Yukawa couplings of charged Higgs boson in a general two-Higgs doublet model where spontaneous violation of CP is presentComment: 6 pages, latex, accepted for publication in Phys. Rev.

    Possibility between earthquake and explosion seismogram differentiation by discrete stochastic non-Markov processes and local Hurst exponent analysis

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    The basic purpose of the paper is to draw the attention of researchers to new possibilities of differentiation of similar signals having different nature. One of examples of such kind of signals is presented by seismograms containing recordings of earthquakes (EQ's) and technogenic explosions (TE's). We propose here a discrete stochastic model for possible solution of a problem of strong EQ's forecasting and differentiation of TE's from the weak EQ's. Theoretical analysis is performed by two independent methods: with the use of statistical theory of discrete non-Markov stochastic processes (Phys. Rev. E62,6178 (2000)) and the local Hurst exponent. Time recordings of seismic signals of the first four dynamic orthogonal collective variables, six various plane of phase portrait of four dimensional phase space of orthogonal variables and the local Hurst exponent have been calculated for the dynamic analysis of the earth states. The approaches, permitting to obtain an algorithm of strong EQ's forecasting and to differentiate TE's from weak EQ's, have been developed.Comment: REVTEX +12 ps and jpg figures. Accepted for publication in Phys. Rev. E, December 200

    DMTPC: A dark matter detector with directional sensitivity

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    By correlating nuclear recoil directions with the Earth's direction of motion through the Galaxy, a directional dark matter detector can unambiguously detect Weakly Interacting Massive Particles (WIMPs), even in the presence of backgrounds. Here, we describe the Dark Matter Time-Projection Chamber (DMTPC) detector, a TPC filled with CF4 gas at low pressure (0.1 atm). Using this detector, we have measured the vector direction (head-tail) of nuclear recoils down to energies of 100 keV with an angular resolution of <15 degrees. To study our detector backgrounds, we have operated in a basement laboratory on the MIT campus for several months. We are currently building a new, high-radiopurity detector for deployment underground at the Waste Isolation Pilot Plant facility in New Mexico.Comment: 4 pages, 2 figures, proceedings for the CIPANP 2009 conference, May 26-31, 200

    Self-interacting Elko dark matter with an axis of locality

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    This communication is a natural and nontrivial continuation of the 2005 work of Ahluwalia and Grumiller on Elko. Here we report that Elko breaks Lorentz symmetry in a rather subtle and unexpected way by containing a `hidden' preferred direction. Along this preferred direction, a quantum field based on Elko enjoys locality. In the form reported here, Elko offers a mass dimension one fermionic dark matter with a quartic self-interaction and a preferred axis of locality. The locality result crucially depends on a judicious choice of phases.Comment: 14 pages (RevTex

    Bound - states for truncated Coulomb potentials

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    The pseudoperturbative shifted - ll expansion technique PSLET is generalized for states with arbitrary number of nodal zeros. Bound- states energy eigenvalues for two truncated coulombic potentials are calculated using PSLET. In contrast with shifted large-N expansion technique, PSLET results compare excellently with those from direct numerical integration.Comment: TEX file, 22 pages. To appear in J. Phys. A: Math. & Ge

    On the Dalitz Plot Approach in Non-leptonic Charm Meson Decays

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    We claim that the non-resonant contribution to non-leptonic charm meson decays may not be constant in the phase space of the reaction. We argue that this can be relevant for any weak reaction. We discuss in detail the decay D+→K−π+π+D^+ \to K^- \pi^+ \pi^+.Comment: Version accepted for publication in Physical Review Letters. 9 pages, Latex, including 2 figure
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