4,290 research outputs found

    Inclusive Pion Production at High PTP_{T}

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    Sizable CP Violation in the Bosonized Standard Model

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    Using the worldline method, we derive an effective action of the bosonic sector of the Standard Model by integrating out the fermionic degrees of freedom. The CP violation stemming from the complex phase in the CKM matrix gives rise to CP-violating operators in the one-loop effective action in the next-to-leading order of a gradient expansion. We calculate the prefactor of the appropriate operators and give general estimates of CP violation in the bosonic sector of the Standard Model. In particular, we show that the effective CP violation for weak gauge fields is not suppressed by the Yukawa couplings of the light quarks and is much larger than the bound given by the Jarlskog determinant.Comment: 15 pages, minor changes, published versio

    Unifying CP violations of quark and lepton sectors

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    A preliminary determination of the Dirac phase in the PMNS matrix is \dell\approx -\frac{\pi}{2}. A rather accurately determined Jarlskog invariant JJ in the CKM matrix is close to the maximum. Since the phases in the CKM and PMNS matrices will be accurately determined in the future, it is an interesting problem to relate these two phases. This can be achieved in a families-unified grand unification if the weak CP violation is introduced spontaneously {\it \`a la} Froggatt and Nielsen at a high energy scale, where only one meaningful Dirac CP phase appears.Comment: 10 pages with 3 figure

    Plans for Kaon Physics at BNL

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    I give an overview of current plans for kaon physics at BNL. The program is centered on the rare decay modes K+ --> pi+ nu nubar and KL --> pi0 nu nubar.Comment: 10 pages, 8 figures. Uses espcrc2.sty. For the proceedings of HIF04: High Intensity Frontier Workshop, La Biodola, Isola D'Elba, June 5-8, 200

    Quark-lepton mass unification at TeV scales

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    A scenario combining a model of early (TeV) unification of quarks and leptons with the physics of large extra dimensions provides a natural mechanism linking quark and lepton masses at TeV scale. This has been dubbed as early quark-lepton mass unification by one of us (PQH) in one of the two models of early quark-lepton unification, which are consistent with data, namely SU(4)_PS \otimes SU(2)_L \otimes SU(2)_R \otimes SU(2)_H. In particular, it focused on the issue of naturally light Dirac neutrino. The present paper will focus on similar issues in the other model, namely SU(4)_PS \otimes SU(3)_L \otimes SU(3)_H.Comment: Accepted for publication in PRD: The new version is in agreement with the accepted manuscrip

    Triangular Textures for Quark Mass Matrices

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    The hierarchical quark masses and small mixing angles are shown to lead to a simple triangular form for the U- and D-type quark mass matrices. In the basis where one of the matrices is diagonal, each matrix element of the other is, to a good approximation, the product of a quark mass and a CKM matrix element. The physical content of a general mass matrix can be easily deciphered in its triangular form. This parameterization could serve as a useful starting point for model building. Examples of mass textures are analyzed using this method.Comment: 10 pages, no figure

    Determining fundamental parameters from the chargino sector in Left-Right Supersymmetric models

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    Analytical expressions relating the fundamental parameters describing the chargino sector in the context of the Left-Right Supersymmetric model are constructed. A general complex extension of the real non-symmetric chargino mass matrix including all possible CP-violating phases is considered. The method used for such a effects is the projector formalism based on the explicit knowledge of two unitary matrices diagonalizing the chargino mass matrix. Some possible scenarios allowing us to extract analytical and numerical values for the unknown parameters are considered. Moreover, an algorithm allowing us to disentangle the fundamental parameters of the chargino sector, based on possible measurements of some class of cross-section observables related to the chargino pair production in e+ee^+ e^- annihilation processes, is described. Some comparisons with the corresponding results in the context of the Minimal Supersymmetric Standard Model are given.Comment: 48 pages, 13 figure

    A description of the neutralino observables in terms of projectors

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    Applying Jarlskog's treatment of the CKM matrix, to the neutralino mass matrix in MSSM for real soft gaugino SUSY breaking and μ\mu-parameters, we construct explicit analytical expressions for the four projectors which acting on any neutralino state project out the mass eigenstates. Analytical expressions for the neutralino mass eigenvalues in terms of the various SUSY parameters, are also given. It is shown that these projectors and mass eigenvalues are sufficient to describe any physical observable involving neutralinos, to any order of perturbation theory. As an example, the ee+χ~i0χ~j0e^-e^+ \to \tilde \chi^0_i \tilde \chi^0_j cross section at tree level is given in terms of these projectors. The expected magnitude of their various matrix elements in plausible SUSY scenarios is also discussed.Comment: 14 pages, no figures. Version to appear in Phys. Rev. D. e-mail: [email protected]

    A Predictive Minimal Model for Neutrino Masses and Mixings

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    A model is considered in which the scale of the heavy singlet neutrinos is a few orders of magnitude below the grand unification scale and where right-handed vector bosons play still a negligible role. In a basis with diagonal up-quark and Dirac-neutrino mass matrices it is assumed that the heavy neutrino mass matrix has only zero elements in its diagonal, in analogy to the light neutrino mass matrix in the Zee model. Connecting then the remaining matrix elements with the small parameter describing the hierarchy of quark masses and mixings and by assuming commutativity of the charged lepton with the down-quark mass matrix, the calculation of all neutrino properties can be performed in terms of the two mass differences relevant for atmospheric and solar neutrino oscillations. CP-violation is directly related to CP-violation in the quark sector.Comment: revtex, 9 pages, two references added, to be published in Phys. Rev. D presented at Neutrino' 2000, Sudbury, Canad

    CP Violation for Leptons at Higher Energy Scales

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    The phase convention independent measure of CP violation for three generations of leptons is evaluated at different energy scales. Unlike in the quark sector, this quantity does not vary much between the weak and the grand unification scales. The behavior of the measure of CP violation in the Standard Model is found to be different from that in the extensions of the Standard Model.Comment: 10 pages, 2 figures, references added, typos correcte
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