3,214 research outputs found

    Real CP violation in a simple extension of the standard model

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    I present a simple three-Higgs-doublet extension of the standard model in which real CP violation takes place. The strong CP problem is attenuated by this model.Comment: 8 page

    Radiative Kaon Decays K±π±π0γK^\pm\to\pi^\pm\pi^0\gamma and Direct CP Violation

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    It is stressed that a measurement of the electric dipole amplitude for direct photon emission in \kpm decays through its interference with inner bremsstrahlung is important for differentiating among various models. Effects of amplitude CP violation in the radiative decays of the charged kaon are analyzed in the Standard Model in conjunction with the large NcN_c approach. We point out that gluon and electromagnetic penguin contributions to the CP-violating asymmetry between the Dalitz plots of \kpm are of equal weight. The magnitude of CP asymmetry ranges from 2×1062\times 10^{-6} to 1×1051\times 10^{-5} when the photon energy in the kaon rest frame varies from 50 MeV to 170 MeV.Comment: Latex, 11 pages, ITP-SB-93-36, IP-ASTP-22-9

    Implicit Density Functional Theory

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    A fermion ground state energy functional is set up in terms of particle density, relative pair density, and kinetic energy tensor density. It satisfies a minimum principle if constrained by a complete set of compatibility conditions. A partial set, which thereby results in a lower bound energy under minimization, is obtained from the solution of model systems, as well as a small number of exact sum rules. Prototypical application is made to several one-dimensional spinless non-interacting models. The effectiveness of "atomic" constraints on model "molecules" is observed, as well as the structure of systems with only finitely many bound states.Comment: 9 pages, 4 figure

    Role of Scalar Meson Resonances in $K_{L}^{0} \rightarrow \pi^{0} \gamma \gamma Decay

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    Corrections to KL0π0γγK_{L}^{0}\rightarrow \pi^{0} \gamma \gamma decay induced by scalar meson exchange are studied within chiral perturbation theory. In spite of bad knowledge of scalar-mesons parameters, the calculated branching ratio can be changed by a few percent.Comment: 18 pages of text, 2 figures (available upon request); preprint IJS-TP-16-94 , TUM-T31-63-94

    Long distance contribution to K+π+ννˉK^+ \to \pi^+ \nu {\bar \nu} decay and O(p4)O(p^4) terms in CHPT

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    The long distance contribution to K+π+ννˉK^+ \to \pi^+ \nu {\bar \nu} is calculated using chiral perturbation theory. The leading contribution comes from O(p4)O(p^4) tree terms. The branching ratio of the O(p4)O(p^4) long distance contribution is found to be of order 10310_{-3} smaller than the short distance contributions.Comment: 12 pages, 1 figure (available upon request

    A perturbative treatment for the energy levels of neutral atoms

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    Energy levels of neutral atoms have been re-examined by applying an alternative perturbative scheme in solving the Schrodinger equation for the Yukawa potential model with a modified screening parameter. The predicted shell binding energies are found to be quite accurate over the entire range of the atomic number ZZ up to 84 and compare very well with those obtained within the framework of hyper-virial-Pade scheme and the method of shifted large-N expansion. It is observed that the new perturbative method may also be applied to the other areas of atomic physics.Comment: 18 page

    FCNC in left-right symmetric theories and constraints on the right-handed scale

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    We revise the limits on the FCNC higgses in manifestly left-right symmetric theories. It is shown that the combination of the Kobayashi-Maskawa CP-violation with the tree level ΔS=2\Delta S=2 higgs exchange gives very large contribution to the CP-violating ϵ\epsilon parameter. It leads to the new strong constraint on the FCNC higgs mass, M>50- 100 TeV, enhanced by factor of the order mt/mc\sqrt{m_t/m_c}. Being addressed to the supersymmetric left-right models, FCNC problem requires both right-handed scale and supersymmetric mass parameters be heavier than 50 TeV for tanβ1tan\beta\sim 1. The most relaxed case corresponds to tanβ2030tan\beta\sim 20- 30 where right-handed scale can be of the order of few TeV.Comment: 11 pages, latex, 3 figure

    The standard model at low energies

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    The hadronic sector of the standard model at low energies is described by a non--decoupling effective field theory, chiral perturbation theory. An introduction is given to the construction of effective chiral Lagrangians, both in the purely mesonic sector and with inclusion of baryons. The connection between the relativistic formulation and the heavy baryon approach to chiral perturbation theory with baryons is reviewed.Comment: Lectures given at the 6th Indian-Summer School on Intermediate Energy Physics, Prague, Aug. 1993, Latex, 26 pages (with a4.sty), UWThPh-1993-3

    A Parametrization for K+π+πe+νK^+\to \pi^+\pi^- e^+\nu

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    We discuss various models and Chiral Perturbation Theory results for the Kl4K_{l4} form factors FF and GG. We check in how much a simple parametrization with a few parameters can be used to extract information from experiment.Comment: 19 pages, 14 figure
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