31,712 research outputs found

    Flavor and CP Violation with Fourth Generations Revisited

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    The Standard Model predicts a very small CP violation phase sin2ΦBsSM0.04\sin2\Phi^{\rm SM}_{B_s} \simeq -0.04%= \arg M_{12} \simeq \arg\,(V^*_{ts}V_{tb})^2in in B_s--\bar B_smixing. mixing. %, i.e. of order \lambda^2\eta.Anyfinitevalueof. Any finite value of \Phi_{B_s}measuredattheTevatronwouldimplyNewPhysics.Withrecenthintsforfinite measured at the Tevatron would imply New Physics. With recent hints for finite \sin2\Phi_{B_s},experimentsattheTevatron,wereconsiderthepossibilityofa4thgeneration.Asrecentdirectsearchboundshavebecomeconsiderablyheavierthan300GeV,wetakethe, % have appeared from CDF and D\O\, experiments at the Tevatron, we reconsider the possibility of a 4th generation. As recent direct search bounds have become considerably heavier than 300 GeV, we take the t'masstobeneartheunitarityboundof500GeV.Combiningthemeasuredvaluesof mass to be near the unitarity bound of 500 GeV. Combining the measured values of \Delta m_{B_s}with with {\cal B}(B \to X_s\ell^+\ell^-),togetherwithtypical, together with typical f_{B_s}values,wefindasizable values, we find a sizable \sin2\Phi^{\rm SM4}_{B_s} \sim -0.33.Using. Using %a typical value of m_{b'} = 480GeV,weextracttherange GeV, we extract the range % a range of values, 0.06 < |V_{t'b}| < 0.13fromtheconstraintsof from the constraints of \Gamma(Z\to b\bar b),, \Delta m_{D}and and {\cal B}(K^+\to\pi^+\nu\bar\nu).Afuturemeasurementof. A future measurement of {\cal B}(K_L\to\pi^0\nu\bar\nu)willdetermine will determine V_{t'd}$.Comment: 8 pages, 11 figure

    Infinite Hopf family of elliptic algebras and bosonization

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    Elliptic current algebras E_{q,p}(\hat{g}) for arbitrary simply laced finite dimensional Lie algebra g are defined and their co-algebraic structures are studied. It is shown that under the Drinfeld like comultiplications, the algebra E_{q,p}(\hat{g}) is not co-closed for any g. However putting the algebras E_{q,p}(\hat{g}) with different deformation parameters together, we can establish a structure of infinite Hopf family of algebras. The level 1 bosonic realization for the algebra E_{q,p}(\hat{g}) is also established.Comment: LaTeX, 11 pages. This is the new and final versio

    Window on Higgs Boson: Fourth Generation bb^\prime Decays Revisited

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    Direct and indirect searches of the Higgs boson suggest that 113 GeV mH\lesssim m_H \lesssim 170 GeV is likely. With the LEP era over and the Tevatron Run II search via ppˉWH+Xp\bar p \to WH+X arduous, we revisit a case where WHWH or ZH+ZH + jets could arise via strong bbˉb^\prime\bar b^\prime pair production. In contrast to 10 years ago, the tight electroweak constraint on tt^\prime--bb^\prime (hence tt^\prime--tt) splitting reduces FCNC bbZb^\prime\to bZ, bHbH rates, making bcWb^\prime\to cW naturally competitive. Such a "cocktail solution" is precisely the mix that could evade the CDF search for bbZb^\prime\to bZ, and the bb^\prime may well be lurking below the top. In light of the Higgs program, this two-in-one strategy should be pursued.Comment: 4 pages, RevTex, 4 eps figures, One more figure, version to be published in Phys. Rev.

    Direct CP Violation in Angular Distribution of BJ/ψKB\to J/\psi K^{*} Decays

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    We show that the study of certain observables in the angular distribution in BJ/ψKB\to J/\psi K^* provide clear test for CP vioaltion beyond the Standard Model. These observables vanish in SM, but in models beyond SM some of them can be large enough to be measured at B factories.Comment: 7 pages, Revte

    Four Statements about the Fourth Generation

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    This summary of the Workshop "Beyond the 3-generation SM in the LHC era" presents a brief discussion of the following four statements about the fourth generation: 1) It is not excluded by EW precision data; 2) It addresses some of the currently open questions; 3) It can accommodate emerging possible hints of new physics; 4) LHC has the potential to discover or fully exclude it.Comment: Summary of the "Beyond the 3-generation SM in the LHC era" Workshop, CERN, September 4-5, 2008; 7 pages. V2: updated bibliography and minor typos fixed. To appear in PMC Physics
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