255 research outputs found

    Hadronic matrix elements from the lattice

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    Lattice matrix elements are briefly reviewed. In the quenched approximation fBf_B, BBB_B and BKB_K are now under good control. Experimental hints for fDSexpt>fDSQQCDf^{\rm expt}_{D_S}> f^{\rm QQCD}_{D_S} are noted; precise determination of fDSf_{D_S} from experiment as well as from the lattice is strongly advocated. Lattice calculations of the form factor for B→πℓνB\to\pi\ell\nu at relatively large value of q2q^2 have made good progress and should be useful in conjunction with precise measurement of the differential spectra expected from BB-factories. Recent attempt at K→ππK\to \pi\pi using staggered quarks is briefly discussed; use of non-perturbative renormalization, improved actions and operators with staggered quarks is emphasized. Due to the good chiral behavior of domain wall quarks it would be useful to study K→ππK\to \pi\pi with this discretization.Comment: 8 pages, Invited talk given at the Third International Conference on B Physics and CP Violation, Taipei, Dec. 3-7, 9

    CP Violation Highlights: Circa 2005

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    Recent highlights in CP violation phenomena are reviewed. B-factory results imply that CP-violation phase in the CKM matrix is the dominant contributor to the observed CP violation in K and B-physics. Deviations from the predictions of the CKM-paradigm due to beyond the Standard Model CP-odd phase are likely to be a small perturbation. Therefore, large data sample of clean B's will be needed. Precise determination of the unitarity triangle, along with time dependent CP in penguin dominated hadronic and radiative modes are discussed. Null tests in B, K and top-physics and separate determination of the K-unitarity triangle are also emphasized.Comment: Invited talk at "Results and Perspectives in Particle Physics", La Thuile, Acosta Valley, Feb27-Mar3, 200

    Towards establishing the spin of warped gravitons

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    We study the possibility of experimental verification of the spin=2 nature of the Kaluza-Klein (KK) graviton which is predicted to exist in the extra-dimensional Randal-Sundrum (RS) warped models. The couplings of these gravitons to the particles located on or near the TeV brane is the strongest as the overlap integral of their profiles in the extra-dimension is large. Among them are unphysical Higgses (WL±W^{\pm}_L and ZLZ_L) and KK excitations of the Standard Model (SM) gauge bosons. We consider the possibility to confirm the spin-2 nature of the first KK mode of the warped graviton (G1G_1) based on the angular distribution of the Z bozon in the graviton rest frame in the gg→G1→WKK(ZKK)W(Z)→WWZ\to G_1 \to W^{KK} (Z^{KK}) W (Z)\to WWZ, gg→G1→ZZ\to G_1\to ZZ and gg→G1→ZKKZ→ZZH\to G_1 \to Z^{KK} Z\to ZZH decay channels. Using Wigner D-matrix properties, we derive the relationship between the graviton spin, signal angular distribution peak value, and other theoretically calculable quantities. We then study the LHC signals for these decay modes and find that with 1000 fb−1^{-1} of data, spin of the RS graviton up to ∼\sim 2 TeV may be confirmed in the pp→WKK(ZKK)W(Z)→WWZ→pp \to W^{KK} (Z^{KK}) W (Z) \to WWZ \to 3 leptons + jet + \slashed{E}_T and pp→ZZ→pp \to ZZ \to 4 leptons decay modes.Comment: 19 pages, 6 figure

    Gravitational Waves From SU(N) Glueball Dark Matter

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    A hidden sector with pure non-abelian gauge symmetry is an elegant and just about the simplest model of dark matter. In this model the dark matter candidate is the lightest bound state made of the confined gauge fields, the dark glueball. In spite of its simplicity, the model has been shown to have several interesting non-standard implications in cosmology. In this work, we explore the gravitational waves from binary boson stars made of self-gravitating dark glueball fields as a natural and important consequence. We derive the dark SU(NN) star mass and radius as functions of the only two fundamental parameters in the model, the glueball mass mm and the number of colors NN, and identify the regions that could be probed by the LIGO and future gravitational wave observatories.Comment: 10 pages, 3 figures. v2: Couple of refs added with very minor changes. v3: Published versio
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