5,974 research outputs found

    Invisible Higgs boson, continuous mass fields and unHiggs mechanism

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    We explore the consequences of an electroweak symmetry breaking sector which exhibits approximately scale invariant dynamics -- i.e., nontrivial fixed point behavior, as in unparticle models. One can think of an unHiggs as a composite Higgs boson with a continuous mass distribution. We find it convenient to represent the unHiggs in terms of a Kallen-Lehmann spectral function, from which it is simple to verify the generation of gauge boson and fermion masses, and unitarization of WW scattering. We show that a spectral function with broad support, which corresponds to approximate fixed point behavior over an extended range of energy, can lead to an effectively invisible Higgs particle, whose decays at LEP or LHC could be obscured by background.Comment: 8 page

    CP-Violation For B→Xsl+l−B \to X_sl^+l^- Including Long-Distance Effects

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    We consider the CP violating effect for B→Xsl+l−B\to X_sl^+l^- process, including both short and long distance effects. We obtain the CP asymmetry parameter and present its variation over the dilepton mass.Comment: 9 pages, Latex file, one figure include

    Constraints on the phase Îł\gamma and new physics from B→KπB\to K\pi Decays

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    Recent results from CLEO on B→KπB\to K\pi indicate that the phase Îł\gamma may be substantially different from that obtained from other fit to the KM matrix elements in the Standard Model. We show that Îł\gamma extracted using B→Kπ,ππB\to K\pi, \pi\pi is sensitive to new physics occurring at loop level. It provides a powerful method to probe new physics in electroweak penguin interactions. Using effects due to anomalous gauge couplings as an example, we show that within the allowed ranges for these couplings information about Îł\gamma obtained from B→Kπ,ππB\to K \pi, \pi\pi can be very different from the Standard Model prediction.Comment: Revised version with analysis done using new data from CLEO. RevTex, 11 Pages with two figure

    Hybrid vehicle assessment. Phase 1: Petroleum savings analysis

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    The results of a comprehensive analysis of near term electric hybrid vehicles are presented, with emphasis on their potential to save significant amounts of petroleum on a national scale in the 1990s. Performance requirements and expected annual usage patterns of these vehicles are first modeled. The projected U.S. fleet composition is estimated, and conceptual hybrid vehicle designs are conceived and analyzed for petroleum use when driven in the expected annual patterns. These petroleum consumption estimates are then compared to similar estimates for projected 1990 conventional vehicles having the same performance and driven in the same patterns. Results are presented in the form of three utility functions and comparisons of sevral conceptual designs are made. The Hybrid Vehicle (HV) design and assessment techniques are discussed and a general method is explained for selecting the optimum energy management strategy for any vehicle mission battery combination. Conclusions and recommendations are presented, and development recommendations are identified

    Prospects for Direct CP Violaton in Exclusive and Inclusive Charmless B decays

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    Within the Standard Model, CP rate asymmetries for B→K−π+,0B\to K^-\pi^{+,0} could reach 10%. With strong final state phases, they could go up to 20--30%, even for Kˉ0π−\bar K^0\pi^- mode which would have opposite sign. We can account for K−π+K^-\pi^{+}, Kˉ0π−\bar K^0\pi^- and ϕK\phi K rate data with new physics enhanced color dipole coupling and destructive interference. Asymmetries could reach 40--60% for KπK\pi and ϕK\phi K modes and are all of the same sign. We are unable to account for K−π0K^-\pi^0 rate. Our inclusive study supports our exclusive results.Comment: Minor changes, correct a small bug in Fig. 1(b). Version to appear in Phys. Rev. Let

    One-loop flavor changing electromagnetic transitions

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    We discuss the effect of the external fermion masses in the flavor-changing radiative transitions of a heavy fermion (quark or lepton) to a lighter fermion at the one-loop level, and point out an often overlooked crucial difference in the sign of a charge factor between transitions of the down type s→dÎłs\to d\gamma and the up type c→uÎłc\to u\gamma. We give formulas for the F→fÎłF\to f\gamma effective vertex in various approximations and the exact formula for t→cÎłt\to c\gamma and Ï„â†’ÎŒÎł\tau \to \mu \gamma.Comment: LaTeX 16 pages + 4 postscript figures. Misprints corrected, some Comments adde

    Relating Green's Functions in Axial and Lorentz Gauges using Finite Field-Dependent BRS Transformations

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    We use finite field-dependent BRS transformations (FFBRS) to connect the Green functions in a set of two otherwise unrelated gauge choices. We choose the Lorentz and the axial gauges as examples. We show how the Green functions in axial gauge can be written as a series in terms of those in Lorentz gauges. Our method also applies to operator Green's functions. We show that this process involves another set of related FFBRS transfomations that is derivable from infinitesimal FBRS. We suggest possible applications.Comment: 20 pages, LaTex, Section 4 expanded, typos corrected; last 2 references modified; (this) revised version to appear in J. Math. Phy

    The CP violating phase Îł\gamma from global fit of rare charmless hadronic B decays

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    We study constraints on the CP violating phase Îł\gamma in the Kobayashi-Maskawa model using available experimental data. We first follow the conventional method to up date the constraint on Îł\gamma by performing a χ2\chi^2 analysis using data from âˆŁÏ”K∣|\epsilon_K|, ΔmBd,s\Delta m_{B_{d,s}} and ∣Vub/Vcb∣|V_{ub}/V_{cb}|. We also include the recent information on sin⁥2ÎČ\sin2\beta in the analysis. We obtain the best fit for Îł\gamma to be 66∘66^\circ and the 95% C.L. allowed range to be 42∘∌87∘42^\circ \sim 87^\circ. We then develop a method to carry out a χ2\chi^2 analysis based on SU(3) symmetry using data from B→ππB\to \pi \pi and B→KπB\to K \pi. We also discuss SU(3) breaking effects from model estimate. We find that present data on B→ππ,KπB\to \pi\pi, K \pi can also give some constraint on Îł\gamma although weaker than the earlier method limited by the present experimental errors. Future improved data will provide more stringent constraint. Finally we perform a combined fit using data from âˆŁÏ”K∣|\epsilon_K|, ΔmBd,s\Delta m_{B_{d,s}}, ∣Vub/Vcb∣|V_{ub}/V_{cb}|, sin⁥2ÎČ\sin2\beta and rare charmless hadronic B decays. The combined analysis gives Îł=67∘\gamma=67^\circ for the best fit value and 43∘∌87∘43^\circ \sim 87^\circ as the 95% C.L. allowed range. Several comments on other methods to determine Îł\gamma based on SU(3) symmetry are also provided.Comment: Revised verion with the new experimental data from Belle and Babar included in the analysis to obtain the global fit for the CP violating phase gamma. RevTex, 32 pages and 8 figure

    Electroweak Model Independent Tests for SU(3) Symmetry in Hadronic B Decays

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    We study effects of new physics beyond the Standard Model on SU(3) symmetry in charmless hadronic two body B decays. It is found that several equalities for some of the decay amplitudes, such as A(Bd(Bu)→π+π−,π+K−(π−Kˉ0))=A(Bs→K+π−,K−K+(K0Kˉ0))A(B_d (B_u) \to \pi^+\pi^-,\pi^+ K^- (\pi^- \bar K^0)) =A(B_s \to K^+ \pi^-, K^- K^+ (K^0 \bar K^0)), A(Bd→π+ρ−,π−ρ+,K−ρ+,π+K∗−)=A(Bs→K+ρ−,π−K∗+,K−K∗+,K+K∗−)A(B_d \to \pi^+\rho^-, \pi^- \rho^+, K^-\rho^+, \pi^+ K^{*-}) = A(B_s \to K^+ \rho^-, \pi^- K^{*+}, K^- K^{*+}, K^+ K^{*-}), A(Bd(Bu)→ρ+ρ−,ρ+K∗−(ρ−Kˉ∗0))=A(Bs→K∗+ρ−,K∗−K∗+(K∗0Kˉ∗0))A(B_d (B_u) \to \rho^+\rho^-, \rho^+ K^{*-}(\rho^- \bar K^{*0})) =A(B_s \to K^{*+} \rho^-, K^{*-} K^{*+} (K^{*0} \bar K^{*0})), predicted by SU(3) symmetry in the SM are not affected by new physics. These relations provide important electroweak model independent tests for SU(3) symmetry in B decays.Comment: 4 pages, revte

    Texture of fermion mass matrices in partially unified theories

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    We investigate the texture of fermion mass matrices in theories with partial unification (for example SU(2)L×SU(2)R×SU(4)c SU(2)_L\times SU(2)_R\times SU(4)_c) at a scale ∌1012\sim 10^{12} GeV. Starting with the low energy values of the masses and the mixing angles, we find only two viable textures with atmost four texture zeros. One of these corresponds to a somewhat modified Fritzsch textures. A theoretical derivataion of these textures leads to new interesting relations among the masses and the mixing angles.Comment: 10 pages(Latex
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