29,227 research outputs found

    Source of CP Violation for the Baryon Asymmetry of the Universe

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    We give a description of why the existence of a fourth generation is likely to provide enough CP violation for baryogenesis, and trace how this observation came about. We survey the current experimental and theoretical pursuits and outline a research agenda, touching upon unitarity violation and very heavy chiral quarks, and comment on how the electroweak phase transition picture might be altered.Comment: Invited talk presented at 2nd International Workshop on Dark Matter, Dark Energy and Matter-antimatter Asymmetry, Hsinchu, Taiwan, November 5-6, 201

    Heavy QQ(bar) "Fireball" Annihilation to Multiple Vector Bosons

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    Drawing analogy of replacing the nucleon by heavy chiral quark QQ, the pion by Goldstone boson GG, and πNN\pi NN coupling by GQQGQQ coupling, we construct a statistical model for QQˉnGQ\bar Q \to nG annihilation, i.e. into nn longitudinal weak bosons. This analogy is becoming prescient since the LHC direct bound mQ>611m_Q > 611 GeV implies strong Yukawa coupling. Taking mQ(1,2)m_Q \in (1, 2) TeV, the mean number ranges from 6 to over 10, with negligible two or three boson production. With individual tt' or bb' decays suppressed either by phase space or quark mixing, and given the strong Yukawa coupling, QQˉnVLQ\bar Q\to nV_L is the likely outcome for very heavy QQˉQ\bar Q production at the LHC.Comment: 4 pages, 1 figur

    Fourth Generation -- Towards Effect of Large Yukawa Coupling

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    In this talk we cover two threads regarding the 4th generation: on CP violation, from Earth up to the Heavens, i.e. from accelerator-based experimental studies, towards baryon asymmetry of the Universe; and on direct search bounds on mtm_{t'} and mbm_{b'}, towards the possibility of electroweak symmetry breaking through large Yukawa couplings. Prospects and discussions are presented.Comment: Plenary talk presented at TOP2010, May 31 - June 4, 2010, Bruges, Belgiu

    What Can We Learn from Charmless Rare B Decays - the Past/Next 3 Years

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    A personal perspective is given on physics of charmless rare B decays: 1997 -- 2003.Comment: 6 pages, 2 eps figures included. Invited talk presented at joint session of the 8th Asia Pacific Physics Conference (APPC 2000) and 3rd ACFA Workshop on Physics/Detector at the Linear Collider (ACFA-LC3), Taipei, Taiwan, August 200

    Effects of New Physics on CP Violation in B Decays

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    We discuss two models with 1 extra CP phase in bsb\leftrightarrow s transition. The CP phase arg(VtsVtb)\arg (V_{t^\prime s}V_{t^\prime b}) with fourth generations, previously ignored, could impact on bs+b\to s\ell^+\ell^-, ΔmBs\Delta m_{B_s} and sin2ΦBs\sin2\Phi_{B_s}, but does not affect EM and strong penguins. With SUSY at TeV scale, a right-handed ``sb~1\widetilde{sb}_{1}'' squark can be driven light by flavor mixing. It does not affect bs+b\to s\ell^+\ell^-, but can generate SϕKS<0S_{\phi K_S} < 0 while giving SηKSsin2ΦBd0.74S_{\eta^\prime K_S} \sim \sin2\Phi_{B_d} \cong0.74. BsB_s mixing and sin2ΦBs\sin2\Phi_{B_s} would likely be large, and SKSπ0γ0S_{K_S\pi^0\gamma}\neq 0 in B0K0γB^0\to K^{*0}\gamma is promising.Comment: 3 pages, 3 figures. Talk presented at EPS2003 Conference, Aachen, Germany, July 200

    Indications for Large Rescattering in Rare B Decays

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    The sign of ACP(Kπ+)<0A_{\rm CP}(K^-\pi^+) < 0, the evidence for Bˉ0π0π0\bar B^0 \to \pi^0\pi^0, and the possibly sizable AππA_{\pi\pi} and SππS_{\pi\pi} in Bˉ0π+π\bar B^0 \to \pi^+\pi^- all suggest that final state rescattering may be needed in BˉPP\bar B\to PP decay, which is echoed by large color suppressed Bˉ0D0h0\bar B^0\to D^0h^0 modes. An SU(3) formalism of 8888{\bf 8}\otimes {\bf 8} \to {\bf 8}\otimes {\bf 8} rescattering in PPPP final states leads to interesting predictions, in particular allowing for small Bˉ0KK+\bar B^0 \to K^-K^+.Comment: 3 pages, 3 figures. Talk presented at EPS2003 Conference, Aachen, Germany, July 200