47,275 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 QQˉ→nGQ\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 t′t' or b′b' decays suppressed either by phase space or quark mixing, and given the strong Yukawa coupling, QQˉ→nVLQ\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 mt′m_{t'} and mb′m_{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

    Indications for Large Rescattering in Rare B Decays

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    The sign of ACP(K−π+)<0A_{\rm CP}(K^-\pi^+) < 0, the evidence for Bˉ0→π0π0\bar B^0 \to \pi^0\pi^0, and the possibly sizable AππA_{\pi\pi} and SππS_{\pi\pi} in Bˉ0→π+π−\bar B^0 \to \pi^+\pi^- all suggest that final state rescattering may be needed in Bˉ→PP\bar B\to PP decay, which is echoed by large color suppressed Bˉ0→D0h0\bar B^0\to D^0h^0 modes. An SU(3) formalism of 8⊗8→8⊗8{\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 Bˉ0→K−K+\bar B^0 \to K^-K^+.Comment: 3 pages, 3 figures. Talk presented at EPS2003 Conference, Aachen, Germany, July 200
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