Flavor and CP Violation with Fourth Generations Revisited

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

Complementarity of Semileptonic BB to K2∗(1430)K_2^*(1430) and K∗(892)K^*(892) Decays in the Standard Model with Fourth Generation

The $B\rightarrow K_{2}^{\ast}(1430)l^{+}l^{-}$ $(l=\mu,\tau)$ decays are analyzed in the Standard Model extended to fourth generation of quarks (SM4). The decay rate, forward-backward asymmetry, lepton polarization asymmetries and the helicity fractions of the final state $K^{*}_{2}(1430)$ meson are obtained using the form factors calculated in the light cone sum rules (LCSR) approach. We have utilized the constraints on different fourth generation parameters obtained from the experimental information on $K$, $B$ and $D$ decays and from the electroweak precision data to explore their impact on the $B\rightarrow K_{2}^{\ast}(1430)l^{+}l^{-}$ decay. We find that the values of above mentioned physical observables deviate deviate significantly from their minimal SM predications. We also identify a number of correlations between various observables in $B\rightarrow K_{2}^{\ast}(1430)l^{+}l^{-}$ and $B\rightarrow K^{\ast}(892)l^{+}l^{-}$ decays. Therefore a combined analysis of these two decays will compliment each other in the searches of SM4 effects in flavor physics.Comment: 28 pages, 12 figure

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

Direct and indirect searches of the Higgs boson suggest that 113 GeV $\lesssim m_H \lesssim$ 170 GeV is likely. With the LEP era over and the Tevatron Run II search via $p\bar p \to WH+X$ arduous, we revisit a case where $WH$ or $ZH +$ jets could arise via strong $b^\prime\bar b^\prime$ pair production. In contrast to 10 years ago, the tight electroweak constraint on $t^\prime$--$b^\prime$ (hence $t^\prime$--$t$) splitting reduces FCNC $b^\prime\to bZ$, $bH$ rates, making $b^\prime\to cW$ naturally competitive. Such a "cocktail solution" is precisely the mix that could evade the CDF search for $b^\prime\to bZ$, and the $b^\prime$ 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.

Four Statements about the Fourth Generation

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

Direct CP Violation in Angular Distribution of B→J/ψK∗B\to J/\psi K^{*} Decays

We show that the study of certain observables in the angular distribution in $B\to J/\psi K^*$ 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

Electroweak Beautygenesis: From b {\to} s CP-violation to the Cosmic Baryon Asymmetry

We address the possibility that CP-violation in $B_s-\bar B_s$ mixing may help explain the origin of the cosmic baryon asymmetry. We propose a new baryogenesis mechanism - "Electroweak Beautygenesis" - explicitly showing that these two CP-violating phenomena can be sourced by a common CP-phase. As an illustration, we work in the Two-Higgs-Doublet model. Because the relevant CP-phase is flavor off-diagonal, this mechanism is less severely constrained by null results of electric dipole moment searches than other scenarios. We show how measurements of flavor observables by the D0, CDF, and LHCb collaborations test this scenario.Comment: 4 pages, 1 figure, 1 tabl