4,329 research outputs found

    Semileptonic B to Scalar meson Decays in the Standard Model with Fourth Generation

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    We study the effects of the fourth generation of quarks on the total branching ratio and the lepton polarizations in BΛ‰0β†’K0βˆ—(1430)l+lβˆ’\bar{B}_{0}\rightarrow K_{0}^{\ast}(1430)l^{+}l^{-}(ll = ΞΌ\mu , Ο„\tau ) decay. Taking fourth generation quark mass mtβ€²m_{t{\prime}} of about 400400 to 600600 GeV with the mixing angle ∣Vtβ€²bβˆ—Vtβ€²s∣|V_{t^{\prime}b}^{\ast}V_{t^{\prime}s}| in the range (0.05βˆ’1.4)Γ—10βˆ’2(0.05-1.4)\times 10^{-2} and using the phase to be 80o80^{o}%, it is found that the branching ratio and lepton polarizations are quite sensitive to these fourth generation parameters. In future the experimental study of this decay will give us an opportunity to study new physics effects, precisely, to search for the fourth generation of quarks % (t^{\prime},b^{\prime}) in an indirect way.Comment: 15 pages, 7 figures; Modification in the text and figures, version is closed to the one accepted for publication in Phys. Rev.

    Kinematic Self-Similar Solutions of Locally Rotationally Symmetric Spacetimes

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    This paper contains locally rotationally symmetric kinematic self-similar perfect fluid and dust solutions. We consider three families of metrics which admit kinematic self-similar vectors of the first, second, zeroth and infinite kinds, not only for the tilted fluid case but also for the parallel and orthogonal cases. It is found that the orthogonal case gives contradiction both in perfect fluid and dust cases for all the three metrics while the tilted case reduces to the parallel case in both perfect fluid and dust cases for the second metric. The remaining cases give self-similar solutions of different kinds. We obtain a total of seventeen independent solutions out of which two are vacuum. The third metric yields contradiction in all the cases.Comment: 17 pages, accepted for publication Brazilian J. Physic
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