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Related papers: Constraining Fourth Generation with $B\to X_s \gam…

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With full 2011 LHC data analyzed, there is no indication for deviation from Standard Model (SM) in CP violating phase for Bs --> J/psi phi, nor in the forward-backward asymmetry for B0 --> K*0 mu+ mu-. SM sensitivity, however, has been…

High Energy Physics - Phenomenology · Physics 2013-05-30 Wei-Shu Hou , Masaya Kohda , Fanrong Xu

We obtain predictions for a number of radiative decays $B_{(s)}\to V\gamma$, $V$ the vector meson, which proceed through the weak-annihilation mechanism. Within the factorization approximation, we take into account the photon emission from…

High Energy Physics - Phenomenology · Physics 2016-01-20 Anastasiya Kozachuk , Dmitri Melikhov , Nikolai Nikitin

We study various FCNC involving heavy quarks in the Standard Model (SM) with a sequential fourth generation. After imposing $B\to X_s\gamma$, $B\to X_sl^+l^-$ and $Z\to b\bar{b}$ constraints, we find ${\cal B}(Z\to s\bar{b}+\bar{s}b)$ can…

High Energy Physics - Phenomenology · Physics 2010-02-03 Abdesslam Arhrib , Wei-Shu Hou

We study the effects of a vector-like SU(2) quark doublet as a fourth generation. In this model we examine the chiral structure and the FCNC in the quark sector by using radiative B meson decays in the allowed region for parameters from…

High Energy Physics - Phenomenology · Physics 2010-11-23 L. T. Handoko , T. Yoshikawa

We discuss the exclusive radiative B-meson decays B -> K* gamma and B -> rho gamma in a model-independent manner. The analysis is based on the heavy-quark limit of QCD. This allows a factorization of perturbatively calculable contributions…

High Energy Physics - Phenomenology · Physics 2009-11-07 Stefan W. Bosch

We study the effect of supersymmetric contributions to the effective quark transition $b\to s\gamma\gamma$, including leading order QCD effects. We apply the discussion to the decay $B_s\to\gamma\gamma$. Even though one-particle irreducible…

High Energy Physics - Phenomenology · Physics 2009-10-30 S. Bertolini , J. Matias

In the aligned two-Higgs-doublet model, the alignment of Yukawa matrices in flavour space guarantees the absence of tree-level flavour-changing neutral currents, while allowing at the same time for new sources of CP violation, implying…

High Energy Physics - Phenomenology · Physics 2015-06-11 Martin Jung , Xin-Qiang Li , Antonio Pich

Based on a new, exact QCD factorization formula for the partial B->X_s+gamma decay rate with a restriction on large photon energy, improved predictions are presented for the partial moments <E_gamma> and <E_gamma^2>-<E_gamma>^2 of the…

High Energy Physics - Phenomenology · Physics 2009-11-11 Matthias Neubert

Recent studies about the impact of the CP-violating complex parameters in supersymmetry on the decays of third generation squarks and about T-odd asymmetries in neutralino and chargino production and decay are reviewed. The CP-even…

High Energy Physics - Phenomenology · Physics 2007-05-23 S. Hesselbach

The experimental status of the Cabibbo-Kobayashi-Maskawa matrix is reviewed. Measurements discussed include B0_(s)-\bar{B}0_(s) mixing and several rare B and K decays with implications for |V_td| and |V_ts|. Extraction of |V_cb| and |V_ub|…

High Energy Physics - Experiment · Physics 2007-05-23 L. Gibbons

In this follow-up work to the High Energy Physics Community Summer Study 2013 (HEP CSS 2013, a.k.a. Snowmass), we explore the scientific capabilities of a future Stage-IV Cosmic Microwave Background polarization experiment (CMB-S4) under…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-11 W. L. K. Wu , J. Errard , C. Dvorkin , C. L. Kuo , A. T. Lee , P. McDonald , A. Slosar , O. Zahn

The rare decay $\bar B\to X_s\gamma$ is an important probe of physics beyond the standard model. The largest uncertainty on the total rate and the CP asymmetry arises from resolved photon contributions. These appear first at order $1/m_b$…

High Energy Physics - Phenomenology · Physics 2019-12-06 Ayesh Gunawardana , Gil Paz

We consider possible new physics contributions to b\to s l^+ l^- assuming the new physics modifies (chromo)magnetic and electric form factors in b\to s \gamma^* and b\to s g with the same chirality structure as in the standard model.…

High Energy Physics - Phenomenology · Physics 2007-05-23 Yeong Gyun Kim , P. Ko , Jae Sik Lee

The presence of a sizeable CP-violating phase in B_s^0-B_s^0-bar mixing would be an unambiguous signal of physics beyond the Standard Model. We analyse various possibilities to detect such a new phase considering both tagged and untagged…

High Energy Physics - Phenomenology · Physics 2014-11-17 Isard Dunietz , Robert Fleischer , Ulrich Nierste

We combine recent progress in measuring the branching ratio of the decay B->X_d gamma$ with the discovery that hadronic uncertainties in the CP-averaged branching ratio drop out to a large extent. Implications of these improvements on the…

High Energy Physics - Phenomenology · Physics 2015-03-19 Andreas Crivellin , Lorenzo Mercolli

Unitarity triangles and characteristic measurables of the $3\times 3$ Cabibbo-Kobayashi-Maskawa (CKM) matrix are discussed. Beyond the $3\times 3$ CKM scheme we make a rephasing-invariant generalization of the Gronau-Wyler-Dunietz approach…

High Energy Physics - Phenomenology · Physics 2015-06-25 Zhi-zhong Xing

$Z^\prime$ models belong to the ones that can most easily explain the anomalies in $b\to s \mu^+\mu^-$ transitions. However, such an explanation by a single $Z^\prime$ gauge boson, as done in the literature, is severly constrained by the…

High Energy Physics - Phenomenology · Physics 2023-02-21 Andrzej J. Buras

We propose a new method for precise determination of |V_{td} / V_{ub}| from the ratios of branching ratios BR(B -> \rho \nu \bar \nu ) / BR(B ->\rho l \nu ) and BR(B -> \pi \nu \bar \nu ) / BR(B -> \pi l \nu ). These ratios depend only on…

High Energy Physics - Phenomenology · Physics 2009-10-30 T. M. Aliev , C. S. Kim

Suggestions for efficiently determining the lifetimes and mass difference of the light and heavy $B_s$ mesons ($B_s^L, B_s^H$) from $B_s \to J/ \psi \phi, D_s^{*+}D_s^{*-}$ decays are given. Using appropriate weighting functions for the…

High Energy Physics - Phenomenology · Physics 2014-11-17 Amol Dighe , Isard Dunietz , Robert Fleischer

Parameters of the heavy four-quark scalar meson $T_{\mathrm{bc\overline{b} \overline{c}}}$ with content $bc \overline{b}\overline{c}$ are calculated by means of the sum rule method. This structure is considered as a diquark-antidiquark…

High Energy Physics - Phenomenology · Physics 2024-09-27 S. S. Agaev , K. Azizi , H. Sundu