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We discuss precision tests of the standard model in radiative and semileptonic rare B-decays and CP-violating asymmetries, and possible signatures of supersymmetry in these processes. Motivated by current data, and with an eye on the…

High Energy Physics - Phenomenology · Physics 2017-08-23 A. Ali

We investigate the influence of the fourth generation of quarks on the branching ratio, the CP-asymmetry and the polarization asymmetries in $B \rar \rho \ell^+ \ell^-$ decay. Taking $|V_{t'd}V_{t'b}|\sim 0.001$ with phase about $10^\circ$,…

High Energy Physics - Phenomenology · Physics 2008-11-26 K. Zeynali , V. Bashiry

If the fourth generation fermions exist, the new quarks could influence the branching ratio of the rare $B\to K^{*}\nu\bar{\nu}$ decay. Two possible solutions of the fourth generation CKM factor $(V^{*}_{\acute{t}s}V_{\acute{t}b})^(\pm)$…

High Energy Physics - Phenomenology · Physics 2014-11-17 Thabit Barakat

We investigate the influence of the fourth generation quarks on the branching ratio and the CP-asymmetry in B -->\pi \ell^+ \ell^- decay. Taking the |V_{t'd}V_{t'b}| ~ 0.001 with phase about 10 degree, which is consistent with the…

High Energy Physics - Phenomenology · Physics 2009-11-13 V. Bashiry , K. Zeynali

Attention is drawn to the several 2-3 $\sigma$ "anomalies" in B, $B_s$ mixings and decays involving CP-observables. Perhaps the most interesting theoretical scenario that could cause such effects is based on warped extra-dimensional models…

High Energy Physics - Phenomenology · Physics 2009-07-14 Amarjit Soni

The long-awaited $B_s\to \mu^+\mu^-$ mode has finally been observed at rate consistent with Standard Model, albeit lower by 1.2$\sigma$. There is some hint for New Physics in the rarer $B_d^0 \to \mu^+\mu^-$ decay, especially if the…

High Energy Physics - Phenomenology · Physics 2015-11-04 Wei-Shu Hou , Masaya Kohda , Fanrong Xu

We consider the combined measurements of CP-averaged decay rates and direct CP asymmetries of $B^\pm\to K^\pm \ell^+ \ell^-$ and $B^\pm\to \pi^\pm \ell^+ \ell^-$ to probe (non-local) four-quark operator matrix element contributions to rare…

High Energy Physics - Phenomenology · Physics 2024-03-21 Jernej F. Kamenik , Nejc Košnik , Martín Novoa-Brunet

We show that a fourth family of quarks with $m_{t'}$ in the range of (400 - 600) GeV provides a rather simple explanation for the several indications of new physics that have been observed involving CP asymmetries of the b-quark. The…

High Energy Physics - Phenomenology · Physics 2010-01-21 Amarjit Soni , Ashutosh Kumar Alok , Anjan Giri , Rukmani Mohanta , Soumitra Nandi

Using firmly established experimental inputs such as epsilon_K, Delta M_d, Delta M_s, BR(B -> tau nu), gamma, V_cb along with corresponding lattice matrix elements which have been well studied and are in full QCD such as B_K, SU3 breaking…

High Energy Physics - Phenomenology · Physics 2015-05-27 Enrico Lunghi , Amarjiit Soni

The Standard Model (SM) does not contain by definition any new physics (NP) contributions to any observable but contains four CKM parameters which are not predicted by this model. We point out that if these four parameters are determined in…

High Energy Physics - Phenomenology · Physics 2024-01-05 Andrzej J. Buras

We give a comprehensive account of the flavour physics of Beyond-Standard-Model (BSM) effects in $b \to c \bar{c} s$ transitions, considering the full set of 20 four-quark operators. We discuss the leading-order structure of their RG mixing…

High Energy Physics - Phenomenology · Physics 2023-07-13 S. Jäger , M. Kirk , A. Lenz , K. Leslie

These lectures review some of the progress made in the quantitative understanding of B decays. The emphasis here is on applications of QCD using perturbative and non-perturbative techniques. In some cases, however, phenomenological models…

High Energy Physics - Phenomenology · Physics 2011-04-15 A. Ali

We estimate the CP asymmetry A_{CP}(q^2) in the decays B --> X_s mu+ mu- and B --> X_d mu+ mu- in the standard model (SM) with an additional fourth generation. We use a parametrization that allows us to explore the complete parameter space…

High Energy Physics - Phenomenology · Physics 2010-02-08 Ashutosh Kumar Alok , Amol Dighe , Shamayita Ray

We study D0-D0 mixing in the presence of a fourth generation of quarks. In particular, we calculate the size of the allowed CP violation which is found at the observable level well beyond anything possible with CKM dynamics. We calculate…

High Energy Physics - Phenomenology · Physics 2015-03-14 Andrzej J. Buras , Björn Duling , Thorsten Feldmann , Tillmann Heidsieck , Christoph Promberger , Stefan Recksiegel

We discuss the most important Physics thus far extracted from studies of B meson decays. Measurements of the four CP violating angles accessible in B decay are reviewed as well as direct CP violation. A detailed discussion of the…

High Energy Physics - Phenomenology · Physics 2009-12-03 Marina Artuso , Elisabetta Barberio , Sheldon Stone

We analyze in the four-generation model the first measurement of the branching ratio of rare kaon decay K^+\to\pi^+\nu\bar{\nu}, using the constraints from \Delta m_K, \epsilon_K, B_d-\bar{B_d} mixing, \Gamma (b\to s\gamma), B_s-\bar{B_s}…

High Energy Physics - Phenomenology · Physics 2009-09-25 T. Hattori , T. Hasuike , S. Wakaizumi

We consider three possible scenarios of new physics in B^0_d-\bar{B}^0_d mixing and propose a simple framework for analyzing their effects. This framework allows us to study the CP asymmetry in semileptonic B_d decays ({\cal A}_{SL}) and…

High Energy Physics - Phenomenology · Physics 2009-10-30 A. I. Sanda , Zhi-zhong Xing

The rare four-fold decay $B_s \to K^*(\to K\pi)\mu^+\mu^- $, governed by the flavor-changing neutral current transition $b \to d\mu^+\mu^-$, provides a sensitive probe for testing the Standard Model (SM) and investigating signatures of new…

High Energy Physics - Phenomenology · Physics 2026-05-12 Zohaib Aarfi , Qazi Maaz Us Salam , Ishtiaq Ahmed , Faisal Munir Bhutta , Rizwan Khalid , M. Ali Paracha

The persistent tensions between inclusive and exclusive determinations of $|V_{cb}|$ and $|V_{ub}|$ weaken the power of theoretically clean rare $K$ and $B$ decays in the search for new physics (NP). We demonstrate how this uncertainty can…

High Energy Physics - Phenomenology · Physics 2022-03-22 Andrzej J. Buras , Elena Venturini

The decays $B_d\to\pi^\mp K^\pm$ and $B^\pm\to\pi^\pm K$ provide interesting constraints on the angle $\gamma$ of the unitarity triangle of the CKM matrix. It is shown that bounds on $\gamma$ can also be obtained from the time evolution of…

High Energy Physics - Phenomenology · Physics 2014-11-17 Robert Fleischer