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Related papers: New physics effects in tree-level decays

200 papers

We analyse present constraints on the SM parameter space and derive, in a model independent way, various bounds on New Physics contributions to $B_d^0$--$\bar B_d^0$ and $B_s^0$--$\bar B_s^0$ mixings. Our analyses include information on a…

High Energy Physics - Phenomenology · Physics 2008-11-26 F. J. Botella , G. C. Branco , M. Nebot

Decays of $B$ mesons with leptons in the final state offer an interesting laboratory to search for possible effects of physics from beyond the Standard Model. In view of puzzling patterns in experimental data, the violation of lepton…

High Energy Physics - Phenomenology · Physics 2021-08-02 Robert Fleischer , Ruben Jaarsma , Gilberto Tetlalmatzi-Xolocotzi

$B$ decays proceeding via $b\to c\ell\nu$ transitions with $\ell=e$ or $\mu$ are tree-level processes in the Standard Model. They are used to measure the CKM element $V_{cb}$, as such forming an important ingredient in the determination of…

High Energy Physics - Phenomenology · Physics 2019-01-30 Martin Jung , David M. Straub

More precise extractions on the two important CKM matrix elements $|V_{cb}|$ and $|V_{ub}|$ are presented up to $1/m_Q^2$ corrections based on the complete heavy quark effective field theory (HQEFT) of QCD. The HQEFT as a large component…

High Energy Physics - Phenomenology · Physics 2007-05-23 Wen-Yu Wang , Yue-Liang Wu , Yu-Feng Zhou

CP-violating effects in non-leptonic $B_s$-meson decays are reviewed. Special emphasis is given to implications arising from the width difference $\Delta\Gamma_s$ between the $B_s$ mass eigenstates. If $\Delta\Gamma_s$ is found to be…

High Energy Physics - Phenomenology · Physics 2016-11-03 Robert Fleischer

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

Despite the observation of significant suppression of $b\to s\mu^+\mu^-$ branching ratios no clear sign of New Physics (NP) has been identified in $\Delta F=2$ observables, in particular to $\varepsilon_K$. Assuming negligible NP…

High Energy Physics - Phenomenology · Physics 2023-05-24 Jason Aebischer , Andrzej J. Buras , Jacky Kumar

Flavour $SU(3)$ symmetry of strong interactions and certain dynamical assumptions have been used in a series of recent publications to extract weak CKM phases from $B$-decays into $\{\pi\pi,\pi K, K\bar K\}$ final states. We point out that…

High Energy Physics - Phenomenology · Physics 2010-11-01 A. J. Buras , R. Fleischer

I report on an updated combination of all currently available tree-level measurements of the CKM angle $\gamma$ from LHCb. This combination currently gives LHCb's most precise value of $\gamma = (73^{+9}_{-10})^\circ$ obtained from $B\to…

High Energy Physics - Experiment · Physics 2014-11-18 Till Moritz Karbach

Through an effective field theory approach, we analyze the new physics corrections to muon and beta decays and their effects on the extractions of V_ud and V_us. Assuming nearly flavor blind NP interactions, we find that the only quantity…

High Energy Physics - Phenomenology · Physics 2010-11-02 Martin Gonzalez-Alonso

We analyze the new physics effects in semileptonic $\bar{B_s} \to K^{*+}(\to K\pi) \ell^- \bar{\nu}_\ell$ decay induced by the $b \to u \ell \nu_{\ell}$ quark level transition. We consider the vector, scalar and tensor new physics Lorentz…

High Energy Physics - Phenomenology · Physics 2025-10-30 Shabana Khan , Dinesh Kumar

I present the status of the elements and parameters of the Cabibbo-Kobayashi-Maskawa (CKM) matrix and summarise the related theoretical progress since "Lepton-Photon 2003". One finds |V_{us}| = 0.2227 +/- 0.0017 from K and tau decays and…

High Energy Physics - Phenomenology · Physics 2009-11-11 Ulrich Nierste

In this paper, we draw constraints on the Cabibbo-Kobayashi-Maskawa (CKM) angle $\alpha$ and the strong phase $\delta$ from the experimental measurements of $\ssb$, the CP-violating asymmetries and branching ratios of $B \to \pi^+ \pi^-,…

High Energy Physics - Phenomenology · Physics 2016-08-16 Zhenjun Xiao , Cai-Dian Lü , Libo Guo

In view of the recent LHCb measurement of Delta A_CP, the difference between the time-integrated CP asymmetries in D --> K+K- and D --> pi+pi- decays, we perform a comparative study of the possible impact of New Physics degrees of freedom…

High Energy Physics - Phenomenology · Physics 2015-06-04 Wolfgang Altmannshofer , Reinard Primulando , Chiu-Tien Yu , Felix Yu

The anomalies in rare $B$ decays endure. We present results of an updated global analysis that takes into account the latest experimental input -- in particular the recent results on $R_K$ and BR$(B_s \to \mu^+\mu^-)$ -- and that…

High Energy Physics - Phenomenology · Physics 2021-11-17 Wolfgang Altmannshofer , Peter Stangl

We show that the study of CP asymmetries in neutral B-meson decays provides a very sensitive probe of flavour-changing neutral currents (FCNC). We introduce two new angles, $\alpha_{SM}$ and $\beta_{SM}$, whose main feature is that they can…

High Energy Physics - Phenomenology · Physics 2010-11-23 G. Barenboim , F. J. Botella , G. C. Branco , O. Vives

If the fourth generation fermions exist, the new quarks could influence the branching ratio of the decay $B_s \to \nu \bar{\nu} \gamma$. We obtain two solutions of the fourth generation CKM factor $V^*_{t's} V_{t'b}$ from the decay of $B…

High Energy Physics - Phenomenology · Physics 2009-10-31 Yusuf Dincer

The rare decays {$B^- \to \tau \bar\nu$}, \mbox{$B \to \tau^+ \tau^-$}, {$b \to X \nu \bar\nu$} and \mbox{$b \to X \tau^+ \tau^-$} all contain third generation leptons in the final state, and hence are sensitive to new physics that couples…

High Energy Physics - Phenomenology · Physics 2008-11-26 Dafne Guetta , Enrico Nardi

Inclusive semileptonic $B\to X_c \ell \bar{\nu}_\ell$ decays, where $\ell = \mu,e$, are by now standard candles in the determination of the CKM element $|V_{cb}|$. These determinations rely on the heavy-quark expansion and use moments of…

High Energy Physics - Phenomenology · Physics 2023-04-20 Matteo Fael , Muslem Rahimi , K. Keri Vos

Measurements of the combined branching ratios for $B^\pm \to \pi^\pm K$ and $B_d \to \pi^\mp K^\pm$ allow interesting constraints on the CKM angle $\gamma$, the ratio $r \equiv |T'|/|P'|$ of the current-current and penguin operator…

High Energy Physics - Phenomenology · Physics 2007-05-23 Robert Fleischer , Thomas Mannel