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Related papers: LHCb anomalies from a natural perspective

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Deviation from the standard model prediction is observed in many semileptonic $B$ decays mediated via $b \to c$ charged current interactions. In particular, current experimental measurements of the ratio of branching ratio $R_D$ and…

High Energy Physics - Phenomenology · Physics 2019-08-20 Rupak Dutta , N Rajeev

The updated analysis of the LHCb Collaboration on the lepton flavor violation suggests that the new physics should couple to muons and electrons with comparable magnitudes, resulting in the anomalies in both rare decay channels, $b…

High Energy Physics - Phenomenology · Physics 2023-11-13 Sang Quang Dinh , Hieu Minh Tran

The Littlest Higgs Model with T-parity (LHT) belongs to the simplest new physics scenarios with new sources of flavour and CP violation. We present a new analysis of quark observables in the LHT model in view of the oncoming flavour…

High Energy Physics - Phenomenology · Physics 2016-04-07 Monika Blanke , Andrzej J. Buras , Stefan Recksiegel

Decays of the kind $B^0_{s,d}\to\ell^+\ell^-$ belong to the most favourable processes for probing the flavour structure of the Standard Model, with outstanding sensitivity to new (pseudo)-scalar contributions. While the branching ratio of…

High Energy Physics - Phenomenology · Physics 2018-05-16 Robert Fleischer

The lepton and dilepton charge asymmetries from $B_{d}$ and $B_{s}$ are predicted to be small in the standard model, whereas new physics could increase their values significantly. In this paper, we explore the use of the lepton asymmetries…

High Energy Physics - Phenomenology · Physics 2009-09-15 Lisa Randall , Shufang Su

Within the Standard Model, the branching fraction of the rare decay $B_s\to K^0\bar K^0$ is related to other decay rates and CP asymmetries through the approximate $SU(3)$ flavor symmetry of the strong interactions and the heavy-quark…

High Energy Physics - Phenomenology · Physics 2025-06-11 Yuval Grossman , Yosef Nir , Matthias Neubert , Yogev Shpilman , Yehonatan Viernik

The LHCb experiment has recently established a sizable width difference between the mass eigenstates of the $B_s$-meson system. This phenomenon leads to a subtle difference at the 10% level between the experimental branching ratios of $B_s$…

High Energy Physics - Phenomenology · Physics 2015-06-11 Robert Fleischer

High precision electroweak tests, such as deviations from the Standard Model expectations of the Lepton Flavor Universality breaking in K->lnu (with l= e or mu), represent a powerful tool to test the Standard Model and, hence, to constrain…

High Energy Physics - Phenomenology · Physics 2009-01-06 A. Masiero , P. Paradisi , R. Petronzio

The data on high-precision flavour observables reveal certain puzzles when compared to Standard Model expectations based on a global fit of the CKM unitarity triangle and general theoretical estimates. The discussion of these tensions in…

High Energy Physics - Phenomenology · Physics 2010-11-02 Martin Jung

We consider the recent LHCb result for $B_c\to J/\psi \tau \nu$ in conjunction with the existing anomalies in $R(D)$ and $R(D^\star)$ within the framework of a right-handed current with enhanced couplings to the third generation. The model…

High Energy Physics - Phenomenology · Physics 2018-05-02 Xiao-Gang He , German Valencia

LHCb has reported hints of lepton-flavor universality violation in the rare decays $B \to K^{(*)} \ell^+\ell^-$, both in high- and low-$q^2$ bins. Although the high-$q^2$ hint may be explained by new short-ranged interactions, the low-$q^2$…

High Energy Physics - Phenomenology · Physics 2020-05-20 Wolfgang Altmannshofer , Michael J. Baker , Stefania Gori , Roni Harnik , Maxim Pospelov , Emmanuel Stamou , Andrea Thamm

We construct a scalar dark matter model with $U(1)_{L_\mu-L_\tau}$ symmetry in which the dark matter interacts with the quark flavours, allowing lepton non-universal $b \to s \ell \bar{\ell}$ decays. The model can solve $b \to s \mu \mu$…

High Energy Physics - Phenomenology · Physics 2019-11-13 Seungwon Baek

We present a simple $U(1)_{B_3-3L_\mu}$ gauge Standard Model extension that can easily account for the anomalies in $R(K)$ and $R(K^*)$ reported by LHCb. The model is economical in its setup and particle content. Among the Standard Model…

High Energy Physics - Phenomenology · Physics 2018-11-07 Cesar Bonilla , Tanmoy Modak , Rahul Srivastava , Jose W. F. Valle

To shed light on the indirect search for new physics beyond the standard model, the long standing discrepancies between the theory and experiment mediated by FCNC $b\to s \ell \ell$ quark level transitions set an ideal testing ground.…

High Energy Physics - Phenomenology · Physics 2023-07-25 Manas K. Mohapatra , Lopamudra Nayak , Rashmi Dhamija , Anjan Giri

Several experimental measurements of $B$ meson decays, in tension with Standard Model predictions, exhibit large sources of Lepton Flavour Universality violation. We perform an analysis of the effects of the global fits to the Wilson…

High Energy Physics - Phenomenology · Physics 2021-10-26 Jorge Alda , Jaume Guasch , Siannah Penaranda

We propose to perform a combined analysis of $B \to \pi\pi$ and $B_s \to K^+ K^-$ modes, in the framework of a global CKM fit. The method optimizes the constraining power of these decays and allows to derive constraints on NP contributions…

High Energy Physics - Phenomenology · Physics 2012-10-17 M. Ciuchini , E. Franco , S. Mishima , L. Silvestrini

Several experiments observed deviations from the Standard Model (SM) in the flavour sector: LHCb found a $4-5\,\sigma$ discrepancy compared to the SM in $b\to s\mu^+\mu^-$ transitions (recently supported by an Belle analysis) and CMS…

High Energy Physics - Phenomenology · Physics 2016-06-23 Andreas Crivellin

In the last few years, the ratios $R_{D^{(*)}}$ and of $R_{K^{(*)}}$ have reportedly exhibited significant deviations from the relevant Standard Model predictions, hinting towards a possible violation of Lepton Flavor Universality and a…

High Energy Physics - Phenomenology · Physics 2019-01-15 Sokratis Trifinopoulos

In light of recent measurements suggesting potential lepton flavor universality violations in semileptonic decays at collider experiments, this article provides a concise study of tree- and loop-level $B$-hadron semileptonic decays, $b \to…

High Energy Physics - Phenomenology · Physics 2025-02-05 Sonali Patnaik , Lopamudra Nayak , Rajeev Singh

LHCb found hints for physics beyond the Standard Model (SM) in $B\to K^*\mu^+\mu^-$, $R(K)$ and $B_s\to\phi\mu^+\mu^-$. These intriguing hints for NP have recently been confirmed by the LHCb measurement of $R(K^*)$ giving a combined…

High Energy Physics - Phenomenology · Physics 2017-06-06 Andreas Crivellin