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Related papers: Patterns of Flavour Violation in Models with Vecto…

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We define a new class of Z' models with neutral flavour-changing interactions at tree level in the down-quark sector. They are related in an exact way to elements of the quark mixing matrix due to an underlying flavoured U(1)' gauge…

High Energy Physics - Phenomenology · Physics 2016-06-30 Martin Jung

LHCb has reported deviations from the Standard Model in $b\to s\mu^+\mu^-$ transitions for which a new neutral gauge boson is a prime candidate for an explanation. As this gauge boson has to couple in a flavour non-universal way to muons…

High Energy Physics - Phenomenology · Physics 2015-09-25 Andreas Crivellin , Lars Hofer , Joaquim Matias , Ulrich Nierste , Stefan Pokorski , Janusz Rosiek

Significant deviations from Standard Model (SM) predictions have been observed in $ b \to s \mu^+ \mu^-$ decays and in the muon $g-2$. Scalar leptoquark extensions of the SM are known to be able to address these anomalies, but generically…

High Energy Physics - Phenomenology · Physics 2021-10-15 Admir Greljo , Peter Stangl , Anders Eller Thomsen

Building on our recent proposal to explain the experimental hints of new physics in $B$ meson decays within the framework of Pati-Salam quark-lepton unification, through the interactions of the $(3,1)_{2/3}$ vector leptoquark, we construct…

High Energy Physics - Phenomenology · Physics 2019-03-22 Bartosz Fornal , Sri Aditya Gadam , Benjamin Grinstein

The Standard Model (SM) is augmented with a $\mathrm{U}(1)_{B-3L_\mu} $ gauge symmetry spontaneously broken above the TeV scale when an SM-singlet scalar condenses. Scalar leptoquarks $S_{1(3)} = (\overline{\mathbf{3}},\, \mathbf{1}…

High Energy Physics - Phenomenology · Physics 2021-08-04 Admir Greljo , Peter Stangl , Anders Eller Thomsen

We present a particular warped extra dimensional model, where the flavour diagonal and flavour non-diagonal Z boson couplings to left-handed down quarks are protected by the custodial symmetry P_LR. After a brief introduction of the model…

High Energy Physics - Phenomenology · Physics 2009-07-22 Stefania Gori

We review and update the constraints on the parameters of the quark flavour mixing matrix $V_{CKM}$ in the standard model and estimate the resulting CP asymmetries in $B$ decays, taking into account recent experimental and theoretical…

High Energy Physics - Phenomenology · Physics 2010-11-23 A. Ali , D. London

We examine flavour-changing neutral-current decays of the top quark, $t\to q \gamma$, $t \to qZ$, $t \to q H$, and $ t\to q g$ (with $q=u, c$), in the Alternative Left-Right Model, a left right-symmetric model featuring exotic quarks and…

High Energy Physics - Phenomenology · Physics 2024-03-04 Mariana Frank , Benjamin Fuks , Sumit K. Garg , Poulose Poulose

It is possible that the standard model (SM) is replaced around some transition energy $\E_{tr}$ by a new, possibly Higgsless, ``flavor gauge theory'' such that the Yukawa (running) parameters of SM at $E \sim \E_{tr}$ show up an…

High Energy Physics - Phenomenology · Physics 2010-11-01 G. Cvetic , C. S. Kim

We study the anatomy and phenomenology of Lepton Flavor Violation (LFV) in the context of Flavored Gauge Mediation (FGM). Within FGM, the messenger sector couples directly to the MSSM matter fields with couplings controlled by the same…

High Energy Physics - Phenomenology · Physics 2014-12-31 Lorenzo Calibbi , Paride Paradisi , Robert Ziegler

We review and update the constraints on the parameters of the quark flavour mixing matrix $V_{CKM}$ in the standard model and estimate the resulting CP asymmetries in $B$ decays, taking into account recent experimental and theoretical…

High Energy Physics - Phenomenology · Physics 2010-11-11 A. Ali , D. London

Recent measurements of $b$-hadron decays show a pattern of consistent tensions with the respective Standard Model (SM) predictions. These tensions appear both in the sector of rare flavour-changing neutral currents and in tree-level…

High Energy Physics - Experiment · Physics 2021-07-13 Johannes Albrecht , Danny van Dyk , Christoph Langenbruch

The concept of lepton flavour universality (LFU), according to which the three lepton families are equivalent except for their masses, is a cornerstone prediction of the Standard Model (SM). LFU can be violated in models beyond the SM by…

High Energy Physics - Experiment · Physics 2019-05-22 Elena Graverini

There has been persistent disagreement between the Standard Model (SM) prediction and experimental measurements of $R_{D^{(*)}}=\mathcal{B}(\bar B \rightarrow D^{(*)} \tau \bar\nu_\tau)/\mathcal{B}(\bar B \rightarrow D^{(*)} l \bar\nu_l)$…

High Energy Physics - Phenomenology · Physics 2019-03-06 Saurabh Bansal , Rodolfo M. Capdevilla , Christopher Kolda

In the present work we consider including the Flavor Changing Neutral Currents (FCNCs) in Left-Right Symmetric model. Within this model a simulation calculation are made of the decay width of Z' LR boson, the production cross section of the…

High Energy Physics - Phenomenology · Physics 2014-10-06 H. M. M. Mansour , N. Bakheet

Leptoquarks (LQs) have been extensively studied in the context of $B$ anomalies. When $U(1)_{L_\mu-L_\tau}$ is introduced to a scalar LQ model with the LQ $S_1$ charged under the new symmetry, $S_1$ primarily couples to the third-generation…

High Energy Physics - Phenomenology · Physics 2023-10-05 Chuan-Hung Chen , Cheng-Wei Chiang

We present a short overview of recent work on the topic of flavour violation in the presence of a sequential fourth generation (4G) of quarks and leptons. We discuss the implications of this simple extension of the Standard Model (SM3) for…

High Energy Physics - Phenomenology · Physics 2010-11-29 Tillmann Heidsieck

We consider scenarios with a heavy $Z^\prime$ gauge boson with flavour non-universal quark and lepton couplings with the goal to illustrate how the cancellation of gauge anomalies generated by the additional U(1)$^\prime$ gauge symmetry…

High Energy Physics - Phenomenology · Physics 2020-03-18 Jason Aebischer , Andrzej J. Buras , Maria Cerdà-Sevilla , Fulvia De Fazio

We extend the Zee model by introducing a vector-like lepton doublet and a flavor dependent global $U(1)$ symmetry. Flavor changing neutral currents in the quark sector can be naturally forbidden at tree level due to the $U(1)$ symmetry,…

High Energy Physics - Phenomenology · Physics 2021-09-15 Toshinori Matsui , Takaaki Nomura , Kei Yagyu

Rare $B$-meson decays, suppressed in the Standard Model (SM) by the GIM mechanism, are sensitive probes of new physics. In particular, loop-level $b \to s$ transitions can reveal effects of heavy virtual particles such as vector-like quarks…

High Energy Physics - Phenomenology · Physics 2025-11-04 Maryam Bibi