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The simplest extension of the SM that generally introduces new sources of flavour and CP violation as well as right-handed currents is the addition of a U(1) gauge symmetry to the SM gauge group. If the corresponding heavy gauge boson Z'…

High Energy Physics - Phenomenology · Physics 2013-03-01 Andrzej J. Buras , Fulvia De Fazio , Jennifer Girrbach

Flavour physics is a priceless window on physics beyond the Standard Model. In particular, flavour violation in the lepton sector looks very promising, as high precision measurements are prospected in future experiments investigating on…

High Energy Physics - Phenomenology · Physics 2013-11-19 R. Alonso , M. B. Gavela , D. Hernandez , L. Merlo , S. Rigolin

We explore predictive flavor models based on subgroups of the standard-model $SU(3)^5$ flavor symmetry. Restricting to products of $SU(3)$, we find that a global $SU(3)^3$ flavor symmetry, broken only by two Yukawa spurions, leads to a…

High Energy Physics - Phenomenology · Physics 2015-05-27 Thomas Appelquist , Yang Bai , Maurizio Piai

Minimal Flavour Violation in its strong or weak versions, based on $U(3)^3$ and $U(2)^3$ respectively, allows suitable extensions of the Standard Model at the TeV scale to comply with current flavour constraints in the quark sector. Here we…

High Energy Physics - Phenomenology · Physics 2016-01-27 Riccardo Barbieri , Fabrizio Senia

We study a simple extension of the Zee model, in which a discrete $Z_2$ symmetry imposed in the original model is replaced by a global $U(1)$ symmetry retaining the same particle content. Due to the $U(1)$ symmetry with flavor dependent…

High Energy Physics - Phenomenology · Physics 2020-01-08 Takaaki Nomura , Kei Yagyu

The Littlest Higgs model with T-parity (LHT) contains new sources of flavour and CP violation both in the quark and the lepton sector. They originate from the interactions of ordinary fermions with mirror fermions mediated by new gauge…

High Energy Physics - Phenomenology · Physics 2007-05-23 Andrzej J. Buras , Cecilia Tarantino

Anomalies in (semi)leptonic $B$-meson decays present interesting patterns that might be revealing the shape of the new physics to come. In order to understand the experimental data, we explore symmetry arguments that lead to the hypothesis…

High Energy Physics - Phenomenology · Physics 2015-05-21 Rodrigo Alonso , Benjamín Grinstein , Jorge Martin Camalich

During the last fifteen years B_{s,d} decays, B_{s,d}^0-\bar B^0_{s,d} mixings, CP-violating asymmetries S_{\psi K_S} and S_{\psi\phi} provided the dominant information about the pattern of flavour violation within the SM and its…

High Energy Physics - Phenomenology · Physics 2015-10-02 Andrzej J. Buras

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

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

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

$U(1)^\prime$ extensions of the standard model with generation-dependent couplings to quarks and leptons are investigated as an explanation of anomalies in rare $B$-decays, with an emphasis on stability and predictivity up to the Planck…

High Energy Physics - Phenomenology · Physics 2022-02-02 Rigo Bause , Gudrun Hiller , Tim Höhne , Daniel F. Litim , Tom Steudtner

We investigate lepton flavour violation in a class of minimal left-right symmetric models where the left-right symmetry is broken by triplet scalars. In this context we present a method to consistently calculate the triplet-Yukawa couplings…

High Energy Physics - Phenomenology · Physics 2017-03-09 Cesar Bonilla , Manuel E. Krauss , Toby Opferkuch , Werner Porod

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

A recent LHCb measurement of the ratio $R_{K^*}$ of $B\to K^*\mu\bar\mu$ to $B\to K^*e\bar e$ branching fractions has produced results in mild tension with the standard model (SM). This adds to the known anomalies also induced by the $b\to…

High Energy Physics - Phenomenology · Physics 2018-02-23 Cheng-Wei Chiang , Xiao-Gang He , Jusak Tandean , Xing-Bo Yuan

We juxtapose global fits of two bottom-up models (an $S_3$ scalar leptoquark model and a ${B_3-L_2}$ $Z^\prime$ model) of \bsll\ anomalies to flavour data in order to quantify statistical preference or lack thereof. The leptoquark model…

High Energy Physics - Phenomenology · Physics 2023-06-09 Ben Allanach , Joe Davighi

We analyse the violations of lepton-flavour universality in the ratios B(P -> l nu)/B(P -> l' nu) using a general effective theory approach, discussing various flavour-symmetry breaking patterns of physics beyond the SM. We find that in…

High Energy Physics - Phenomenology · Physics 2009-11-05 Alberto Filipuzzi , Gino Isidori

We review the present status of CP violating problem in supersymmetric extensions of the standard model. We analyze the constraints imposed by the experimental limits of the electron, neutron, and mercury electric dipole moments on the…

High Energy Physics - Phenomenology · Physics 2014-11-17 Shaaban Khalil

This is a written version of a series of lectures aimed at graduate students in particle theory/string theory/particle experiment familiar with the basics of the Standard Model. We explain the many reasons for the interest in flavour…

High Energy Physics - Phenomenology · Physics 2010-10-14 Y. Nir

We discuss in detail the constraints on partial compositeness coming from flavour and CP violation in the leptonic sector. In a first part we present a formulation of partial compositeness in terms of a flavour symmetry group and a set of…

High Energy Physics - Phenomenology · Physics 2016-01-27 Ferruccio Feruglio , Paride Paradisi , Andrea Pattori