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Related papers: Safe $Z'$ for LFUV

200 papers

We study lepton flavor violating (LFV) $B$ decays in a general two Higgs doublet model with sub-TeV exotic scalars. Two different parameter spaces are explored: one dominated by extra top Yukawa coupling $\rho_{tt}$, the other by LFV…

High Energy Physics - Phenomenology · Physics 2023-05-24 Wei-Shu Hou , Girish Kumar , Sven Teunissen

I present a model addressing coherently the naturalness problem of the electroweak scale and the observed pattern of deviations from the Standard Model in semi-leptonic decays of $B$ mesons. The Higgs and the two scalar leptoquarks…

High Energy Physics - Phenomenology · Physics 2018-07-23 David Marzocca

Motivated by the $b\to s\ell^+\ell^-$ anomalies recently reported by the LHCb collaboration, I present a class of flavored U(1)' gauge extensions of the Standard Model that naturally accommodates them and possesses a rich phenomenology.…

High Energy Physics - Phenomenology · Physics 2015-12-22 Javier Fuentes-Martin

We consider lepton flavor violating Higgs decay, specifically $h \to \mu\tau$, in a leptoquark model. We introduce two scalar leptoquarks with the $SU(3)_c \times SU(2)_L \times U(1)_Y$ quantum numbers, $(3,2,7/6)$ and $(3,2,1/6)$, which do…

High Energy Physics - Phenomenology · Physics 2016-01-13 Seungwon Baek , Kenji Nishiwaki

Several experiments reported hints for the violation of lepton flavor or lepton flavor universality in processes involving muons. Most prominently, there is the hint for a non-zero rate of the flavor violating Higgs decay $h \to \tau\mu$ at…

High Energy Physics - Phenomenology · Physics 2016-12-07 Wolfgang Altmannshofer , Marcela Carena , Andreas Crivellin

We study the flavor universality of the lepton couplings with the W and Z bosons. Currently, it is constrained by the electroweak precision observables. We focus on the leptonic decay of the pion. It is shown that the decay is expected to…

High Energy Physics - Phenomenology · Physics 2014-04-18 Motoi Endo , Takahiro Yoshinaga

We describe a possibility to explain the $2.6\sigma$ deviation from lepton flavour universality observed by the LHCb collaboration in $B^+\to K^+\ell^+\ell^-$ decays in the context of minimal composite Higgs models. We find that a sizable…

High Energy Physics - Phenomenology · Physics 2015-10-16 Peter Stangl

We discuss the exclusive lepton flavor violating (LFV) decays modes based on $b\to d\ell_i\ell_j$ and $b\to s\ell_i\ell_j$ by considering the ground state mesons and baryons. After spelling out the expressions for such decay rates in a low…

High Energy Physics - Phenomenology · Physics 2024-07-30 Damir Bečirević , Florentin Jaffredo , João Paulo Pinheiro , Olcyr Sumensari

We investigate a gauge extension of the Standard Model in light of the observed hints of lepton universality violation in $b \to c \ell \nu$ and $b \to s \ell^+ \ell^-$ decays at BaBar, Belle and LHCb. The model consists of an extended…

High Energy Physics - Phenomenology · Physics 2016-12-19 Sofiane M. Boucenna , Alejandro Celis , Javier Fuentes-Martin , Avelino Vicente , Javier Virto

$U(1)^\prime$ 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

Tests of lepton flavour universality in charged-current $B$ decays offer an excellent opportunity to test the Standard Model, and show hints of new physics in analyses performed by the LHCb, Belle and BaBar experiments. These proceedings…

High Energy Physics - Experiment · Physics 2019-07-03 Suzanne Klaver

Motivated by the recent LHCb results of lepton flavour violation on b decays into s and b decays into c transitions we study the lepton flavour violating (LFV) baryonic decays {Lambda}_b decays into {Lambda}l_i^+ l_j^- in non-universal Z^'…

High Energy Physics - Phenomenology · Physics 2023-10-18 S. Biswas , P. Nayek , P. Maji , S. Sahoo

We consider a class of minimal extensions of the Standard Model with an extra massive neutral gauge boson Z'. They include both family-universal models, where the extra U(1) is associated with (B-L), and non-universal models where the Z' is…

High Energy Physics - Phenomenology · Physics 2010-07-06 Ennio Salvioni

The lepton flavor violating decays $h\to e_b^\pm e_a^\mp $, $Z\to e_b^\pm e_a^\mp$, and $e_b\to e_a \gamma$ will be discussed in the framework of the Two Higgs doublet model with presence of new inverse seesaw neutrinos and a singly charged…

High Energy Physics - Phenomenology · Physics 2024-03-29 T. T. Hong , Q. Duyet Tran , T. Phong Nguyen , L. T. Hue , N. H. T. Nha

$B$-anomalies may suggest New Physics at the TeV scale breaking flavor universality. In particular, 4321 gauge models can successfully explain them in a consistent way. In this talk we explore how to UV complete the 4321 model in a 5D…

High Energy Physics - Phenomenology · Physics 2022-07-04 Javier M. Lizana

Little Higgs Models are promising constructs to solve the hierarchy problem affecting the Higgs boson mass for generic new physics. However, their preservation of lepton universality forbids them to account for the $H\to\tau\mu$ CMS hint…

High Energy Physics - Phenomenology · Physics 2016-09-08 Andrea Lami , Pablo Roig

We calculate the new physics effects to the branching ratios of the lepton flavor conserving decays Z -> l^+ l^- in the framework of the general two Higgs Doublet model. We predict the upper limits for the couplings…

High Energy Physics - Phenomenology · Physics 2009-11-07 E. O. Iltan

The lepton flavor violating $Z^{\prime}\to\tau\mu$ decay is studied in the context of several extended models that predict the existence of the new gauge boson named $Z^\prime$. A calculation of the strength of the lepton flavor violating…

High Energy Physics - Phenomenology · Physics 2015-06-04 J. I. Aranda , J. Montano , F. Ramirez-Zavaleta , J. J. Toscano , E. S. Tututi

In these proceedings we discuss a flavor-safe explanation of the anomaly found in $R_K= {\cal B}(B \to K \mu^+ \mu^-)/{\cal B}(B \to K e^+ e^-)$ by LHCb, within the framework of composite Higgs models. We present a model featuring a…

High Energy Physics - Phenomenology · Physics 2016-10-20 Adrian Carmona , Florian Goertz

The recent B-meson anomalies are coherently explained at the TeV scale by 4321 gauge models with hierarchical couplings reminiscent of the Standard Model Yukawas. We show that such models arise as the low-energy limit of a complete theory…

High Energy Physics - Phenomenology · Physics 2022-08-31 Javier Fuentes-Martin , Gino Isidori , Javier M. Lizana , Nudzeim Selimovic , Ben A. Stefanek