Publications associées à Flavor-changing neutral current

Testing lepton flavour universality in $B^+\to K^+\pi^+\pi^-\ell^+\ell^-$ decays with LHCb

This PhD thesis aims at testing one of the fundamental properties of the Standard Model (SM) of particle physics: the lepton flavour universality (LFU), which states that

W

and

Z

bosons are equally coupled to the three lepton generations. In this work, ...

EPFL2023

Measurement of the B+ -> rho0 mu+ nu differential branching fraction

Veronica Sølund Kirsebom

The tension between different determinations of the CKM matrix element Vub using measurements of either exclusive or inclusive semileptonic decays represents a long-standing puzzle in flavour physics. To resolve this, measurements of new exclusive channels ...

EPFL2023

Search for Higgs boson and observation of Z boson through their decay into a charm quark-antiquark pair in boosted topologies in proton-proton collisions at √s=13 TeV

Matthias Finger, Konstantin Androsov, Qian Wang, Jan Steggemann, Yiming Li, Anna Mascellani, Varun Sharma, Xin Chen, Rakesh Chawla, Matteo Galli

A search for the standard model (SM) Higgs boson (H) produced with transverse momentum (p(T)) greater than 450 GeV and decaying to a charm quark-antiquark (c (c) over bar) pair is presented. The search is performed using proton-proton collision data collec ...

Amer Physical Soc2023

Test of Lepton Universality in b→sℓ+ℓ− Decays

The first simultaneous test of muon-electron universality using

B^{+}\rightarrow K^{+}\ell^{+}\ell^{-}

and

B^{0}\rightarrow K^{*0}\ell^{+}\ell^{-}

decays is performed, in two ranges of the dilepton invariant-mass squared,

q^{2}

. The analysis uses bea ...

2023

An allowed window for heavy neutral leptons below the kaon mass

Alexey Boyarsky, Kyrylo Bondarenko, Oleg Ruchayskiy, Inar Timiryasov, Juraj Klaric

The extension of the Standard Model with two gauge-singlet Majorana fermions can simultaneously explain two beyond-the-Standard-model phenomena: neutrino masses and oscillations, as well as the origin of the matter-antimatter asymmetry in the Universe. The ...

Springer Nature2021

On lepton number violation in heavy neutrino decays at colliders

Marco Drewes, Juraj Klaric

We study the perspective to observe lepton number violating signatures from heavy Majorana neutrino decays at colliders in view of the requirement to explain the light neutrino masses via the seesaw mechanism. In the minimal model with only two heavy neutr ...

Springer Nature2019

Search for B- -> mu(-)(nu)over-bar(mu) Decays at the Belle Experiment

Olivier Schneider, Sun Hee Kim, Mingkui Wang, Chao Wang, Tara Nanut, Tagir Aushev, Joo Yeon Kim, Timothy Chi Hin Liew, Chang-Hyun Park, Seyed Sina Mirrazavi Salehian

We report the results of a search for the rare, purely leptonic decay B- -> mu(-)(nu) over bar (mu) performed with a 711 fb(-1) data sample that contains 772 x 10(6) B (B) over bar pairs, collected near the Upsilon(4S) resonance with the Belle detector at ...

2018

The bearable compositeness of leptons

Luca Vecchi

Partial compositeness as a theory of flavor in the lepton sector is assessed. We begin presenting the first systematic analysis of neutrino mass generation in this context, and identifying the distinctive mass textures. We then update the bounds from charg ...

Springer Nature2018

Study of charmonium production in b-hadron decays and first evidence for the decay B-s(0) -> phi phi phi

Olivier Schneider, Yiming Li, Aurelio Bay, Guido Haefeli, Frédéric Blanc, Christoph Frei, Tatsuya Nakada, Luca Pescatore, François Fleuret, Elena Graverini

Using decays to f-meson pairs, the inclusive production of charmonium states in b-hadron decays is studied with pp collision data corresponding to an integrated luminosity of 3.0 fb(-1), collected by the LHCb experiment at centre-of-mass energies of 7 and ...

Springer Nature2017

Constraints on violation of Lorentz invariance from atmospheric showers initiated by multi-TeV photons

Sergey Sibiryakov

Parameterizing hypothetical violation of Lorentz invariance at high energies using the framework of effective quantum field theory, we discuss its effect on the formation of atmospheric showers by very-high-energy gamma rays. In the scenario where Lorentz ...

Iop Publishing Ltd2017