Related papers: Diagnosing New Physics with LUV and LFV B Decays
In recent years, significant experimental indications that point towards Lepton Flavour Universality violating effects in B-decays, involving $b \to c \tau \nu$ and $b \to s \ell^+ \ell^-$ have been accumulated. A possible New Physics…
In this work we assess the potential of discovering new physics by searching for lepton-flavour-violating (LFV) decays of the $Z$ boson, $Z\to \ell_i \ell_j$, at the proposed circular $e^+e^-$ colliders CEPC and FCC-ee. Both projects plan…
The number of leptons may or may not be a conserved quantity. The Standard Model predicts that it is (in perturbative processes), but there is the well known possibility that new physics violates lepton number in one or two units. The first…
In light of recent results from the LHC, MEG and neutrino experiments, we revisit the issue of charged lepton flavour violation (LFV) in supersymmetric theories with massive neutrinos, where flavour-violating soft supersymmetry-breaking…
Many models for physics beyond the Standard Model predict lepton-flavour violating decays of charged leptons at a level which may become observable very soon. In the present paper we investigate the decays of a Tau into three charged…
Intriguing results for tests of the universality of electrons and muons through measurements of rates of $B\to K \ell^+ \ell^-$ and similar decays have been in the spotlight for years. The LHCb collaboration has recently reported new…
The recent measurements of lepton flavor university (LFU) violating observables in semileptonic $b \to c \ell \bar{\nu} $ and $b\to s\ell^+ \ell^-$ transitions by various experiments exhibit $(2-3)\sigma$ deviations from their corresponding…
While the LHC did not observe direct evidence for physics beyond the standard model, indirect hints for new physics were uncovered in the flavour sector in the decays $B\to K^*\mu^+\mu^-$, $B\to K\mu^+\mu^-/B\to Ke^+e^-$,…
In the Standard Model of particle physics, lepton flavour and lepton number are conserved quantities although no fundamental symmetry demands their conservation. I present recent results of searches for lepton flavour and lepton number…
We study two- and three-body lepton flavor violating (LFV) decays involving leptons and neutral vector bosons $V=\rho^0, \omega, \phi, J/\psi, \Upsilon, Z^0$, as well as pseudo-scalar $P=\pi^0, \eta, \eta', \eta_c$ and scalar $S=f_0(500),…
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…
I review the signals for New Physics in CP-violating measurements in B and Lambda_b decays. I also discuss ways of identifying this New Physics, should such a signal be found.
Lepton flavor violations in charged lepton give good signatures for the new physics. We review recent searches for lepton flavor violation in tau decays at B-factories. In these searches, optimization for background reduction is important…
Recently, several new experimental results of the test of lepton flavor universality (LFU) in $B\to D^{(\ast)}$ semi-leptonic decays were announced: the first result of $R_{D}$ from the LHCb Run 1 data, the first results of $R_{D}$ and…
Several measurements of tree- and loop-level b-hadron decays performed in the recent years hint at a possible violation of Lepton Universality. This article presents an experimental and theoretical overview of the current status of the…
Motivated by the recent experimental progress on the $R_{D^{(\ast)}}$ and $R_{K^{(\ast)}}$ anomalies in $B$-decays, we consider an extension of the Standard Model by a single vector leptoquark field. We study how one can achieve the…
We discuss the current status of lepton flavour universality observables in semileptonic charged and neutral current $B$ meson decays. We recapitulate the current experimental situation. Assuming the current tensions with the SM are of…
$\tau$ is playing an important role in the current B-physics indications from experiments of lepton flavor universality violations(LFUV). This suggests it be given increasing attention theoretically in the coming years, given also the fact…
General expressions for one-loop contributions associated with lepton-flavor violating decays of the standard model-like Higgs boson $h\to e_b^\pm e_a^\mp$ and gauge boson $Z\to e^\pm_b e_a^\mp$ are introduced in the unitary gauge. The…
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…