Related papers: How the tau-lepton mass can be understood
In a version of the 3-3-1 model proposed by Duong and Ma the introduction of the scalar sextet for giving mass to the charged leptons is avoided by adding a singlet charged lepton. We show that in this case the $\tau$ lepton gains mass…
The Z to tau tau cross section is measured with the ATLAS experiment at the LHC in four different final states determined by the decay modes of the tau leptons: muon-hadron, electron-hadron, electron-muon, and muon-muon. The analysis is…
The invariant mass of tau lepton pairs turns out to be smaller than the resonant mass of their mother particle and the invariant mass distribution is stretched wider than the width of the resonant mass as significant fraction of tau lepton…
Analytic formulae are given for order alpha_s perturbative QCD corrections to the double differential distribution of the tau lepton energy and the invariant mass of the tau + antineutrino system in semileptonic decays of the bottom quark.…
The tau -> mu nu nu branching ratio has been measured using data collected from 1990 to 1995 by the OPAL detector at the LEP collider. The resulting value of B(tau -> mu nu nu) = 0.1734 +- 0.0009(stat) +- 0.0006(syst) has been used in…
The large number of $\tau$ leptons available at the Belle II experiment makes it possible to study their properties and the extent of their compositeness. Our strategy relies on three observables defined in terms of elements of the…
A model in which quarks and leptons consist of three "more elementary" particles of spin 1/2 is proposed. A gauge field theory with SU(4) symmetry that corresponds to this model predicts the existence of two new bosons.
For a resonance decaying to $\tau^+\tau^-$, it is difficult to reconstruct its mass accurately because of the presence of neutrinos in the decay products of the $\tau$ leptons. If the resonance is heavy enough, we show that its mass can be…
The minimal model of spontaneously broken leptonic colour and discrete quark-lepton symmetry predicts that charged leptons have the same masses as their partner charge $+2/3$ quarks up to small radiative corrections. By invoking a different…
The top quark mass is currently measured to delta m_t^{exp,Tevatron} = 2.9 GeV and will be measured at the LHC to a precision of delta m_t^{exp,LHC} \approx 1-2 GeV. We show that even this impressive precision will not be sufficient for…
The masses of quarks and leptons in units of $m_t$ are expressed in powers of $\sigma=\sqrt{m_c/m_t}$. The regularities found suggest specific mass matrices. They reproduce all masses and mixings in striking agreement with observation. A 90…
Using the effective Lagrangian formalism, the anomalous magnetic and electric dipole moments of the tau-lepton in the $\mu^{+}\mu^{-} \rightarrow \mu^{+}\gamma^{*} \gamma^{*} \mu^{-}\rightarrow \mu^{+}\tau \bar{\tau}\mu^{-}$ process at the…
In a recent paper a model of quark and lepton masses was proposed. Without any family symmetries almost all the qualitative and quantitative features of the quark and lepton masses and Kobayashi-Maskawa mixing angles are explained,…
Fermion mass matrices generally rotate in generation space under scale changes, which can lead to fermions of different generations transmuting into one another. The effect is examined in detail and its cross-section calculated for $\gamma…
In recent papers a microscopic model for the SM Higgs mechanism has been proposed, and an idea how to determine the 24 quark and lepton masses of all 3 generations has emerged in that framework. This idea is worked out in detail here by…
The tau -> mu nu nu branching ratio has been measured using data collected from 1990 to 1995 by the OPAL detector at the LEP collider. The resulting value of B(tau->mu nu nu) = 0.1734 +/- 0.0009(stat) +/- 0.0005(syst) has been used in…
ATLAS has made several measurements of the top quark mass using proton-proton collision data recorded in 2012 at the LHC with a centre-of-mass energy of 8 TeV. Those summarised here include an indirect determination of the top quark pole…
We present a revised version of the so-called "yukawaon model", which was proposed for the purpose of a unified description of the lepton mixing matrix $U_{PMNS}$ and the quark mixing matrix $V_{CKM}$. It is assumed from a phenomenological…
A measurement of the lifetime of the tau lepton has been made using a sample of 1671 $Z^0\rightarrow\tau^+\tau^-$ decays collected by the SLD detector at SLC. The measurement benefits from the small and stable collision region at SLC and…
We test whether or not the tau lepton manifests the same couplings as the mu lepton by investigating the relative decay rates in purely leptonic D+ meson decays. Specifically, we place the first upper limit on the ratio R=Gamma(D+ -> tau+…