Related papers: Isosinglet vectorlike leptons at $e^+e^-$ collider…
Based on 471 million BB pairs collected with the BABAR detector at the PEP-II e+e- collider, we perform a series of measurements on rare decays B->K(*)l+l-, where l+l- is either e+e- or mu+mu-. The measurements include total branching…
The magnetic moment of the $\tau$ lepton is an interesting quantity that is potentially sensitive to physics beyond the Standard Model. Electroweak gauge invariance implies that a heavy new physics contribution to it takes the form of an…
A search for new particles has been conducted using events with two high transverse momentum (pt) tau leptons that decay hadronically, at least two high-pt jets, and missing transverse energy from the tau lepton decays. The analysis is…
Tau-lepton decays with up to two $\pi^0$'s in the final state, $\tau^+ \to \pi^+ \bar{\nu}_\tau$, $\rho^+ (\pi^+\pi^0) \bar{\nu}_\tau$, $a^+_1 (\pi^+\pi^0\pi^0) \bar{\nu}_\tau$, are used to study the performance of the barrel part of the…
A fermion can be chiral or vectorlike with respect to a given symmetry, depending on its coupling to the corresponding gauge boson. Vectorlike fermions have a distinct property that their left-handed and right-handed components behave in…
The tau is the only known lepton that can decay hadronically. From this class of decays, high precision measurements of several quantities can be extracted: the CKM matrix element $V_{us}$, the mass of the strange quark, etc. Also, as a…
Simple models are proposed where the baryon and lepton number are gauged and spontaneously broken near the weak scale. The models use a fourth generation that is vector-like with respect to the strong, weak and electromagnetic interactions…
We point out that at future hadron colliders the ratio of cross sections for $pp\to Z'\to \ell^+\ell^-$ in two rapidity bins is a useful probe of the relative couplings of the $Z'$ to $u$ and $d$ quarks. Combined with the forward-backward…
An unspecified strong dynamics may give rise to composite vectors sufficiently light that their interactions, among themselves or with the electroweak gauge bosons, be approximately described by an effective Lagrangian invariant under…
We review the phenomenology of electro-weak bosons produced in hadron-hadron collisions. In particular, we discuss the transverse momentum distribution of lepton pairs with invariant mass close to the Z peak. We describe the theoretical…
A weakly coupled new neutral gauge boson forms a narrow resonance that is hard to discover directly in e+e- collisions. However, if the gauge boson mass is below the center-of-mass energy, it can be produced through processes where the…
Rare B hadron decays provide an excellent test bench for the Standard Model and can probe new physics models. We review the experimental progress of the searches for rare leptonic B decays ($b\rightarrow \ell^+ \ell^-$ and $b\rightarrow s…
A combination of searches for the single production of vector-like top quarks ($T$) is presented. These analyses are based on proton$-$proton collisions at $\sqrt{s}=13$ TeV recorded in 2015$-$2018 with the ATLAS detector at the Large…
I review possible signals at hadron colliders of bileptons, namely doubly-charged vectors or scalars with lepton number L=+/- 2, as predicted by a 331 model, based on a SU(3)_c x SU(3)_L x U(1)_X symmetry. In particular, I account for a…
Rare lepton decays of the B(s), D and K mesons are sensitive probes of New Physics. In particular, the search for the decays $B^0_(s) -> \mu^+ \mu^-$ provides information on the presence of new (pseudo-)scalar particles. LHCb is well suited…
The Electron-Ion Collider~(EIC), a forthcoming powerful high-luminosity facility, represents an exciting opportunity to explore new physics. In this article, we study the potential of the EIC to probe the coupling between axion-like…
Although the LHC experiments have searched for and excluded many proposed new particles up to masses close to 1 TeV, there are many scenarios that are difficult to address at a hadron collider. This talk will review a number of these…
A search for beyond the standard model spin-0 bosons, $\phi$, that decay into pairs of electrons, muons, or tau leptons is presented. The search targets the associated production of such bosons with a W or Z gauge boson, or a top…
We perform a detailed analysis of the potentiality of the CERN Large Hadron Collider to study the single production of leptoquarks via $pp \to e^\pm q\to$ leptoquark $\to e^\pm q$, with $e^\pm$ generated by the splitting of photons radiated…
We review world-average measurements of the tau lepton electroweak couplings, in both decay (including Michel parameters) and in production ($Z^0\to \tau^+\tau^-$ and $W^-\to\tau^-\nubar_\tau$). We review the searches for anomalous weak and…