Related papers: Two-to-two processes at an electron-muon collider
Transforming a $\mu$ to a $\tau$, then the $\tau$ to to an $e$, results in $\mu \to e$. In an EFT framework, we explore the sensitivity of $\mu\to e$ observables to products of $(\mu\to \tau)\times (\tau \to e)$ interactions, and show that…
The anomalous magnetic moments of leptons represent excellent probes of the Standard Model and therefore also of possible new physics effects. In particular, the persisting hint of new physics in the muon $g$-2 motivates the investigation…
For the first time the experiments ALEPH, DELPHI, L3 and OPAL have presented preliminary results for fermion-pair and photon-pair production in e+e- collisions on the full LEP2 data set. The details of the experimental measurements and…
We present a comprehensive and gauge-invariant study of the neutrino dipole portal at the energy frontier. Assuming negligible active-sterile mixing, we analyze sterile neutrino production via dimension-6 dipole operators coupling to the…
Muon colliders are an exciting possibility for reaching the highest energies possible on the shortest timescale. They potentially combine the greatest strengths of $e^+e^-$ and $pp$ colliders by bridging the energy versus precision…
We report on studies of the sensitivity to extra gauge bosons of the reactions e^+ e^- -> nu nubar gamma and e gamma -> nu q + X to extract discovery limits for W' 's. The discovery potential for a W' is, for some models, comparable to that…
We investigate the unique potential of a high-energy muon collider to probe lepton-flavor-violating signals arising from physics beyond the Standard Model (SM). Low-energy, precision searches for charged lepton-flavor violation (LFV) are…
We study the effects of non-commutative QED (NCQED) in fermion pair production, $\gamma + \gamma \to f + \bar{f}$ and Compton scattering, $e + \gamma \to e + \gamma$. Non-commutative geometries appear naturally in the context of…
We study single top production at linear lepton colliders with $\sqrt{s} = 0.5$, 1 and 3 TeV. A preliminary analysis shows that despite the large $t\bar t$ background at $\sqrt{s} = 0.5$ and 1 TeV it is possible to obtain a good sensitivity…
The six-fermion production processes $e^+e^-\to q\bar q l^+ l^-\nu\bar\nu$, with all the lepton flavours and $q=u,d,c,s$, relevant to the study of the intermediate-mass Higgs boson at future $e^+e^-$ linear colliders, are analysed. A Monte…
We study the effects of non-commutative QED (NCQED) in fermion pair production, gamma + gamma to f + \bar{f} and Compton scattering, e + gamma to e + gamma. Non-commutative geometries give rise to 3- and 4-point photon vertices and to…
The BaBar Collaboration has an intensive program of studying hadronic cross sections at low-energy $e^+e^-$ collisions, accessible via initial-state radiation. Our measurements allow significant improvements in the precision of the…
We investigate the sensitivity of a future 10 TeV muon collider to dimension-6 operators in the Standard Model Effective Field Theory (SMEFT), focusing on Higgs and top quark production processes. The analysis includes two-fermion and…
The charge asymmetry in top quark production at hadron colliders is sensitive to beyond-the-Standard-Model four-fermion interactions. In this study we compare the sensitivity of cross-section and charge asymmetry measurements to effective…
At very high energies, pair production ($\gamma\to e^+e^-$) exhibits many interesting features. The momentum transfer from the target is very small, so the reaction probes the macroscopic properties of the target, rather than individual…
Cross sections for the production of two isolated muons up to high di-muon masses are measured in ep collisions at HERA with the H1 detector in a data sample corresponding to an integrated luminosity of 71 pb^-1 at a centre of mass energy…
We present the results of a search for the production of an excited state of the muon, mu*, in proton antiproton collisions at sqrt s = 1.96 TeV. The data have been collected with the D0 experiment at the Fermilab Tevatron Collider and…
It is shown that at muon colliders with the energy in the region of 100 TeV the process of coherent pair creation by the muon in the field of the opposing beam becomes important and imposes some limitations on collider parameters.
An observation of Charged Lepton Flavor Violation (CLFV) would be unambiguous evidence for physics beyond the Standard Model. The Mu2e and COMET experiments, under construction, are designed to push the sensitivity to CLFV in the mu to e…
The exclusive production of baryon-antibaryon pairs in the collisions of two quasi-real photons has been studied using different detectors at e+e- colliders. Results are presented for $\gamma\gamma\to$ proton antiproton,…