On the production of a lepton pair in the collision of ultrarelativistic neutral particle with nonzero magnetic moment with nuclei
Abstract Explicit formulas which describe muon pair production in reaction γν→μ+μ−ν through neutrino magnetic moment are obtained and used to derive in the leading approximation cross section of muon pair production in νN-scattering due to neutrino magnetic moment. This cross section appears to be proportional to log4Eν. Comparison with experimental data on tridents production provides an upper bound μνμ
Neutrino trident scattering at near detectors
A bstractNeutrino trident scattering is a rare Standard Model process where a charged-lepton pair is produced in neutrino-nucleus scattering. To date, only the dimuon final-state has been observed, with around 100 total events, while the other channels are as yet unexplored. In this work, we compute the trident production cross section by performing a complete four-body phase space calculation for different hadronic targets. This provides a correct estimate both of the coherent and the diffractive contributions to these cross sections, but also allows us to address certain inconsistencies in the literature related to the use of the Equivalent Photon Approximation in this context. We show that this approximation can give a reasonable estimate only for the production of dimuon final-states in coherent scattering, being inadmissible for all other cases considered. We provide estimates of the number and distribution of trident events at several current and future near detector facilities subjected to intense neutrino beams from accelerators: five liquid-argon detectors (SBND, μBooNE, ICARUS, DUNE and νSTORM), the iron detector of T2K (INGRID) and three detectors made of composite material (MINOS, NOνA and MINERνA). We find that for many experiments, trident measurements are an attainable goal and a valuable addition to their near detector physics programme.
Neutrino production of lepton pairs through the point four-fermion interaction
SummaryThe total cross-sections for production of lepton pairs through the point four-fermion interaction by high-energy neutrinos and antineutrinos in the nuclear electromagnetic field are calculated numerically from the threshold up to very high energies where the asymptotic formulae are applicable. The asymptotic cross-sections are calculated analytically and found to be (for high enough energies) in excellent agreement with the exact numerical calculations. The importance of such detailed calculations, especially in the search for the intermediate vector boson, is stressed. Appendix B contains many details of the invariant phase-space calculations.RiassuntoSi calcolano numericamente le sezioni efficaci totali per la produzione di coppie di leptoni tramite l’interazione quadrifermionica puntiforme da parte di neutrini ed antineutrini di alta energia nel campo elettromagnetico nucleare, dalla soglia alle altissime energie alle quali si possono applicare le formule asintotiche. Si calcolano analiticamente le sezioni efficaci asintotiche e si trova che (per energie abbastanza alte) esse concordano molto bene con quelle ottenute con calcoli numerici esatti. Si mette in rilievo l’importanza di questi calcoli dettagliati, specialmente per la ricerca del bosone vettoriale intermedio. L’Appendice B contiene molti dettagli del calcolo dello spazio delle fasi invariante.