Search for heavy neutrinos with the T2K near detector ND280
Physical Review D American Physical Society 100:5 (2019) 052006
Abstract:
This paper reports on the search for heavy neutrinos with masses in the range $140 < M_N < 493$ MeV/c$^2$ using the off-axis near detector ND280 of the T2K experiment. These particles can be produced from kaon decays in the standard neutrino beam and then subsequently decay in ND280. The decay modes under consideration are $N \to \ell^{\pm}_{\alpha} \pi^{\mp}$ and $N \to \ell^+_{\alpha} \ell^-_{\beta} \nu (\bar\nu)$ ($\alpha,\beta=e,\mu$). A search for such events has been made using the Time Projection Chambers of ND280, where the background has been reduced to less than two events in the current dataset in all channels. No excess has been observed in the signal region. A combined Bayesian statistical approach has been applied to extract upper limits on the mixing elements of heavy neutrinos to electron-, muon- and tau- flavoured currents ($U_e^2$, $U_{\mu}^2$, $U_{\tau}^2$) as a function of the heavy neutrino mass, e.g. $U_e^2 < 10^{-9}$ at $90\%$ C.L. for a mass of $390$ MeV/c$^2$. These constraints are competitive with previous experiments.Search for supersymmetry in final states with two same-sign or three leptons and jets using 36 fb(-1) of root s = 13 TeV pp collision data with the ATLAS detector (vol 09, 084, 2017)
JOURNAL OF HIGH ENERGY PHYSICS 2019:8 (2019) ARTN 121
Abstract:
© 2019, The Author(s). One correction is made to the figure 4e of the paper.Search for chargino and neutralino production in final states with a Higgs boson and missing transverse momentum at s√=13 TeV with the ATLAS detector
Physical Review D American Physical Society 100:1 (2019) 012006
Abstract:
A search is conducted for the electroweak pair production of a chargino and a neutralino pp → χ˜ 1 χ˜ 0 2, where the chargino decays into the lightest neutralino and a W boson, χ˜ 1 → χ˜ 0 1W, while the neutralino decays into the lightest neutralino and a Standard Model-like 125 GeV Higgs boson, χ˜ 0 2 → χ˜ 0 1h. Fully hadronic, semileptonic, diphoton, and multilepton (electrons, muons) final states with missing transverse momentum are considered in this search. Higgs bosons in the final state are identified by either two jets originating from bottom quarks (h → bb¯), two photons (h → γγ), or leptons from the decay modes h → WW, h → ZZ or h → ττ. The analysis is based on 36.1 fb−1 of ffiffi s p ¼ 13 TeV proton-proton collision data recorded by the ATLAS detector at the Large Hadron Collider. Observations are consistent with the Standard Model expectations, and 95% confidence-level limits of up to 680 GeV in χ˜ 1 =χ˜ 0 2 mass are set in the context of a simplified supersymmetric model.Search for dark matter with a 231-day exposure of liquid argon using DEAP-3600 at SNOLAB
Physical Review D American Physical Society (APS) 100:2 (2019) 022004
Search for neutral-current induced single photon production at the ND280 near detector in T2K
Journal of Physics G: Nuclear and Particle Physics IOP Publishing 46:8 (2019) 08LT01