2017/10/31 by LHCb collaboration, R. Aaij, B. Adeva +796 · 1 citation
Physics and Astronomy · #hep-ex
paper · pdf · doi:10.1103/physrevlett.120.061801
published as Phys. Rev. Lett. 120, 061801 (2018) · All figures and tables, along with any supplementary material and additional information, are available at https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2017-038.html
arxiv created 2018/02/09 · arxiv updated 2018/02/14
Searches are performed for both prompt-like and long-lived dark photons, A′, produced in proton-proton collisions at a center-of-mass energy of 13 TeV, using A′→μ+μ- decays and a data sample corresponding to an integrated luminosity of 1.6 fb-1 collected with the LHCb detector. The prompt-like A′ search covers the mass range from near the dimuon threshold up to 70 GeV, while the long-lived A′ search is restricted to the low-mass region 214<m(A′)<350 MeV. No evidence for a signal is found, and 90% confidence level exclusion limits are placed on the γ-A′ kinetic-mixing strength. The constraints placed on prompt-like dark photons are the most stringent to date for the mass range 10.6 < m(A′) < 70 GeV, and are comparable to the best existing limits for m(A′) < 0.5 GeV. The search for long-lived dark photons is the first to achieve sensitivity using a displaced-vertex signature.