TY  - JOUR
AU  - NA64 Collaboration (Andreev, Y. M. et al
AU  - Molina Bueno, L.
AU  - Tuzi, M.
PY  - 2024
DA  - 2024//
TI  - First Results in the Search for Dark Sectors at NA64 with the CERN SPS High Energy Muon Beam
T2  - Phys. Rev. Lett.
JO  - Physical Review Letters
SP  - 211803
EP  - 7pp
VL  - 132
IS  - 21
PB  - Amer Physical Soc
AB  - We report the first search for dark sectors performed at the NA64 experiment employing a high energy muon beam and a missing energy-momentum technique. Muons from the M2 beamline at the CERN Super Proton Synchrotron with a momentum of 160 GeV/c are directed to an active target. The signal signature consists of a single scattered muon with momentum < 80 GeV/c in the final state, accompanied by missing energy, i.e., no detectable activity in the downstream calorimeters. For a total dataset of (1.98 +/- 0.02) x 10(10) muons on target, no event is observed in the expected signal region. This allows us to set new limits on the remaining (m(Z)'; g(Z)') parameter space of a new Z' (L-mu – L-tau) vector boson which could explain the muon (g – 2)(mu) anomaly. Additionally, our study excludes part of the parameter space suggested by the thermal dark matter relic abundance. Our results pave the way to explore dark sectors and light dark matter with muon beams in a unique and complementary way to other experiments.
SN  - 0031-9007
UR  - https://arxiv.org/abs/2401.01708
UR  - https://doi.org/10.1103/PhysRevLett.132.211803
DO  - 10.1103/PhysRevLett.132.211803
LA  - English
N1  - WOS:001239696000003
ID  - NA64CollaborationAndreev_etal2024
ER  -