Yu M Andreev, D Banerjee, B Banto Oberhauser, J Bernhard, P Bisio, A Celentano, N Charitonidis, A G Chumakov, D Cooke, P Crivelli, E Depero, A V Dermenev, S V Donskov, R R Dusaev, T Enik, V N Frolov, R B Galleguillos Silva, A Gardikiotis, S V Gertsenberger, S Girod, S N Gninenko, M Hösgen, V A Kachanov, Y Kambar, A E Karneyeu, E A Kasianova, G D Kekelidze, B Ketzer, D V Kirpichnikov, M M Kirsanov, V N Kolosov, V A Kramarenko, L V Kravchuk, N V Krasnikov, S V Kuleshov, V E Lyubovitskij, V Lysan, A Marini, L Marsicano, V A Matveev, R Mena Fredes, R G Mena Yanssen, L Molina Bueno, M Mongillo, D V Peshekhonov, V A Polyakov, B Radics, K M Salamatin, V D Samoylenko, H Sieber, D A Shchukin, O Soto, V O Tikhomirov, I V Tlisova, A N Toropin, M Tuzi, B I Vasilishin, P V Volkov, V Yu Volkov, I V Voronchikhin, J Zamora-Saá, A S Zhevlakov
Thermal dark matter models with particle χ masses below the electroweak scale can provide an explanation for the observed relic dark matter density. This would imply the existence of a new feeble interaction between the dark and ordinary matter. We report on a new search for the sub-GeV χ production through the interaction mediated by a new vector boson, called the dark photon A^{'}, in collisions of 100 GeV electrons with the active target of the NA64 experiment at the CERN SPS. With 9.37×10^{11} electrons on target collected during 2016-2022 runs NA64 probes for the first time the well-motivated region of parameter space of benchmark thermal scalar and fermionic dark matter models...
October 20, 2023: Physical Review Letters