Search for dark photon decays to μ+μ− at NA62
E. Cortina, J. Jerhot, A. Kleimenova, N. Lurkin, M. Zamkovsky, T. Numao, B. Velghe, V. W. S. Wong, D. Bryman, Z. Hives, T. Husek, Karol Kampf, M. Koval, B. De Martino, M. Perrin‐Terrin, Atakan Tugberk Akmete, R. Aliberti, L. Di Lella, N. Doble, L. Peruzzo, Simone Schuchmann, H. Wahl, R. Wanke, P. Dalpiaz, A. Mazzolari, I. Neri, F. Petrucci, M. Soldani, L. Bandiera, A. Cotta Ramusino, A. Gianoli, M. Romagnoni, A. Sytov, M. Lenti, P. Lo Chiatto, R. Marchevski, Ilaria Panichi, G. Ruggiero, A. Bizzeti, Francesca Bucci, A. Antonelli, V. Kozhuharov, G. Lanfranchi, S. Martellotti, M. Moulson, T. Spadaro, G. Tinti, F. Ambrosino, Mariaelena d'Errico, R. Fiorenza, R. Giordano, P. Massarotti, M. Mirra, M. Napolitano, I. Rosa, G. Saracino, G. Anzivino, F. Brizioli, P. Cenci, V. Duk, R. Lollini, P. Lubrano, M. Pepé, M. Piccini, F. Costantini, M. Giorgi, S. Giudici, G. Lamanna, E. Lari, E. Pedreschi, J. Pinzino, M. Sozzi, R. Fantechi, F. Spinella, I. Mannelli, M. Raggi, A. Biagioni, Paolo Cretaro, Ottorino Frezza, A. Lonardo, M. Turisini, P. Vicini, Roberto Ammendola, V. Bonaiuto, A. Fucci, Á. Salamon, F. Sargeni, R. Arcidiacono, B. Bloch-Devaux, E. Menichetti, E. Migliore, C. Biino, A. Filippi, F. Marchetto, D. Soldi, A. Briano Olvera, J. Engelfried, N. Estrada-Tristan, R. Piandani, M. A. Reyes Santos
Abstract
A bstract The NA62 experiment at CERN, designed to study the ultra-rare decay K + → π + $$ \nu \overline{\nu} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>ν</mml:mi> <mml:mover> <mml:mi>ν</mml:mi> <mml:mo>¯</mml:mo> </mml:mover> </mml:math> , has also collected data in beam-dump mode. In this configuration, dark photons may be produced by protons dumped on an absorber and reach a decay volume beginning 80 m downstream. A search for dark photons decaying in flight to μ + μ − pairs is reported, based on a sample of 1 . 4 × 10 17 protons on dump collected in 2021. No evidence for a dark photon signal is observed. A region of the parameter space is excluded at 90% CL, improving on previous experimental limits for dark photon masses between 215 and 550 MeV /c 2 .