Journal Article

Search for π0 decays to invisible particles

Martellotti, S., Ceccucci, A., Doble, N., Kudenko, Y., Guida, R., Coward, D., Lehmann Miotto, G., Kampf, K., Wanke, R., Döbrich, B., Lanfranchi, G., Obraztsov, V., Emelyanov, D., Soldi, D., Newson, F., Duval, F., Federici, L., Kleimenova, A., Kekelidze, V., Mirra, M., Saracino, G., Sozzi, M., Bache, T., Biino, C., Korotkova, A., Cortina Gil, E., Bonaiuto, V., Carmignani, J., Santoni, C., Leonardi, E., Husek, T., Holzer, E. B., Lurkin, N., Swallow, J., Brunetti, M. B., Massarotti, P., Polenkevich, I., Pepe, M., Lubrano, P., Goudzovski, E., Velghe, B., Fucci, A., Parkinson, C., Filippi, A., Cotta Ramusino, A., Numao, T., Lamanna, G., Blazek, T., Baeva, A., Zinchenko, A., Khoriauli, G., Molokanova, N., Movchan, S., Romano, A., Litov, L., Conovaloff, A., Perrin-Terrin, M., Sugonyaev, V., Sergi, A., Fedotov, S., Khotyantsev, A., Vicini, P., Boretto, M., Biagioni, A., Bragadireanu, A. M., Hutchcroft, D., Napolitano, M., Anzivino, G., Pedreschi, E., Minucci, E., Norton, A., Palladino, V., Marchetto, F., Hutanu, O. E., Maurice, E., Ryjov, V., Page, R., Piandani, R., Imbergamo, E., Koval, M., Menichetti, E., Kunze, J., Padolski, S., Brizioli, F., Cooper, P., Wr

2021

Overview

A bstract The NA62 experiment at the CERN SPS reports a study of a sample of 4 × 10 9 tagged π 0 mesons from K + → π + π 0 ( γ ), searching for the decay of the π 0 to invisible particles. No signal is observed in excess of the expected background fluctuations. An upper limit of 4 . 4 × 10 − 9 is set on the branching ratio at 90% confidence level, improving on previous results by a factor of 60. This result can also be interpreted as a model- independent upper limit on the branching ratio for the decay K + → π + X , where X is a particle escaping detection with mass in the range 0.110–0.155 GeV /c 2 and rest lifetime greater than 100 ps. Model-dependent upper limits are obtained assuming X to be an axion-like particle with dominant fermion couplings or a dark scalar mixing with the Standard Model Higgs boson.

• Publisher: Springer Berlin Heidelberg,Springer Nature B.V,Springer Nature
• Subject: Atoms & subatomic particles / Beyond Standard Model / Charged particles / Classical and Quantum Gravitation / Collaboration / Confidence intervals / Couplings / Elementary Particles / Exotics / Experiments / Fermions / Fixed target experiments / Fysik / Higgs bosons / High energy physics / Mesons / Natural Sciences / Naturvetenskap / Particle decay / Physical Sciences / Physics / Physics and Astronomy / Quantum Field Theories / Quantum Field Theory / Quantum Physics / Rare decay / Regular Article - Experimental Physics / Relativity Theory / Sensors / Standard model (particle physics) / String Theory / Subatomic Physics / Subatomär fysik / Synchrotrons