@article{7535fee421b943da8bc9f3fa21e7c20d,
title = "Measurement of the K+ → π+γγ decay",
abstract = "A sample of 3984 candidates of the K+→π+γγ decay, with an estimated background of 291±14 events, was collected by the NA62 experiment at CERN during 2017–2018. In order to describe the observed di-photon mass spectrum, the next-to-leading order contribution in chiral perturbation theory was found to be necessary. The decay branching ratio in the full kinematic range is measured to be (9.61±0.17)×10−7. The first search for production and prompt decay of an axion-like particle with gluon coupling in the process K+→π+a, a→γγ is also reported.",
author = "\{The NA62 Collaboration\} and \{Cortina Gil\}, E. and A. Kleimenova and E. Minucci and S. Padolski and P. Petrov and A. Shaikhiev and R. Volpe and T. Numao and Y. Petrov and B. Velghe and Wong, \{V. W.S.\} and D. Bryman and J. Fu and Z. Hives and T. Husek and J. Jerhot and K. Kampf and M. Zamkovsky and \{De Martino\}, B. and M. Perrin-Terrin and B. D{\"o}brich and S. Lezki and Akmete, \{A. T.\} and R. Aliberti and G. Khoriauli and J. Kunze and D. Lomidze and L. Peruzzo and M. Vormstein and R. Wanke and P. Dalpiaz and M. Fiorini and A. Mazzolari and I. Neri and A. Norton and F. Petrucci and M. Soldani and H. Wahl and L. Bandiera and \{Cotta Ramusino\}, A. and A. Gianoli and M. Romagnoni and A. Sytov and E. Iacopini and G. Latino and M. Lenti and \{Lo Chiatto\}, P. and I. Panichi and A. Parenti and E. Maurice",
note = "Publisher Copyright: {\textcopyright} 2024 The Author",
year = "2024",
month = mar,
day = "1",
doi = "10.1016/j.physletb.2024.138513",
language = "English",
volume = "850",
journal = "Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics",
issn = "0370-2693",
}