A sample of 3984 candidates of the decay, with an estimated background of 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 . The first search for production and prompt decay of an axion-like particle with gluon coupling in the process , is also reported.
Measurement of the K+ → π+γγ decay
Giudici, S.;Pedreschi, E.;Sozzi, M.;Spinella, F.;Pinzino, J.;Angelucci, B.;
2024-01-01
Abstract
A sample of 3984 candidates of the decay, with an estimated background of 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 . The first search for production and prompt decay of an axion-like particle with gluon coupling in the process , is also reported.File in questo prodotto:
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