Study of the decay in the OKA experiment

M. M. Shapkin; S. A. Akimenko; A. V. Artamonov; A. M. Blik; V. S. Burtovoy; V. N. Bychkov; S. V. Donskov; V. A. Duk; A. P. Filin; S. N. Filippov; A. M. Gorin; E. N. Gushchin; A. V. Inyakin; G. D. Kekelidze; G. V. Khaustov; S. A. Kholodenko; A. A. Khudyakov; V. N. Kolosov; A. S. Konstantinov; V. I. Kravtsov; Yu. G. Kudenko; V. F. Kurshetsov; V. A. Lishin; V. M. Lysan; M. V. Medynsky; Yu. V. Mikhailov; V. F. Obraztsov; V. A. Polyakov; A. Yu. Polyarush; A. V. Popov; V. I. Romanovsky; V. I. Rykalin; A. S. Sadovsky; V. D. Samoilenko; V. K. Semenov; O. V. Stenyakin; O. G. Tchikilev; V. A. Uvarov; O. P. Yushchenko; B. Zh. Zalikhanov

doi:10.1140/epjc/s10052-019-6797-1

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2023 Impact factor 4.2

Particles and Fields

Open Access

Eur. Phys. J. C (2019) 79: 296
https://doi.org/10.1140/epjc/s10052-019-6797-1

Regular Article - Experimental Physics

Study of the decay $K^{+}\rightarrow \pi ^{+}\pi ^{-}\pi ^{+}\gamma$ in the OKA experiment

M. M. Shapkin¹, S. A. Akimenko¹, A. V. Artamonov¹, A. M. Blik¹, V. S. Burtovoy¹, V. N. Bychkov³, S. V. Donskov¹, V. A. Duk²^,4, A. P. Filin¹, S. N. Filippov², A. M. Gorin¹, E. N. Gushchin², A. V. Inyakin¹, G. D. Kekelidze³, G. V. Khaustov¹, S. A. Kholodenko¹, A. A. Khudyakov², V. N. Kolosov¹, A. S. Konstantinov¹, V. I. Kravtsov², Yu. G. Kudenko²^,5^,6, V. F. Kurshetsov¹, V. A. Lishin¹, V. M. Lysan³, M. V. Medynsky¹, Yu. V. Mikhailov¹, V. F. Obraztsov¹, V. A. Polyakov¹, A. Yu. Polyarush², A. V. Popov¹, V. I. Romanovsky¹, V. I. Rykalin¹, A. S. Sadovsky¹^*, V. D. Samoilenko¹, V. K. Semenov¹, O. V. Stenyakin¹, O. G. Tchikilev¹, V. A. Uvarov¹, O. P. Yushchenko¹ and B. Zh. Zalikhanov³

¹ NRC “Kurchatov Institute”-IHEP, 142281, Protvino, Russia
² Institute for Nuclear Research of the Russian Academy of Sciences, 117312, Moscow, Russia
³ Joint Institute of Nuclear Research, 141980, Dubna, Russia
⁴ Present address: University of Birmingham, Birmingham, UK
⁵ Also at National Research Nuclear University (MEPhI), Moscow, Russia
⁶ Institute of Physics and Technology, Moscow, Russia

^* e-mail: Alexander.Sadovskiy@ihep.ru

Received: 10 January 2019
Accepted: 19 March 2019
Published online: 2 April 2019

Abstract

A high statistics data sample of the decays of $$K^+$$ mesons to three charged particles was accumulated by the OKA experiment in 2012 and 2013. This allowed to select a clean sample of about 450 events with $K^{+}\rightarrow \pi ^{+}\pi ^{-}\pi ^{+}\gamma$ decays with the energy of the photon in the kaon rest frame greater than 30 MeV. The measured branching fraction of the $K^{+}\rightarrow \pi ^{+}\pi ^{-}\pi ^{+}\gamma$ , with $E_{\gamma }^{*} > 30\ \hbox {MeV}$ is equal to $(0.71 \pm 0.05) \times 10^{-5}$ . The measured differential branching fraction over photon energy is compared with the prediction of the chiral perturbation theory to ${\mathcal {O}}(p^{4})$ . A search for an up-down asymmetry of the photon with respect to the hadronic system decay plane is also performed.