Observation of $$K^{+} \rightarrow \pi ^{+}\pi ^{0}\pi ^{0}\gamma $$ decay

• Published in: The European physical journal. C, Particles and fields Vol. 84; no. 4
• Main Authors: Artamonov, A. V., Bychkov, V. N., Donskov, S. V., Filin, A. P., Filippov, S. N., Gorin, A. M., Gushchin, E. N., Inyakin, A. V., Kekelidze, G. D., Khaustov, G. V., Kholodenko, S. A., Khudyakov, A. A., Kolosov, V. N., Kravtsov, V. I., Kudenko, Yu. G., Kulik, A. V., Kurshetsov, V. F., Lishin, V. A., Lysan, V. M., Medynsky, M. V., Obraztsov, V. F., Okhotnikov, A. V., Polyakov, V. A., Polyarush, A. Yu, Romanovsky, V. I., Rykalin, V. I., Sadovsky, A. S., Samoylenko, V. D., Shapkin, M. M., Tiurin, I. S., Uvarov, V. A., Yushchenko, O. P., Zalikhanov, B. Zh
• Format: Journal Article
• Language: English
• Published: 02.04.2024
• ISSN: 1434-6052; 1434-6052
• DOI: 10.1140/epjc/s10052-024-12674-0

Abstract The $$K^{+} \rightarrow \pi ^{+}\pi ^{0}\pi ^{0}\gamma $$ K + → π + π 0 π 0 γ decay is observed by the OKA collaboration. About 60 events of the decay observed with signal:noise $$\approx 1$$ ≈ 1 . The branching ratio obtained by normalization to $$K^{+} \rightarrow \pi ^{+}\pi ^{0}\pi ^{0}$$ K + → π + π 0 π 0 is measured to be $$(3.7 \pm 0.9(stat) \pm 0.3(syst))\times 10^{-6}$$ ( 3.7 ± 0.9 ( s t a t ) ± 0.3 ( s y s t ) ) × 10 - 6 for $$E_{\gamma }^*>10\,\textrm{MeV}$$ E γ ∗ > 10 MeV . The branching ratio, $$\gamma $$ γ energy spectrum and angular distribution are consistent with ChPT prediction.