A search for $\mu^+\to e^+\gamma$ with the first dataset of the MEG II experiment

Autor: MEG II collaboration, Afanaciev, K., Baldini, A. M., Ban, S., Baranov, V., Benmansour, H., Biasotti, M., Boca, G., Cattaneo, P. W., Cavoto, G., Cei, F., Chiappini, M., Chiarello, G., Corvaglia, A., Cuna, F., Maso, G. Dal, De Bari, A., De Gerone, M., Barusso, L. Ferrari, Francesconi, M., Galli, L., Gallucci, G., Gatti, F., Gerritzen, L., Grancagnolo, F., Grandoni, E. G., Grassi, M., Grigoriev, D. N., Hildebrandt, M., Ieki, K., Ignatov, F., Ikeda, F., Iwamoto, T., Karpov, S., Kettle, P. -R., Khomutov, N., Kobayashi, S., Kolesnikov, A., Kravchuk, N., Krylov, V., Kuchinskiy, N., Kyle, W., Libeiro, T., Malyshev, V., Matsushita, A., Meucci, M., Mihara, S., Molzon, W., Mori, Toshinori, Nakao, M., Nicolò, D., Nishiguchi, H., Ochi, A., Ogawa, S., Onda, R., Ootani, W., Oya, A., Palo, D., Panareo, M., Papa, A., Pettinacci, V., Popov, A., Renga, F., Ritt, S., Rossella, M., Rozhdestvensky, A., Schwendimann, P., Shimada, K., Signorelli, G., Takahashi, M., Tassielli, G. F., Toyoda, K., Uchiyama, Y., Usami, M., Venturini, A., Vitali, B., Voena, C., Yamamoto, K., Yanai, K., Yonemoto, T., Yoshida, K., Yudin, Yu. V.

The MEG II experiment, based at the Paul Scherrer Institut in Switzerland, reports the result of a search for the decay $\mu^+\to e^+\gamma$ from data taken in the first physics run in 2021. No excess of events over the expected background is observe

Externí odkaz: http://arxiv.org/abs/2310.12614

Measurement of the pion form factor with CMD-3 detector and its implication to the hadronic contribution to muon (g-2)

Autor: Collaboration, CMD-3, Ignatov, F. V., Akhmetshin, R. R., Amirkhanov, A. N., Anisenkov, A. V., Aulchenko, V. M., Bashtovoy, N. S., Berkaev, D. E., Bondar, A. E., Bragin, A. V., Eidelman, S. I., Epifanov, D. A., Epshteyn, L. B., Erofeev, A. L., Fedotovich, G. V., Gorkovenko, A. O., Grancagnolo, F. J., Grebenuk, A. A., Gribanov, S. S., Grigoriev, D. N., Ivanov, V. L., Karpov, S. V., Kasaev, A. S., Kazanin, V. F., Khazin, B. I., Kirpotin, A. N., Koop, I. A., Korobov, A. A., Kozyrev, A. N., Kozyrev, E. A., Krokovny, P. P., Kuzmenko, A. E., Kuzmin, A. S., Logashenko, I. B., Lukin, P. A., Lysenko, A. P., Mikhailov, K. Yu., Obraztsov, I. V., Okhapkin, V. S., Otboev, A. V., Perevedentsev, E. A., Pestov, Yu. N., Popov, A. S., Razuvaev, G. P., Rogovsky, Yu. A., Ruban, A. A., Ryskulov, N. M., Ryzhenenkov, A. E., Semenov, A. V., Senchenko, A. I., Shatunov, P. Yu., Shatunov, Yu. M., Shebalin, V. E., Shemyakin, D. N., Shwartz, B. A., Shwartz, D. B., Sibidanov, A. L., Solodov, E. P., Talyshev, A. A., Timoshenko, M. V., Titov, V. M., Tolmachev, S. S., Vorobiov, A. I., Yudin, Yu. V., Zemlyansky, I. M., Zhadan, D. S., Zharinov, Yu. M., Zubakin, A. S.

Publikováno v: Phys. Rev. Lett. 132, 231903 (2024)

The cross section of the process $e^+e^-\to\pi^+\pi^-$ has been measured in the center-of-mass energy range from 0.32 to 1.2 GeV with the CMD-3 detector at the electron-positron collider VEPP-2000. The measurement is based on an integrated luminosity

Externí odkaz: http://arxiv.org/abs/2309.12910

Measurement of the branching fraction of $J/\psi\rightarrow\rho\pi$ at KEDR

Autor: Anashin, V. V., Anchugov, O. V., Andrianov, A. V., Astrelina, K. V., Aulchenko, V. M., Baldin, E. M., Baranov, G. N., Barladyan, A. K., Barnyakov, A. Yu., Barnyakov, M. Yu., Basok, I. Yu., Batrakov, A. M., Bekhtenev, E. A., Belikov, O. V., Berkaev, D. E., Blinov, A. E., Blinov, V. E., Blinov, M. F., Bobrov, A. V., Bobrovnikov, V. S., Bogomyagkov, A. V., Bolkhovityanov, D. Yu., Bondar, A. E., Buzykaev, A. R., Cheblakov, P. B., Dorohov, V. L., Emanov, F. A., Gambaryan, V. V., Grigoriev, D. N., Kaminskiy, V. V., Karnaev, S. E., Karpov, G. V., Karpov, S. V., Karukina, K. Yu., Kashtankin, D. P., Kasyanenko, P. V., Katcin, A. A., Kharlamova, T. A., Kiselev, V. A., Kononov, S. A., Krasnov, A. A., Kravchenko, E. A., Kudryavtsev, V. N., Kulikov, V. F., Kuyanov, I. A., Levichev, E. B., Logachev, P. V., Maksimov, D. A., Maltseva, Yu. I., Malyshev, V. M., Maslennikov, A. L., Meshkov, O. I., Mishnev, S. I., Morozov, I. A., Morozov, I. I., Nikiforov, D. A., Nikitin, S. A., Nikolaev, I. B., Okunev, I. N., Oreshkin, S. B., Osipov, A. A., Ovtin, I. V., Pavlenko, A. V., Peleganchuk, S. V., Piminov, P. A., Podgornov, N. A., Prisekin, V. G., Rezanova, O. L., Ruban, A. A., Savinov, G. A., Shamov, A. G., Shekhtman, L. I., Shvedov, D. A., Shwartz, B. A., Simonov, E. A., Sinyatkin, S. V., Skrinsky, A. N., Sokolov, A. V., Starostina, E. V., Sukhanov, D. P., Sukharev, A. M., Talyshev, A. A., Tayursky, V. A., Telnov, V. I., Tikhonov, Yu. A., Todyshev, K. Yu., Tribendis, A. G., Tumaikin, G. M., Usov, Yu. V., Vorobiov, A. I., Zhilich, V. N., Zhukov, A. A., Zhulanov, V. V., Zhuravlev, A. N.

We present the study of the decay $J/\psi \rightarrow \rho\pi$. The results are based on of 5.2~million $J/\psi$ events collected by the KEDR detector at the VEPP-4M collider. The branching fractions are measured to be $\B(J/\psi \rightarrow \rho\pi)

Externí odkaz: http://arxiv.org/abs/2211.13520

Charged particle identification with the liquid xenon calorimeter of the CMD-3 detector

Autor: Ivanov, V. L., Fedotovich, G. V., Akhmetshin, R. R., Amirkhanov, A. N., Anisenkov, A. V., Aulchenko, V. M., Bashtovoy, N. S., Bondar, A. E., Bragin, A. V., Eidelman, S. I., Epifanov, D. A., Epshteyn, L. B., Erofeev, A. L., Gayazov, S. E., Grebenuk, A. A., Gribanov, S. S., Grigoriev, D. N., Ignatov, F. V., Karpov, S. V., Kazanin, V. F., Korobov, A. A., Kozyrev, A. N., Kozyrev, E. A., Krokovny, P. P., Kuzmenko, A. E., Kuzmin, A. S., Logashenko, I. B., Lukin, P. A., Mikhailov, K. Yu., Okhapkin, V. S., Pestov, Yu. N., Popov, A. S., Razuvaev, G. P., Ruban, A. A., Ryskulov, N. M., Ryzhenenkov, A. E., Semenov, A. V., Shebalin, V. E., Shemyakin, D. N., Shwartz, B. A., Solodov, E. P., Titov, V. M., Talyshev, A. A., Tolmachev, S. S., Vorobiov, A. I., Yudin, Yu. V.

The paper describes a method of the charged particle identification, developed for the \mbox{CMD-3} detector, installed at the VEPP-2000 $e^{+}e^{-}$ collider. The method is based on the application of the boosted decision trees classifiers, trained

Externí odkaz: http://arxiv.org/abs/2008.05548

Search for lepton flavour violating muon decay mediated by a new light particle in the MEG experiment

Autor: Baldini, A. M., Berg, F., Biasotti, M., Boca, G., Cattaneo, P. W., Cavoto, G., Cei, F., Chiappini, M., Chiarello, G., Chiri, C., Corvaglia, A., de Bari, A., De Gerone, M., Francesconi, M., Galli, L., Gatti, F., Grancagnolo, F., Grassi, M., Grigoriev, D. N., Hildebrandt, M., Hodge, Z., Ieki, K., Ignatov, F., Iwai, R., Iwamoto, T., Kobayashi, S., Kettle, P. -R., Kyle, W., Khomutov, N., Kolesnikov, A., Kravchuk, N., Kuchinskiy, N., Libeiro, T., Lim, G. M. A., Malyshev, V., Matsuzawa, N., Meucci, M., Mihara, S., Molzon, W., Mori, Toshinori, Mtchedilishvili, A., Nakao, M., Natori, H., Nicolò, D., Nishiguchi, H., Nishimura, M., Ogawa, S., Onda, R., Ootani, W., Oya, A., Palo, D., Panareo, M., Papa, A., Pettinacci, V., Pizzigoni, G., Popov, A., Renga, F., Ritt, S., Rozhdestvensky, A., Rossella, M., Sawada, R., Schwendimann, P., Signorelli, G., Stoykov, A., Tassielli, G. F., Toyoda, K., Uchiyama, Y., Usami, M., Voena, C., Yanai, K., Yudin, Yu. V.

We present the first direct search for lepton flavour violating muon decay mediated by a new light particle X, $\mu^+ \to \mathrm{e}^+\mathrm{X}, \mathrm{X} \to \gamma\gamma$. This search uses a dataset resulting from $7.5\times 10^{14}$ stopped muon

Externí odkaz: http://arxiv.org/abs/2005.00339