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1. Development and property study of the extremely thin 12 \texorpdfstring{$\mu m$} C-type straw tubes with 5-mm diameter for a Straw Tracker System of COMET

Author

Tsverava, N., Adamov, G., Chokheli, D., Nishiguchi, H., Toriashvili, T., and Tsamalaidze, Z.

Subjects
Physics - Instrumentation and Detectors, High Energy Physics - Experiment
Abstract

The COMET experiment focuses on searching for the direct conversion of a muon into an electron with aluminum nuclei without emitting a neutrino (so-called $\mu\rightarrow e$ conversion). This conversion violates charged lepton flavor conservation law, a fundamental principle in the Standard Model. The COMET experiment requirement is to achieve the muon-to-electron conversation sensitivity on a level of $10^{-17}$. The Straw Tracker System (STS) based on straw tubes could provide the necessary spatial resolution of 150 $\mu$m and the electron momentum resolution better than 200 keV/c. The COMET experiment will be separated into two phases. Phase-I will operate with the 3.2 kW 8-GeV-proton beam, and Phase-II will operate with beam intensity increased to 56 kW. STS must operate in a vacuum with 1 bar internal pressure applied to straws. The initial design of 10-mm-diameter straws developed for phase-I will not be as efficient with the 20 times increased beam intensity of Phase II, but the new STS design based on 5-mm-diameter 12-$\mu$m thick straws could fully satisfy the required efficiency. The mechanical properties of these straws, such as sagging, elongation, dependence of the diameter on over-pressure, etc, are discussed in this article.

Published
2024

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

Author

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., and Yudin, Yu. V.

Subjects
High Energy Physics - Experiment
Abstract

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 observed, yielding an upper limit on the branching ratio of B($\mu^+\to e^+\gamma$) < $7.5 \times 10^{-13}$ (90% C.L.). The combination of this result and the limit obtained by MEG gives B($\mu^+\to e^+\gamma$) < $3.1 \times 10^{-13}$ (90% C.L.), which is the most stringent limit to date. A ten-fold larger sample of data is being collected during the years 2022-2023, and data-taking will continue in the coming years., Comment: 10 pages, 6 figures. To be published in EPJC

Published
2023

3. Operation and performance of MEG II detector

Author

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, Morsani, F., 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., Raffaelli, F., Renga, F., Ritt, S., Rossella, M., Rozhdestvensky, A., Schwendimann, P., Shimada, K., Signorelli, G., Stoykov, A., 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., and Yudin, Yu. V.

Subjects
Physics - Instrumentation and Detectors, High Energy Physics - Experiment
Abstract

The MEG II experiment, located at the Paul Scherrer Institut (PSI) in Switzerland, is the successor to the MEG experiment, which completed data taking in 2013. MEG II started fully operational data taking in 2021, with the goal of improving the sensitivity of the mu+ -> e+ gamma decay down to 6e-14 almost an order of magnitude better than the current limit. In this paper, we describe the operation and performance of the experiment and give a new estimate of its sensitivity versus data acquisition time., Comment: 42 pages, 55 figures. Submitted to EPJC

Published
2023

4. A search for μ+→e+γ with the first dataset of the MEG II experiment

Author

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., and Yudin, Yu. V.

Published
2024
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5. Search for lepton flavour violating muon decay mediated by a new light particle in the MEG experiment

Author

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., and Yudin, Yu. V.

Subjects
High Energy Physics - Experiment
Abstract

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 muons collected by the MEG experiment at the Paul Scherrer Institut in the period 2009--2013. No significant excess is found in the mass region 20--45 MeV/c$^2$ for lifetimes below 40 ps, and we set the most stringent branching ratio upper limits in the mass region of 20--40 MeV/c$^2$, down to $\mathcal{O}(10^{-11})$ at 90\% confidence level.

Published
2020
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7. COMET Phase-I Technical Design Report

Author

The COMET Collaboration, Abramishvili, R., Adamov, G., Akhmetshin, R. R., Allin, A., Angélique, J. C., Anishchik, V., Aoki, M., Aznabayev, D., Bagaturia, I., Ban, G., Ban, Y., Bauer, D., Baygarashev, D., Bondar, A. E., Cârloganu, C., Carniol, B., Chau, T. T., Chen, J. K., Chen, S. J., Cheung, Y. E., da Silva, W., Dauncey, P. D., Densham, C., Devidze, G., Dornan, P., Drutskoy, A., Duginov, V., Eguchi, Y., Epshteyn, L. B., Evtoukhovich, P., Fayer, S., Fedotovich, G. V., Finger Jr, M., Finger, M., Fujii, Y., Fukao, Y., Gabriel, J. L., Gay, P., Gillies, E., Grigoriev, D. N., Gritsay, K., Hai, V. H., Hamada, E., Hashim, I. H., Hashimoto, S., Hayashi, O., Hayashi, T., Hiasa, T., Ibrahim, Z. A., Igarashi, Y., Ignatov, F. V., Iio, M., Ishibashi, K., Issadykov, A., Itahashi, T., Jansen, A., Jiang, X. S., Jonsson, P., Kachelhoffer, T., Kalinnikov, V., Kaneva, E., Kapusta, F., Katayama, H., Kawagoe, K., Kawashima, R., Kazak, N., Kazanin, V. F., Kemularia, O., Khvedelidze, A., Koike, M., Kormoll, T., Kozlov, G. A., Kozyrev, A. N., Kravchenko, M., Krikler, B., Kumsiashvili, G., Kuno, Y., Kuriyama, Y., Kurochkin, Y., Kurup, A., Lagrange, B., Lai, J., Lee, M. J., Li, H. B., Litchfield, R. P., Li, W. G., Loan, T., Lomidze, D., Lomidze, I., Loveridge, P., Macharashvili, G., Makida, Y., Mao, Y. J., Markin, O., Matsuda, Y., Melkadze, A., Melnik, A., Mibe, T., Mihara, S., Miyamoto, N., Miyazaki, Y., Idris, F. Mohamad, Azmi, K. A. Mohamed Kamal, Moiseenko, A., Moritsu, M., Mori, Y., Motoishi, T., Nakai, H., Nakai, Y., Nakamoto, T., Nakamura, Y., Nakatsugawa, Y., Nakazawa, Y., Nash, J., Natori, H., Niess, V., Nioradze, M., Nishiguchi, H., Noguchi, K., Numao, T., O'Dell, J., Ogitsu, T., Ohta, S., Oishi, K., Okamoto, K., Okamura, T., Okinaka, K., Omori, C., Ota, T., Pasternak, J., Paulau, A., Picters, D., Ponariadov, V., Quémener, G., Ruban, A. A., Rusinov, V., Sabirov, B., Sakamoto, H., Sarin, P., Sasaki, K., Sato, A., Sato, J., Semertzidis, Y. K., Shigyo, N., Shoukavy, Dz., Slunecka, M., Stöckinger, D., Sugano, M., Tachimoto, T., Takayanagi, T., Tanaka, M., Tang, J., Tao, C. V., Teixeira, A. M., Tevzadze, Y., Thanh, T., Tojo, J., Tolmachev, S. S., Tomasek, M., Tomizawa, M., Toriashvili, T., Trang, H., Trekov, I., Tsamalaidze, Z., Tsverava, N., Uchida, T., Uchida, Y., Ueno, K., Velicheva, E., Volkov, A., Vrba, V., Abdullah, W. A. T. Wan, Warin-Charpentier, P., Wong, M. L., Wong, T. S., Wu, C., Xing, T. Y., Yamaguchi, H., Yamamoto, A., Yamanaka, M., Yamane, T., Yang, Y., Yano, T., Yao, W. C., Yeo, B., Yoshida, H., Yoshida, M., Yoshioka, T., Yuan, Y., Yudin, Yu. V., Zdorovets, M. V., Zhang, J., Zhang, Y., and Zuber, K.

Subjects
Physics - Instrumentation and Detectors, High Energy Physics - Experiment
Abstract

The Technical Design for the COMET Phase-I experiment is presented in this paper. COMET is an experiment at J-PARC, Japan, which will search for neutrinoless conversion of muons into electrons in the field of an aluminium nucleus ($\mu-e$ conversion, $\mu^- N \to e^- N$); a lepton flavor violating process. The experimental sensitivity goal for this process in the Phase-I experiment is $3.1\times10^{-15}$, or 90 % upper limit of branching ratio of $7\times 10^{-15}$, which is a factor of 100 improvement over the existing limit. The expected number of background events is 0.032. To achieve the target sensitivity and background level, the 3.2 kW 8 GeV proton beam from J-PARC will be used. Two types of detectors, CyDet and StrECAL, will be used for detecting the \mue conversion events, and for measuring the beam-related background events in view of the Phase-II experiment, respectively. Results from simulation on signal and background estimations are also described., Comment: A minor correction applied in Eq. 3

Published
2018
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8. The design of the MEG II experiment

Author

Baldini, A. M., Baracchini, E., Bemporad, C., Berg, F., Biasotti, M., Boca, G., Cattaneo, P. W., Cavoto, G., Cei, F., Chiappini, M., Chiarello, G., Chiri, C., Cocciolo, G., Corvaglia, A., de Bari, A., De Gerone, M., D'Onofrio, A., Francesconi, M., Fujii, Y., Galli, L., Gatti, F., Grancagnolo, F., Grassi, M., Grigoriev, D. N., Hildebrandt, M., Hodge, Z., Ieki, K., Ignatov, F., Iwai, R., Iwamoto, T., Kaneko, D., Kasami, K., Kettle, P. -R., Khazin, B. I., Khomutov, N., Korenchenko, A., Kravchuk, N., Libeiro, T., Maki, M., Matsuzawa, N., Mihara, S., Milgie, M., Molzon, W., Mori, Toshinori, Morsani, F., Mtchedilishvili, A., Nakao, M., Nakaura, S., Nicoló, D., Nishiguchi, H., Nishimura, M., Ogawa, S., Ootani, W., Panareo, M., Papa, A., Pepino, A., Piredda, G., Popov, A., Raffaelli, F., Renga, F., Ripiccini, E., Ritt, S., Rossella, M., Rutar, G., Sawada, R., Signorelli, G., Simonetta, M., Tassielli, G. F., Uchiyama, Y., Usami, M., Venturini, M., Voena, C., Yoshida, K., Yudin, Yu. V., and Zhang, Y.

Subjects
Physics - Instrumentation and Detectors, High Energy Physics - Experiment
Abstract

The MEG experiment, designed to search for the mu+->e+ gamma decay at a 10^-13 sensitivity level, completed data taking in 2013. In order to increase the sensitivity reach of the experiment by an order of magnitude to the level of 6 x 10-14 for the branching ratio, a total upgrade, involving substantial changes to the experiment, has been undertaken, known as MEG II. We present both the motivation for the upgrade and a detailed overview of the design of the experiment and of the expected detector performance., Comment: 61 pages and 97 figures

Published
2018
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10. A Fast High-Voltage Switching Multiwire Proportional Chamber

Author

Natori, H., Teshima, N., Aoki, M., Nishiguchi, H., Nguyen, T. D., Takezaki, Y., Furuya, Y., Ito, S., Mihara, S., Nagao, D., Nakatsugawa, Y., Nguyen, T. M., Seiya, Y., Shimizu, K., and Yamamoto, K.

Subjects
Physics - Instrumentation and Detectors, High Energy Physics - Experiment, Nuclear Experiment
Abstract

A new experiment, called DeeMe, which is designed to search for $\mu$-e conversions with a sensitivity of $\mathcal{O}(10^{-14})$, is in preparation at the Japan Proton Accelerator Research Complex (J-PARC). It utilizes a high-quality pulsed proton beam from the Rapid Cycling Synchrotron at J-PARC. The detector for DeeMe must tolerate large pulses of prompt charged particles whose instantaneous hit rate is as large as 70 GHz/mm$^2$ in a time width of 200 ns and detect a single electron that arrives with delayed timing on the order of microseconds. A special wire chamber has been developed with a new dynamic gain control technique that reduces space charge effects. In this paper, we detail the novel detector scheme and operation verification., Comment: To be published in PTEP

Published
2016

12. Muon polarization in the MEG experiment: predictions and measurements

Author

Baldini, A. M., Bao, Y., Baracchini, E., Bemporad, C., Berg, F., Biasotti, M., Boca, G., Cattaneo, P. W., Cavoto, G., Cei, F., Chiarello, G., Chiri, C., De Bari, A., De Gerone, M., DÓnofrio, A., Dussoni, S., Fujii, Y., Galli, L., Gatti, F., Grancagnolo, F., Grassi, M., Graziosi, A., Grigoriev, D. N., Haruyama, T., Hildebrandt, M., Hodge, Z., Ieki, K., Ignatov, F., Iwamoto, T., Kaneko, D., Kang, T. I., Kettle, P. R., Khazin, B. I., Khomutov, N., Korenchenko, A., Kravchuk, N., Lim, G. M. A., Mihara, S., Molzon, W., Mori, T., Mtchedlishvili, A., Nakaura, S., Nicolò, D., Nishiguchi, H., Nishimura, M., Ogawa, S., Ootani, W., Panareo, M., Papa, A., Pepino, A., Piredda, G., Pizzigoni, G., Popov, A., Renga, F., Ripiccini, E., Ritt, S., Rossella, M., Rutar, G., Sawada, R., Sergiampietri, F., Signorelli, G., Tassielli, G., Tenchini, F., Uchiyama, Y., Venturini, M., Voena, C., Yamamoto, A., Yoshida, K., You, Z., and Yudin, Y. V.

Subjects
High Energy Physics - Experiment, Physics - Instrumentation and Detectors
Abstract

The MEG experiment makes use of one of the world's most intense low energy muon beams, in order to search for the lepton flavour violating process $\mu^{+} \rightarrow {\rm e}^{+} \gamma$. We determined the residual beam polarization at the thin stopping target, by measuring the asymmetry of the angular distribution of Michel decay positrons as a function of energy. The initial muon beam polarization at the production is predicted to be $P_{\mu} = -1$ by the Standard Model (SM) with massless neutrinos. We estimated our residual muon polarization to be $P_{\mu} = -0.85 \pm 0.03 ~ {\rm (stat)} ~ { }^{+ 0.04}_{-0.05} ~ {\rm (syst)}$ at the stopping target, which is consistent with the SM predictions when the depolarizing effects occurring during the muon production, propagation and moderation in the target are taken into account. The knowledge of beam polarization is of fundamental importance in order to model the background of our ${\megsign}$ search induced by the muon radiative decay: $\mu^{+} \rightarrow {\rm e}^{+} \bar{\nu}_{\mu} \nu_{\rm e} \gamma$.

Published
2015
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14. Measurement of the radiative decay of polarized muons in the MEG experiment

Author

MEG Collaboration, Baldini, A. M., Bao, Y., Baracchini, E., Bemporad, C., Berg, F., Biasotti, M., Boca, G., Cattaneo, P. W., Cavoto, G., Cei, F., Chiarello, G., Chiri, C., de Bari, A., De Gerone, M., D'Onofrio, A., Dussoni, S., Fujii, Y., Galli, L., Gatti, F., Grancagnolo, F., Grassi, M., Graziosi, A., Grigoriev, D. N., Haruyama, T., Hildebrandt, M., Hodge, Z., Ieki, K., Ignatov, F., Iwamoto, T., Kaneko, D., Kang, Tae Im, Kettle, P. -R., Khazin, B. I., Khomutov, N., Korenchenko, A., Kravchuk, N., Lim, G. M. A., Mihara, S., Molzon, W., Mori, Toshinori, Mtchedlishvili, A., Nakaura, S., Nicolò, D., Nishiguchi, H., Nishimura, M., Ogawa, S., Ootani, W., Panareo, M., Papa, A., Pepino, A., Piredda, G., Pizzigoni, G., Popov, A., Renga, F., Ripiccini, E., Ritt, S., Rossella, M., Rutar, G., Sawada, R., Sergiampietri, F., Signorelli, G., Tassielli, G. F., Tenchini, F., Uchiyama, Y., Venturini, M., Voena, C., Yamamoto, A., Yoshida, K., You, Z., and Yudin, Yu. V.

Subjects
High Energy Physics - Experiment, High Energy Physics - Phenomenology, Physics - Instrumentation and Detectors
Abstract

We studied the radiative muon decay $\mu^+ \to e^+\nu\bar{\nu}\gamma$ by using for the first time an almost fully polarized muon source. We identified a large sample (~13000) of these decays in a total sample of 1.8x10^14 positive muon decays collected in the MEG experiment in the years 2009--2010 and measured the branching ratio B($\mu^+ \to e^+\nu\bar{\nu}\gamma$) = (6.03+-0.14(stat.)+-0.53(sys.))x10^-8 for E_e > 45 MeV and E_{\gamma} > 40 MeV, consistent with the Standard Model prediction. The precise measurement of this decay mode provides a basic tool for the timing calibration, a normalization channel, and a strong quality check of the complete MEG experiment in the search for $\mu^+ \to e^+\gamma$ process., Comment: 8 pages, 7 figures. Added an introduction to NLO calculation which was recently calculated. Published version

Published
2013
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15. The MEG detector for ${\mu}+\to e+{\gamma}$ decay search

Author

Adam, J., Bai, X., Baldini, A. M., Baracchini, E., Bemporad, C., Boca, G., Cattaneo, P. W., Cavoto, G., Cei, F., Cerri, C., Corbo, M., Curalli, N., De Bari, A., De Gerone, M., Del Frate, L., Doke, S., Dussoni, S., Egger, J., Fratini, K., Fujii, Y., Galli, L., Galeotti, S., Gallucci, G., Gatti, F., Golden, B., Grassi, M., Graziosi, A., Grigoriev, D. N., Haruyama, T., Hisamatsu, M. Hildebrandt Y., Ignatov, F., Iwamoto, T., Kaneko, D., Kasami, K., Kettle, P. -R., Khazin, B. I., Korenchenko, O. Kiselev A., Kravchuk, N., Lim, G., Maki, A., Mihara, S., Molzon, W., Mori, T., Morsani, F., Mzavia, D., Nardò, R., Natori, H., Nicolò, D., Nishiguchi, H., Ootani, Y. Nishimura W., Ozone, K., Panareo, M., Papa, A., Pazzi, R., Piredda, G., Popov, A., Raffaelli, F., Renga, F., Ripiccini, E., Ritt, S., Rossella, M., Sawada, R., Schneebeli, M., Sergiampietri, F., Signorelli, G., Suzuki, S., Tenchini, F., Topchyan, C., Uchiyama, Y., Voena, R. Valle C., Xiao, F., Yamada, S., Yamamoto, S., Yamashita, S., Yudin, Yu. V., and Zanello, D.

Subjects
Physics - Instrumentation and Detectors, High Energy Physics - Experiment
Abstract

The MEG (Mu to Electron Gamma) experiment has been running at the Paul Scherrer Institut (PSI), Switzerland since 2008 to search for the decay \meg\ by using one of the most intense continuous $\mu^+$ beams in the world. This paper presents the MEG components: the positron spectrometer, including a thin target, a superconducting magnet, a set of drift chambers for measuring the muon decay vertex and the positron momentum, a timing counter for measuring the positron time, and a liquid xenon detector for measuring the photon energy, position and time. The trigger system, the read-out electronics and the data acquisition system are also presented in detail. The paper is completed with a description of the equipment and techniques developed for the calibration in time and energy and the simulation of the whole apparatus., Comment: 59 pages, 90 figures

Published
2013
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16. New constraint on the existence of the mu+-> e+ gamma decay

Author

MEG Collaboration, Adam, J., Bai, X., Baldini, A. M., Baracchini, E., Bemporad, C., Boca, G., Cattaneo, P. W., Cavoto, G., Cei, F., Cerri, C., de Bari, A., De Gerone, M., Doke, T., Dussoni, S., Egger, J., Fratini, K., Fujii, Y., Galli, L., Gallucci, G., Gatti, F., Golden, B., Grassi, M., Graziosi, A., Grigoriev, D. N., Haruyama, T., Hildebrandt, M., Hisamatsu, Y., Ignatov, F., Iwamoto, T., Kaneko, D., Kettle, P. -R., Khazin, B. I., Khomotov, N., Kiselev, O., Korenchenko, A., Kravchuk, N., Lim, G., Maki, A., Mihara, S., Molzon, W., Mori, T., Mzavia, D., Nardo, R., Natori, H., Nicolo, D., Nishiguchi, H., Nishimura, Y., Ootani, W., Panareo, M., Papa, A., Pazzi, R., Piredda, G., Popov, A., Renga, F., Ripiccini, E., Ritt, S., Rossella, M., Sawada, R., Sergiampietri, F., Signorelli, G., Suzuki, S., Tenchini, F., Topchyan, C., Uchiyama, Y., Valle, R., Voena, C., Xiao, F., Yamada, S., Yamamoto, A., Yamashita, S., You, Z., Yudin, Yu. V., and Zanello, D.

Subjects
High Energy Physics - Experiment, Physics - Instrumentation and Detectors
Abstract

The analysis of a combined data set, totaling 3.6 \times 10^14 stopped muons on target, in the search for the lepton flavour violating decay mu^+ -> e^+ gamma is presented. The data collected by the MEG experiment at the Paul Scherrer Institut show no excess of events compared to background expectations and yield a new upper limit on the branching ratio of this decay of 5.7 \times 10^-13 (90% confidence level). This represents a four times more stringent limit than the previous world best limit set by MEG., Comment: 5 pages, 3 figures, a version accepted in Phys. Rev. Lett

Published
2013

17. MEG Upgrade Proposal

Author

Baldini, A. M., Cei, F., Cerri, C., Dussoni, S., Galli, L., Grassi, M., Nicolò, D., Raffaelli, F., Sergiampietri, F., Signorelli, G., Tenchini, F., Bagliani, D., De Gerone, M., Gatti, F., Baracchini, E., Fujii, Y., Iwamoto, T., Kaneko, D., Mori, T., Nishimura, M., Ootani, W., Sawada, R., Uchiyama, Y., Boca, G., Cattaneo, P. W., de Bari, A., Nardò, R., Rossella, M., Cascella, M., Grancagnolo, F., L'Erario, A., Maffezzoli, A., Miccoli, A., Onorato, G., Palamà, G., Panareo, M., Pepino, A., Rella, S., Tassielli, G. F., Zavarise, G., Cavoto, G., Graziosi, A., Piredda, G., Ripiccini, E., Voena, C., Grigoriev, D. N., Ignatov, F., Khazin, B. I., Popov, A., Yudin, Yu. V., Haruyama, T., Mihara, S., Nishiguchi, H., Yamamoto, A., Hildebrandt, M., Kettle, P. -R., Papa, A., Renga, F., Ritt, S., Stoykov, A., Kang, T. I., Lim, G., Molzon, W., You, Z., Khomutov, N., Korenchenko, A., Kravchuk, N., and Kuchinksy, N.

Subjects
Physics - Instrumentation and Detectors, High Energy Physics - Experiment, High Energy Physics - Phenomenology
Abstract

We propose the continuation of the MEG experiment to search for the charged lepton flavour violating decay (cLFV) \mu \to e \gamma, based on an upgrade of the experiment, which aims for a sensitivity enhancement of one order of magnitude compared to the final MEG result, down to the $6 \times 10^{-14}$ level. The key features of this new MEG upgrade are an increased rate capability of all detectors to enable running at the intensity frontier and improved energy, angular and timing resolutions, for both the positron and photon arms of the detector. On the positron-side a new low-mass, single volume, high granularity tracker is envisaged, in combination with a new highly segmented, fast timing counter array, to track positron from a thinner stopping target. The photon-arm, with the largest liquid xenon (LXe) detector in the world, totalling 900 l, will also be improved by increasing the granularity at the incident face, by replacing the current photomultiplier tubes (PMTs) with a larger number of smaller photosensors and optimizing the photosensor layout also on the lateral faces. A new DAQ scheme involving the implementation of a new combined readout board capable of integrating the diverse functions of digitization, trigger capability and splitter functionality into one condensed unit, is also under development. We describe here the status of the MEG experiment, the scientific merits of the upgrade and the experimental methods we plan to use., Comment: A. M. Baldini and T. Mori Spokespersons. Research proposal submitted to the Paul Scherrer Institute Research Committee for Particle Physics at the Ring Cyclotron. 131 Pages

Published
2013

18. New limit on the lepton-flavour violating decay mu -> e gamma

Author

MEG collaboration, Adam, J., Bai, X., Baldini, A. M., Baracchini, E., Bemporad, C., Boca, G., Cattaneo, P. W., Cavoto, G., Cei, F., Cerri, C., de Bari, A., De Gerone, M., Doke, T., Dussoni, S., Egger, J., Fratini, K., Fujii, Y., Galli, L., Gallucci, G., Gatti, F., Golden, B., Grassi, M., Grigoriev, D. N., Haruyama, T., Hildebrandt, M., Hisamatsu, Y., Ignatov, F., Iwamoto, T., Kettle, P. -R., Khazin, B. I., Kiselev, O., Korenchenko, A., Kravchuk, N., Maki, A., Mihara, S., Molzon, W., Mori, T., Mzavia, D., Natori, H., Nicolò, D., Nishiguchi, H., Nishimura, Y., Ootani, W., Panareo, M., Papa, A., Pazzi, R., Piredda, G., Popov, A., Renga, F., Ritt, S., Rossella, M., Sawada, R., Sergiampietri, F., Signorelli, G., Suzuki, S., Tenchini, F., Topchyan, C., Uchiyama, Y., Valle, R., Voena, C., Xiao, F., Yamada, S., Yamamoto, A., Yamashita, S., Yudin, Yu. V., and Zanello, D.

Subjects
High Energy Physics - Experiment, High Energy Physics - Phenomenology
Abstract

We present a new result based on an analysis of the data collected by the MEG detector at the Paul Scherrer Institut in 2009 and 2010, in search of the lepton flavour violating decay mu->e gamma. The likelihood analysis of the combined data sample, which corresponds to a total of 1.8 x 10**14 muon decays, gives a 90% C.L. upper limit of 2.4 x 10**-12 on the branching ratio of the mu->e gamma decay, constituting the most stringent limit on the existence of this decay to date., Comment: 5 pages, 2 figures, accepted for publication at Phys. Rev. Lett

Published
2011
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19. A limit for the mu -> e gamma decay from the MEG experiment

Author

MEG collaboration, Adam, J., Bai, X., Baldini, A., Baracchini, E., Barchiesi, A., Bemporad, C., Boca, G., Cattaneo, P. W., Cavoto, G., Cecchet, G., Cei, F., Cerri, C., De Bari, A., De Gerone, M., Doke, T., Dussoni, S., Egger, J., Galli, L., Gallucci, G., Gatti, F., Golden, B., Grassi, M., Grigoriev, D. N., Haruyama, T., Hildebrandt, M., Hisamatsu, Y., Ignatov, F., Iwamoto, T., Kaneko, D., Kettle, P. -R., Khazin, B. I., Kiselev, O., Korenchenko, A., Kravchuk, N., Maki, A., Mihara, S., Molzon, W., Mori, T., Mzavia, D., Natori, H., Nardò, R., Nicolò, D., Nishiguchi, H., Nishimura, Y., Ootani, W., Panareo, M., Papa, A., Pazzi, R., Piredda, G., Popov, A., Renga, F., Ritt, S., Rossella, M., Sawada, R., Schneebeli, M., Sergiampietri, F., Signorelli, G., Suzuki, S., Topchyan, C., Tumakov, V., Uchiyama, Y., Valle, R., Voena, C., Xiao, F., Yamada, S., Yamamoto, A., Yamashita, S., Yudin, Yu. V., and Zanello, D.

Subjects
High Energy Physics - Experiment, High Energy Physics - Phenomenology
Abstract

A search for the decay mu -> e gamma, performed at PSI and based on data from the initial three months of operation of the MEG experiment, yields an upper limit on the branching ratio of BR(mu -> e gamma) < 2.8 x 10**-11 (90% C.L.). This corresponds to the measurement of positrons and photons from ~ 10**14 stopped mu-decays by means of a superconducting positron spectrometer and a 900 litre liquid xenon photon detector., Comment: 13 pages, 9 figures. v2: improved estimate of photon reconstruction efficiency

Published
2009
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20. Absorption of Scintillation Light in a 100 $\ell$ Liquid Xenon$\gamma$ Ray Detector and Expected Detector Performance

Author

Baldini, A., Bemporad, C., Cei, F., Doke, T., Grassi, M., Grebenuk, A. A., Grigoriev, D. N., Haruyama, T., Kasami, K., Kikuchi, J., Maki, A., Mashimo, T., Mihara, S., Mitsuhashi, T., Mori, T., Nicolo`, D., Nishiguchi, H., Ootani, W., Ozone, K., Papa, A., Pazzi, R., Ritt, S., Sawada, R., Sergiampietri, F., Signorelli, G., Suzuki, S., Terasawa, K., Yamashita, M., Yamashita, S., Yoshimura, T., and Yuri, Yu.

Subjects
Physics - Instrumentation and Detectors, High Energy Physics - Experiment
Abstract

An 800L liquid xenon scintillation $\gamma$ ray detector is being developed for the MEG experiment which will search for $\mu^+\to\mathrm{e}^+\gamma$ decay at the Paul Scherrer Institut. Absorption of scintillation light of xenon by impurities might possibly limit the performance of such a detector. We used a 100L prototype with an active volume of 372x372x496 mm$^3$ to study the scintillation light absorption. We have developed a method to evaluate the light absorption, separately from elastic scattering of light, by measuring cosmic rays and $\alpha$ sources. By using a suitable purification technique, an absorption length longer than 100 cm has been achieved. The effects of the light absorption on the energy resolution are estimated by Monte Carlo simulation., Comment: 18 pages, 10 figures (eps). Submitted to Nucl. Instr. and Meth. A

Published
2004
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21. Liquid Xe scintillation calorimetry and Xe optical properties

Author

Baldini, A., Bemporad, C., Cei, F., Doke, T., Grassi, M., Haruyama, T., Mihara, S., Mori, T., Nicolò, D., Nishiguchi, H., Ootani, W., Ozone, K., Papa, A., Pazzi, R., Sawada, R., Sergiampietri, F., Signorelli, G., Suzuki, S., and Terasawa, K.

Subjects
Physics - Instrumentation and Detectors, High Energy Physics - Experiment
Abstract

The optical properties of LXe in the vacuum ultra violet (VUV), determining the performance of a scintillation calorimeter, are discussed in detail. The available data, measured in a wider spectral region from visible to UV light, and in a large range of Xe densities, from gas to liquid, are examined. It is shown that this information can be used for deriving the LXe optical properties in the VUV. A comparison is made with the few direct measurements in LXe for VUV light resulting from the LXe excitation by ionizing particles. A useful relation is obtained which connects the Rayleigh scattering length to the refractive index in LXe., Comment: 20 pages, 12 figures

Published
2004
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24. Search for the lepton flavour violating decay μ + → e + γ with the full dataset of the MEG experiment: MEG Collaboration

Author

Baldini, A. M., Bao, Y., Baracchini, E., Bemporad, C., Berg, F., Biasotti, M., Boca, G., Cascella, M., Cattaneo, P. W., Cavoto, G., Cei, F., Cerri, C., Chiarello, G., Chiri, C., Corvaglia, A., de Bari, A., De Gerone, M., Doke, T., D’Onofrio, A., Dussoni, S., Egger, J., Fujii, Y., Galli, L., Gatti, F., Grancagnolo, F., Grassi, M., Graziosi, A., Grigoriev, D. N., Haruyama, T., Hildebrandt, M., Hodge, Z., Ieki, K., Ignatov, F., Iwamoto, T., Kaneko, D., Kang, T. I., Kettle, P.-R., Khazin, B. I., Khomutov, N., Korenchenko, A., Kravchuk, N., Lim, G. M. A., Maki, A., Mihara, S., Molzon, W., Mori, Toshinori, Morsani, F., Mtchedilishvili, A., Mzavia, D., Nakaura, S., Nardò, R., Nicolò, D., Nishiguchi, H., Nishimura, M., Ogawa, S., Ootani, W., Orito, S., Panareo, M., Papa, A., Pazzi, R., Pepino, A., Piredda, G., Pizzigoni, G., Popov, A., Raffaelli, F., Renga, F., Ripiccini, E., Ritt, S., Rossella, M., Rutar, G., Sawada, R., Sergiampietri, F., Signorelli, G., Simonetta, M., Tassielli, G. F., Tenchini, F., Uchiyama, Y., Venturini, M., Voena, C., Yamamoto, A., Yoshida, K., You, Z., Yudin, Yu. V., and Zanello, D.

Published
2016
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25. Muon polarization in the MEG experiment: predictions and measurements: The MEG Collaboration

Author

Baldini, A. M., Bao, Y., Baracchini, E., Bemporad, C., Berg, F., Biasotti, M., Boca, G., Cattaneo, P. W., Cavoto, G., Cei, F., Chiarello, G., Chiri, C., Bari, A. De, Gerone, M. De, D’Onofrio, A., Dussoni, S., Fujii, Y., Galli, L., Gatti, F., Grancagnolo, F., Grassi, M., Graziosi, A., Grigoriev, D. N., Haruyama, T., Hildebrandt, M., Hodge, Z., Ieki, K., Ignatov, F., Iwamoto, T., Kaneko, D., Kang, T. I., Kettle, P.-R., Khazin, B. I., Khomutov, N., Korenchenko, A., Kravchuk, N., Lim, G. M. A., Mihara, S., Molzon, W., Mori, Toshinori, Mtchedlishvili, A., Nakaura, S., Nicolò, D., Nishiguchi, H., Nishimura, M., Ogawa, S., Ootani, W., Panareo, M., Papa, A., Pepino, A., Piredda, G., Pizzigoni, G., Popov, A., Renga, F., Ripiccini, E., Ritt, S., Rossella, M., Rutar, G., Sawada, R., Sergiampietri, F., Signorelli, G., Tassielli, G. F., Tenchini, F., Uchiyama, Y., Venturini, M., Voena, C., Yamamoto, A., Yoshida, K., You, Z., and Yudin, Yu. V.

Published
2016
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26. Measurement of the radiative decay of polarized muons in the MEG experiment

Author

Baldini, A. M., Bao, Y., Baracchini, E., Bemporad, C., Berg, F., Biasotti, M., Boca, G., Cattaneo, P. W., Cavoto, G., Cei, F., Chiarello, G., Chiri, C., de Bari, A., De Gerone, M., D’Onofrio, A., Dussoni, S., Fujii, Y., Galli, L., Gatti, F., Grancagnolo, F., Grassi, M., Graziosi, A., Grigoriev, D. N., Haruyama, T., Hildebrandt, M., Hodge, Z., Ieki, K., Ignatov, F., Iwamoto, T., Kaneko, D., Kang, Tae Im, Kettle, P.-R., Khazin, B. I., Khomutov, N., Korenchenko, A., Kravchuk, N., Lim, G. M. A., Mihara, S., Molzon, W., Mori, Toshinori, Mtchedlishvili, A., Nakaura, S., Nicolò, D., Nishiguchi, H., Nishimura, M., Ogawa, S., Ootani, W., Panareo, M., Papa, A., Pepino, A., Piredda, G., Pizzigoni, G., Popov, A., Renga, F., Ripiccini, E., Ritt, S., Rossella, M., Rutar, G., Sawada, R., Sergiampietri, F., Signorelli, G., Tassielli, G. F., Tenchini, F., Uchiyama, Y., Venturini, M., Voena, C., Yamamoto, A., Yoshida, K., You, Z., Yudin, Yu. V., and The MEG Collaboration

Published
2016
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28. Calibration and monitoring of the MEG experiment by a proton beam from a Cockcroft–Walton accelerator

Author

Adam, J., Bai, X., Baldini, A., Baracchini, E., Bemporad, C., Boca, G., Cattaneo, P.W., Cavoto, G., Cei, F., Cerri, C., Corbo, M., Curalli, N., de Bari, A., De Gerone, M., Doke, T., Dussoni, S., Egger, J., Fratini, K., Fujii, Y., Galli, L., Gallucci, G., Gatti, F., Golden, B., Grassi, M., Grigoriev, D.N., Haruyama, T., Hildebrandt, M., Ignatov, F., Iwamoto, T., Kettle, P.-R., Khazin, B.I., Kiselev, O., Korenchenko, A., Kravchuk, N., Maki, A., Mihara, S., Molzon, W., Mori, T., Mzavia, D., Natori, H., Nicolò, D., Nishiguchi, H., Nishimura, Y., Ootani, W., Panareo, M., Papa, A., Pazzi, R., Piredda, G., Popov, A., Renga, F., Ritt, S., Rossella, M., Sawada, R., Sergiampietri, F., Signorelli, G., Tenchini, F., Topchyan, C., Uchiyama, Y., Valle, R., Voena, C., Xiao, F., Yamamoto, A., Yudin, Yu.V., and Zanello, D.

Published
2011
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31. Liquid xenon scintillation calorimetry and Xe optical properties

Author

Baldini, A., Bemporad, C., Cei, F., Doke, T., Grassi, M., Haruyama, T., Mihara, S., Mori, T., Nicolo, D., Nishiguchi, H., Ootani, W., Ozone, K., Papa, A., Pazzi, R., Sawada, R., Sergiampietri, F., Signorelli, G., Suzuki, S., and Terasawa, K.

Subjects
Dielectrics -- Research, Xenon -- Research, Business, Electronics, Electronics and electrical industries
Abstract

The optical properties of liquid xenon (LXe) in the vacuum ultra violet (VUV), determining the performance of a scintillation calorimeter, are discussed in detail. The available data, measured in a wider spectral region from visible to UV light, and in a large range of Xe densities, from gas to liquid, are examined. It is shown that this information can be used for deriving the LXe optical properties in the VUV. A comparison is made with the few direct measurements in LXe for VUV light resulting from the LXe excitation by ionizing particles. A useful relation is obtained which connects the Rayleigh scattering length to the refractive index in LXe. Index Terms--Liquid xenon, VUV light.

Published
2006

35. Photochemical properties of benzophenone adsorbed on Ti-Al binary oxides: the effects of the surface acidity

Author

Nishiguchi, H., Zhang, J -L., Anpo, M., and Masuhara, H.

Subjects
Isomerization -- Observations, Photochemistry -- Observations, Benzophenone -- Chemical properties, Chemicals, plastics and rubber industries
Abstract

The major photoproducts from benzophenone (BP) adsorbed on the Ti---Al binary oxides were benzhydrol and benzpinacol where benzhydrol yield depended on Ti---Al ratio. The conclusions drawn were that more yield of benzhydrol was observed when BP protonated species were more predominant on the surfaces.

Published
2001

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

Author

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

Published
2020
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39. Absorption of scintillation light in a 100 l liquid xenon [formula omitted]-ray detector and expected detector performance

Author

Baldini, A., Bemporad, C., Cei, F., Doke, T., Grassi, M., Grebenuk, A.A., Grigoriev, D.N., Haruyama, T., Kasami, K., Kikuchi, J., Maki, A., Mashimo, T., Mihara, S., Mitsuhashi, T., Mori, T., Nicolò, D., Nishiguchi, H., Ootani, W., Ozone, K., Papa, A., Pazzi, R., Ritt, S., Sawada, R., Sergiampietri, F., Signorelli, G., Suzuki, S., Terasawa, K., Yamashita, M., Yamashita, S., Yoshimura, T., and Yuri, Yu.

Published
2005
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48. The design of the MEG II experiment

Author

Baldini, A., Baracchini, E., Bemporad, C., Berg, F., Biasotti, M., Boca, G., Cattaneo, P., Cavoto, G., Cei, F., Chiappini, M., Chiarello, G., Chiri, C., Cocciolo, G., Corvaglia, A., Bari, A., Gerone, M., D’Onofrio, A., Francesconi, M., Fujii, Y., Galli, L., Gatti, F., Grancagnolo, F., Grassi, M., Grigoriev, D., Hildebrandt, M., Hodge, Z., Ieki, K., Ignatov, F., Iwai, R., Iwamoto, T., Kaneko, D., Kasami, K., Kettle, P.R., Khazin, B., Khomutov, N., Korenchenko, A., Kravchuk, N., Libeiro, T., Maki, M., Matsuzawa, N., Mihara, S., Milgie, M., Molzon, W., Mori, Toshinori, Morsani, F., Mtchedilishvili, A., Nakao, M., Nakaura, S., Nicolò, D., Nishiguchi, H., Nishimura, M., Ogawa, S., Ootani, W., Panareo, M., Papa, A., Pepino, A., Piredda, G., Popov, A., Raffaelli, F., Renga, F., Ripiccini, E., Ritt, S., Rossella, M., Rutar, G., Sawada, R., Signorelli, G., Simonetta, M., Tassielli, G., Uchiyama, Y., Usami, M., Venturini, M., Voena, C., Yoshida, K., Yudin, Yu., and Zhang, Y.

Abstract

The MEG experiment, designed to search for the $${\mu ^+ \rightarrow \hbox {e}^+ \gamma }$$ μ+→e+γ decay, completed data-taking in 2013 reaching a sensitivity level of $${5.3\times 10^{-13}}$$ 5.3×10-13 for the branching ratio. In order to increase the sensitivity reach of the experiment by an order of magnitude to the level of $$6\times 10^{-14}$$ 6×10-14 , a total upgrade, involving substantial changes to the experiment, has been undertaken, known as MEG II. We present both the motivation for the upgrade and a detailed overview of the design of the experiment and of the expected detector performance.

Published
2018

50. Commissioning of liquid Xe detector with VUV-MPPC readout for MEG II experiment

Author

OGAWA, Shinji, primary, Francesconi, M., additional, Galli, L., additional, Ieki, K., additional, Iwamoto, T., additional, R.Kettle, P, additional, Kobayashi, S., additional, Libeiro, T., additional, Matsuzawa, N., additional, Mihara, S., additional, Molzon, W., additional, Mori, T., additional, Nishiguchi, H., additional, Onda, R., additional, Ootani, W., additional, Papa, A., additional, and Ritt, S., additional

Published
2019
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