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32 results on '"Koop, I."'

1. Measurement of deuteron carbon vector analyzing powers in the kinetic energy range 170-380 MeV

Author

JEDI Collaboration, Müller, F., Zurek, M., Bagdasarian, Z., Barion, L., Berz, M., Ciepal, I., Ciullo, G., Dymov, S., Eversmann, D., Gaisser, M., Gebel, R., Grigoryev, K., Grzonka, D., Hejny, V., Hempelmann, N., Hetzel, J., Hinder, F., Kacharava, A., Kamerdzhiev, V., Keshelashvili, I., Koop, I., Kulikov, A., Lehrach, A., Lenisa, P., Lomidze, N., Lorentz, B., Maanen, P., Macharashvili, G., Magiera, A., Mchedlishvili, D., Nass, A., Nikolaev, N. N., Pesce, A., Prasuhn, D., Pretz, J., Rathmann, F., Rolando, V., Rosenthal, M., Saleev, A., Schmidt, V., Senichev, Y., Shergelashvili, D., Shmakova, V., Silenko, A., Slim, J., Soltner, H., Stahl, A., Stassen, R., Stephenson, E., Ströher, H., Tabidze, M., Tagliente, G., Talman, R., Trinkel, F., Uzikov, Yu., Valdau, Yu., Valetov, E., Weidemann, C., Wronska, A., and Wüstner, P.

Subjects
Nuclear Experiment, High Energy Physics - Experiment
Abstract

A measurement of vector analyzing powers in elastic deuteron-carbon scattering has been performed at the Cooler Synchrotron COSY of Forschungszentrum J\"ulich, Germany. Seven kinetic beam energies between 170 and 380 MeV have been used. A vector-polarized beam from a polarized deuteron source was injected, accelerated to the final desired energy and stored in COSY. A thin needle-shaped diamond strip was used as a carbon target, onto which the beam was slowly steered. Elastically scattered deuterons were identified in the forward direction using various layers of scintillators and straw tubes. Where data exist in the literature (at 200 and 270 MeV), excellent agreement of the angular shape was found. The beam polarization of the presented data was deduced by fitting the absolute scale of the analyzing power to these references. Our results extend the world data set and are necessary for polarimetry of future electric dipole moment searches at storage rings. They will as well serve as an input for theoretical description of polarized hadron-hadron scattering.

Published
2020

2. Storage Ring to Search for Electric Dipole Moments of Charged Particles -- Feasibility Study

Author

Abusaif, F., Aggarwal, A., Aksentev, A., Alberdi-Esuain, B., Andres, A., Atanasov, A., Barion, L., Basile, S., Berz, M., Böhme, C., Böker, J., Borburgh, J., Canale, N., Carli, C., Ciepał, I., Ciullo, G., Contalbrigo, M., De Conto, J. -M., Dymov, S., Felden, O., Gaisser, M., Gebel, R., Giese, N., Gooding, J., Grigoryev, K., Grzonka, D., Tahar, M. Haj, Hahnraths, T., Heberling, D., Hejny, V., Hetzel, J., Hölscher, D., Javakhishvili, O., Jorat, L., Kacharava, A., Kamerdzhiev, V., Karanth, S., Keshelashvili, I., Koop, I., Kulikov, A., Laihem, K., Lamont, M., Lehrach, A., Lenisa, P., Lomidze, I., Lomidze, N., Lorentz, B., Macharashvili, G., Magiera, A., Makino, K., Martin, S., Mchedlishvili, D., Meißner, U. -G., Metreveli, Z., Michaud, J., Müller, F., Nass, A., Natour, G., Nikolaev, N., Nogga, A., Okropiridze, D., Pesce, A., Poncza, V., Prasuhn, D., Pretz, J., Rathmann, F., Ritman, J., Rosenthal, M., Saleev, A., Schott, M., Sefzick, T., Senichev, Y., Shankar, R., Shergelashvili, D., Shmakova, V., Siddique, S., Silenko, A., Simon, M., Slim, J., Soltner, H., Stahl, A., Stassen, R., Stephenson, E., Straatmann, H., Ströher, H., Tabidze, M., Tagliente, G., Talman, R., Uzikov, Y., Valdau, Y., Valetov, E., Vilella, E., Vitz, M., Vossebeld, J., Wagner, T., Weidemann, C., Wirzba, A., Wrońska, A., Wüstner, P., Zupranski, P., and Żurek, M.

Subjects
High Energy Physics - Experiment, Nuclear Experiment, Physics - Accelerator Physics
Abstract

The proposed method exploits charged particles confined as a storage ring beam (proton, deuteron, possibly $^3$He) to search for an intrinsic electric dipole moment (EDM) aligned along the particle spin axis. Statistical sensitivities could approach 10$^{-29}$ e$\cdot$cm. The challenge will be to reduce systematic errors to similar levels. The ring will be adjusted to preserve the spin polarisation, initially parallel to the particle velocity, for times in excess of 15 minutes. Large radial electric fields, acting through the EDM, will rotate the polarisation from the longitudinal to the vertical direction. The slow rise in the vertical polarisation component, detected through scattering from a target, signals the EDM. The project strategy is outlined. A stepwise plan is foreseen, starting with ongoing COSY activities that demonstrate technical feasibility. Achievements to date include reduced polarization measurement errors, long horizontal plane polarization lifetimes, and control of the polarization direction through feedback from scattering measurements. The project continues with a proof-of-capability measurement (precursor experiment; first direct deuteron EDM measurement), an intermediate prototype ring (proof-of-principle; demonstrator for key technologies), and finally a high-precision electric-field storage ring., Comment: 243 pages

Published
2019
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3. Spin tune mapping as a novel tool to probe the spin dynamics in storage rings

Author

Saleev, A., Nikolaev, N. N., Rathmann, F., Augustyniak, W., Bagdasarian, Z., Bai, M., Berz, M., Chekmenev, S., Ciullo, G., Dymov, S., Eversmann, D., Gaisser, M., Gebel, R., Grigoryev, K., Grzonka, D., Guidoboni, G., Heberling, D., Hempelmann, N., Hejny, V., Hetzel, J., Hinder, F., Kacharava, A., Kamerdzhiev, V., Keshelashvili, I., Koop, I., Kulikov, A., Lehrach, A., Lenisa, P., Lomidze, N., Lorentz, B., Maanen, P., Macharashvili, G., Mchedlishvili, D., Magiera, A., Mey, S., Nass, A., Pesce, A., Prasuhn, D., Pretz, J., Rosenthal, M., Schmidt, V., Semertzidis, Y., Senichev, Y., Shmakova, V., Silenko, A., Slim, J., Stahl, A., Stassen, R., Stephenson, E., Stockhorst, H., Ströher, H., Engblom, P. Thörngren, Tabidze, M., Tagliente, G., Talman, R., Trinkel, F., Uzikov, Yu., Valdau, Yu., Valetov, E., Vassiliev, A., Weidemann, C., Wrońska, A., Wüstner, P., and Zuprański, P.

Subjects
Physics - Accelerator Physics, Nuclear Experiment, Physics - Instrumentation and Detectors
Abstract

Precision experiments, such as the search for electric dipole moments of charged particles using storage rings, demand for an understanding of the spin dynamics with unprecedented accuracy. The ultimate aim is to measure the electric dipole moments with a sensitivity up to 15 orders in magnitude better than the magnetic dipole moment of the stored particles. This formidable task requires an understanding of the background to the signal of the electric dipole from rotations of the spins in the spurious magnetic fields of a storage ring. One of the observables, especially sensitive to the imperfection magnetic fields in the ring is the angular orientation of stable spin axis. Up to now, the stable spin axis has never been determined experimentally, and in addition, the JEDI collaboration for the first time succeeded to quantify the background signals that stem from false rotations of the magnetic dipole moments in the horizontal and longitudinal imperfection magnetic fields of the storage ring. To this end, we developed a new method based on the spin tune response of a machine to artificially applied longitudinal magnetic fields. This novel technique, called \textit{spin tune mapping}, emerges as a very powerful tool to probe the spin dynamics in storage rings. The technique was experimentally tested in 2014 at the cooler synchrotron COSY, and for the first time, the angular orientation of the stable spin axis at two different locations in the ring has been determined to an unprecedented accuracy of better than $2.8\mu$rad., Comment: 32 pages, 15 figures, 7 tables

Published
2017
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4. Measurement of the $e^+e^- \to K^+K^-\pi^+\pi^-$ cross section with the CMD-3 detector at the VEPP-2000 collider

Author

Shemyakin, D. N., Fedotovich, G. V., Akhmetshin, R. R., Amirkhanov, A. N., Anisenkov, A. V., Aulchenko, V. M., Banzarov, V. Sh., 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., Ivanov, V. L., Karpov, S. V., Kazanin, V. F., Koop, I. A., Korobov, A. A., Kovalenko, O. A., Kozyrev, A. N., Kozyrev, E. A., Krokovny, P. P., Kuzmenko, A. E., Kuzmin, A. S., Logashenko, I. B., Lysenko, A. P., Lukin, P. A., Mikhailov, K. Yu., Okhapkin, V. S., Pestov, Yu. N., Perevedentsev, E. A., Popov, A. S., Razuvaev, G. P., Rogovsky, Yu. A., Ruban, A. A., Ryskulov, N. M., Ryzhenenkov, A. E., Shebalin, V. E., Shwartz, B. A., Shwartz, D. B., Sibidanov, A. L., Shatunov, Yu. M., Solodov, E. P., Titov, V. M., Talyshev, A. A., Vorobiov, A. I., Yudin, Yu. V., and Zemlyansky, I. M.

Subjects
High Energy Physics - Experiment, Nuclear Experiment
Abstract

The process $e^+e^- \to K^+K^-\pi^+\pi^-$ has been studied in the center-of-mass energy range from 1500 to 2000\,MeV using a data sample of 23 pb$^{-1}$ collected with the CMD-3 detector at the VEPP-2000 $e^+e^-$ collider. Using about 24000 selected events, the $e^+e^- \to K^+K^-\pi^+\pi^-$ cross section has been measured with a systematic uncertainty decreasing from 11.7\% at 1500-1600\,MeV to 6.1\% above 1800\,MeV. A preliminary study of $K^+K^-\pi^+\pi^-$ production dynamics has been performed.

Published
2015
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5. New method for a continuous determination of the spin tune in storage rings and implications for precision experiments

Author

Eversmann, D., Hejny, V., Hinder, F., Kacharava, A., Pretz, J., Rathmann, F., Rosenthal, M., Trinkel, F., Andrianov, S., Augustyniak, W., Bagdasarian, Z., Bai, M., Bernreuther, W., Bertelli, S., Berz, M., Bsaisou, J., Chekmenev, S., Chiladze, D., Ciullo, G., Contalbrigo, M., de Vries, J., Dymov, S., Engels, R., Esser, F. M., Felden, O., Gaisser, M., Gebel, R., Glückler, H., Goldenbaum, F., Grigoryev, K., Grzonka, D., Guidoboni, G., Hanhart, C., Heberling, D., Hempelmann, N., Hetzel, J., Hipple, R., Hölscher, D., Ivanov, A., Kamerdzhiev, V., Kamys, B., Keshelashvili, I., Khoukaz, A., Koop, I., Krause, H-J., Krewald, S., Kulikov, A., Lehrach, A., Lenisa, P., Lomidze, N., Lorentz, B., Maanen, P., Macharashvili, G., Magiera, A., Maier, R., Makino, K., Marianski, B., Mchedlishvili, D., Meißner, Ulf-G., Mey, S., Nass, A., Natour, G., Nikolaev, N., Nioradze, M., Nogga, A., Nowakowski, K., Pesce, A., Prasuhn, D., Ritman, J., Rudy, Z., Saleev, A., Semertzidis, Y., Senichev, Y., Shmakova, V., Silenko, A., Slim, J., Soltner, H., Stahl, A., Stassen, R., Statera, M., Stephenson, E., Stockhorst, H., Straatmann, H., Ströher, H., Tabidze, M., Talman, R., Engblom, P. Thörngren, Trzcinski, A., Uzikov, Yu., Valdau, Yu., Valetov, E., Vassiliev, A., Weidemann, C., Wilkin, C., Wirzba, A., Wronska, A., Wüstner, P., Zakrzewska, M., Zaplatin, E., Zupranski, P., and Zyuzin, D.

Subjects
Physics - Accelerator Physics, Nuclear Experiment
Abstract

A new method to determine the spin tune is described and tested. In an ideal planar magnetic ring, the spin tune - defined as the number of spin precessions per turn - is given by $\nu_s = \gamma G$ (gamma is the Lorentz factor, $G$ the magnetic anomaly). For 970 MeV/c deuterons coherently precessing with a frequency of ~120 kHz in the Cooler Synchrotron COSY, the spin tune is deduced from the up-down asymmetry of deuteron carbon scattering. In a time interval of 2.6 s, the spin tune was determined with a precision of the order $10^{-8}$, and to $1 \cdot 10^{-10}$ for a continuous 100 s accelerator cycle. This renders the presented method a new precision tool for accelerator physics: controlling the spin motion of particles to high precision is mandatory, in particular, for the measurement of electric dipole moments of charged particles in a storage ring., Comment: 6 pages, 6 figures

Published
2015
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6. Study of the process $e^+e^- \to \eta\eta\gamma$ in the energy range $\sqrt{s} = \mbox{1.17--2.00}$ GeV with the SND detector

Author

SND Collaboration, Achasov, M. N., Barnyakov, A. Yu., Beloborodov, K. I., Berdyugin, A. V., Berkaev, D. E., Bogdanchikov, A. G., Botov, A. A., Dimova, T. V., Druzhinin, V. P., Kirpotin, A. N., Kardapoltsev, L. V., Kasaev, A. S., Kharlamov, A. G., Koop, I. A., Korol, A. A., Kovrizhin, D. P., Kupich, A. S., Martin, K. A., Melnikova, N. A., Muchnoy, N. Yu., Obrazovsky, A. E., Pakhtusova, E. V., Pugachev, K. V., Rabusov, D. V., Rogovsky, Yu. A., Senchenko, A. I., Serednyakov, S. I., Shatilov, D. N., Shatunov, Yu. M., Shtol, D. A., Shwartz, D. B., Silagadze, Z. K., Surin, I. K., Timoshenko, M. V., Usov, Yu. V., Zhabin, V. N., and Zhulanov, V. V.

Subjects
Astrophysics::High Energy Astrophysical Phenomena, High Energy Physics::Experiment, Nuclear Experiment, High Energy Physics - Experiment
Abstract

The process $e^+e^-\to\eta\eta\gamma$ is studied in the center-of-mass energy range 1.17-2.00 GeV using data with an integrated luminosity of 201 pb$^{-1}$collected by the SND detector at the VEPP-2000 $e^+e^-$ collider. The $e^+e^-\to\eta\eta\gamma$ cross section is measured for the first time. It is shown that the dominant mechanism of this reaction is the transition through the $\phi\eta$ intermediate state. Our result on the $e^+e^-\to\eta\eta\gamma$ cross section is consistent with the $e^+e^-\to\phi\eta$ measurement in the $\phi\to K^+ K^-$ mode. The search for radiative processes contributing to the $e^+e^-\to\eta\eta\gamma$ cross section is performed, and no significant signal is observed., Comment: 6 pages, 3 figures, to be submitted to European Physical Journal C. arXiv admin note: text overlap with arXiv:2006.05465

Published
2021

7. Possible Studies at the First Stage of the NICA Collider Operation with Polarized and Unpolarized Proton and Deuteron Beams

Author

Abramov, V. V., Aleshko, A., Baskov, V. A., Boos, E., Bunichev, V., Dalkarov, O. D., El-Kholy, R., Galoyan, A., Guskov, A. V., Kim, V. T., Kokoulina, E., Koop, I. A., Kostenko, B. F., Kovalenko, A. D., Ladygin, V. P., Larionov, A. B., L'vov, A. I., Milstein, A. I., Nikitin, V. A., Nikolaev, N. N., Popov, A. S., Polyanskiy, V. V., Richard, J. -M., Salnikov, S. G., Shavrin, A. A., Shatunov, P. Yu., Shatunov, Yu. M., Selyugin, O. V., Strikman, M., Tomasi-Gustafsson, E., Uzhinsky, V. V., Uzikov, Yu. N., Wang, Q., Zhao, Q., Zelenov, A. V., Institut de Physique des 2 Infinis de Lyon (IP2I Lyon), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), Département de Physique Nucléaire (ex SPhN) (DPHN), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and HEP, INSPIRE

Subjects
Nuclear and High Energy Physics, p p: scattering, [PHYS.HEXP] Physics [physics]/High Energy Physics - Experiment [hep-ex], p deuteron: scattering, [PHYS.PHYS.PHYS-ACC-PH]Physics [physics]/Physics [physics]/Accelerator Physics [physics.acc-ph], Nuclear Theory, FOS: Physical sciences, short-range, polarized beam, color: transparency, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], correlation: short-range, spin: dependence, 7. Clean energy, 01 natural sciences, invariance: CP, High Energy Physics - Experiment, bottom, High Energy Physics - Experiment (hep-ex), High Energy Physics - Phenomenology (hep-ph), strangeness, multiquark, parity: violation, NICA, deep inelastic scattering, 0103 physical sciences, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], charmed baryon, 010306 general physics, Nuclear Experiment, nucleon nucleon: interaction, Dubna Lab, bottom baryon, 010308 nuclear & particles physics, strong interaction, nucleus, p: beam, deuteron: beam, [PHYS.HPHE] Physics [physics]/High Energy Physics - Phenomenology [hep-ph], High Energy Physics - Phenomenology, [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], High Energy Physics::Experiment, scattering: wide-angle, time reversal: violation, charm, threshold: charm
Abstract

This paper contains suggestions for experiments with usage of the Spin Physics Detector (SPD) at the first stage of the SPD NICA Programme developing at JINR. Double polarized pp-, dd- and pd- collisions at c.m.s. NN energies of 3.4-10 GeV, which will be accessible at the initial stage of experiments, allow one to study spin dependence of the NN interaction, search for multiquark states at double strangeness, charm and beauty thresholds, study the short-range structure of the deuteron. Double polarized pd scattering offer a possibility to test the Standard Model through the search for T-invariance violation., 140 pages, 44 figures, prepared for Physics of Elementary Particles and Atomic Nuclei

Published
2021
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8. Storage ring to search for electric dipole moments of charged particles: Feasibility study

Author

Abusaif, F., Aggarwal, A., Aksentev, A., Alberdi-Esuain, B., Andres, A., Atanasov, A., Barion, L., Basile, S., Berz, M., Beyß, M., Böhme, C., Böker, J., Borburgh, J., Canale, N., Carli, C., Ciepał, I., Ciullo, G., Contalbrigo, M., De Conto, J.-M., Dymov, S., Felden, O., Gagoshidze, M., Gaisser, M., Gebel, R., Giese, N., Gooding, J., Grigoryev, K., Grzonka, D., Haj Tahar, M., Hahnraths, T., Heberling, D., Hejny, V., Hetzel, J., Hölscher, D., Javakhishvili, O., Jorat, L., Kacharava, A., Kamerdzhiev, V., Karanth, S., Käseberg, C., Keshelashvili, I., Koop, I., Kulikov, A., Laihem, K., Lamont, M., Lehrach, A., Lenisa, P., Lomidze, I., Lomidze, N., Lorentz, B., Macharashvili, G., Magiera, A., Makino, K., Martin, S., Mchedlishvili, D., Meißner, U.-G, Metreveli, Z., Michaud, J., Müller, F., Nass, A., Natour, G., Nikolaev, N., Nogga, A., Okropiridze, D., Pesce, A., Poncza, V., Prasuhn, D., Pretz, J., Rathmann, F., Ritman, J., Rosenthal, M., Saleev, A., Schott, M., Sefzick, T., Senichev, Y., Shankar, R., Shergelashvili, D., Shmakova, V., Siddique, S., Silenko, A., Simon, M., Slim, J., Soltner, H., Stahl, A., Stassen, R., Stephenson, E., Straatmann, H., Ströher, H., Tabidze, M., Tagliente, G., Talman, R., Uzikov, Y., Valdau, Y., Valetov, E., Vilella, E., Vitz, M., Vossebeld, J., Wagner, T., Weidemann, C., Wirzba, A., Wrońska, A., Wüstner, P., Zupranski, P., Zurek., M., Laboratoire de Physique Subatomique et de Cosmologie (LPSC), and Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)

Subjects
Accelerator Physics (physics.acc-ph), [PHYS.PHYS.PHYS-ACC-PH]Physics [physics]/Physics [physics]/Accelerator Physics [physics.acc-ph], FOS: Physical sciences, feedback, Juelich COSY PS, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], High Energy Physics - Experiment, High Energy Physics - Experiment (hep-ex), particle: velocity, synchrotron, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Nuclear Physics - Experiment, spin: polarization, Nuclear Experiment (nucl-ex), Nuclear Experiment, lifetime, deuteron: electric moment, scattering, sensitivity, charged particle, Accelerators and Storage Rings, particle: spin, electric field, Automatic Keywords, dipole: electric, Physics - Accelerator Physics, statistical, Particle Physics - Experiment
Abstract

The proposed method exploits charged particles confined as a storage ring beam (proton, deuteron, possibly $^3$He) to search for an intrinsic electric dipole moment (EDM) aligned along the particle spin axis. Statistical sensitivities could approach 10$^{-29}$ e$\cdot$cm. The challenge will be to reduce systematic errors to similar levels. The ring will be adjusted to preserve the spin polarisation, initially parallel to the particle velocity, for times in excess of 15 minutes. Large radial electric fields, acting through the EDM, will rotate the polarisation from the longitudinal to the vertical direction. The slow rise in the vertical polarisation component, detected through scattering from a target, signals the EDM. The project strategy is outlined. A stepwise plan is foreseen, starting with ongoing COSY activities that demonstrate technical feasibility. Achievements to date include reduced polarization measurement errors, long horizontal plane polarization lifetimes, and control of the polarization direction through feedback from scattering measurements. The project continues with a proof-of-capability measurement (precursor experiment; first direct deuteron EDM measurement), an intermediate prototype ring (proof-of-principle; demonstrator for key technologies), and finally a high-precision electric-field storage ring., 243 pages

Published
2021
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9. Study of the process $e^+e^- \to \eta\pi^0\gamma$ in the energy range $\sqrt{s} = \mbox{1.05-2.00}$ GeV with the SND detector

Author

SND Collaboration, Achasov, M. N., Barnyakov, A. Yu., Baykov, A. A., Beloborodov, K. I., Berdyugin, A. V., Berkaev, D. E., Bogdanchikov, A. G., Botov, A. A., Dimova, T. V., Druzhinin, V. P., Golubev, V. B., Kirpotin, A. N., Kardapoltsev, L. V., Kasaev, A. S., Kharlamov, A. G., Koop, I. A., Korol, A. A., Kovrizhin, D. P., Kupich, A. S., Martin, K. A., Melnikova, N. A., Muchnoy, N. Yu., Obrazovsky, A. E., Pakhtusova, E. V., Pugachev, K. V., Rabusov, D. V., Rogovsky, Yu. A., Savchenko, Y. S., Senchenko, A. I., Serednyakov, S. I., Shatilov, D. N., Shatunov, Yu. M., Shtol, D. A., Shwartz, D. B., Silagadze, Z. K., Surin, I. K., Timoshenko, M. V., Usov, Yu. V., Zhabin, V. N., and Zhulanov, V. V.

Subjects
High Energy Physics::Experiment, Nuclear Experiment, High Energy Physics - Experiment
Abstract

The process $e^+e^-\to\eta\pi^0\gamma$ is studied in the center-of-mass energy range 1.05-2.00 GeV using data with an integrated luminosity of 94.5 pb$^{-1}$ collected by the SND detector at the VEPP-2000 $e^+e^-$ collider. The $e^+e^-\to\eta\pi^0\gamma$ cross section is measured for the first time. It is shown that the dominant mechanism of this reaction is the transition through the $\omega\eta$ intermediate state. The measured cross section of the subprocess $e^+e^-\to\omega\eta\to\eta\pi^0\gamma$ is consistent with previous measurements in the $e^+e^-\to\pi^+\pi^-\pi^0\eta$ mode. It is found, with a significance of 5.6$\sigma$, that the process $e^+e^-\to\eta\pi^0\gamma$ is not completely described by hadronic vector-pseudoscalar intermediate states. The cross section of this missing contribution, which can originate from radiation processes, e. g. $e^+e^-\to a_{0}(1450)\gamma$, is measured. It is found to be 15-20 pb in the wide energy range from 1.3 to 1.9 GeV., Comment: 10 pages, 6 figures, to be submitted to European Physical Journal C

Published
2020

10. Measurement of the $e^{+}e^{-}\rightarrow\eta\pi^{+}\pi^{-}$ cross section with the CMD-3 detector at the VEPP-2000 collider

Author

Gribanov, S. S., Popov, A. S., Akhmetshin, R. R., Amirkhanov, A. N., Anisenkov, A. V., Aulchenko, V. M., Banzarov, V. Sh., 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., Gayazov, S. E., Grancagnolo, F. J., Grebenuk, A. A., Grigoriev, D. N., Ignatov, F. V., Ivanov, V. L., Karpov, S. V., Kazanin, V. F., Kirpotin, A. N., Koop, I. A., Korobov, A. A., Kovalenko, O. 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., Otboev, A. V., Pestov, Yu. N., Razuvaev, G. P., Rogovsky, Yu. A., Ruban, A. A., Ryskulov, N. M., Ryzhenenkov, A. E., Semenov, A. V., Senchenko, A. I., Shatunov, Yu. M., Shatunov, P. Yu., Shebalin, V. E., Shemyakin, D. N., Shwartz, B. A., Shwartz, D. B., Sibidanov, A. L., Solodov, E. P., Titov, V. M., Talyshev, A. A., Tolmachev, S. S., Vorobiov, A. I., Zemlyansky, I. M., and Yudin, Yu. V.

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

The cross section of the process $e^{+}e^{-}\rightarrow\eta\pi^{+}\pi^{-}$ is measured using the data collected with the CMD-$3$ detector at the VEPP-$2000$ collider in the center-of-mass energy range from $1.1$ to $2.0$ GeV. The decay mode $\eta\rightarrow\gamma\gamma$ is used for $\eta$ meson reconstruction in the data sample corresponding to an integrated luminosity of $78.3$ pb$^{-1}$. The energy dependence of the $e^{+}e^{-}\rightarrow\eta\pi^{+}\pi^{-}$ cross section is fitted within the framework of vector meson dominance in order to extract the $\Gamma(\rho(1450)\rightarrow{^{+}e^{-}})\mathcal{B}(\rho(1450)\rightarrow\eta\pi^{+}\pi^{-})$ and the $\Gamma(\rho(1700)\rightarrow{e^{+}e^{-}})\mathcal{B}(\rho(1700)\rightarrow\eta\pi^{+}\pi^{-})$ products. Based on conservation of vector current, the analysed data are used to test the relationship between the $e^{+}e^{-}\rightarrow\eta\pi^{+}\pi^{-}$ cross section and the spectral function in $\tau^-\rightarrow\eta\pi^-\pi^0\nu_\tau$ decay. The $e^{+}e^{-}\rightarrow\eta\pi^{+}\pi^{-}$ cross section measured with the CMD-$3$ detector is in good agreement with the previous measurements.

Published
2019

11. Feasibility Study for an EDM Storage Ring

Author

Abusaif, F., Aggarwal, A., Aksentev, A., Alberdi-Esuain, B., Barion, L., Basile, S., Berz, M., Beyß, M., Böhme, C., Böker, J., Borburgh, J., Carli, C., Ciepał, I., Ciullo, G., Contalbrigo, M., M Conto, J., Dymov, S., Engels, R., Felden, O., Gagoshidze, M., Gaisser, M., Gebel, R., Giese, N., Grigoryev, K., Grzonka, D., Hanraths, T., Hanhart, C., Heberling, D., Hejny, V., Hetzel, J., Hölscher, D., Otari Javakhishvili, Kacharava, A., Karanth, S., Käseberg, C., Kamerdzhiev, V., Keshelashvili, I., Koop, I., Kulikov, A., Laihem, K., Lamont, M., Lehrach, A., Lenisa, P., Lomidze, N., Lorentz, B., Macharashvili, G., Magiera, A., Maier, R., Makino, K., Martin, S., Mchedlishvili, D., G Meißner, U., Metreveli, Z., Michaud, J., Müller, F., Nass, A., Natour, G., Nikolaev, N., Nogga, A., Pesce, A., Poncza, V., Prasuhn, D., Pretz, J., Rathmann, F., Ritman, J., Rosenthal, M., Saleev, A., Schott, M., Sefzick, T., Senichev, Y., Shergelashvili, D., Shmakova, V., Siddique, S., Silenko, A., Simon, M., Slim, J., Soltner, H., Stahl, A., Stassen, R., Stephenson, E., Straatmann, H., Ströher, H., Tabidze, M., Tagliente, G., Tahar, M., Talman, R., Yu. Uzikov, Yu. Valdau, Valetov, E., Wagner, T., Weidemann, C., Wilkin, C., Wirzba, A., Wrońska, A., Wüstner, P., Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), and CPEDM

Subjects
Accelerator Physics (physics.acc-ph), experimental methods, deuteron: electric moment, hep-ex, [PHYS.PHYS.PHYS-ACC-PH]Physics [physics]/Physics [physics]/Accelerator Physics [physics.acc-ph], FOS: Physical sciences, costs, Juelich COSY PS, sensitivity, Accelerators and Storage Rings, High Energy Physics - Experiment, High Energy Physics - Experiment (hep-ex), beam optics, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Physics - Accelerator Physics, spin: polarization, Nuclear Experiment, Particle Physics - Experiment, accelerator: design, activity report, physics.acc-ph
Abstract

This project exploits charged particles confined as a storage ring beam (proton, deuteron, possibly $^3$He) to search for an intrinsic electric dipole moment (EDM, $\vec d$) aligned along the particle spin axis. Statistical sensitivities can approach $10^{-29}$~e$\cdot$cm. The challenge will be to reduce systematic errors to similar levels. The ring will be adjusted to preserve the spin polarization, initially parallel to the particle velocity, for times in excess of 15 minutes. Large radial electric fields, acting through the EDM, will rotate the polarization ($\vec d \times\vec E$). The slow rise in the vertical polarization component, detected through scattering from a target, signals the EDM. The project strategy is outlined. It foresees a step-wise plan, starting with ongoing COSY activities that demonstrate technical feasibility. Achievements to date include reduced polarization measurement errors, long horizontal-plane polarization lifetimes, and control of the polarization direction through feedback from the scattering measurements. The project continues with a proof-of-capability measurement (precursor experiment; first direct deuteron EDM measurement), an intermediate prototype ring (proof-of-principle; demonstrator for key technologies), and finally the high precision electric-field storage ring.

Published
2019

12. Search for the process $\mathbf{e^+e^- \to\eta}$

Author

Achasov, M. N., Barnyakov, A. Yu., Beloborodov, K. I., Berdyugin, A. V., Berkaev, D. E., Bogdanchikov, A. G., Botov, A. A., Dimova, T. V., Druzhinin, V. P., Golubev, V. B., Kardapoltsev, L. V., Kasaev, A. S., Kharlamov, A. G., Koop, I. A., Korneev, L. A., Korol, A. A., Kovrizhin, D. P., Koshuba, S. V., Kupich, A. S., Litvinov, R. A., Martin, K. A., Melnikova, N. A., Muchnoi, N. Yu., Obrazovsky, A. E., Pakhtusova, E. V., Pugachev, K. V., Rogovsky, Yu. A., Senchenko, A. I., Serednyakov, S. I., Silagadze, Z. K., Shatilov, D. N., Shatunov, Yu. M., Shtol, D. A., Shwartz, D. B., Surin, I. K., Usov, Yu. V., Vasiljev, A. V., Zhabin, V. N., and Zhulanov, V. V.

Subjects
High Energy Physics::Experiment, Nuclear Experiment, High Energy Physics - Experiment
Abstract

A search for the rare decay $\eta \rightarrow e^+e^-$ is performed using the inverse process $e^+e^- \rightarrow \eta$ in the decay mode $\eta\to\pi^0\pi^0\pi^0 $. We analyze data with an integrated luminosity of 654 nb$^{-1} $ accumulated at the VEPP-2000 $e^+e^-$ collider with the SND detector at the center-of-mass energy $E=m_\eta c ^2\approx 548 $ MeV, and set the upper limit $ {\cal B} (\eta \rightarrow e^+ e^-) < 7 \times 10^{-7} $ at the 90\% confidence level., Comment: 9 pages, 4 figures

Published
2018

13. Measurement of the $e^+e^- \to \eta\pi^+\pi^-$ cross section with the SND detector at the VEPP-2000 collider

Author

Achasov, M. N., Barnyakov, A. Yu., Beloborodov, K. I., Berdyugin, A. V., Berkaev, D. E., Bogdanchikov, A. G., Botov, A. A., Dimova, T. V., Druzhinin, V. P., Golubev, V. B., Kardapoltsev, L. V., Kharlamov, A. G., Koop, I. A., Korol, A. A., Kovrizhin, D. P., Koshuba, S. V., Kupich, A. S., Lysenko, A. P., Martin, K. A., Melnikova, N. A., Muchnoi, N. Yu., Obrazovsky, A. E., Pakhtusova, E. V., Perevedentsev, E. A., Pugachev, K. V., Rogozina, E. V., Serednyakov, S. I., Silagadze, Z. K., Shatunov, Yu. M., Shatunov, P. Yu., Shtol, D. A., Surin, I. K., Tikhonov, Yu. A., Usov, Yu. V., Vasiljev, A. V., and Zemlyansky, I. M.

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

The $e^+e^- \to \eta\pi^+\pi^-$ cross section is measured at the SND detector in the $\eta$ decay mode $\eta\to 3\pi^0$. The analysis is based on the data sample with an integrated luminosity of 32.7 pb$^{-1}$ collected at the VEPP-2000 $e^+e^-$ collider in the center-of-mass energy range $\sqrt{s}=1.075-2.000$ GeV. The data obtained in the $\eta\to 3\pi^0$ decay mode are found to be in agreement with the previous SND measurements in the $\eta\to \gamma\gamma$ mode. Therefore the measurements in the two modes are combined., Comment: 8 pages, 5 figures

Published
2017

14. Measurement of the $e^+e^- \to \omega\eta$ cross section below $\sqrt{s}=2$ GeV

Author

Achasov, M. N., Barnyakov, A. Yu., Beloborodov, K. I., Berdyugin, A. V., Bogdanchikov, A. G., Botov, A. A., Dimova, T. V., Druzhinin, V. P., Golubev, V. B., Kardapoltsev, L. V., Kasaev, A. S., Kharlamov, A. G., Kirpotin, A. N., Kovrizhin, D. P., Koop, I. A., Korol, A. A., Koshuba, S. V., Kupich, A. S., Martin, K. A., Melnikova, N. A., Obrazovsky, A. E., Pakhtusova, E. V., Senchenko, A. I., Serednyakov, S. I., Silagadze, Z. K., Shatunov, Yu. M., Shtol, D. A., Shwartz, D. B., Skrinsky, A. N., Surin, I. K., Tikhonov, Yu. A., and Vasiljev, A. V.

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

The cross section for the process $e^+e^- \to \omega\eta$ is measured in the center-of-mass energy range 1.34--2.00 GeV. The analysis is based on data collected with the SND detector at the VEPP-2000 $e^+e^-$ collider. The measured $e^+e^- \to \omega\eta$ cross section is the most accurate to date. A significant discrepancy is observed between our data and previous BABAR measurement., Comment: 15 pages, 5 figures, 3 tables

Published
2016

15. Study of the process $e^+e^-\to\omega\eta\pi^0$ in the energy range $\sqrt{s} <2$ GeV with the SND detector

Author

Achasov, M. N., Aulchenko, V. M., Barnyakov, A. Yu., Beloborodov, K. I., Berdyugin, A. V., Berkaev, D. E., Bogdanchikov, A. G., Botov, A. A., Dimova, T. V., Druzhinin, V. P., Golubev, V. B., Kardapoltsev, L. V., Kharlamov, A. G., Koop, I. A., Korol, A. A., Kovrizhin, D. P., Koshuba, S. V., Kupich, A. S., Lysenko, A. P., Melnikova, N. A., Martin, K. A., Pakhtusova, E. V., Obrazovsky, A. E., Perevedentsev, E. A., Rogovsky, Yu. A., Serednyakov, S. I., Silagadze, Z. K., Shatunov, Yu. M., Shatunov, P. Yu., Shtol, D. A., Skrinsky, A. N., Surin, I. K., Tikhonov, Yu. A., Usov, Yu. V., Vasiljev, A. V., and Zemlyansky, I. M.

Subjects
High Energy Physics::Experiment, Nuclear Experiment, High Energy Physics - Experiment
Abstract

The process $e^+e^-\to\omega\eta\pi^0$ is studied in the energy range $1.45-2.00$ GeV using data with an integrated luminosity of 33 pb$^{-1}$ accumulated by the SND detector at the $e^+e^-$ collider VEPP-2000. The $e^+e^-\to\omega\eta\pi^0$ cross section is measured for the first time. The cross section has a threshold near 1.75 GeV. Its value is about 2 nb in the energy range $1.8-2.0$ GeV. The dominant intermediate state for the process $e^+e^- \to \omega\eta\pi^0$ is found to be $\omega a_0(980)$., Comment: 7 pages, 6 figures

Published
2016

16. How to reach a thousand-second in-plane polarization lifetime with 0.97−GeV/c deuterons in a storage ring

Author

Guidoboni, G., Stephenson, E., Böker, J., Wüstner, P., Zakrzewska, M., Zuprański, P., Zyuzin, D., Stroeher, Hans, Mey, Sebastian, Stahl, Achim, JEDI Collaboration, Böhme, C., Bsaisou, J., Chekmenev, S., Chiladze, D., Ciullo, G., Contalbrigo, M., de Conto, J.-M., Dymov, S., Engels, Ralf W., Andrianov, S., Esser, F. M., Eversmann, D., Felden, O., Gaisser, M., Gebel, R., Glückler, H., Goldenbaum, F., Grigoryev, K., Grzonka, D., Hahnraths, T., Augustyniak, W., Heberling, D., Hejny, V., Hempelmann, N., Hetzel, J., Hinder, F., Hipple, R., Hölscher, D., Ivanov, A., Kacharava, A., Kamerdzhiev, V., Bagdasarian, Z., Kamys, B., Keshelashvili, I., Khoukaz, A., Koop, I., Krause, H.-J., Krewald, S., Kulikov, A., Lehrach, A., Lenisa, P., Lomidze, N., Bai, M., Lorentz, B., Maanen, P., Macharashvili, G., Magiera, A., Maier, R., Makino, K., Mariański, B., Mchedlishvili, D., Meißner, Ulf-G., Mey, S., Baylac, M., Morse, W., Müller, F., Nass, A., Natour, G., Nikolaev, N., Nioradze, M., Nowakowski, K., Orlov, Y., Pesce, A., Prasuhn, D., Bernreuther, W., Pretz, J., Rathmann, F., Ritman, J., Rosenthal, M., Rudy, Z., Saleev, A., Sefzick, T., Semertzidis, Y., Senichev, Y., Shmakova, V., Bertelli, S., Silenko, A., Simon, M., Slim, J., Soltner, H., Stassen, R., Statera, M., Stockhorst, H., Straatmann, H., Tabidze, M., Talman, R., Berz, M., Thörngren Engblom, P., Trinkel, F., Trzciński, A., Uzikov, Yu., Valdau, Yu., Valetov, E., Vassiliev, A., Weidemann, C., Wilkin, C., Wrońska, A., Laboratoire de Physique Subatomique et de Cosmologie (LPSC), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Centre National de la Recherche Scientifique (CNRS), and JEDI

Subjects
ANOMALOUS MAGNETIC-MOMENTS, ELECTRIC-DIPOLE MOMENTS, SENSITIVITY, [PHYS.PHYS.PHYS-ACC-PH]Physics [physics]/Physics [physics]/Accelerator Physics [physics.acc-ph], ddc:550, Socio-culturale, Physics::Accelerator Physics, Nuclear Experiment
Abstract

International audience; We observe a deuteron beam polarization lifetime near 1000 s in the horizontal plane of a magnetic storage ring (COSY). This long spin coherence time is maintained through a combination of beam bunching, electron cooling, sextupole field corrections, and the suppression of collective effects through beam current limits. This record lifetime is required for a storage ring search for an intrinsic electric dipole moment on the deuteron at a statistical sensitivity level approaching 10−29 e cm.

Published
2016
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17. On a search for the $\eta \rightarrow e^+ e^-$ decay at the VEPP-2000 $e^+e^-$ collider

Author

Achasov, M. N., Barnyakov, A. Yu., Berdyugin, K. I. Beloborodov A. V., Bogdanchikov, A. G., Botov, A. A., Dimova, T. V., Druzhinin, V. P., Golubev, V. B., Kardapoltsev, L. V., Kharlamov, A. G., Koop, I. A., Korneev, L. A., Korol, A. A., Kovrizhin, D. P., Kupich, A. S., Lysenko, A. P., Martin, K. A., Muchnoi, N. Yu., Obrazovsky, A. E., Pakhtusova, E. V., Perevedentsev, E. A., Rogovsky, Yu. A., Senchenko, A. I., Serednyakov, S. I., Silagadze, Z. K., Shatunov, Yu. M., Shtol, D. A., Shwartz, D. B., Skrinsky, A. N., Surin, I. K., Tikhonov, Yu. A., Usov, Yu. V., Vasiljev, A. V., and Zemlyansky, I. M.

Subjects
High Energy Physics::Experiment, Nuclear Experiment, High Energy Physics - Experiment
Abstract

A sensitivity of the VEPP-2000 $e^+e^-$ collider in a search for the rare decay $\eta \rightarrow e^+ e^-$ has been studied. The inverse reaction $e^+ e^- \rightarrow \eta$ is proposed for this search. We have analyzed a data sample with an integrated luminosity of 108 nb$^{-1}$ collected with the SND detector in the center-of-mass energy range 520-580 MeV and found no background events for the reaction $e^+ e^- \rightarrow \eta$ in the decay mode $\eta\to\pi^0\pi^0\pi^0$. In the absence of background, a sensitivity to ${\cal B}(\eta \rightarrow e^+ e^-)$ of $10^{-6}$ can be reached during two weeks of VEPP-2000 operation. Such a sensitivity is better than the current upper limit on ${\cal B}(\eta \rightarrow e^+ e^-)$ by a factor of 2.3., Comment: 5 pages, 2 figures, accepted for publication in JETP Letters

Published
2015

18. Search for the $\eta^{\prime}\to e^+e^-$ decay with the SND detector

Author

Achasov, M. N., Aulchenko, V. M., Barnyakov, A. Yu., Beloborodov, K. I., Berdyugin, A. V., Berkaev, D. E., Bogdanchikov, A. G., Botov, A. A., Dimova, T. V., Druzhinin, V. P., Golubev, V. B., Kardapoltsev, L. V., Kasaev, A. S., Kharlamov, A. G., Kirpotin, A. N., Koop, I. A., Korol, A. A., Koshuba, S. V., Kovrizhin, D. P., Kupich, A. S., Martin, K. A., Muchnoi, N. Yu., Obrazovsky, A. E., Otboev, A. V., Pakhtusova, E. V., Senchenko, A. I., Serednyakov, S. I., Shatunov, P. Yu., Shatunov, Yu. M., Shtol, D. A., Shwartz, D. B., Silagadze, Z. K., Surin, I. K., Tikhonov, Yu. A., Usov, Yu. V., Vasiljev, A. V., and Zemlyansky, I. M.

Subjects
High Energy Physics::Experiment, Nuclear Experiment, High Energy Physics - Experiment
Abstract

A search for the process $e^+e^- \to \eta^\prime$ has been performed with the SND detector at the VEPP-2000 $e^+e^-$ collider. The data were accumulated at the center-of-mass energy of $957.78\pm 0.06$ MeV with an integrated luminosity of about 2.9 pb$^{-1}$. For reconstruction of the $\eta^\prime$ meson five decay chains have been used: $\eta^{\prime}\to\eta\pi^+\pi^-$ followed by the $\eta$ decays to $\gamma\gamma$ and $3\pi^0 $, and $\eta^{\prime} \to \eta\pi^0\pi^0$ followed by the $\eta$ decays to $\pi^+\pi^-\pi^0$, $\gamma\gamma$, and $3\pi^0$. As a result, the upper limit has been set on the $\eta^\prime$ electronic width: $\Gamma_{\eta^{\prime}\to e^+e^-} < 0.0020$ eV at the 90\% confidence level., Comment: 12 pages, 6 figures

Published
2015

19. Measurement of the $e^+e^- \to \eta\pi^+\pi^-$ cross section in the center-of-mass energy range 1.22--2.00 GeV with the SND detector at the VEPP-2000 collider

Author

Aulchenko, V. M., Achasov, M. N., Barnyakov, A. Yu., Beloborodov, K. I., Berdyugin, A. V., Bogdanchikov, A. G., Botov, A. A., Dimova, T. V., Druzhinin, V. P., Golubev, V. B., Kardapoltsev, L. V., Kharlamov, A. G., Koop, I. A., Korol, A. A., Koshuba, S. V., Kovrizhin, D. P., Kupich, A. S., Martin, K. A., Obrazovsky, A. E., Pakhtusova, E. V., Senchenko, A. I., Serednyakov, S. I., Silagadze, Z. K., Shatunov, Yu. M., Shatunov, P. Ju., Shtol, D. A., Shwartz, D. B., Skrinsky, A. N., Surin, I. K., Tikhonov, Yu. A., Usov, Yu. V., and Vasiljev, A. V.

Subjects
High Energy Physics::Experiment, Nuclear Experiment, High Energy Physics - Experiment
Abstract

In the experiment with the SND detector at the VEPP-2000 $e^+e^-$ collider the cross section for the process $e^+e^-\to\eta\pi^+\pi^-$ has been measured in the center-of-mass energy range from 1.22 to 2.00 GeV. Obtained results are in agreement with previous measurements and have better accuracy. The energy dependence of the $e^+e^-\to\eta\pi^+\pi^-$ cross section has been fitted with the vector-meson dominance model. From this fit the product of the branching fractions $B(\rho(1450)\to\eta\pi^+\pi^-)B(\rho(1450)\to e^+e^-)$ has been extracted and compared with the same products for $\rho(1450)\to\omega\pi^0$ and $\rho(1450)\to\pi^+\pi^-$ decays. The obtained cross section data have been also used to test the conservation of vector current hypothesis., Comment: 9 pages, 7 figures

Published
2014

20. Study of the process $e^+e^-\to n\bar{n}$ at the VEPP-2000 $e^+e^-$ collider with the SND detector

Author

Achasov, M. N., Barnyakov, A. Yu., Beloborodov, K. I., Berdyugin, A. V., Berkaev, D. E., Bogdanchikov, A. G., Botov, A. A., Dimova, T. V., Druzhinin, V. P., Golubev, V. B., Kardapoltsev, L. V., Kasaev, A. S., Kharlamov, A. G., Kirpotin, A. N., Koop, I. A., Korol, A. A., Koshuba, S. V., Kovrizhin, D. P., Kupich, A. S., Martin, K. A., Obrazovsky, A. E., Pakhtusova, E. V., Rogovsky, Yu. A., Senchenko, A. I., Serednyakov, S. I., Silagadze, Z. K., Shatunov, Yu. M., Shtol, D. A., Shwartz, D. B., Skrinsky, A. N., Surin, I. K., Tikhonov, Yu. A., Usov, Yu. V., and Vasiljev, A. V.

Subjects
High Energy Physics - Experiment (hep-ex), Physics::Instrumentation and Detectors, Physics::Accelerator Physics, FOS: Physical sciences, High Energy Physics::Experiment, Nuclear Experiment, High Energy Physics - Experiment
Abstract

The process $e^+e^-\to n\bar{n}$ has been studied at the VEPP-2000 $e^+e^-$ collider with the SND detector in the energy range from threshold up to 2 GeV. As a result of the experiment, the $e^+e^-\to n\bar{n}$ cross section and effective neutron form factor have been measured.

Published
2014
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21. Study of the process $e^+e^-\to\eta\gamma$ in the center-of-mass energy range 1.07--2.00 GeV

Author

Achasov, M. N., Aulchenko, V. M., Barnyakov, A. Yu., Beloborodov, K. I., Berdyugin, A. V., Bogdanchikov, A. G., Botov, A. A., Dimova, T. V., Druzhinin, V. P., Golubev, V. B., Grevtsov, K. A., Kardapoltsev, L. V., Kharlamov, A. G., Kovrizhin, D. P., Koop, I. A., Korol, A. A., Koshuba, S. V., Lysenko, A. P., Martin, K. A., Obrazovsky, A. E., Pakhtusova, E. V., Perevedentsev, E. A., Romanov, A. L., Serednyakov, S. I., Silagadze, Z. K., Skrinsky, A. N., Surin, I. K., Tikhonov, Yu. A., Vasiljev, A. V., Shatunov, P. Yu., Shatunov, Yu. M., and Shtol, D. A.

Subjects
High Energy Physics - Phenomenology, Astrophysics::High Energy Astrophysical Phenomena, High Energy Physics::Experiment, Nuclear Experiment, High Energy Physics - Experiment
Abstract

The $e^+e^-\to\eta\gamma$ cross section has been measured in the center-of-mass energy range 1.07--2.00 GeV using the decay mode $\eta\to 3\pi^0$, $\pi^0\to \gamma\gamma$. The analysis is based on 36 pb$^{-1}$ of integrated luminosity collected with the SND detector at the VEPP-2000 $e^+e^-$ collider. The measured cross section of about 35 pb at 1.5 GeV is explained by decays of the $\rho(1450)$ and $\phi(1680)$ resonances., Comment: 9 pages, 5 figures, 1 table

Published
2013

22. Study of e+e- --> omega pi0 --> pi0 pi0 gamma in the energy range 1.05--2.00 GeV with SND

Author

Achasov, M. N., Aulchenko, V. M., Barnyakov, A. Yu., Beloborodov, K. I., Berdyugin, A. V., Bogdanchikov, A. G., Botov, A. A., Dimova, T. V., Druzhinin, V. P., Golubev, V. B., Grevtsov, K. A., Kardapoltsev, L. V., Kharlamov, A. G., Kovrizhin, D. P., Koop, I. A., Korol, A. A., Koshuba, S. V., Lysenko, A. P., Martin, K. A., Nesterenko, I. N., Obrazovsky, A. E., Pakhtusova, E. V., Perevedentsev, E. A., Romanov, A. L., Serednyakov, S. I., Silagadze, Z. K., Skovpen, K. Yu., Skrinsky, A. N., Surin, I. K., Tikhonov, Yu. A., Vasiljev, A. V., Shatunov, P. Yu., Shatunov, Yu. M., Shtol, D. A., and Zemlyansky, I. M.

Subjects
High Energy Physics::Experiment, Nuclear Experiment, High Energy Physics - Experiment
Abstract

The cross section for the process e+e- --> omega pi0 --> pi0 pi0 gamma has been measured in the energy range 1.05--2.00 GeV. The experiment has been performed at the e+e- collider VEPP-2000 with the SND detector. The measured e+e- --> omega pi0 cross section above 1.4 GeV is the most accurate to date. Below 1.4 GeV our data are in good agreement with the previous SND and CMD-2 measurements. Data on the e+e- --> omega pi0 cross section are well described by the VMD model with two excited rho-like states. From the measured cross section we have extracted the gamma^* --> omega pi0 transition form factor. It has been found that the VDM model cannot describe simultaneously our data and data obtained from the omega --> pi0 mu+ mu- decay. We have also tested CVC hypothesis comparing our results on the e+e- --> omega pi0 cross section with data on the tau- --> omega pi- nu_{tau} decay., Comment: 12 pages, 6 figures

Published
2013

23. Measurement of the e+e- -> K+K- cross section in the energy range s**(1/2) = 1.04 - 1.38 GeV with the SND detector in the experiment at the VEPP-2M e+e- collider

Author

Achasov, M. N., Beloborodov, K. I., Berdyugin, A. V., Bogdanchikov, A. G., Bukin, A. D., Bukin, D. A., Dimova, T. V., Druzhinin, V. P., Golubev, V. B., Koop, I. A., Korol, A. A., Koshuba, S. V., Pakhtusova, E. V., Perevedentsev, E. A., Serednyakov, S. I., Shatunov, Yu. M., Silagadze, Z. K., Skrinsky, A. N., Usov, Yu. V., and Vasiljev, A. V.

Subjects
High Energy Physics::Experiment, Astrophysics::Earth and Planetary Astrophysics, Nuclear Experiment, High Energy Physics - Experiment
Abstract

The cross section of the process $e^+e^- \to K^+K^-$ was measured in the energy range $\sqrt{s}$ = 1.04--1.38 GeV in the SND experiment at the VEPP-2M $e^+e^-$ collider. The measured cross section is described by the model of vector meson dominance with contributions from the light vector mesons $\rho$, $\omega$, $\phi$ and their lowest excitations. The mean statistical accuracy of the measurement is 4.4 %, and the systematic uncertainty is 5.2 %., Comment: 20 pages, 11 figures

Published
2007

24. Experimental Study of the Reaction $e^+e^-\to K_SK_L$ in the Energy Range $\sqrt{s}=1.04 \div 1.38$ GeV

Author

Achasov, M. N., Beloborodov, K. I., Berdyugin, A. V., Bozhenok, A. V., Bukin, D. A., Dimova, T. V., Druzhinin, V. P., Golubev, V. B., Koop, I. A., Korol, A. A., Koshuba, S. V., Lysenko, A. P., Otboev, A. V., Pakhtusova, E. V., Serednyakov, S. I., Shatunov, Yu. M., Sidorov, V. A., Silagadze, Z. K., Skrinsky, A. N., and Vasiliev, A. V.

Subjects
High Energy Physics::Experiment, Nuclear Experiment, High Energy Physics - Experiment
Abstract

We present a measurement of the $e^+e^-\to K_SK_L$ cross section in the energy range $\sqrt{s}=1.04 \div 1.38$ GeV. For the energy $\sqrt{s}\geq 1.2$ GeV the cross section exceeds vector meson dominance model predictions with only $\rho(770)$, $\omega(783)$, and $\phi(1020)$ mesons taken into account. Measured cross section agrees well with previous measurements., Comment: 15 pages, 5 figures

Published
2006

25. Experimental Study of the Reaction $e^+e^-\to K_SK_L$ in the Energy Range $\sqrt{s}=1.04 ��1.38$ GeV

Author

Achasov, M. N., Beloborodov, K. I., Berdyugin, A. V., Bozhenok, A. V., Bukin, D. A., Dimova, T. V., Druzhinin, V. P., Golubev, V. B., Koop, I. A., Korol, A. A., Koshuba, S. V., Lysenko, A. P., Otboev, A. V., Pakhtusova, E. V., Serednyakov, S. I., Shatunov, Yu. M., Sidorov, V. A., Silagadze, Z. K., Skrinsky, A. N., and Vasiliev, A. V.

Subjects
High Energy Physics - Experiment (hep-ex), FOS: Physical sciences, High Energy Physics::Experiment, Nuclear Experiment
Abstract

We present a measurement of the $e^+e^-\to K_SK_L$ cross section in the energy range $\sqrt{s}=1.04 ��1.38$ GeV. For the energy $\sqrt{s}\geq 1.2$ GeV the cross section exceeds vector meson dominance model predictions with only $��(770)$, $��(783)$, and $��(1020)$ mesons taken into account. Measured cross section agrees well with previous measurements., 15 pages, 5 figures

Published
2006
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26. Measurement of the e+e- -> pi+pi- cross section with the CMD-2 detector in the 370-520 MeV c.m. energy range

Author

Akhmetshin, R. R., Aulchenko, V. M., Banzarov, V. Sh., Barkov, L. M., Bashtovoy, N. S., Bondar, A. E., Bondarev, D. V., Bragin, A. V., Dhawan, S. K., Eidelman, S. I., Epifanov, D. A., Fedotovich, G. V., Gabyshev, N. I., Gorbachev, D. A., Grebenuk, A. A., Grigoriev, D. N., Hughes, V. W., Ignatov, F. V., Karpov, S. V., Kazanin, V. F., Khazin, B. I., Koop, I. A., Krokovny, P. P., Kuzmin, A. S., Logashenko, I. B., Lukin, P. A., Lysenko, A. P., Mikhailov, K. Yu., Milshtein, A. I., Nesterenko, I. N., Nikulin, M. A., Okhapkin, V. S., Otboev, A. V., Perevedentsev, E. A., Popov, A. S., Redin, S. I., Roberts, B. L., Root, N. I., Ruban, A. A., Ryskulov, N. M., Shamov, A. G., Shatunov, Yu. M., Shwartz, B. A., Sibidanov, A. L., Sidorov, V. A., Skrinsky, A. N., Smakhtin, V. P., Snopkov, I. G., Solodov, E. P., Thompson, J. A., Yudin, Yu. V., Zaitsev, A. S., and Zverev, S. G.

Subjects
High Energy Physics - Experiment (hep-ex), Nuclear Theory, FOS: Physical sciences, High Energy Physics::Experiment, Nuclear Experiment
Abstract

The cross section of the process e+e- -> pi+pi- has been measured at the CMD-2 detector in the 370-520 MeV center-of-mass (c.m.) energy range. A systematic uncertainty of the measurement is 0.7 %. Using all CMD-2 data on the pion form factor, the pion electromagnetic radius was calculated. The cross section of muon pair production was also determined., 11 pages, 4 figures

Published
2006
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27. Conceptual Design for a Polarized Proton-Antiproton Collider Facility at Gsi

Author

Bradamante, F., Koop, I., Otboev, A., Parkhomchuk, V., Shatunov, V. Reva P., and Shatunov, Yu.

Subjects
Accelerator Physics (physics.acc-ph), Physics - Instrumentation and Detectors, Physics::Accelerator Physics, FOS: Physical sciences, Physics - Accelerator Physics, High Energy Physics::Experiment, Instrumentation and Detectors (physics.ins-det), Nuclear Experiment
Abstract

Two possible options of polarized proton-antiproton collider at the future HESR storage ring are considered. It is shown that the modifications of the present HESR project which are needed to arrange for the polarized proton-antiproton collisions are relatively moderate. An achievable luminosity of 5x10^31 cm^-2 sec^-1 will provide a possibility to carry out experiments in the CM energy range 10-30 GeV, a particularly interesting option for Drell-Yan physics., Comment: 26 pages, 23 figures, new version with some correction to the original text

Published
2005
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28. Experimental Study of rho -> pi0 pi0 gamma and omega -> pi0 pi0 gamma Decays

Author

Achasov, M. N., Beloborodov, K. I., Berdyugin, A. V., Bogdanchikov, A. G., Bozhenok, A. V., Bukin, D. A., Burdin, S. V., Vasiljev, A. V., Golubev, V. B., Dimova, T. V., Druzhinin, V. P., Ivanchenko, V. N., Korol, A. A., Koop, I. A., Koshuba, S. V., Otboev, A. V., Pakhtusova, E. V., Salnikov, A. A., Serednyakov, S. I., Sidorov, V. A., Silagadze, Z. K., Skrinsky, A. N., Skripkin, A. G., Usov, Yu. V., Shary, V. V., and Shatunov, Yu. M.

Subjects
Astrophysics::High Energy Astrophysical Phenomena, High Energy Physics::Experiment, Astrophysics::Cosmology and Extragalactic Astrophysics, Nuclear Experiment, High Energy Physics - Experiment
Abstract

The e+e- -> pi0 pi0 gamma process was studied in the SND experiment at VEPP-2M e+e- collider in the energy region 0.60-0.97 GeV. From the analysis of the energy dependence of measured cross section the branching ratios B(omega -> pi0 pi0 gamma)= (6.6 +1.4-0.8(stat) +-0.6(syst))x10^-5 and B(rho -> pi0 pi0 gamma)=(4.1 +1.0-0.9(stat) +-0.3(syst))x10^-5 were obtained., Comment: 16 pages, 7 figures, submitted to Phys. Lett. B

Published
2002

29. Search for the radiative decay $\eta \to \pi^0 \gamma \gamma$ in the SND experiment at VEPP-2M

Author

Achasov, M. N., Beloborodov, K. I., Berdyugin, A. V., Bozhenok, A. V., Bogdanchikov, A. G., Bukin, D. A., Burdin, S. V., Dimova, T. V., Drozdetsky, A. A., Druzhinin, V. P., Ganyushin, D. I., Golubev, V. B., Ivanchenko, V. N., Koop, I. A., Korol, A. A., Koshuba, S. V., Otboev, A. V., Pakhtusova, E. V., Salnikov, A. A., Shary, V. V., Serednyakov, S. I., Shatunov, Yu. M., Sidorov, V. A., Silagadze, Z. K., Skripkin, A. G., Valishev, A. A., Vasiljev, A. V., and Velikzhanin, Yu. S.

Subjects
High Energy Physics - Phenomenology, Physics::Instrumentation and Detectors, Astrophysics::High Energy Astrophysical Phenomena, High Energy Physics::Experiment, Nuclear Experiment, High Energy Physics - Experiment
Abstract

The $\eta \to \pi^0 \gamma \gamma$ decay was investigated by the SND detector at VEPP-2M $e^+e^-$ collider in the reaction $e^+e^-\to\phi\to \eta\gamma$. Here we present the results and some details of this study. We report an upper limit (90% c.l.) $Br(\eta \to \pi^0 \gamma \gamma), Comment: 24 pages, 6 figures, LaTex. To be published in Nucl. Phys. B

Published
2001

30. The process $e^+e^-\to\pi^+\pi^-\pi^0$ in the energy range 2E_0=1.04 - 1.38 GeV

Author

Achasov, M. N., Aulchenko, V. M., Baru, S. E., Beloborodov, K. I., Berdyugin, A. V., Bozhenok, A. V., Bukin, A. D., Bukin, D. A., Burdin, S. V., Dimova, T. V., Dolinsky, S. I., Druzhinin, V. P., Dubrovin, M. S., Gaponenko, I. A., Golubev, V. B., Ivanchenko, V. N., Koop, I. A., Ivanov, P. M., Korol, A. A., Koshuba, S. V., Pakhtusova, E. V., Perevedentsev, E. A., Salnikov, A. A., Serednyakov, S. I., Shary, V. V., Shatunov, Yu. M., Sidorov, V. A., Silagadze, Z. K., Skrinsky, A. N., Usov, Y. V., Varganov, A. V., Vasilyev, A. V., and Velikzhanin, Yu. S.

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

In the experiment with the SND detector at VEPP-2M e^+e^- collider the process $e^+e^-\to\pi^+\pi^-\pi^0$ was studied in the energy range 2E_0 from 1.04 to 1.38 GeV. A broad peak was observed with the visible mass $M_{vis}=1220\pm 20$ MeV and cross section in the maximum $\sigma_0\simeq 4$ nb. The peak can be interpreted as a $\omega$-like resonance $\omega (1200)$., Comment: 10 pages LATEX and 5 figures

Published
1999

31. First Observation of PHI(1020)--->PI0+PI0+GAMMA Decay

Author

Achasov, M. N., Aulchenko, V. M., Berdyugin, A. V., Bozhenok, A. V., Bukin, A. D., Bukin, D. A., Burdin, S. V., Dimova, T. V., Dolinsky, S. I., Druzhinin, V. P., Dubrovin, M. S., Gaponenko, I. A., Golubev, V. B., Ivanchenko, V. N., Koop, I. A., Korol, A. A., Koshuba, S. V., Pakhtusova, E. V., Perevedentsev, E. A., Salnikov, A. A., Serednyakov, S. I., Shary, V. V., Shatunov, Yu. M., Sidorov, V. A., Silagadze, Z. K., Skrinsky, A. N., Usov, Yu. V., and Velikzhanin, Yu. S.

Subjects
Astrophysics::High Energy Astrophysical Phenomena, High Energy Physics::Experiment, Nuclear Experiment, High Energy Physics - Experiment
Abstract

In the SND experiment at the VEPP-2M electron-positron collider the PHI(1020)--->PI0+PI0+GAMMA decay was studied. The branching ratio B(PHI--->PI0+PI0+GAMMA)=(1.14+-0.10+-0.12)x10^{-4} was measured. It was shown, that the F0(980)GAMMA mechanism dominates in this decay and the 4-quark model of F0(980) describes our data most consistently., Comment: 6 pages, 6 figures, 1 table, Will be published in Phys.Lett.B

Published
1998

32. Evidence of phi --> pi0 pi0 gamma and phi --> pi0 eta gamma decays in SND experiment at VEPP-2M

Author

Achasov, M. N., Berdyugin, A. V., Bozhenok, A. V., Bukin, A. D., Bukin, D. A., Burdin, S. V., Dimova, T. V., Druzhinin, V. P., Dubrovin, M. S., Gaponenko, I. A., Golubev, V. B., Ivanchenko, V. N., Koop, I. A., Korol, A. A., Koshuba, S. V., Pakhtusova, E. V., Salnikov, A. A., Serednyakov, S. I., Shary, V. V., Shatunov, Yu. M., Sidorov, V. A., Silagadze, Z. K., Skrinsky, A. N., and Usov, Yu. V.

Subjects
High Energy Physics - Experiment (hep-ex), Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, High Energy Physics::Experiment, Nuclear Experiment
Abstract

Preliminary results on the study of e+e- --> phi(1020) --> pi0 pi0 gamma, eta pi0 gamma processes from SND experiment at VEPP-2M collider in Novosibirsk are presented. Branching ratios of rare radiative phi --> pi0 pi0 gamma and phi --> pi0 eta gamma decays are measured: B(phi --> pi0 pi0 gamma ) = (1.1 +- 0.2) * 10^-4 (invariant mass (pi0 pi0) < 800 MeV), B(phi --> eta pi0 gamma ) = (1.3 +- 0.5) * 10^-4., Talk at the HADRON97 conference, BNL, Aug 24-30 1997; LaTeX, 4 pages, 4 eps figures

Published
1997
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