Search

Your search keyword '"Kulish E"' showing total 384 results
Start Over Author "Kulish E"
384 results on '"Kulish E"'

1. The \pi^+\pi^- Coulomb interaction study and its use in the data processing

Author

Adeva, B., Afanasyev, L., Anania, A., Aogaki, S., Benelli, A., Brekhovskikh, V., Cechak, T., Chiba, M., Chliapnikov, P., Drijard, D., Dudarev, A., Dumitriu, D., Federicova, P., Gorin, A., Gritsay, K., Guaraldo, C., Gugiu, M., Hansroul, M., Hons, Z., Horikawa, S., Iwashita, Y., Kluson, J., Kobayashi, M., Kruglova, L., Kulikov, A., Kulish, E., Lamberto, A., Lanaro, A., Lednicky, R., Marinas, C., Martincik, J., Nemenov, L., Nikitin, M., Okada, K., Olchevskii, V., Pentia, M., Penzo, A., Plo, M., Prusa, P., Rappazzo, G., Vidal, A. Romero, Ryazantsev, A., Rykalin, V., Saborido, J., Schacher, J., Sidorov, A., Smolik, J., Takeutchi, F., Trojek, T., Trusov, S., Urban, T., Vrba, T., Yazkov, V., Yoshimura, Y., and Zrelov, P.

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

In this work the Coulomb effects (Coulomb correlations) in $\pi^+\pi^-$ pairs produced in p + Ni collisions at 24 GeV/$c$, are studied using experimental $\pi^+\pi^-$ pair distributions in $Q$, the relative momentum in the pair center of mass system (c.m.s), and its projections $Q_L$ (longitudinal component) and $Q_t$ (transverse component) relative to the pair direction in the laboratory system (l.s.). The $Q$, $Q_L$, and $Q_t$ distributions of the {\sl Coulomb pairs} in the c.m.s. have been simulated assuming they are described by the phase space modified by the known point-like Coulomb correlation function $A_C(Q)$, corrected for small effects due to the nonpoint-like pair production and the strong two-pion interaction. The same distributions of {\sl non-Coulomb pairs} have been simulated according to the phase space, but without $A_C(Q)$. It is shown that the number of {\sl Coulomb pairs} in all $Q_t$ intervals, including the small $Q_t$ (small opening angles $\theta$ in the l.s.) is calculated with the theoretical precision better than 2\%. The comparison of the simulated and experimental numbers of {\sl Coulomb pairs} at small $Q_t$ allows us to check and correct the detection efficiency for the pairs with small $\theta$ (0.06 mrad and smaller). It is shown that {\sl Coulomb pairs} can be used as a new physical tool to check and correct the quality of the simulated events. The special property of the {\sl Coulomb pairs} is the possibility of checking and correcting the detection efficiency, especially for the pairs with small opening angles.

Published
2024

2. The BM@N spectrometer at the NICA accelerator complex

Author

Afanasiev, S., Agakishiev, G., Aleksandrov, E., Aleksandrov, I., Alekseev, P., Alishina, K., Astakhov, V., Atkin, E., Aushev, T., Azorskiy, V., Babkin, V., Balashov, N., Barak, R., Baranov, A., Baranov, D., Baranova, N., Barbashina, N., Baznat, M., Bazylev, S., Belov, M., Blau, D., Bocharnikov, V., Bogdanova, G., Bolozdynya, A., Bondar, E., Boos, E., Buryakov, M., Buzin, S., Chebotov, A., Chemezov, D., Chen, J. H., Demanov, A., Dementev, D., Dmitriev, A., Drnoyan, J., Dryablov, D., Dryuk, A., Dubinchik, B., Dulov, P., Egorov, A., Egorov, D., Elsha, V., Fediunin, A., Fedosimova, A., Filippov, I., Filozova, I., Finogeev, D., Gabdrakhmanov, I., Galavanov, A., Gavrischuk, O., Gertsenberger, K., Golosov, O., Golovatyuk, V., Grigoriev, P., Golubeva, M., Guber, F., Ibraimova, S., Idrisov, D., Idrissova, T., Iusupova, A., Ivashkin, A., Izvestnyy, A., Kabadzhov, V., Kanokova, Sh., Kapishin, M., Kapitonov, I., Karjavin, V., Karmanov, D., Karpushkin, N., Kattabekov, R., Kekelidze, V., Khabarov, S., Kharlamov, P., Khudaiberdyev, G., Khukhaeva, A., Khvorostukhin, A., Kiryushin, Yu., Klimai, P., Kolesnikov, V., Kolozhvari, A., Kopylov, Yu., Korolev, M., Kovachev, L., Kovalev, I., Kruglova, I., Kovalev, Yu., Kozlov, I., Kozlov, V., Kuklin, S., Kulish, E., Kurganov, A., Kutergina, V., Kuznetsov, A., Ladygin, E., Lanskoy, D., Lashmanov, N., Lebedev, I., Lenivenko, V., Lednicky, R., Leontiev, V., Liapin, D., Litvinenko, E., Ma, Y. G., Makankin, A., Makhnev, A., Malakhov, A., Mamaev, M., Martemianov, A., Martovitsky, E., Mashitsin, K., Merkin, M., Merts, S., Morozov, S., Murin, Yu., Musaev, K., Musulmanbekov, G., Myasnikov, A., Myktybekov, D., Nagdasev, R., Nemnyugin, S., Nikitin, D., Novozhilov, S., Olimov, Kh., Olimov, K., Palichik, V., Parfenov, P., Pelevanyuk, I., Peresunko, D., Piyadin, S., Platonova, M., Plotnikov, V., Podgainy, D., Pukhaeva, N., Ratnikov, F., Reshetova, S., Rogov, V., Romanov, I., Rufanov, I., Rukoyatkin, P., Rumyantsev, M., Rybakov, T., Sakulin, D., Sedykh, S., Serebryakov, D., Shabanov, A., Segal, I., Semak, A., Sergeev, S., Serikkanov, A., Sheremetev, A., Sheremeteva, A., Shchipunov, A., Shitenkov, M., Shopova, M., Shumikhin, V., Shutov, A., Shutov, V., Shodmonov, M., Slepnev, I., Slepnev, V., Slepov, I., Smirnov, A., Smolyanin, T., Solomin, A., Sorin, A., Sosnovtsev, V., Spaskov, V., Stavinskiy, A., Stekhanov, V., Stepanenko, Yu., Streletskaya, E., Streltsova, O., Strikhanov, M., Sukhov, E., Suvarieva, D., Taer, G., Taranenko, A., Tarasov, N., Tarasov, O., Teremkov, P., Terletsky, A., Teryaev, O., Tcholakov, V., Tikhomirov, V., Timoshenko, A., Tojiboev, O., Topilin, N., Tretyakova, T., Troshin, V., Truttse, A., Tserruya, I., Tskhay, V., Tyapkin, I., Ustinov, V., Vasendina, V., Velichkov, V., Volkov, V., Voronin, A., Voytishin, N., Yuldashev, B., Yurevich, V., Zamiatin, N., Zavertyaev, M., Zhang, S., Zhavoronkova, I., Zhezher, V., Zhigareva, N., Zinchenko, A., Zubankov, A., Zubarev, E., and Zuev, M.

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

BM@N (Baryonic Matter at Nuclotron) is the first experiment operating and taking data at the Nuclotron/NICA ion-accelerating complex.The aim of the BM@N experiment is to study interactions of relativistic heavy-ion beams with fixed targets. We present a technical description of the BM@N spectrometer including all its subsystems., Comment: 34 pages, 47 figures, 6 tables

Published
2023

4. Production of $\pi^+$ and $K^+$ mesons in argon-nucleus interactions at 3.2 AGeV

Author

Afanasiev, S., Agakishiev, G., Aleksandrov, E., Aleksandrov, I., Alekseev, P., Alishina, K., Atkin, E., Aushev, T., Babkin, V., Balashov, N., Baranov, A., Baranov, D., Baranova, N., Barbashina, N., Baznat, M., Bazylev, S., Belov, M., Blau, D., Bogdanova, G., Bogoslovsky, D., Bolozdynya, A., Boos, E., Buryakov, M., Buzin, S., Chebotov, A., Chen, J., Dementev, D., Dmitriev, A., Dryablov, D., Dryuk, A., Dulov, P., Egorov, D., Elsha, V., Fediunin, A., Filippov, I., Filozova, I., Finogeev, D., Gabdrakhmanov, I., Galavanov, A., Gavrischuk, O., Gertsenberger, K., Golovatyuk, V., Golubeva, M., Guber, F., Iusupova, A., Ivashkin, A., Izvestnyy, A., Kabadzhov, V., Kapishin, M., Kapitonov, I., Karjavin, V., Karmanov, D., Karpushkin, N., Kattabekov, R., Kekelidze, V., Khabarov, S., Kharlamov, P., Khukhaeva, A., Khvorostukhin, A., Kiryushin, Yu., Klimai, P., Klimansky, D., Kolesnikov, V., Kolozhvari, A., Kopylov, Yu., Korolev, M., Kovachev, L., Kovalev, I., Kovalev, Yu., Kozlov, I., Kozlov, V., Kudryashov, I., Kuklin, S., Kulish, E., Kurganov, A., Kuznetsov, A., Ladygin, E., Lanskoy, D., Lashmanov, N., Lenivenko, V., Lednický, R., Leontiev, V., Litvinenko, E., Ma, Yu-G., Makankin, A., Makhnev, A., Malakhov, A., Martemianov, A., Martovitsky, E., Mashitsin, K., Merkin, M., Merts, S., Morozov, A., Morozov, S., Murin, Yu., Musulmanbekov, G., Myasnikov, A., Nagdasev, R., Nekrasowa, E., Nemnyugin, S., Nikitin, D., Novozhilov, S., Palchik, V., Pelevanyuk, I., Peresunko, D., Petukhov, O., Petukhov, Yu., Piyadin, S., Platonova, M., Plotnikov, V., Podgainy, D., Rogov, V., Rufanov, I., Rukoyatkin, P., Rumyantsev, M., Sakulin, D., Sergeev, S., Sheremetev, A., Sheremeteva, A., Shchipunov, A., Shitenkov, M., Shopova, M., Shumikhin, V., Shutov, A., Shutov, V., Slepnev, I., Slepnev, V., Slepov, I., Solomin, A., Sorin, A., Sosnovtsev, V., Spaskov, V., Stavinskiy, A., Stepanenko, Yu., Streletskaya, E., Streltsova, O., Strikhanov, M., Sukhov, N., Suvarieva, D., Taer, G., Tarasov, N., Tarasov, O., Teremkov, P., Terletsky, A., Teryaev, O., Tcholakov, V., Tikhomirov, V., Timoshenko, A., Topilin, N., Tretyakova, T., Tskhay, V., Tsvetkov, E., Tyapkin, I., Vasendina, V., Velichkov, V., Volkov, V., Voronin, A., Voytishin, N., Yurevich, V., Yumatova, I., Zamiatin, N., Zavertyaev, M., Zhang, S., Zherebtsova, E., Zhezher, V., Zhigareva, N., Zinchenko, A., Zubankov, A., Zubarev, E., and Zuev, M.

Subjects
High Energy Physics - Experiment, Nuclear Experiment
Abstract

First physics results of the BM@N experiment at the Nuclotron/NICA complex are presented on {\pi}+ and K+ meson production in interactions of an argon beam with fixed targets of C, Al, Cu, Sn and Pb at 3.2 AGeV. Transverse momentum distributions, rapidity spectra and multiplicities of $\pi^+$ and $K^+$ mesons are measured. The results are compared with predictions of theoretical models and with other measurements at lower energies., Comment: 29 pages, 20 figures

Published
2023
Full Text
View/download PDF

5. Performance of the BM@N GEM/CSC tracking system at the Nuclotron beam

Author

Galavanov A., Kapishin M., Kapusniak K., Karjavine V., Khabarov S., Kirushin Y., Kolesnikov A., Kulish E., Lenivenko V., Makankin A., Maksymchuk A., Mehl B., De Oliveira R., Plotnikov V., Pokatashkin G., Rodriguez A., Rumyantcev M., Rufanov I., Sidorenko V., Vasiliev S., and Vishnevskiy A.

Subjects
Physics, QC1-999
Abstract

BM@N (Baryonic Matter at the Nuclotron) is a fixed target experiment aimed to study nuclear matter in the relativistic heavy-ion collisions at the Nuclotron accelerator in JINR. The BM@N tracking system is based on Gas Electron Multipliers (GEM) detectors mounted inside the BM@N analyzing magnet. The Cathode Strip Chamber (CSC) is installed outside the magnet. The CSC is used for improvement of particles momentum identification. The structure of the GEM detectors and the CSC prototype and the results of study of their characteristics are presented. The GEM detectors and CSC are integrated into the BM@N experimental setup and data acquisition system. The results of first tests of the GEM tracking system and CSC in last runs are shortly reviewed.

Published
2019
Full Text
View/download PDF

6. Investigation of $K^+K^-$ pairs in the effective mass region near $2m_K$

Author

Adeva, B., Afanasyev, L., Anania, A., Aogaki, S., Benelli, A., Brekhovskikh, V., Cechak, T., Chiba, M., Chliapnikov, P., Drijard, D., Dudarev, A., Dumitriu, D., Federicova, P., Gorin, A., Gritsay, K., Guaraldo, C., Gugiu, M., Hansroul, M., Hons, Z., Horikawa, S., Iwashita, Y., Karpukhin, V., Kluson, J., Kobayashi, M., Kruglova, L., Kulikov, A., Kulish, E., Lamberto, A., Lanaro, A., Lednicky, R., Mariñas, C., Martincik, J., Nemenov, L., Nikitin, M., Okada, K., Olchevskii, V., Pentia, M., Penzo, A., Plo, M., Prusa, P., Rappazzo, G., Vidal, A. Romero, Ryazantsev, A., Rykalin, V., Saborido, J., Schacher, J., Sidorov, A., Smolik, J., Takeutchi, F., Trojek, T., Trusov, S., Urban, T., Vrba, T., Yazkov, V., Yoshimura, Y., and Zrelov, P.

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

The DIRAC experiment at CERN investigated in the reaction $\rm{p}(24~\rm{GeV}/c) + Ni$ the particle pairs $K^+K^-, \pi^+ \pi^-$ and $p \bar{p}$ with relative momentum $Q$ in the pair system less than 100 MeV/c. Because of background influence studies, DIRAC explored three subsamples of $K^+K^-$ pairs, obtained by subtracting -- using time-of-flight (TOF) technique -- background from initial $Q$ distributions with $K^+K^-$ sample fractions more than 70\%, 50\% and 30\%. The corresponding pair distributions in $Q$ and in its longitudinal projection $Q_L$ were analyzed first in a Coulomb model, which takes into account only Coulomb final state interaction (FSI) and assuming point-like pair production. This Coulomb model analysis leads to a $K^+K^-$ yield increase of about four at $Q_L=0.5$ MeV/c compared to 100 MeV/c. In order to study contributions from strong interaction, a second more sophisticated model was applied, considering besides Coulomb FSI also strong FSI via the resonances $f_0(980)$ and $a_0(980)$ and a variable distance $r^*$ between the produced $K$ mesons. This analysis was based on three different parameter sets for the pair production. For the 70\% subsample and with best parameters, $3680\pm 370$ $K^+K^-$ pairs was found to be compared to $3900\pm 410$ $K^+K^-$ extracted by means of the Coulomb model. Knowing the efficiency of the TOF cut for background suppression, the total number of detected $K^+K^-$ pairs was evaluated to be around $40000\pm 10\%$, which agrees with the result from the 30\% subsample. The $K^+K^-$ pair number in the 50\% subsample differs from the two other values by about three standard deviations, confirming -- as discussed in the paper -- that experimental data in this subsample is less reliable.

Published
2022
Full Text
View/download PDF

7. The BM@N spectrometer at the NICA accelerator complex

Author

Afanasiev, S., Agakishiev, G., Aleksandrov, E., Aleksandrov, I., Alekseev, P., Alishina, K., Astakhov, V., Atkin, E., Aushev, T., Azorskiy, V., Babkin, V., Balashov, N., Barak, R., Baranov, A., Baranov, D., Baranova, N., Barbashina, N., Baznat, M., Bazylev, S., Belov, M., Blau, D., Bocharnikov, V., Bogdanova, G., Bolozdynya, A., Bondar, E., Boos, E., Buryakov, M., Buzin, S., Chebotov, A., Chemezov, D., Chen, J.H., Demanov, A., Dementev, D., Dmitriev, A., Drnoyan, J., Dryablov, D., Dryuk, A., Dubinchik, B., Dulov, P., Egorov, A., Egorov, D., Elsha, V., Fediunin, A., Fedosimova, A., Filippov, I., Filozova, I., Finogeev, D., Gabdrakhmanov, I., Galavanov, A., Gavrischuk, O., Gertsenberger, K., Golosov, O., Golovatyuk, V., Grigoriev, P., Golubeva, M., Guber, F., Ibraimova, S., Idrisov, D., Idrissova, T., Iusupova, A., Ivashkin, A., Izvestnyy, A., Kabadzhov, V., Kanokova, Sh., Kapishin, M., Kapitonov, I., Karjavin, V., Karmanov, D., Karpushkin, N., Kattabekov, R., Kekelidze, V., Khabarov, S., Kharlamov, P., Khudaiberdyev, G., Khukhaeva, A., Khvorostukhin, A., Kiryushin, Yu., Klimai, P., Kolesnikov, V., Kolozhvari, A., Kopylov, Yu., Korolev, M., Kovachev, L., Kovalev, I., Kruglova, I., Kovalev, Yu., Kozlov, I., Kozlov, V., Kuklin, S., Kulish, E., Kurganov, A., Kutergina, V., Kuznetsov, A., Ladygin, E., Lanskoy, D., Lashmanov, N., Lebedev, I., Lenivenko, V., Lednicky, R., Leontiev, V., Lyapin, D., Litvinenko, E., Ma, Y.G., Makankin, A., Makhnev, A., Malakhov, A., Mamaev, M., Martemianov, A., Martovitsky, E., Mashitsin, K., Merkin, M., Merts, S., Morozov, S., Murin, Yu., Musaev, K., Musulmanbekov, G., Myasnikov, A., Myktybekov, D., Nagdasev, R., Nemnyugin, S., Nikitin, D., Novozhilov, S., Olimov, Kh., Olimov, K., Palichik, V., Parfenov, P., Pelevanyuk, I., Peresunko, D., Piyadin, S., Platonova, M., Plotnikov, V., Podgainy, D., Pukhaeva, N., Ratnikov, F., Reshetova, S., Rogov, V., Romanov, I., Rufanov, I., Rukoyatkin, P., Rumyantsev, M., Rybakov, T., Sakulin, D., Sedykh, S., Serebryakov, D., Shabanov, A., Segal, I., Semak, A., Sergeev, S., Serikkanov, A., Sheremetev, A., Sheremeteva, A., Shchipunov, A., Shitenkov, M., Shopova, M., Shumikhin, V., Shutov, A., Shutov, V., Shodmonov, M., Slepnev, I., Slepnev, V., Slepov, I., Smirnov, A., Smolyanin, T., Solomin, A., Sorin, A., Sosnovtsev, V., Spaskov, V., Stavinskiy, A., Stekhanov, V., Stepanenko, Yu., Streletskaya, E., Streltsova, O., Strikhanov, M., Sukhov, E., Suvarieva, D., Taer, G., Taranenko, A., Tarasov, N., Tarasov, O., Teremkov, P., Terletsky, A., Teryaev, O., Tcholakov, V., Tikhomirov, V., Timoshenko, A., Tojiboev, O., Topilin, N., Tretyakova, T., Troshin, V., Truttse, A., Tserruya, I., Tskhay, V., Tyapkin, I., Ustinov, V., Vasendina, V., Velichkov, V., Volkov, V., Voronin, A., Voytishin, N., Yuldashev, B., Yurevich, V., Zamiatin, N., Zavertyaev, M., Zhang, S., Zhavoronkova, I., Zhezher, V., Zhigareva, N., Zinchenko, A., Zubankov, A., Zubarev, E., and Zuev, M.

Published
2024
Full Text
View/download PDF

8. Unperturbed inverse kinematics nucleon knockout measurements with a 48 GeV/c carbon beam

Author

Patsyuk, M., Kahlbow, J., Laskaris, G., Duer, M., Lenivenko, V., Segarra, E. P., Atovullaev, T., Johansson, G., Aumann, T., Corsi, A., Hen, O., Kapishin, M., Panin, V., Piasetzky, E., Abraamyan, Kh., Afanasiev, S., Agakishiev, G., Alekseev, P., Atkin, E., Aushev, T., Babkin, V., Balandin, V., Baranov, D., Barbashina, N., Batyuk, P., Bazylev, S., Beck, A., Bertulani, C. A., Blaschke, D., Blau, D., Bogoslovsky, D., Bolozdynya, A., Boretzky, K., Burtsev, V., Buryakov, M., Buzin, S., Chebotov, A., Chen, J., Ciszewski, A., Cruz-Torres, R., Dabrowska, B., Dmitriev, D. Dabrowski A., Dryablov, A., Dulov, P., Egorov, D., Fediunin, A., Filippov, I., Filippov, K., Finogeev, D., Gabdrakhmanov, I., Galavanov, A., Gasparic, I., Gavrischuk, O., Gertsenberger, K., Gillibert, A., Golovatyuk, V., Golubeva, M., Guber, F., Ivanova, Yu., Ivashkin, A., Izvestnyy, A., Kakurin, S., Karjavin, V., Karpushkin, N., Kattabekov, R., Kekelidze, V., Khabarov, S., Kiryushin, Yu., Kisiel, A., Kolesnikov, V., Kolozhvari, A., Kopylov, Yu., Korover, I., Kovachev, L., Kovalenko, A., Kovalev, Yu., Kugler, A., Kuklin, S., Kulish, E., Kuznetsov, A., Ladygin, E., Lashmanov, N., Litvinenko, E., Lobastov, S., Loher, B., Ma, Y. -G., Makankin, A., Maksymchyuk, A., Malakhov, A., Mardor, I., Merts, S., Morozov, A., Morozov, S., Musulmanbekov, G., Nagdasev, R., Nikitin, D., Palchik, V., Peresunko, D., Peryt, M., Petukhov, O., Petukhov, Yu., Piyadin, S., Plotnikov, V., Pokatashkin, G., Potrebenikov, Yu., Rogachevsky, O., Rogov, V., Roslon, K., Rossi, D., Rufanov, I., Rukoyatkin, P., Rumyantsev, M., Sakulin, D., Samsonov, V., Scheit, H., Schmidt, A., Sedykh, S., Selyuzhenkov, I., Senger, P., Sergeev, S., Shchipunov, A., Sheremeteva, A., Shitenkov, M., Shumikhin, V., Shutov, A., Shutov, V., Simon, H., Slepnev, I., Slepnev, V., Slepov, I., Sorin, A., Sosnovtsev, V., Spaskov, V., Starecki, T., Stavinskiy, A., Streletskaya, E., Streltsova, O., Strikhanov, M., Sukhov, N., Suvarieva, D., Tanaka, J., Taranenko, A., Tarasov, N., Tarasov, O., Tarasov, V., Terletsky, A., Teryaev, O., Tcholakov, V., Tikhomirov, V., Timoshenko, A., Topilin, N., Topko, B., Tornqvist, H., Tyapkin, I., Vasendina, V., Vishnevsky, A., Voytishin, N., Wagner, V., Warmusz, O., Yaron, I., Yurevich, V., Zamiatin, N., Zhang, Song, Zherebtsova, E., Zhezher, V., Zhigareva, N., Zinchenko, A., Zubarev, E., and Zuev, M.

Subjects
Nuclear Experiment, Nuclear Theory
Abstract

From superconductors to atomic nuclei, strongly-interacting many-body systems are ubiquitous in nature. Measuring the microscopic structure of such systems is a formidable challenge, often met by particle knockout scattering experiments. While such measurements are fundamental for mapping the structure of atomic nuclei, their interpretation is often challenged by quantum mechanical initial- and final-state interactions (ISI/FSI) of the incoming and scattered particles. Here we overcome this fundamental limitation by measuring the quasi-free scattering of 48 GeV/c 12C ions from hydrogen. The distribution of single protons is studied by detecting two protons at large angles in coincidence with an intact 11B nucleus. The 11B detection is shown to select the transparent part of the reaction and exclude the otherwise large ISI/FSI that would break the 11B apart. By further detecting residual 10B and 10Be nuclei, we also identified short-range correlated (SRC) nucleon-nucleon pairs, and provide direct experimental evidence for the separation of the pair wave-function from that of the residual many-body nuclear system. All measured reactions are well described by theoretical calculations that do not contain ISI/FSI distortions. Our results thus showcase a new ability to study the short-distance structure of short-lived radioactive atomic nuclei at the forthcoming FAIR and FRIB facilities. These studies will be pivotal for developing a ground-breaking microscopic understanding of the structure and properties of nuclei far from stability and the formation of visible matter in the universe., Comment: Accepted for publication in Nature Physics. 28 pages, 19 figures, and 1 table including main text, Methods, and Supplementary materials

Published
2021
Full Text
View/download PDF

13. First measurement of a long-lived $\pi^+ \pi^-$ atom lifetime

Author

Adeva, B., Afanasyev, L., Anania, A., Aogaki, S., Benelli, A., Brekhovskikh, V., Cechak, T., Chiba, M., Chliapnikov, P. V., Doskarova, P., Drijard, D., Dudarev, A., Dumitriu, D., Fluerasu, D., Gorin, A., Gorchakov, O., Gritsay, K., Guaraldo, C., Gugiu, M., Hansroul, M., Hons, Z., Horikawa, S., Iwashita, Y., Karpukhin, V., Kluson, J., Kobayashi, M., Kruglov, V., Kruglova, L., Kulikov, A., Kulish, E., Lamberto, A., Lanaro, A., Lednicky, R., Mariñas, C., Martincik, J., Nemenov, L., Nikitin, M., Okada, K., Olchevskii, V., Ovsiannikov, V., Pentia, M., Penzo, A., Plo, M., Prusa, P., Rappazzo, G. F., Vidal, A. Romero, Ryazantsev, A., Rykalin, V., Saborido, J., Schacher, J., Sidorov, A., Smolik, J., Takeutchi, F., Trojek, T., Trusov, S., Vrba, T., Yazkov, V., Yoshimura, Y., and Zrelov, P.

Subjects
High Energy Physics - Experiment, Nuclear Experiment
Abstract

The adapted DIRAC experiment at the CERN PS accelerator observed for the first time long-lived hydrogen-like $\pi^+\pi^-$ atoms, produced by protons hitting a beryllium target. A part of these atoms crossed the gap of 96~mm and got broken up in the 2.1~\textmu{}m thick platinum foil. Analysing the observed number of atomic pairs, $n_A^L= \left.436^{+157}_{-61}\right|_\mathrm{tot}$, the lifetime of the 2$p$ state is found to be ${\tau_{2p}=(\left.0.45^{+1.08}_{-0.30}\right|_\mathrm{tot}) \cdot10^{-11}}$s, not contradicting the corresponding QED $2p$ state lifetime ${\tau_{2p}^\mathrm{QED}=1.17 \cdot 10^{-11}}$s. This lifetime value is three orders of magnitude larger than our previously measured value of the $\pi^+\pi^-$ atom ground state lifetime $\tau=(\left.3.15^{+0.28}_{-0.26}\right|_\mathrm{tot})\cdot 10^{-15}$s. Further studies of long-lived $\pi^+\pi^-$ atoms will allow to measure energy differences between $p$ and $s$ atomic states and so to determine $\pi\pi$ scattering lengths with the aim to check QCD predictions., Comment: 7 pages, 8 figures

Published
2018
Full Text
View/download PDF

15. Measurement of the $\pi K$ atom lifetime and the $\pi K$ scattering length

Author

DIRAC Collaboration, Adeva, B., Afanasyev, L., Allkofer, Y., Amsler, C., Anania, A., Aogaki, S., Benelli, A., Brekhovskikh, V., Cechak, T., Chiba, M., Chliapnikov, P., Drijard, D., Dudarev, A., Dumitriu, D., Federicova, P., Fluerasu, D., Gorin, A., Gorchakov, O., Gritsay, K., Guaraldo, C., Gugiu, M., Hansroul, M., Hons, Z., Horikawa, S., Iwashita, Y., Karpukhin, V., Kluson, J., Kobayashi, M., Kruglov, V., Kruglova, L., Kulikov, A., Kulish, E., Kuptsov, A., Lamberto, A., Lanaro, A., Lednicky, R., Marinas, C., Martincik, J., Nemenov, L., Nikitin, M., Okada, K., Olchevskii, V., Pentia, M., Penzo, A., Plo, M., Prusa, P., Rappazzo, G., Vidal, A. Romero, Ryazantsev, A., Rykalin, V., Saborido, J., Schacher, J., Sidorov, A., Smolik, J., Takeutchi, F., Tauscher, L., Trojek, T., Trusov, S., Urban, T., Vrba, T., Yazkov, V., Yoshimura, Y., Zhabitsky, M., and Zrelov, P.

Subjects
High Energy Physics - Experiment, Nuclear Experiment
Abstract

After having announced the statistically significant observation (5.6~$\sigma$) of the new exotic $\pi K$ atom, the DIRAC experiment at the CERN proton synchrotron presents the measurement of the corresponding atom lifetime, based on the full $\pi K$ data sample: $\tau = (5.5^{+5.0}_{-2.8}) \cdot 10^{-15}s$. By means of a precise relation ($<1\%$) between atom lifetime and scattering length, the following value for the S-wave isospin-odd $\pi K$ scattering length $a_0^{-}~=~\frac{1}{3}(a_{1/2}-a_{3/2})$ has been derived: $\left|a_0^-\right| = (0.072^{+0.031}_{-0.020}) M_{\pi}^{-1}$., Comment: 18 pages, 17 figures

Published
2017
Full Text
View/download PDF

20. First $\pi K$ atom lifetime and $\pi K$ scattering length measurements

Author

Adeva, B., Afanasyev, L., Allkofer, Y., Amsler, C., Anania, A., Aogaki, S., Benelli, A., Brekhovskikh, V., Cechak, T., Chiba, M., Chliapnikov, P., Ciocarlan, C., Constantinescu, S., Doskarova, P., Drijard, D., Dudarev, A., Duma, M., Dumitriu, D., Fluerasu, D., Gorin, A., Gorchakov, O., Gritsay, K., Guaraldo, C., Gugiu, M., Hansroul, M., Hons, Z., Horikawa, S., Iwashita, Y., Karpukhin, V., Kluson, J., Kobayashi, M., Kruglov, V., Kruglova, L., Kulikov, A., Kulish, E., Kuptsov, A., Lamberto, A., Lanaro, A., Lednicky, R., Mariñas, C., Martincik, J., Nemenov, L., Nikitin, M., Okada, K., Olchevskii, V., Pentia, M., Penzo, A., Plo, M., Ponta, T., Prusa, P., Rappazzo, G., Vidal, A. Romero, Ryazantsev, A., Rykalin, V., Schacher, J., Sidorov, A., Smolik, J., Sugimoto, S., Takeutchi, F., Tauscher, L., Trojek, T., Trusov, S., Urban, T., Vrba, T., Yazkov, V., Yoshimura, Y., Zhabitsky, M., and Zrelov, P.

Subjects
Nuclear Experiment, High Energy Physics - Experiment
Abstract

The results of a search for hydrogen-like atoms consisting of $\pi^{\mp}K^{\pm}$ mesons are presented. Evidence for $\pi K$ atom production by 24 GeV/c protons from CERN PS interacting with a nickel target has been seen in terms of characteristic $\pi K$ pairs from their breakup in the same target ($178 \pm 49$) and from Coulomb final state interaction ($653 \pm 42$). Using these results the analysis yields a first value for the $\pi K$ atom lifetime of $\tau=(2.5_{-1.8}^{+3.0})$ fs and a first model-independent measurement of the S-wave isospin-odd $\pi K$ scattering length $\left|a_0^-\right|=\frac{1}{3}\left|a_{1/2}-a_{3/2}\right|= \left(0.11_{-0.04}^{+0.09} \right)M_{\pi}^{-1}$ ($a_I$ for isospin $I$)., Comment: 14 pages, 8 figures

Published
2014
Full Text
View/download PDF

28. Upgraded DIRAC spectrometer at CERN PS for the investigation of ππ and πK atoms

Author

Adeva, B., Afanasyev, L., Allkofer, Y., Amsler, C., Anania, A., Aogaki, S., Benelli, A., Brekhovskikh, V., Caragheorgheopol, Gh., Cechak, T., Chiba, M., Chliapnikov, P., Ciocarlan, C., Constantinescu, S., Detraz, C., Doskarova, P., Drijard, D., Dudarev, A., Duma, M., Dumitriu, D., Fluerasu, D., Gorin, A., Gorchakov, O., Gritsay, K., Guaraldo, C., Gugiu, M., Hansroul, M., Hons, Z., Horikawa, S., Iwashita, Y., Karpukhin, V., Kluson, J., Kobayashi, M., Kruglov, V., Kruglova, L., Kulikov, A., Kulish, E., Kuptsov, A., Lamberto, A., Lanaro, A., Lednicky, R., Mariñas, C., Martincik, J., Nemenov, L., Nikitin, M., Okada, K., Olchevskii, V., Pentia, M., Penzo, A., Plo, M., Prusa, P., Rappazzo, G.F., Vidal, A. Romero, Ryazantsev, A., Rykalin, V., Saborido, J., Schacher, J., Sidorov, A., Smolik, J., Takeutchi, F., Tauscher, L., Trojek, T., Trusov, S., Ullaland, O., Urban, T., Vrba, T., Yazkov, V., Yoshimura, Y., Zhabitsky, M., and Zrelov, P.

Published
2016
Full Text
View/download PDF

38. Investigation of <math><msup><mi>K</mi><mo>+</mo></msup><msup><mi>K</mi><mo>−</mo></msup></math> pairs in the effective mass region near <math><mn>2</mn><msub><mi>m</mi><mi>K</mi></msub></math>

Author

Adeva, B., Afanasyev, L., Anania, A., Aogaki, S., Benelli, A., Brekhovskikh, V., Cechak, T., Chiba, M., Chliapnikov, P., Drijard, D., Dudarev, A., Dumitriu, D., Federicova, P., Gorin, A., Gritsay, K., Guaraldo, C., Gugiu, M., Hansroul, M., Hons, Z., Horikawa, S., Iwashita, Y., Karpukhin, V., Kluson, J., Kobayashi, M., Kruglova, L., Kulikov, A., Kulish, E., Lamberto, A., Lanaro, A., Lednicky, R., Mari??as, C., Martincik, J., Nemenov, L., Nikitin, M., Okada, K., Olchevskii, V., Pentia, M., Penzo, A., Plo, M., Prusa, P., Rappazzo, G., Romero Vidal, A., Ryazantsev, A., Rykalin, V., Saborido, J., Schacher, J., Sidorov, A., Smolik, J., Takeutchi, F., Trojek, T., Trusov, S., Urban, T., Vrba, T., Yazkov, V., Yoshimura, Y., and Zrelov, P.

Abstract

The DIRAC experiment at CERN investigated in the reaction p(24 GeV/c)+Ni the particle pairs K+K−,π+π−, and pp¯ with relative momentum Q in the pair system less than 100 MeV/c. Because of background influence studies, DIRAC explored three subsamples of K+K− pairs, obtained by subtracting-using the time-of-flight (TOF) technique-the background from initial Q distributions with K+K− sample fractions more than 70%, 50%, and 30%. The corresponding pair distributions in Q and in its longitudinal projection QL were analyzed first in a Coulomb model, which takes into account only the Coulomb final-state interaction (FSI) and assuming pointlike pair production. This Coulomb model analysis leads to a K+K− yield increase of about four at QL=0.5 MeV/c compared to 100 MeV/c. In order to study contributions from strong interaction, a second more sophisticated model was applied, considering also strong FSI via the resonances f0(980) and a0(980) and a variable distance r* between the produced K mesons besides Coulomb FSI. This analysis was based on three different parameter sets for the pair production. For the 70% subsample and with the best parameters, 3680±370 K+K− pairs were found to be compared to 3900±410 K+K− extracted by means of the Coulomb model. Knowing the efficiency of the TOF cut for background suppression, the total number of detected K+K− pairs was evaluated to be around 40000±10%, which agrees with the result from the 30% subsample. The K+K− pair number in the 50% subsample differs from the two other values by about three standard deviations, confirming—as discussed in the paper—that experimental data in this subsample is less reliable. In summary, the upgraded DIRAC experiment observed increased K+K− production at small relative momentum Q. The pair distribution in Q is well described by Coulomb FSI, whereas a potential influence from strong interaction in this Q region is insignificant within experimental errors.

Published
2022

Catalog

Books, media, physical & digital resources
See catalog results