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1. In-medium Properties of \eta' Meson

Author

Collaboration, Mariana Nanova for CBELSA/TAPS

Subjects
Nuclear Experiment
Abstract

Using the Crystal Barrel(CB)/TAPS detector system at the ELSA accelerator facility in Bonn the \eta' photoproduction off nuclei (C, Ca, Nb and Pb) was studied via the hadronic decay channel \eta' -> \pi^0\pi^0\eta . Recent results on the in-medium properties of the \eta'-meson, derived from the transparency ratio measurements, are presented. The absorption of the \eta'-meson in nuclear matter is compared to the properties of other mesons (\eta, \omega)., Comment: 6 pages, 3 figures, Talk at International School of Nuclear Physics,33rd Course: From Quarks and Gluons to Hadrons and Nuclei, Erice-Sicily, Sept. 16-24, 2011

Published
2011
Full Text
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2. Comment on 'Search for η′ Bound Nuclei in the C12(γ,p) Reaction with Simultaneous Detection of Decay Products'

Author

K. Itahashi, Yasumoto Tanaka, Volker Metag, Hiroyuki Fujioka, and Mariana Nanova

Subjects
Physics, Particle physics, 0103 physical sciences, General Physics and Astronomy, 010306 general physics, 01 natural sciences, Nuclear theory
Abstract

We comment on a recent paper by the LEPS2/BGOegg Collaboration [Phys. Rev. Lett. 124, 202501 (2020), arXiv:2005.03449].

Published
2021

3. The potential of $\varLambda $ and $\varXi ^-$ studies with PANDA at FAIR

Author

M. Sachs, I. K. Keshk, Xi-Guang Cao, M. Traxler, Yan Liang, G. Mazza, C. Fritzsch, T. Holtmann, S. Godre, A. N. Skachkova, Edward Lisowski, E. Rosenthal, S. Yogesh, Y. K. Sun, H. Pace, D. A. Morozov, H. Deppe, J. Pütz, A. G. Denig, S. Ryzhikov, Hans-Georg Zaunick, Dirk Grunwald, A. Kantsyrev, Paolo Mengucci, Christoph Herold, P. Eugenio, Grzegorz Filo, A. Boukharov, M. Kesselkaul, Concettina Sfienti, A. Kulkarni, M. Lattery, J. Frech, A. Hayrapetyan, W. Zhu, A. A. Piskun, Zbigniew Rudy, V. E. Blinov, S. Spataro, Jens Hartmann, S. Schlimme, D. Branford, C. Schwarz, Michaela Thiel, G. Golovanov, T. Wasem, J. Schwiening, P. Wieczorek, E. Pyata, Ch. Hammann, D. Lehmann, Chinorat Kobdaj, V. Moiseev, P. Balanutsa, B. J. Liu, S. Bodenschatz, F. E. Maas, N. Wongprachanukul, Lorenzo Scalise, M. Hoek, A. K. Saxena, M. Virius, M. Steinke, N. Rathod, A.A. Efremov, A. Samartsev, I. Shein, Alexander Olshevskiy, Herbert Koch, V. Panjushkin, K. Nowakowski, S. Belostotski, S. Bukreeva, Ulrich Wiedner, U. Thöring, A.S. Vodopianov, J. Kellers, L. Robison, Ting Xiao, V. Crede, Egle Tomasi-Gustafsson, R. Karabowicz, P. Srisawad, F. Feldbauer, J. Reher, D. Kazlou, M. Yu. Barabanov, W. Kühn, M. Steinen, P. Wintz, D. Wölbing, A. Dbeyssi, M. Kunze, C. Hargens, A. Pitka, A. Lehmann, I. Augustin, Mathias Fink, P. Terlecki, A. E. Yakutin, Magnus Wolke, I. Kisel, V. Varentsov, U. Thoma, Nicola Bianchi, D. Bettoni, Antoni Szczurek, Dan Pantea, M. Slunecka, D. I. Glazier, H. H. Leithoff, Genady Gavrilov, P. Jiang, T. Simantathammakul, Felice Iazzi, E. Widmann, D. G. Ireland, C. Motzko, K.-T. Brinkmann, M. Schmidt, Johann Marton, J. Tao, W. Eyrich, M. Straube, Krzysztof Swientek, B. Krusche, N. K. Walford, S. Vejdani, G. Perez Andrade, Richard Wheadon, N. Kratochwil, H. Li, L. Jokhovets, S.G. Pivovarov, W. Ikegami Andersson, S. Grieser, A. Gerhardt, H. Qi, W. Lauth, S. Diehl, R. Beck, Krzysztof Korcyl, Angelo Rivetti, K. Makonyi, Yupeng Yan, P. P. Natali, G. Kesik, K. N. Basant, I. Lehmann, A. V. Stavinskiy, W. Esmail, M. Preston, A. Gillitzer, D. Calvo, Ayut Limphirat, A. Demekhin, J. Müllers, M. Pelizäus, Andrew Levin, Gianangelo Bracco, N. Quin, D. Lersch, V. Chernetsky, M. Domagala, N. Minaev, A. Balashoff, U. Müller, N. Hüsken, V. Abramov, Torbjörn Bäck, A. Ali, S. Pflüger, C. Yu, G. Boca, R. Klasen, N. Kristi, J. Zmeskal, T. Nasawad, A. Dolgolenko, A. Belousov, B. Wohlfahrt, H. Xu, R. Dosdall, E. Maslova, Gianni Barucca, M.P. Bussa, B. Seitz, J. S. Díaz, G. Hunter, M. Volf, V.Kh. Dodokhov, Piotr Lebiedowicz, A. Scholl, Grzegorz Korcyl, H. Loehner, Mohammed Al-Turany, Andrzej Kupsc, R. W. Novotny, L. Montalto, A. E. Blinov, J. Kannika, Andrey Uzunian, R. Lalik, P. N. Deepak, P.-E. Tegnér, E. Antokhin, A. Gerasimov, P. De Remigis, X. Zhou, Petr Gallus, P. Orsich, I. Prochazka, Valentino Rigato, S. Maldaner, M. Himmelreich, V. M. Abazov, J. Płażek, Kazem Azizi, James Ritman, S. Wolff, Andrea Bianconi, Nicola Paone, W. Nalti, S. Kegel, I. A. Kuyanov, M. Steinacher, A. Chlopik, V. Lucherini, A. Belias, K. K. Seth, Mario Bragadireanu, C. J. Schmidt, V. Freudenreich, A. Ehret, G. V. Fedotov, J. Li, A. Galoyan, G. Neue, P. Schakel, M. Wojciechowski, B. Kopf, C. Liu, P. Gianotti, X. Ma, R. Kappert, Oleg V. Missevitch, J. Pereira-de-Lira, X. Zhang, D. Melnychuk, Paweł Moskal, I. Köseoglu, Bo Cederwall, K. Götzen, M. Finger, M. Marcisovsky, A. Derevschikov, V. Goryachev, V. Jary, R. Kunne, Y. Zhou, G. Reicherz, C. Schnier, J. G. Messchendorp, M. Michałek, T. Erlen, D. Miehling, G. D. Alexeev, Hasko Stenzel, A. Fechtchenko, L. Schmitt, J. Rieger, M. Zyzak, Michael Papenbrock, F. Schupp, Sean A Dobbs, J. Pochodzalla, S. Chernichenko, S. Shimanski, A. Mustafa, K. Dutta, M. Kümmel, S. Bökelmann, S. Sun, Bruce Yabsley, I. Zimmermann, E.K. Koshurnikov, B. Zwieglinski, O. Malyshev, H. Flemming, O. Korchak, U. Kurilla, F. Nerling, M. Pugach, Claude Amsler, G. Huang, A. Akram, L. Sohl, B. J. Roy, S. Wronka, Andrey V. Izotov, Vaclav Vrba, A. Malige, M. Kuhlmann, E. Prencipe, R. Böhm, R. Schubert, Matthias Richter, M. Krebs, L. Nogach, Frank Goldenbaum, B. Ramstein, X. Y. Shen, Paul Alois Buhler, S. I. Manaenkov, A. Aycock, M. Küßner, A. Khoukaz, E. Luschevskaya, K. Khosonthongkee, C. Wenzel, M. Pfaffinger, J. Lühning, P. Poznański, Fabrizio Daví, S. Koch, O. Corell, M. Kavatsyuk, Bernd Voss, B. Hetz, Daniele Rinaldi, J. Regina, L. Capozza, J. Novy, V. Ferapontov, A. Kozela, D. Y. Kirin, U. Lynen, T. Johansson, S. Orfanitski, M. Tomasek, A. Derichs, Andrea Lavagno, Krisztian Peters, A. Ryazantsev, Daniel Duda, Valery Dormenev, M. Peskova, X. A. Xiong, O. Noll, M. Rossbach, M. Fritsch, N. I. Zhuravlev, Tomasz Fiutowski, S. Zimmermann, Y. Melnik, V. A. Matveev, A. Täschner, P. Salabura, S.A. Kononov, T. Triffterer, J. S. Lange, K. Pysz, K. Kalita, W. Erni, Ajay Kumar Rai, D. P. Watts, Lennart Isaksson, Utpal N. Roy, M. Strickert, M. Böhm, M. Albrecht, Y. Bettner, Boris Batyunya, A. Hamdi, J. Hofmann, Jize Zhao, R. Dzhygadlo, T. Held, V. V. Tokmenin, K. Manasatitpong, Andrei Fedorov, H. Orth, Hans Calén, M. Urban, G. Zhao, F. Lisowski, Witold Przygoda, D. Prasuhn, M. Zambrana, W. Schäfer, S. Bleser, A. K. Hergemöller, M. Pesek, Y. A. Tikhonov, A. Filippi, M. Peter, Volker Metag, M. Moritz, A. Kripko, J. Tarasiuk, S. Schadmand, G. Schepers, S. Poslavskiy, Andreas Martin Heinz, Anne-Laure Martin, L. Brück, Antonin Kveton, V. Mochalov, D. Steinschaden, M. Bölting, N. Er, Ch. Schmidt, Mikhail Korzhik, V. Astakhov, Konstantin Beloborodov, H. Denizli, T. Saito, R. Hagdorn, Pawel Marciniewski, D. Veretennikov, C. Morales Morales, Harphool Kumawat, Karin Schönning, Marek Idzik, M. O. Distler, A. Golubev, E. Ladygina, G. Kozlov, Tobias Stockmanns, C. Hahn, N. Cao, T. Sefzick, Giovanni Lancioni, V. Serdyuk, B. Ketzer, Jerzy Smyrski, D. Bonaventura, P. Wüstner, Yu. Yu. Lobanov, V. Pothodi Chackara, Mariana Nanova, B. Salisbury, E. A. Kravchenko, L. Tomasek, D. Bumrungkoh, Patrick Achenbach, W. Alkakhi, V. Uzhinsky, Y. Goncharenko, Harald Merkel, A. Atac, D. Rodríguez Piñeiro, A. Verkheev, P. Fedorets, S. Nakhoul, F. H. Heinsius, Q. Hu, N. B. Skachkov, S. Pongampai, R. Schmitz, E. A. Strokovsky, Zhiyong Liu, H. Peng, V. Arefiev, K. Föhl, D. Liu, P. Semenov, V. Rodin, Keval Gandhi, P. Kulessa, O. Miklukho, A. Vasiliev, P. Brand, A. A. Zhdanov, R. Kliemt, P. Grasemann, A. Yu. Barnyakov, Z. Li, A. Meschanin, Michael Düren, S. Ahmed, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Institut de Physique Nucléaire d'Orsay (IPNO), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), PANDA, Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), BAİBÜ, Fen Edebiyat Fakültesi, Fizik Bölümü, Denizli, Haluk, and 0-Belirlenecek

Subjects
+Antixi+Xi%22">anti-p p --> Antixi Xi, Hadron, hyperon: pair production, correction: efficiency, 01 natural sciences, 13.30.-a, symmetry: CP, High Energy Physics - Experiment, Subatomär fysik, benchmark, Subatomic Physics, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Electromagnetic Form-Factors, Nuclear Experiment, Spin-½, Physics, Antihyperon Production, Hyperon, PANDA, strong interaction, Observable, hyperon: production, 13.88.+, +Antilambda+Lambda%22">anti-p p --> Antilambda Lambda, Production (computer science), Low-Energy, Nuclear and High Energy Physics, Particle physics, Cp-Violation, +Lambda+pi%22">Xi- --> Lambda pi, Bar (music), spin: correlation, Strong interaction, Hyperons, nonperturbative, 13.60.R, hyperon: decay, 0103 physical sciences, anti-p p: scattering, ddc:530, anti-p: beam, 010306 general physics, polarization, 010308 nuclear & particles physics, background, High Energy Physics::Phenomenology, antihyperon, [No Keywords], Exchange, 13.75.-n, Decay, hyperon: ground state, Antiproton, High Energy Physics::Experiment
Abstract

The antiproton experiment PANDA at FAIR is designed to bring hadron physics to a new level in terms of scope, precision and accuracy. In this work, its unique capability for studies of hyperons is outlined. We discuss ground-state hyperons as diagnostic tools to study non-perturbative aspects of the strong interaction, and fundamental symmetries. New simulation studies have been carried out for two benchmark hyperon-antihyperon production channels: $\bar{p}p \to \bar{\Lambda}\Lambda$ and $\bar{p}p \to \bar{\Xi}^+\Xi^-$. The results, presented in detail in this paper, show that hyperon-antihyperon pairs from these reactions can be exclusively reconstructed with high efficiency and very low background contamination. In addition, the polarisation and spin correlations have been studied, exploiting the weak, self-analysing decay of hyperons and antihyperons. Two independent approaches to the finite efficiency have been applied and evaluated: one standard multidimensional efficiency correction approach, and one efficiency independent approach. The applicability of the latter was thoroughly evaluated for all channels, beam momenta and observables. The standard method yields good results in all cases, and shows that spin observables can be studied with high precision and accuracy already in the first phase of data taking with PANDA., Comment: 26 pages, 16 figures. Changes: Revised title and abstract and corrections/clarifications in the text according to suggestions by journal referees

Published
2021

4. Study of excited $$arvec{arXi }$$ baryons with the $$overline{ ext{ P }}$$ANDA detector

Author

Egle Tomasi-Gustafsson, R. Karabowicz, A. Kripko, M. Domagala, U. Müller, Pawel Marciniewski, D. Veretennikov, Xuan Zhang, Y. A. Tikhonov, A. Hamdi, J. Hofmann, A. Filippi, A. Golubev, Tobias Stockmanns, V. Abramov, C. Hahn, A. Belias, K. Nowakowski, V. Serdyuk, M. Pelizä, Z. Tavukoglu, B. Ketzer, Jerzy Smyrski, J. Pütz, O. Malyshev, U. Kurilla, Konstantin Beloborodov, V. Chauhan, R. W. Novotny, A. Kantsyrev, P. Balanutsa, B. J. Liu, D. G. Ireland, Petr Gallus, G. D. Alexeev, D. Bonaventura, A. V. Stavinskiy, C. Motzko, K.-T. Brinkmann, H. Denizli, V. Crede, I. Zimmermann, E.K. Koshurnikov, Jize Zhao, R. Dzhygadlo, Kazem Azizi, A. Chlopik, Fabrizio Daví, V. Ferapontov, D. Y. Kirin, P. Wüstner, M. Fritsch, N. I. Zhuravlev, D. Rodríguez Piñeiro, Dan Pantea, A. Täschner, W. Eyrich, T. Held, W. Esmail, T. Triffterer, V. V. Tokmenin, K. Manasatitpong, W. Kühn, A. Khoukaz, A. Ali, Alexander Olshevskiy, S. Koch, J. Rieger, R. Hagdorn, S. Godre, V. Lucherini, T. Erlen, Herbert Koch, Y. K. Sun, Mariana Nanova, A. Verkheev, M. Marcisovsky, P. Fedorets, Yan Liang, Claude Amsler, M. Slunecka, S. Nakhoul, J. Müllers, Krisztian Peters, J. Oppotsch, A. Malige, N. Hüsken, B. Salisbury, G. Huang, S. Sun, F. Nerling, A. A. Piskun, F. H. Heinsius, G. Mazza, S. I. Manaenkov, O. Noll, A. T. Olgun, E. Antokhin, A. Gerasimov, S. Spataro, P. Salabura, D. Bumrungkoh, Q. Hu, Kamal K. Seth, D. P. Watts, S. Shimanski, V. Uzhinsky, M. Krebs, S. Bodenschatz, Karin Schönning, C. Yu, G. Perez-Andrade, G. Boca, Krzysztof Swientek, V. E. Blinov, P. De Remigis, C. J. Schmidt, Paolo Mengucci, Christoph Herold, F. Lisowski, E. A. Strokovsky, N. B. Skachkov, Y. Goncharenko, Harald Merkel, Lennart Isaksson, S. Maldaner, S. Pongampai, F. Khalid, W. Lauth, F. Feldbauer, G. Reicherz, Volker Metag, C. Mannweiler, M. Moritz, L. Montalto, Piotr Lebiedowicz, D. Prasuhn, A. Scholl, Michaela Thiel, R. Schmitz, S. Pflüger, J. Kannika, M. Albrecht, M. Volf, V.Kh. Dodokhov, P. Poznański, Marek Idzik, M. O. Distler, I. Shein, T. Wasem, J. Schwiening, T. Sefzick, Giovanni Lancioni, J. Tarasiuk, E. Ladygina, Hans-Georg Zaunick, A. E. Blinov, N. Wongprachanukul, W. Schäfer, S. Schadmand, G. Schepers, Yu. Yu. Lobanov, I. Augustin, Mathias Fink, D. Lehmann, P. Terlecki, P. Eugenio, Concettina Sfienti, S. Poslavskiy, M. Virius, S. Schlimme, C. Schwarz, Andreas Martin Heinz, Andrey Uzunian, B. Zwieglinski, M. Lattery, A. E. Yakutin, P.-E. Tegnér, H. Peng, J. Pereira-de-Lira, Ting Xiao, A.A. Efremov, James Ritman, L. Brück, Antonin Kveton, V. Mochalov, V. M. Abazov, S. Wolff, E. A. Kravchenko, E. Prencipe, F. E. Maas, R. Beck, Krzysztof Korcyl, Lorenzo Scalise, Gianangelo Bracco, L. Tomasek, Patrick Achenbach, A. Derevschikov, E. Vishnevsky, D. Melnychuk, M. Firlej, P. Srisawad, A. Dbeyssi, J. Petersen, I. Köseoglu, D. Miehling, M. Bölting, J. Regina, P. Wintz, J. Reher, W. Alkakhi, H. H. Leithoff, S. Bleser, S. Kegel, N. Er, S. Pankonin, Antoni Szczurek, D. Kazlou, M. Yu. Barabanov, Dirk Grunwald, L. Capozza, L. Linzen, D. Liu, V. Freudenreich, A. Ehret, C. Liu, Yupeng Yan, P. Gianotti, R. Dosdall, Ch. Schmidt, M. Steinen, Y. Zhou, A. Demekhin, A. Galoyan, M. Preston, Zhengtai Liu, T. Holtmann, Paweł Moskal, Mikhail Korzhik, A. Boukharov, D. Klostermann, S. Orfanitski, E. Pyata, P. P. Natali, G. Golovanov, M. Pesek, Ch. Hammann, C. Schnier, J. G. Messchendorp, P. Semenov, V. Rodin, Valentino Rigato, B. Kopf, Keval Gandhi, Daniel Duda, Andrea Bianconi, D. I. Glazier, A. Gillitzer, A. Akram, H. Flemming, M. Kümmel, M. Steinke, I. A. Kuyanov, N. Rathod, D. Calvo, D. Wölbing, R. Böhm, Ali Yilmaz, F. Schupp, Sean A Dobbs, J. Pochodzalla, U. Lynen, S. Chernichenko, B. Krusche, Felice Iazzi, Richard Wheadon, X. Y. Shen, L. Jokhovets, S.G. Pivovarov, R. Kappert, A. Lehmann, Ayut Limphirat, P. Kulessa, I. Lehmann, Andrea Lavagno, N. Kristi, T. Nasawad, A. Dolgolenko, M. Peskova, J. Płażek, Tomasz Fiutowski, L. Nogach, G. V. Fedotov, E. Luschevskaya, E. Maslova, R. Lalik, K. Khosonthongkee, C. Wenzel, M. Pfaffinger, Grzegorz Korcyl, O. Miklukho, A. N. Skachkova, Edward Lisowski, V. Jary, M. Kavatsyuk, M. Himmelreich, H. Deppe, A. G. Denig, A. Vasiliev, A. Derichs, J. Frech, A. Hayrapetyan, W. Zhu, Chinorat Kobdaj, P. Brand, E. Rosenthal, S. Belostotski, Ulrich Wiedner, A.S. Vodopianov, J. Kellers, U. Keskin, U. Thoma, R. Kliemt, A. Yu. Barnyakov, Bo Cederwall, K. Götzen, A. Meschanin, Michael Düren, Johann Marton, V. Chernetsky, Gianni Barucca, H. Loehner, Vaclav Vrba, M. Sachs, I. K. Keshk, Xi-Guang Cao, M. Traxler, S. Diehl, Andrew Levin, M.P. Bussa, S. Yerlikaya, Nicola Paone, A. Samartsev, P. Jiang, A. Fechtchenko, L. Schmitt, Michael Papenbrock, Bernd Voss, B. Hetz, Daniele Rinaldi, V. Moiseev, Magnus Wolke, V. Varentsov, M. Schmidt, N. Minaev, A. Balashoff, Mohammed Al-Turany, Andrzej Kupsc, P. Orsich, M. Steinacher, M. Finger, V. Panjushkin, H. Xu, M. Michałek, S. Bökelmann, S. Wronka, Andrey V. Izotov, M. Bukharova, G. Neue, R. Schubert, M. Tomasek, D. A. Morozov, S. Zimmermann, J. Grochowski, P. Wieczorek, S. Ryzhikov, M. Hoek, A. Gerhardt, H. Qi, Jens Hartmann, B. Seitz, S. Bukreeva, X. Zhou, G. Kesik, I. Prochazka, Mario Bragadireanu, K. Pysz, S. Coen, O. Korchak, K. Kalita, M. Küßner, O. Corell, T. Johansson, A. Ryazantsev, Y. Melnik, V. A. Matveev, S.A. Kononov, H. Orth, Hans Calén, M. Urban, G. Zhao, Witold Przygoda, T. Simantathammakul, J. Moron, J. Li, Oleg V. Missevitch, Frank Goldenbaum, Ajay Kumar Rai, M. Strickert, M. Böhm, Grzegorz Filo, M. Kunze, W. Ikegami Andersson, R. Klasen, S. Vestrick, Paul Alois Buhler, J. Lühning, J. Novy, Valery Dormenev, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay

Subjects
Nuclear and High Energy Physics, hyperon: particle source, Hadron, Type (model theory), [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], 01 natural sciences, decay modes, Combinatorics, Tree (descriptive set theory), excited state: spectrum, 0103 physical sciences, ddc:530, structure, 010306 general physics, Nuclear Experiment, Physics, 010308 nuclear & particles physics, baryon: excited state, Spectrum (functional analysis), Hyperon, anti-p, Baryon, statistics, efficiency, Excited state, Production (computer science), acceptance
Abstract

The European physical journal / A 57(4), 149 (2021). doi:10.1140/epja/s10050-021-00444-5, Published by Springer, Heidelberg

Published
2021

5. PANDA Phase One: PANDA collaboration

Author

R. Klasen, S. Vestrick, Grzegorz Filo, S. Diehl, M. Kunze, W. Ikegami Andersson, A. V. Stavinskiy, Yupeng Yan, Felice Iazzi, D. Rodríguez Piñeiro, J. Müllers, Andrew Levin, Paul Alois Buhler, J. Lühning, J. Novy, Valery Dormenev, James Ritman, Piotr Lebiedowicz, L. Montalto, M. Küßner, A. Scholl, Frank Goldenbaum, Ali Yilmaz, Yan Liang, W. Esmail, M.P. Bussa, A. Ali, L. Jokhovets, S.G. Pivovarov, D. Bonaventura, A. Verkheev, S. Rimjaem, M. Preston, A. T. Olgun, Konstantin Beloborodov, P. Fedorets, A. Hamdi, M. Volf, S. Yerlikaya, S. Nakhoul, J. Kannika, O. Corell, A. Vasiliev, G. Mazza, E. Antokhin, A. Gerasimov, Egle Tomasi-Gustafsson, J. Hofmann, R. Karabowicz, V.Kh. Dodokhov, A. E. Blinov, P.-E. Tegnér, Andrey Uzunian, S. Wolff, M. Steinen, L. Linzen, Y. Zhou, F. H. Heinsius, Zhengtai Liu, P. De Remigis, C. J. Schmidt, I. Lehmann, H. Denizli, H. Deppe, Ajay Kumar Rai, T. Johansson, T. Holtmann, A. G. Denig, V. Panjushkin, J. Frech, A. Hayrapetyan, W. Zhu, L. Nogach, E. Vishnevsky, D. Melnychuk, Q. Hu, I. Köseoglu, Andrea Bianconi, J. Pereira-de-Lira, A. Derevschikov, A. Belias, O. Malyshev, D. Miehling, Nicola Paone, K. Pysz, A. Ryazantsev, D. I. Glazier, G. Reicherz, R. Hagdorn, M. Strickert, M. Böhm, Chinorat Kobdaj, P. Brand, Vladimir Blinov, P. Wüstner, X. Y. Shen, Paolo Mengucci, Christoph Herold, M. Pelizäus, G. V. Fedotov, T. Nasawad, A. Dolgolenko, N. B. Skachkov, S. Pongampai, S. Coen, Y. Melnik, V. A. Matveev, U. Kurilla, V. Jary, B. Zwieglinski, F. Khalid, A. Gillitzer, D. Calvo, Andreas Martin Heinz, M. Kavatsyuk, Mariana Nanova, S. Belostotski, K. Nowakowski, Claude Amsler, T. Erlen, K. Kalita, M. Domagala, A. Derichs, Ulrich Wiedner, E. Prencipe, L. Brück, R. Schmitz, Antonin Kveton, V. Mochalov, A.S. Vodopianov, J. Kellers, J. Rieger, G. Huang, N. Wongprachanukul, Bo Cederwall, K. Götzen, A. N. Skachkova, Edward Lisowski, J. Pütz, U. Müller, C. Motzko, K.-T. Brinkmann, S.A. Kononov, Dirk Grunwald, G. Neue, U. Thoma, R. Lalik, A. Kantsyrev, S. Sun, M. Virius, B. Salisbury, J. Oppotsch, Jize Zhao, R. Dzhygadlo, T. Held, F. Nerling, G. D. Alexeev, M. Bölting, A. Boukharov, G. Golovanov, I. Zimmermann, N. Er, A. Malige, S. Godre, Ting Xiao, M. Wojciechowski, Ch. Schmidt, T. Simantathammakul, B. Seitz, P. Balanutsa, B. J. Liu, V. Crede, M. Krebs, E. Rosenthal, Y. K. Sun, D. G. Ireland, W. Kühn, V. Abramov, Z. Tavukoglu, Mikhail Korzhik, A. Kripko, S. Spataro, D. Bumrungkoh, V. M. Abazov, R. Schubert, H. Flemming, Vaclav Vrba, S. I. Manaenkov, S. Kegel, A. Lehmann, U. Keskin, Hans-Georg Zaunick, R. Kliemt, V. Uzhinsky, Karin Schönning, X. Zhou, R. Böhm, S. Maldaner, J. Moron, D. P. Watts, E.K. Koshurnikov, M. Slunecka, P. Poznański, M. Firlej, P. Srisawad, A. Yu. Barnyakov, D. Kazlou, M. Yu. Barabanov, J. Płażek, V. Chauhan, R. W. Novotny, S. Schlimme, C. Schwarz, Y. Goncharenko, Lennart Isaksson, P. Eugenio, Kamal K. Seth, Concettina Sfienti, Harald Merkel, H. Xu, A. Meschanin, Marek Idzik, Mario Bragadireanu, Kazem Azizi, M. Lattery, C. Yu, G. Perez-Andrade, G. Boca, C. Liu, A. Chlopik, Johann Marton, Jens Hartmann, A. Samartsev, M. O. Distler, Dan Pantea, W. Eyrich, P. Gianotti, J. Li, E. Ladygina, Michael Düren, M. Albrecht, M. Tomasek, J. Regina, Michaela Thiel, I. Shein, L. Capozza, V. Chernetsky, Y. A. Tikhonov, Oleg V. Missevitch, V. Lucherini, Lorenzo Scalise, Fabrizio Daví, J. Petersen, F. E. Maas, A. Filippi, Gianni Barucca, T. Wasem, J. Reher, J. Schwiening, P. Wintz, O. Korchak, M. Marcisovsky, Volker Metag, S. Zimmermann, N. Hüsken, S. Pankonin, P. Jiang, Antoni Szczurek, C. Schnier, H. Orth, S. Bukreeva, H. Loehner, S. Orfanitski, D. Lehmann, C. Mannweiler, V. Ferapontov, D. Y. Kirin, M. Moritz, C. Hahn, D. A. Morozov, J. Grochowski, A. A. Piskun, Hans Calén, Christoph Hanhart, S. Bodenschatz, J. Tarasiuk, Christian S. Fischer, M. Urban, G. Zhao, T. Sefzick, A. Demekhin, P. Wieczorek, Giovanni Lancioni, Daniel Duda, M. Hoek, A. Akram, S. Ryzhikov, Yu. Yu. Lobanov, E. A. Strokovsky, A. Galoyan, F. Feldbauer, S. Shimanski, A.A. Efremov, Paweł Moskal, H. Peng, G. Kesik, S. Schadmand, B. Kopf, G. Schepers, B. Krusche, J. G. Messchendorp, V. V. Tokmenin, K. Manasatitpong, A. Dbeyssi, M. Fritsch, Witold Przygoda, S. Poslavskiy, Valentino Rigato, A. Khoukaz, M. Kümmel, D. Klostermann, S. Koch, E. A. Kravchenko, M. Sachs, Ayut Limphirat, L. Tomasek, I. K. Keshk, D. Liu, P. P. Natali, A. Gerhardt, H. Qi, I. A. Kuyanov, Patrick Achenbach, Alexander Olshevskiy, W. Alkakhi, N. Kristi, H. H. Leithoff, N. I. Zhuravlev, P. Semenov, V. Rodin, Keval Gandhi, E. Maslova, Xi-Guang Cao, M. Traxler, Herbert Koch, A. Täschner, Grzegorz Korcyl, Krisztian Peters, P. Kulessa, Sinead M. Ryan, F. Schupp, Sean A Dobbs, J. Pochodzalla, M. Himmelreich, S. Chernichenko, O. Noll, T. Triffterer, F. Lisowski, P. Salabura, Krzysztof Swientek, Pawel Marciniewski, D. Veretennikov, W. Lauth, Xuan Zhang, I. Prochazka, D. Prasuhn, Johann Haidenbauer, S. Pflüger, W. Schäfer, A. Golubev, Tobias Stockmanns, S. Bleser, V. Serdyuk, M. Michałek, B. Ketzer, Jerzy Smyrski, S. Bökelmann, V. Freudenreich, A. Ehret, S. Wronka, R. Kappert, Andrey V. Izotov, M. Bukharova, E. Luschevskaya, K. Khosonthongkee, C. Wenzel, M. Pfaffinger, E. Pyata, Ch. Hammann, M. Steinke, A. Fechtchenko, L. Schmitt, Michael Papenbrock, N. Rathod, D. Wölbing, Richard Wheadon, U. Lynen, Andrea Lavagno, M.F.M. Lutz, Bernd Voss, B. Hetz, Daniele Rinaldi, Tomasz Fiutowski, V. Moiseev, Magnus Wolke, V. Varentsov, M. Schmidt, N. Minaev, A. Balashoff, Mohammed Al-Turany, Andrzej Kupsc, P. Orsich, M. Steinacher, M. Finger, I. Augustin, Mathias Fink, P. Terlecki, A. E. Yakutin, R. Beck, Krzysztof Korcyl, Gianangelo Bracco, R. Dosdall, and O. Miklukho

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Luminosity (scattering theory), 010308 nuclear & particles physics, Physics::Instrumentation and Detectors, Physics beyond the Standard Model, Hadron, Detector, Strong interaction, 01 natural sciences, Antiproton, 0103 physical sciences, Facility for Antiproton and Ion Research, 010306 general physics, Nuclear Experiment, Storage ring
Abstract

The Facility for Antiproton and Ion Research (FAIR) in Darmstadt, Germany, provides unique possibilities for a new generation of hadron-, nuclear- and atomic physics experiments. The future antiProton ANnihilations at DArmstadt (PANDA or $$\overline{\mathrm{P}}$$ P ¯ ANDA) experiment at FAIR will offer a broad physics programme, covering different aspects of the strong interaction. Understanding the latter in the non-perturbative regime remains one of the greatest challenges in contemporary physics. The antiproton–nucleon interaction studied with PANDA provides crucial tests in this area. Furthermore, the high-intensity, low-energy domain of PANDA allows for searches for physics beyond the Standard Model, e.g. through high precision symmetry tests. This paper takes into account a staged approach for the detector setup and for the delivered luminosity from the accelerator. The available detector setup at the time of the delivery of the first antiproton beams in the HESR storage ring is referred to as the Phase One setup. The physics programme that is achievable during Phase One is outlined in this paper.

Published
2021

6. Measurement of the helicity asymmetry E for the reaction $$ \gamma p\rightarrow \pi ^0 p$$

Author

H. Schmieden, D. E. Bayadilov, A. B. Gridnev, Mariana Nanova, T. Rostomyan, M. Gottschall, M. Urban, V. Sokhoyan, D. Walther, M. Dieterle, T. Seifen, Ch. Hammann, A. Thiel, A. Winnebeck, Frank Frommberger, Matthew Lang, M. Kube, I. Keshelashvili, J. Hannappel, A. V. Anisovich, Jörg H. Müller, Jens Hartmann, V. Crede, Lilian Witthauer, Ulrich Wiedner, U. Thoma, P. Mahlberg, G. Reicherz, Frank Klein, V. Metag, Y. Wunderlich, K. Koop, K. Spieker, A. V. Sarantsev, A. Wilson, M. Bichow, Ch. Honisch, Ch. Schmidt, S. Friedrich, K. Makonyi, R. Beck, H. Dutz, K.-Th. Brinkmann, H. van Pee, P. Klassen, H. Eberhardt, D. Werthmüller, M. Grüner, S. Kammer, F. Dietz, R. Ewald, F. Afzal, H. Kalinowsky, E. Gutz, D. Piontek, I. V. Lopatin, T. C. Jude, Wolfgang Hillert, Ch. Wendel, D. Elsner, R. W. Novotny, Ph. Hoffmeister, V. A. Nikonov, J. Müllers, Eberhard Klempt, B. Krusche, W. Meyer, and K. Fornet-Ponse

Subjects
Nuclear physics, Physics, Nuclear and High Energy Physics, Photon, media_common.quotation_subject, Hadron, Bremsstrahlung, Nuclear fusion, Electron, Photon energy, Helicity, Asymmetry, media_common
Abstract

A measurement of the double-polarization observable E for the reaction $$\gamma p\rightarrow \pi ^0 p$$ γ p → π 0 p is reported. The data were taken with the CBELSA/TAPS experiment at the ELSA facility in Bonn using the Bonn frozen-spin butanol (C$$_4$$ 4 H$$_9$$ 9 OH) target, which provided longitudinally-polarized protons. Circularly-polarized photons were produced via bremsstrahlung of longitudinally-polarized electrons. The data cover the photon energy range from $$E_\gamma =600$$ E γ = 600 to 2310 MeV and nearly the complete angular range. The results are compared to and have been included in recent partial wave analyses.

Published
2021

7. Observation of the pη′ Cusp in the New Precise Beam Asymmetry Σ Data for γp→pη

Author

Cbelsa, F. Afzal, L Richter, S. Ciupka, U-G Meißner, V. Metag, W. Meyer, M. Grüner, K. Koop, T. Seifen, Lilian Witthauer, H. Kalinowsky, Matthew Lang, D. Piontek, N. Stausberg, M. Urban, I. V. Lopatin, A. V. Sarantsev, T. C. Jude, Frank Frommberger, M. Becker, B. Mitlasóczki, H. Schmieden, M. Dieterle, V. Sokhoyan, H. van Pee, D. E. Bayadilov, P. Klassen, K. Spieker, K. Nikonov, B. Krusche, A. B. Gridnev, Mariana Nanova, B. Salisbury, Wolfgang Hillert, J. Hannappel, C. Sowa, J. Hoff, E. Gutz, Ch. Honisch, J. Schultes, H. Dutz, G. Urff, Ch. Schmidt, Y. Wunderlich, Ulrich Wiedner, Frank Klein, V. Crede, U. Thoma, D. Elsner, S. Friedrich, A. Wilson, R. W. Novotny, Ph. Hoffmeister, A. Thiel, V. Novinskiy, P. Mahlberg, A. V. Anisovich, Francesco Messi, I. Keshelashvili, Ch. Wendel, F. Kalischewski, K.-T. Brinkmann, T. Triffterer, P. Kroenert, G. Reicherz, D. Walther, Jörg H. Müller, Jens Hartmann, D. Rönchen, T. Rostomyan, M. Gottschall, E. Blanke, D. Schaab, R. Beck, Ch. Hammann, A. Winnebeck, J. Müllers, Eberhard Klempt, and V. A. Nikonov

Subjects
Physics, Photon, Meson, media_common.quotation_subject, Partial wave analysis, Nuclear Theory, Solid angle, General Physics and Astronomy, Observable, Polarization (waves), 01 natural sciences, Asymmetry, Nuclear physics, 0103 physical sciences, Physics::Accelerator Physics, Nuclear Experiment, 010306 general physics, Nucleon, media_common
Abstract

Data on the beam asymmetry Σ in the photoproduction of η mesons off protons are reported for tagged photon energies from 1130 to 1790 MeV (mass range from W=1748 MeV to W=2045 MeV). The data cover the full solid angle that allows for a precise moment analysis. For the first time, a strong cusp effect in a polarization observable has been observed that is an effect of a branch-point singularity at the pη^{'} threshold [E_{γ}=1447 MeV (W=1896 MeV)]. The latest BnGa partial wave analysis includes the new beam asymmetry data and yields a strong indication for the N(1895)1/2^{-} nucleon resonance, demonstrating the importance of including all singularities for a correct determination of partial waves and resonance parameters.

Published
2020

8. The $\eta^{\prime}$ η -carbon potential at low meson momenta

Author

D. Elsner, K. Koop, Frank Frommberger, V. Metag, Ph. Hoffmeister, J. Müller, B. Krusche, E. Gutz, D. Kaiser, K.-T. Brinkmann, T. Triffterer, C. Sowa, J. Müllers, A. Wilson, S. Friedrich, T. Seifen, Matthew Lang, J. Hannappel, B. Bantes, Francesco Messi, Ulrich Wiedner, E. Ya. Paryev, U. Thoma, D. Walther, Jens Hartmann, F. Afzal, Ch. Hammann, Reinhard Beck, P. Drexler, V. Crede, Ch. Honisch, Y. Wunderlich, D. Piontek, Ch. Schmidt, Hans-Georg Zaunick, H. Eberhardt, T. C. Jude, M. Becker, Ch. Funke, Ch. Wendel, D. Werthmüller, Wolfgang Hillert, M. Grüner, I. Keshelashvili, T. Rostomyan, Lilian Witthauer, M. Gottschall, S. Böse, K. Makonyi, M. Urban, V. Sokhoyan, H. van Pee, Friedrich Klein, K. Spieker, D. Schaab, R. Schmitz, A. Thiel, F. Kalischewski, H. Schmieden, D. E. Bayadilov, and Mariana Nanova

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Meson, 010308 nuclear & particles physics, Hadron, Carbon-12, Elementary particle, 01 natural sciences, Baryon, 0103 physical sciences, High Energy Physics::Experiment, Production (computer science), Nuclear Experiment, 010306 general physics, Nucleon, Boson
Abstract

The production of $\eta^{\prime}$ mesons in coincidence with forward-going protons has been studied in photon-induced reactions on 12C and on a liquid hydrogen (LH2) target for incoming photon energies of 1.3-2.6 GeV at the electron accelerator ELSA. The $\eta^{\prime}$ mesons have been identified via the $\eta^{\prime} \rightarrow \pi^{0} \pi^{0}\eta \rightarrow 6 \gamma$ decay registered with the CBELSA/TAPS detector system. Coincident protons have been identified in the MiniTAPS BaF2 array at polar angles of $2^{\circ} \le \theta_{p} \le 11^{\circ}$ . Under these kinematic constraints the $\eta^{\prime}$ mesons are produced with relatively low kinetic energy ( $\approx 150$ MeV) since the coincident protons take over most of the momentum of the incident-photon beam. For the C-target this allows the determination of the real part of the $\eta^{\prime}$ -carbon potential at low meson momenta by comparing with collision model calculations of the $\eta^{\prime}$ kinetic energy distribution and excitation function. Fitting the latter data for $\eta^{\prime}$ mesons going backwards in the center-of-mass system yields a potential depth of $V = -(44 \pm 16(stat) \pm 15(syst))$ MeV, consistent with earlier determinations of the potential depth in inclusive measurements for average $\eta^{\prime}$ momenta of $\approx 1.1$ GeV/c. Within the experimental uncertainties, there is no indication of a momentum dependence of the $\eta^{\prime}$ -carbon potential. The LH2 data, taken as a reference to check the data analysis and the model calculations, provide differential and integral cross sections in good agreement with previous results for $\eta^{\prime}$ photoproduction off the free proton.

Published
2018

9. Measurement of double polarisation asymmetries in ω -photoproduction

Author

Frank Frommberger, V. Metag, F. Diez, M. Bichow, Ch. Hammann, T. Seifen, I. Jaegle, F. Kalischewski, D. Elsner, M. Kube, V. Crede, P. Drexler, A. Winnebeck, K. Fornet-Ponse, H. Schmieden, J. Müller, R. W. Novotny, B. Bantes, D. Walther, Ph. Hoffmeister, D. E. Bayadilov, K. Koop, U. Thoma, A. B. Gridnev, Mariana Nanova, S. Böse, A. Wilson, Yasser Maghrbi, H. Kalinowsky, Eberhard Klempt, H. Dutz, J. Hannappel, S. Runkel, H. Eberhardt, R. Ewald, Ulrich Wiedner, W. Meyer, St. Schaepe, V. A. Nikonov, T. Rostomyan, I. Keshelashvili, R. Schmitz, B. Krusche, Ch. Honisch, M. Grüner, Ch. Schmidt, A. Thiel, S. Friedrich, G. Reicherz, M. Gottschall, Friedrich Klein, Ch. Wendel, V. V. Sumachev, Wolfgang Hillert, R. Beck, Jens Hartmann, E. Gutz, S. Kammer, Th. Challand, Ch. Funke, K. Makonyi, Matthew Lang, K.-Th. Brinkmann, D. Kaiser, S. Reeve, H. van Pee, V. Kleber, D. Piontek, I. V. Lopatin, T. C. Jude, Yu. A. Beloglazov, A. V. Sarantsev, A. V. Anisovich, M. Urban, and V. Sokhoyan

Subjects
Physics, Nuclear and High Energy Physics, Photon, Meson, Partial wave analysis, Meson production, Resonance, Photon energy, Helicity, Omega, lcsh:QC1-999, Light mesons (SCB0), Nuclear physics, Baryon, Polarisation in interactions and scattering, Light mesons (SCB0), Nuclear Experiment, lcsh:Physics
Abstract

The first measurements of the beam-target-helicity-asymmetries $E$ and $G$ in the photoproduction of $\omega$-mesons off protons at the CBELSA/TAPS experiment are reported. $E$ ($G$) was measured using circularly (linearly) polarised photons and a longitudinally polarised target. $E$ was measured over the photon energy range from close to threshold ($E_\gamma = 1108$~MeV) to $E_\gamma = 2300$~MeV and $G$ at a single energy interval of $1108 < E_\gamma, Comment: 6 pages, 6 figures

Published
2015
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10. New data on γ→p→→ηp with polarized photons and protons and their implications for N⁎ → Nη decays

Author

P. Klassen, V. Hannen, J. Herick, Reinhard Beck, Ch. Wendel, S. Kammer, Jens Hartmann, V. Metag, H. van Pee, F. Dietz, P. Mahlberg, Ch. Honisch, Ch. Schmidt, Th. Challand, S. Böse, T. C. Jude, H. Kalinowsky, M. Bichow, K. Koop, T. Rostomyan, M. Becker, I. Jaegle, G. Reicherz, A. Berlin, A. Käser, Friedrich Klein, M. Gottschall, D. Kaiser, A. Wilson, R. Schmitz, T. Seifen, R. Ewald, C. Rosenbaum, Yasser Maghrbi, F. Afzal, H. Dutz, O. Jahn, H. Eberhardt, D. Elsner, A. Thiel, R. W. Novotny, Ph. Hoffmeister, V. Crede, S. Goertz, A. V. Anisovich, J. Müller, H. Schmieden, D. E. Bayadilov, A. B. Gridnev, Mariana Nanova, M. Grüner, B. Roth, Frank Frommberger, Matthew Lang, S. Friedrich, K. Makonyi, Francesco Messi, B. Bantes, J. Hannappel, Wolfgang Hillert, M. Kube, E. Gutz, Ulrich Wiedner, M. Urban, V. Kleber, U. Thoma, V. Sokhoyan, F. Kalischewski, I. Keshelashvili, W. Meyer, J. Müllers, Eberhard Klempt, K. Fornet-Ponse, C. Funke, D. V. Novinski, Lilian Witthauer, Ch. Hammann, B. Krusche, P. Drexler, A. Winnebeck, V. A. Nikonov, M. Dieterle, K.-T. Brinkmann, Yu. A. Beloglazov, A. V. Sarantsev, D. Piontek, I. V. Lopatin, and D. Walther

Subjects
Physics, Nuclear physics, Nuclear and High Energy Physics, Photon, Meson, 010308 nuclear & particles physics, 0103 physical sciences, Polarization observables, Solid angle, 010306 general physics, Branching (polymer chemistry), Nucleon, 01 natural sciences
Abstract

The polarization observables T , E , P , H , and G in photoproduction of η mesons off protons are measured for photon energies from threshold to W = 2400 MeV (T), 2280 MeV (E), 1620 MeV ( P , H ), or 1820 MeV (G), covering nearly the full solid angle. The data are compared to predictions from the SAID, MAID, JuBo, and BnGa partial-wave analyses. A refit within the BnGa approach including further data yields precise branching ratios for the Nη decay of nucleon resonances. A Nη-branching ratio of 0.33 ± 0.04 for N ( 1650 ) 1 / 2 − is found, which reduces the large and controversially discussed Nη-branching ratio difference of the two lowest mass J P = 1 / 2 − -resonances significantly.

Published
2020

11. Photoproduction of $ \eta{^\prime}$ -mesons off the deuteron

Author

S. Lugert, D. Walther, S. Hoeffgen, D. Trnka, I. Jaegle, M. Ostrick, Eberhard Klempt, A. V. Anisovich, Matthew Lang, U. Thoma, Kanzo Nakayama, T. Szczepanek, D. Menze, V. Metag, J. Junkersfeld, Fei Huang, V. Kleber, Wolfgang Hillert, V. Crede, H. Loehner, H. van Pee, Yu. A. Beloglazov, A. V. Sarantsev, T. Mertens, D. V. Novinski, S. Kammer, J. C. S. Bacelar, R. Gregor, R. Castelijns, V. A. Nikonov, M. Kotulla, C. Funke, L. Tiator, R. Ewald, O. Bartholomy, D. Elsner, Lalit Mohan Pant, R. Varma, Friedrich Klein, H. Dutz, Ch. Wendel, B. Krusche, Ch. Schmidt, R. W. Novotny, A. Suele, V. V. Sumachev, J. G. Messchendorp, S. Shende, B. Schoch, A. Fix, H. Kalinowsky, V. Sokhoyan, I. V. Lopatin, H. Schmieden, D. E. Bayadilov, A. B. Gridnev, Mariana Nanova, R. Beck, S. Schadmand, Ankhi Roy, E. Gutz, B. Bantes, Frank Frommberger, Frank Klein, and M. Pfeiffer

Subjects
Physics, Nuclear and High Energy Physics, Photon, Proton, Meson, Nuclear Theory, Particle accelerator, law.invention, Nuclear physics, Recoil, Deuterium, law, Neutron, High Energy Physics::Experiment, Nucleon, Nuclear Experiment
Abstract

Quasi-free photoproduction of $ \eta{^\prime}$ -mesons off nucleons bound in the deuteron has been measured with the combined Crystal Barrel - TAPS detector. The experiment was done at a tagged photon beam of the ELSA electron accelerator in Bonn for incident photon energies from the production threshold up to 2.5GeV. The $ \eta{^\prime}$ -mesons have been detected in coincidence with recoil protons and recoil neutrons. The quasi-free proton data are in good agreement with the results for free protons, indicating that nuclear effects have no significant impact. The coincidence with recoil neutrons provides the first data for the $ \gamma$ n $ \rightarrow$ n $ \eta{^\prime}$ reaction. In addition, also first estimates for coherent $ \eta{^\prime}$ -production off the deuteron have been obtained. In agreement with model predictions, the total cross-section for this channel is found to be very small, at most at the level of a few nb. The data are compared to model calculations taking into account contributions from nucleon resonances and t -channel exchanges

Published
2018

12. Photoproduction of η -mesons off nuclei for Eγ ⩽ 2.2 GeV

Author

Lalit Mohan Pant, B. Bantes, M. Pfeiffer, D. Menze, R. Ewald, S. Hoeffgen, Ankhi Roy, Ch. Wendel, V. V. Sumachev, H. Kalinowsky, Matthew Lang, A. Ehmanns, R. Varma, D. Elsner, I. Jaegle, S. Kammer, R. Castelijns, H. Dutz, S. Shende, V. Sokhoyan, S. Lugert, D. Trnka, B. Krusche, R. W. Novotny, Ph. Hoffmeister, K. Essig, J. Langheinrich, T. Szczepanek, A. Suele, O. Bartholomy, S. Schadmand, Ulrich Mosel, R. Gregor, Yu. A. Beloglazov, M. Konrad, R. W. Gothe, Eberhard Klempt, J. C. S. Bacelar, M. Kotulla, C.-H. Weinheimer, B. Schoch, C. Morales, M. Ostrick, I. Fabry, Michael Fuchs, R. Beck, E. Gutz, J. Lotz, V. Metag, V. Crede, Ch. Schmidt, Frank Klein, Friedrich Klein, V. Kleber, H. Schmieden, I. V. Lopatin, D. E. Bayadilov, A. B. Gridnev, Mariana Nanova, H. van Pee, D. V. Novinski, J. G. Messchendorp, K. Fornet-Ponse, D. Walther, C. Funke, I. Horn, A. Radkov, T. Mertens, U. Thoma, P. Muehlich, J. Junkersfeld, and H. Loehner

Subjects
Mass number, Physics, Nuclear and High Energy Physics, Meson, Nuclear Theory, Nuclear matter, Resonance (particle physics), Nuclear physics, Pion, Production (computer science), High Energy Physics::Experiment, Absorption (logic), Nucleon, Nuclear Experiment
Abstract

Photoproduction of $\eta$ mesons off $^{12}$C, $^{40}$Ca, $^{93}$Nb, and $^{nat}$Pb nuclei has been measured with a tagged photon beam with energies between 0.6 and 2.2 GeV. The experiment was performed at the Bonn ELSA accelerator with the combined setup of the Crystal Barrel and TAPS calorimeters. It aimed at the in-medium properties of the S$_{11}$(1535) nucleon resonance and the study of the absorption properties of nuclear matter for $\eta$ mesons. Careful consideration was given to contributions from $\eta\pi$ final states and secondary production mechanisms of $\eta$-mesons e.g. from inelastic $\pi N$ reactions of intermediate pions. The analysis of the mass number scaling shows that the nuclear absorption cross section $\sigma_{N\eta}$ for $\eta$ mesons is constant over a wide range of the $\eta$ momentum. The comparison of the excitation functions to data off the deuteron and to calculations in the framework of a BUU-model show no unexplained in-medium modifications of the S$_{11}$(1535)., Comment: Accepted for publication in Eur. Phys. J. A

Published
2018

13. Strangeness photoproduction at the BGO-OD experiment

Author

V. Metag, V. Tarakanov, R. Joosten, O. Freyermuth, S. Friedrich, D. Burdeynyi, K. Kohl, Francesco Messi, A. Polonski, D. Novinskiy, Hans-Georg Zaunick, G. Gervino, J. Hannappel, J. Bieling, R. Messi, A. Fantini, Wolfgang Hillert, D. Hammann, K.-T. Brinkmann, D. Moricciani, P. L. Cole, R. Jahn, P. Pedroni, B. Krusche, Giuseppe Mandaglio, V. Lisin, D. Elsner, G. Scheluchin, A. Stugelev, A. M. Lapik, Frank Klein, R. Di Salvo, A. Bella, A. Braghieri, Reinhard Beck, Frank Frommberger, T. Zimmermann, A. N. Mushkarenkov, V. V. Sumachev, P. Levi Sandri, I. V. Lopatin, T. C. Jude, Patrick Bauer, E. Gutz, V. G. Nedorezov, D. Walther, S. Boese, V. Vegna, M. Romaniuk, S. Alef, B.-E. Reitz, F. Ghio, H. Schmieden, D. E. Bayadilov, A. B. Gridnev, and Mariana Nanova

Subjects
Settore FIS/01, Physics, Calorimeter (particle physics), Meson, Nuclear Theory, Momentum transfer, Hadron, Constituent quark, Strangeness, strangeness photoproduction, Baryon, Nuclear physics, Nuclear Experiment, Nucleon
Abstract

The BGO-OD experiment at the ELSA accelerator facility uses an energy tagged bremstrahlung photon beam to investigate the excitation spectrum of the nucleon. The setup consists of a highly segmented BGO calorimeter surrounding the target, with a particle tracking magnetic spectrometer at forward angles. BGO-OD is ideal for investigating the photoproduction of hadrons of non-zero strangeness. The high momentum resolution at forward angles covers a kinematic region where t-channel exchange mechanisms play a dominant role. Access to this low momentum transfer region also allows the investigation of degrees of freedom not derived from constituent quark models, for example, the role of (vector) meson - baryon interactions and dynamically generated states in photoproduction reactions. Data taking for the first part of an extensive physics programme is complete and preliminary results and ongoing analysis are presented. (Less)

Published
2018

14. Missing-mass spectroscopy of the C12(p,d) reaction near the η′ -meson production threshold

Author

R. Knöbel, J. Zhao, Hans Geissel, Yasumoto Tanaka, Daisuke Jido, V. Metag, J. S. Winfield, H. Yamakami, J. Gellanki, C. Scheidenberger, M. Takechi, Y. Igarashi, Hooi Jin Ong, Imrich Szarka, C. Rappold, Yassid Ayyad, C. Guo, M. Iwasaki, Peter Strmen, Christine Hornung, Ryugo S. Hayano, K. Itahashi, R. Kanungo, Isao Tanihata, M.N. Harakeh, S. Terashima, Moritz P. Reiter, J. L. Rodriguez-Sanchez, N. Ikeno, E. Haettner, E. Widmann, Satoru Hirenzaki, E. Gutz, T. Nishi, X. Xu, Yuni N. Watanabe, S. Friedrich, K.-T. Brinkmann, Helmut Weick, Herbert A. Simon, Nasser Kalantar-Nayestanaki, I. G. Mukha, Y. Higashi, Bao-Hua Sun, Hideko Nagahiro, Ken Suzuki, Branislav Sitar, N. Kurz, J. Benlliure, Mariana Nanova, S. Pietri, Tomofumi Nagae, A. Prochazka, and Hiroyuki Fujioka

Subjects
Physics, 010308 nuclear & particles physics, Nuclear Theory, Momentum transfer, Eta meson, Mass spectrometry, 01 natural sciences, Particle identification, Spectral line, Nuclear physics, Deuterium, 0103 physical sciences, Bound state, Atomic physics, Nuclear Experiment, 010306 general physics, Spectroscopy
Abstract

Excitation-energy spectra of $^{11}\mathrm{C}$ nuclei near the ${\ensuremath{\eta}}^{\ensuremath{'}}$-meson production threshold have been measured by missing-mass spectroscopy using the $^{12}\mathrm{C}(p,d)$ reaction. A carbon target has been irradiated with a 2.5 GeV proton beam supplied by the synchrotron SIS-18 at GSI to produce ${\ensuremath{\eta}}^{\ensuremath{'}}$-meson bound states in $^{11}\mathrm{C}$ nuclei. Deuterons emitted at ${0}^{\ensuremath{\circ}}$ in the reaction have been momentum analyzed by the fragment separator (FRS), used as a high-resolution spectrometer. No distinct structure due to the formation of ${\ensuremath{\eta}}^{\ensuremath{'}}$-mesic states is observed although a high statistical sensitivity is achieved in the experimental spectra. Upper limits on the formation cross sections of ${\ensuremath{\eta}}^{\ensuremath{'}}$-mesic states are determined, and thereby a constraint imposed on the ${\ensuremath{\eta}}^{\ensuremath{'}}$-nucleus interaction is discussed.

Published
2018

15. Mesons in the medium - experimental probes for chiral symmetry restoration?

Author

Cbelsa and Mariana Nanova

Subjects
Physics, Quantum chromodynamics, education.field_of_study, Particle physics, Chiral symmetry, Meson, Nuclear Theory, Population, Hadron, Strong interaction, Crystal, Bound state, Nuclear Experiment, education
Abstract

The in-medium modifications of hadron properties have been identified as one of the key problems in understanding the non-perturbative sector of QCD. Several theoretical papers discuss the possibility of a partial restoration of chiral symmetry in a strongly interacting environment. However, is it possible to find experimental evidence for partial symmetry restoration by studying the in-medium behaviour of mesons, and the meson-nucleus interaction. Is this interaction sufficiently strong to allow even the formation of mesic states only bound by the strong interaction? The answers can be given by studying the meson-nucleus complex potential. The experimental approaches to deduce this potential and the experimental results from CBELSA/TAPS are presented and discussed. Data taken on a C and Nb target at the Crystal Barrel (CB)/TAPS detector system at the ELSA accelerator facility in Bonn have been analyzed to deduce the η'- and ω-nucleus potential. The data for both mesons are consistent with a weakly attractive potential. The formation and population of ω-nucleus and η'-nucleus bound states is discussed. In case of the ω meson the in-medium width is found to be larger than the potential depth which hampers a successful experimental identification of ω-mesic states. The relatively small in-medium width of the η' meson encourages ongoing experiments to search for η'-nucleus bound states.

Published
2017

16. The polarization observables T , P , and H and their impact onγp→pπ0multipoles

Author

Ph. Thämer, Reinhard Beck, M. Grüner, V. Hannen, Matthew Lang, J. Herick, B. Roth, Ch. Honisch, Ch. Schmidt, K. Makonyi, K.-Th. Brinkmann, S. Reeve, H. van Pee, Eberhard Klempt, D. V. Novinski, Yu. A. Beloglazov, D. Elsner, M. Becker, Ch. Wendel, V. Crede, A. V. Sarantsev, S. Friedrich, W. Meyer, V. Metag, F. Kalischewski, Francesco Messi, R. W. Novotny, B. Krusche, Ph. Hoffmeister, St. Goertz, Lilian Witthauer, A. Käser, V. A. Nikonov, D. Piontek, I. V. Lopatin, A. V. Anisovich, J. Hannappel, P. Klassen, T. C. Jude, M. Urban, M. Dieterle, Ulrich Wiedner, V. Sokhoyan, A. Thiel, U. Thoma, Ch. Funke, Wolfgang Hillert, M. Bichow, H. Schmieden, D. E. Bayadilov, A. B. Gridnev, Mariana Nanova, K. Fornet-Ponse, S. Böse, Ch. Hammann, H. Kalinowsky, D. Walther, A. Winnebeck, A. Wilson, T. Seifen, Frank Frommberger, M. Kube, K. Koop, G. Reicherz, Friedrich Klein, R. Schmitz, O. Jahn, J. Müller, Ch. Rosenbaum, H. Dutz, H. Eberhardt, E. Gutz, I. Keshelashvili, St. Runkel, A. Berlin, T. Rostomyan, D. Kaiser, M. Gottschall, and Jens Hartmann

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Photon, Linear polarization, media_common.quotation_subject, Partial wave analysis, Electron, Polarization (waves), Asymmetry, Nuclear physics, Nuclear Experiment, Nucleon, Multipole expansion, media_common
Abstract

Data on the polarization observables T, P, and H for the reaction gamma p -> p pi(0) are reported. Compared to earlier data from other experiments, our data are more precise and extend the covered range in energy and angle substantially. The results were extracted from azimuthal asymmetries measured using a transversely polarized target and linearly polarized photons. The data were taken at the Bonn electron stretcher accelerator ELSA with the CBELSA/TAPS detector. Within the Bonn-Gatchina partial wave analysis, the new polarization data lead to a significant narrowing of the error band for the multipoles for neutral-pion photoproduction. (C) 2015 The Authors. Published by Elsevier B.V.

Published
2015

17. Data onIsandIcinγ→p→pπ0π0reveal cascade decays ofN(1900)viaN(1520)π

Author

H. Schmieden, D. E. Bayadilov, Mariana Nanova, M. Pfeiffer, Y. Beloglazov, H. Dutz, A. Suele, D. Walther, E. Gutz, D. Piontek, V. Crede, T. Szczepanek, J. C. S. Bacelar, A. V. Sarantsev, I. V. Lopatin, Matthew Lang, Frank Frommberger, Lalit Mohan Pant, M. Fuchs, V. Kleber, R. Gregor, Friedrich Klein, A. Gridnev, V. Metag, M. Kotulla, V. Sokhoyan, A. V. Anisovich, Ch. Schmidt, U. Thoma, A. Thiel, R. Ewald, M. Ostrick, S. Kammer, S. Lugert, J. G. Messchendorp, J. Junkersfeld, T. Mertens, Herbert Löhner, Eberhard Klempt, Ch. Funke, I. Jaegle, D. Trnka, R. Varma, B. Bantes, V. A. Nikonov, I. Horn, R. Beck, R. Castelijns, D. V. Novinski, B. Krusche, H. Kalinowsky, Ankhi Roy, Ch. Wendel, V. V. Sumachev, Wolfgang Hillert, D. Elsner, R. W. Novotny, Ph. Hoffmeister, O. Bartholomy, H. van Pee, S. Shende, Frank Klein, and A. Wilson

Subjects
Baryon, Physics, Nuclear physics, Nuclear and High Energy Physics, Pion, Photon, Linear polarization, Partial wave analysis, Photon polarization, Pi, Dalitz plot
Abstract

Photoproduction of two neutral pions off the proton is studied using linearly polarized photons, and the polarization observables I-s and I-c are measured for the first time. These two observables are unique to multi-meson final states; they characterize correlations between the linear photon polarization and the direction of outgoing single particles in photoproduction of three-body final states. The I-s and I-c distributions suggest that, in the 1.8 to 2.0 GeV mass region, the N(1520) 3/2(-)pi intermediate state is reached with reaction dynamics consistent with a dominant J(P) = 3/2(+) wave. These data are included in the Bonn-Gatchina (BnGa) partial wave analysis which is based on a large variety of data; the analysis confirms a significant contribution from the reaction chain gamma p -> N(1900)3/2(+) -> N(1520)3/2(-)pi(0) -> p pi(0)pi(0). (C) 2015 The Authors. Published by Elsevier B.V.

Published
2015

18. Measurement of polarisation observables inKs0Σ+photoproduction off the proton

Author

Volker Metag, H. Dutz, S. Schadmand, T. Mertens, T. C. Jude, Matthew Lang, H. Schmieden, R. Ewald, D. E. Bayadilov, K. Fornet-Ponse, A. B. Gridnev, Mariana Nanova, D. Walther, A. Suele, V. Sokhoyan, Friedrich Klein, J. G. Messchendorp, V. Kleber, T. Szczepanek, M. Ostrick, Herbert Löhner, A. Roy, I. Jaegle, K.-T. Brinkmann, I. V. Lopatin, Ch. Schmidt, R. Varma, V. Crede, E. Gutz, D. Trnka, O. Jahn, R. Beck, Wolfgang Hillert, Lalit Mohan Pant, B. Bantes, S. Kammer, Ch. Funke, D. Elsner, Yu. A. Beloglazov, A. V. Sarantsev, V. A. Nikonov, R. W. Novotny, A. V. Anisovich, Ph. Hoffmeister, B. Schoch, D. Menze, Eberhard Klempt, J. Hannappel, Ch. Wendel, V. V. Sumachev, U. Thoma, J. Junkersfeld, S. Shende, H. Kalinowsky, D. V. Novinski, H. van Pee, B. Krusche, O. Bartholomy, Frank Klein, and Frank Frommberger

Subjects
Physics, Nuclear physics, Nuclear and High Energy Physics, Photon, Proton, Partial wave analysis, Hyperon, Bremsstrahlung, Photon energy, Nuclear Experiment, Nucleon, 7. Clean energy, Sigma baryon
Abstract

The reaction γ p → K S 0 Σ + is studied in the photon energy range from threshold. Linearly polarised photon beams from coherent bremsstrahlung enabled the first measurement of photon beam asymmetries in this reaction up to E γ = 1650 MeV . In addition, the recoil hyperon polarisation was determined through the asymmetry in the weak decay Σ + → p π 0 up to E γ = 2250 MeV . The data are compared to partial wave analyses, and the possible impact on the interpretation of a recently observed prominent structure in the cross section near the K ⁎ thresholds is discussed.

Published
2014

19. Search for η′ Mesic Nuclei in GSI/FAIR

Author

Yasumoto Tanaka, Y. Higashi, E. Widmann, H. Fujioka, Christine Hornung, M. Takechi, Y. Igarashi, I. G. Mukha, Ken Suzuki, Yuni N. Watanabe, N. Ikeno, Satoru Hirenzaki, Peter Strmen, S. Pietri, K.-T. Brinkmann, S. Friedrich, C. Guo, Hans Geissel, Moritz P. Reiter, Nasser Kalantar-Nayestanaki, E. Haettner, Isao Tanihata, M. Iwasaki, T. Nishi, Helmut Weick, J. Zhao, A. Prochazka, X. Xu, E. Gutz, Hooi Jin Ong, J. Benlliure, Tomofumi Nagae, J. Gellanki, Ryugo S. Hayano, V. Metag, J. S. Winfield, H. Yamakami, C. Scheidenberger, R. Knoebel, R. Kanungo, Mariana Nanova, Daisuke Jido, Bao-Hua Sun, Hideko Nagahiro, K. Itahashi, Yassid Ayyad, M.N. Harakeh, S. Terashima, Branislav Sitar, Imrich Szarka, C. Rappold, N. Kurz, Herbert A. Simon, and J. L. Rodriguez-Sanchez

Subjects
Physics, Nuclear physics, Meson, chemistry, chemistry.chemical_element, Anomaly (physics), Nuclear matter, Carbon
Published
2017

20. Excitation Spectra of Carbon Nuclei near \(\eta '\) Emission Threshold

Author

Peter Strmen, J. Zhao, Isao Tanihata, Rituparna Kanungo, Satoru Terashima, Hiroyuki Fujioka, Yoshiki Tanaka, J. L. Rodriguez-Sanchez, Christine Hornung, Eberhard Widmann, Nasser Kalantar-Nayestanaki, Hooi Jin Ong, R. Knoebel, Ryugo S. Hayano, Helmut Weick, J. S. Winfield, Imrich Szarka, C. Rappold, Muhsin N. Harakeh, H. Yamakami, J. Benlliure, Mariana Nanova, Christoph Scheidenberger, Kenta Itahashi, Kai-Thomas Brinkmann, Haik Simon, Satoru Hirenzaki, Volker Metag, Bao-Hua Sun, Moritz P. Reiter, Emma Haettner, X. Xu, Hideko Nagahiro, Natsumi Ikeno, I. G. Mukha, Y. Higashi, A. Prochazka, Yuni N. Watanabe, Maya Takechi, C. Guo, Yassid Ayyad, Nikolaus Kurz, Ken Suzuki, M. Iwasaki, Y. Igarashi, E. Gutz, J. Gellanki, Daisuke Jido, Branislav Sitar, Takahiro Nishi, S. Pietri, Tomofumi Nagae, Hans Geissel, and Stefan Friedrich

Subjects
Physics, Cross section (physics), chemistry, Excitation spectra, Carbon nucleus, chemistry.chemical_element, Atomic physics, Carbon
Published
2017

21. Feasibility study for the measurement of πN transition distribution amplitudes at P¯ANDA in p¯p→J/ψπ0

Author

Tristan Weber, Michaela Thiel, T. Wasem, J. Schwiening, M. Kube, R. Schmitz, D. Lehmann, A. Trzcinski, A. Amoroso, A.A. Efremov, Alexander Olshevskiy, R. Klasen, Herbert Koch, M. Maggiora, A. Dbeyssi, Dipanwita Dutta, F. E. Maas, A. Chlopik, E. Etzelmüller, P. Wintz, V. Lucherini, P. Schakel, P. De Remigis, Krzysztof Swientek, G.S. Shabratova, H. Deppe, Angelo Rivetti, Riccardo Introzzi, K. Dutta, P. Wieczorek, V. M. Datar, W. Lauth, E. A. Strokovsky, L. Busso, M. Hoek, F. Balestra, G. Maniscalco, D. Khaneft, R. Schnell, S. Vejdani, N. G. Minaev, V. Chernetsky, B. Seitz, U. Thoma, K. K. Seth, Mario Bragadireanu, Amiran Tomaradze, B. Fröhlich, S. Pflüger, Valentino Rigato, Franco Bradamante, I. A. Kuyanov, E. Gutz, V. M. Abazov, D. P. Watts, Lennart Isaksson, M. Albrecht, V. Arefiev, T. Schröder, B. Singh, G. Sonika, A. Fechtchenko, C. Rosenbaum, L. Schmitt, Bernd Voss, B. Hetz, S. Sanchez, Magnus Wolke, S.A. Zaporozhets, A. Filippi, S. Coli, Bhavin Patel, A. Khoukaz, Markus Ball, A. Pitka, Krisztian Peters, B. Ramstein, K. Khosonthongkee, M. Pfaffinger, Torbjörn Bäck, D. Veretennikov, J. Pütz, R.A. Salmin, P. Balanutsa, B. J. Liu, A. Hayrapetyan, Chinorat Kobdaj, R. W. Novotny, P. Genova, W. Kühn, P. F. Dalpiaz, S. Belostotski, Ulrich Wiedner, A.S. Vodopianov, Yu.N. Rogov, Wojciech Krzemien, M. Wojciechowski, T. Erlen, Giuseppe Giraudo, B. Zwieglinski, H. Smit, E. Prencipe, J. Jaworowski, R.A. Kunne, S. Lusso, A.G. Fedunov, P. Musiol, C. Schnier, Yan Liang, H. Ohm, Paolo Montagna, A. Karavdina, G. Mazza, N. K. Walford, G. Boca, Boris Batyunya, M. Zyzak, V. Varentsov, M. Kuhlmann, M. Zühlsdorf, V. V. Tokmenin, G. Sterzenbach, M. Tiemens, Stanisław Kistryn, A. Kumar, Alessandro Bressan, F. Lisowski, Paul Alois Buhler, V. Carassiti, D. Prasuhn, M. Zambrana, R. Dzhygadlo, J. Lühning, M.K. Suleimanov, O. Noll, P. Salabura, M. Patsyuk, Christian Schmidt, Johann Zmeskal, M. Barnyakov, A. A. Piskun, F. Feldbauer, Susanna Costanza, Zbigniew Rudy, V. E. Blinov, F. De Mori, Alexander D. Vasiliev, V. Metag, C. Sfienti, Utpal Roy, E. Perevalova, M. Cardinali, R. Birsa, R. Teshev, Aleksandra Wrońska, Egle Tomasi-Gustafsson, F. Uhlig, K. Pysz, T. Sefzick, M. Steinen, V.B. Chandratre, M. Krebs, Matthias Richter, J. P. Wessels, W. Schäfer, M. Fritsch, M. Korjik, J. Rieke, Andreas Lehrach, M. Kavatsyuk, A. Kulkarni, R. F. Parodi, R. Karabowicz, A. Sanchez-Lorente, T.A. Pocheptsov, Valery Dormenev, A. Magiera, H. Flemming, Vassili Kachanov, K. Kalita, W. Erni, P. Poznański, T. Holtmann, O. Miklukho, J. Pychy, S. Bleser, Yu. Yu. Lobanov, Zhiqing Liu, T. Quagli, D. Branford, O. Corell, Konstantin Beloborodov, Dirk Grunwald, Jize Zhao, R. Böhm, L. Capozza, L. Ferrero, A. K. Hergemöller, T. Held, Mario Greco, A. Wilms, Alessandro Drago, I. Augustin, Mathias Fink, A. E. Yakutin, N. Belikov, D. I. Glazier, Sergey Nazarenko, D. Kang, A. Boukharov, M. Kesselkaul, V. Abramov, A. N. Skachkova, S. Bukreeva, U. Thöring, Hans-Georg Zaunick, A. Ryazantsev, S. Marcello, C. Guaraldo, V. Pothodi Chackara, K. Makonyi, A.I. Zinchenko, S. Ryzhikov, S. Orfanitski, Edward Lisowski, K. A. Martin, Ajit Kumar Mohanty, L. Lavezzi, Kirill M. Semenov-Tian-Shansky, S.A. Kononov, L. Gruber, Grzegorz Filo, M. Domagala, L. Cao, V. Di Pietro, S. Grieser, B. Ketzer, S. Schlimme, Marten Ole Schmidt, Alberto Rotondi, M. Michel, C. Schwarz, S. I. Manaenkov, E. A. Kravchenko, R. Beck, A. Gillitzer, Krzysztof Korcyl, B. Slowinski, G. Kesik, Felice Iazzi, U. Müller, D. Calvo, B. Krusche, C. Wang, M. Steinke, A. Gerhardt, V. L. Malyshev, I. Marishev, E. Widmann, Gianangelo Bracco, Harald Kleines, N. I. Zhuravlev, A. Lehmann, D. Nicmorus Marinescu, Patrick Achenbach, A. Apostolou, D. Walther, Johann Marton, C. Sowa, T. Saito, R. Dosdall, Ayut Limphirat, A. Belias, Dan Pantea, A. Täschner, A. Mustafa, D. Marchand, P. Kulessa, M. Galuska, C. Ugur, W. Ikegami Andersson, M. Savrie, C. Hammann, J. C. van der Weele, D. Wölbing, G.B. Pontecorvo, Vivekanand Jha, Hasko Stenzel, D. Przyborowski, P. Drexler, Antoni Szczurek, Tord Johansson, A. Gerasimov, T. Triffterer, A. Britting, S. Ahmed, Mihai Caprini, W. Eyrich, A. Kozela, V. Grishin, O. Malyshev, U. Kurilla, Yupeng Yan, H. Sohlbach, S. Leiber, P. Strzempek, X. Y. Shen, V. V. Mochalov, M. I. Martínez, U. Lynen, I. Lehmann, M. Bai, A. A. Zhdanov, M. Preston, M. Urban, M. Mikirtychyants, I. K. Keshk, Andrea Lavagno, Grzegorz Korcyl, H. Ahmadi, J. Biernat, A. Lai, M. Traxler, Richard Wheadon, M. Pelizäus, A. Cotta Ramusino, D. Rodríguez Piñeiro, Markus Büscher, R. Kliemt, M. M. Macri, V. Kormilitsin, A. Yu. Barnyakov, Z. Li, Ivan Kisel, Arpit Parmar, Tomasz Fiutowski, C. Schmidt, C. Morales Morales, J. Płażek, Michael Düren, Z. J. Sun, H. Loehner, M. Pugach, P. Fedorets, K. Suzuki, A. P. Onuchin, E. Fioravanti, Andrea Bianconi, B. Ma, Yu.M. Mel'nik, M. Deiseroth, F. H. Heinsius, D. G. Ireland, J. S. Lange, Anne-Laure Martin, B. Wohlfahrt, H. Xu, J. Van de Wiele, P. N. Deepak, D. A. Morozov, N. Hüsken, Livio Bianchi, Günter Kemmerling, S. Löchner, B. Galnander, Jifeng Hu, N. B. Skachkov, G. D. Alexeev, T. Ullrich, I. Zimmermann, B. J. Roy, E.K. Koshurnikov, D. Steinschaden, M. Michałek, Bruce Yabsley, M. N. Wagner, S. Wronka, Smbat Grigoryan, Paola Gianotti, Andrey V. Izotov, T. Kuske, S. C. Li, A. G. Zorin, A. Davidenko, M. Lindemulder, V. Astakhov, Andreas Herten, V.I. Lobanov, V.Kh. Dodokhov, Oleg V. Missevitch, Y. Wang, C. Hahn, A. Pyszniak, M.G. Sapozhnikov, L. V. Malinina, Andrey Uzunian, Andrei Fedorov, H. Orth, A. Ehret, Alastair J. Wilson, L. V. Nogach, R. Nellen, Hans Calén, I. Garzia, A.F. Makarov, Harphool Kumawat, S. I. Serednyakov, A. Galoyan, Paweł Moskal, Karin Schönning, W. Czyzycki, J. G. Messchendorp, A. Riccardi, M. Kümmel, A. Sokolov, Maria Krawczyk, Ting Xiao, S. Godre, A. G. Denig, Marek Idzik, M. O. Distler, Frank Goldenbaum, P. Srisawad, G. Kozlov, K. Biguenko, P.J.J. Lemmens, S. Spataro, M. Yu. Barabanov, S. Maldaner, A. Zambanini, Ajay Kumar Rai, I. Shein, M. Böhm, M. Rossbach, A. Demekhin, Yury Tikhonov, A. A. Derevschikov, C. Fritzsch, M. Babai, J. S. Díaz, V. K. Rodionov, A. E. Blinov, A. Cebulla, S. Reiter, A. Samartsev, Bartosz Mindur, V. N. Goryachev, H. B. Liu, B. Kopf, E. Atomssa, C. Wendel, Sean A Dobbs, J. Pochodzalla, Yu.I. Davydov, Genady Gavrilov, Andrew Levin, M.P. Bussa, G. Rosner, S. Jasper, Ankhi Roy, J. Olave, A. Bersani, Bo Cederwall, K. Götzen, B. Kamys, P. Wüstner, Piotr Lebiedowicz, D. Bettoni, A. Dolgolenko, P.-E. Tegnér, Mariana Nanova, D. Melnychuk, V. Akishina, P. A. Semenov, V. Balanutsa, P. Mahlberg, H. Leithoff, Victor Bobrovnikov, M. Papenbrock, L. Fava, R. Valente, R. Veenstra, C. Motzko, K.-T. Brinkmann, F. Nerling, V. Uzhinsky, Harald Merkel, M. Destefanis, D. Lin, Y.M. Goncharenko, M. C. Mora Espí, N. Divani Veis, Pawel Marciniewski, Mohammed Al-Turany, Q. Hu, Andrzej Kupsc, M. Steinacher, Tobias Stockmanns, J. Ritman, S. Diehl, V. Serdyuk, Jerzy Smyrski, A. Gromliuk, M. Mignone, M. Moritz, S. Sosio, S. Schadmand, G. Schepers, S. Poslavskiy, and Joachim Pettersson

Subjects
Quantum chromodynamics, Physics, Particle physics, Luminosity (scattering theory), Annihilation, Meson, 010308 nuclear & particles physics, 7. Clean energy, 01 natural sciences, Particle identification, Nuclear physics, Factorization, Antiproton, 0103 physical sciences, High Energy Physics::Experiment, 010306 general physics, Bar (unit)
Abstract

The exclusive charmonium production process in (P) over barp annihilation with an associated pi 0 meson (p) over barp -> J/psi pi(0) is studied in the framework of QCD collinear factorization. The feasibility of measuring this reaction through the J/psi -> e(+) e(-) decay channel with the AntiProton ANnihilation at DArmstadt ((P) over bar ANDA) experiment is investigated. Simulations on signal reconstruction efficiency as well as the background rejection from various sources including the (P) over barp -> pi(+)pi(-)pi(0) and (p) over barp -> J/psi pi(0)pi(0) reactions are performed with PANDAROOT, the simulation and analysis software framework of the (P) over bar ANDA experiment. It is shown that the measurement can be done at (P) over bar ANDA with significant constraining power under the assumption of an integrated luminosity attainable in four to five months of data taking at the maximum design luminosity.

Published
2017

22. Photoproduction of eta mesons from the neutron: cross sections and double polarization observable E

Author

Ch. Hammann, V. Metag, A. Winnebeck, M. Grüner, Wolfgang Hillert, T. Seifen, J. Müllers, T. Rostomyan, A. V. Anisovich, M. Gottschall, Frank Klein, K. Koop, Friedrich, M. Bichow, D. Elsner, B. Bantes, Jörg H. Müller, D. Piontek, M. Dieterle, Frank Frommberger, I. V. Lopatin, Jens Hartmann, V. Crede, R. Beck, Alastair J. Wilson, T. C. Jude, Ph. Hoffmeister, Suvadeep Bose, V. A. Nikonov, A. V. Sarantsev, E. Gutzınst, Ch. Honisch, Ch. Schmidt, B. Krusche, N. K. Walford, V. Kleber, Lilian Witthauer, D. Hammann, A. Käser, P. Klassen, K. Makonyi, Matthew Lang, H. van Pee, F. Kalischewski, D. Kaiser, S. Kammer, H. Schmieden, D. E. Bayadilov, H. Dutz, A. B. Gridnev, Mariana Nanova, Th. Challand, Ch. Funke, H. Kalinowsky, P. Mahlberg, H. Eberhardt, J. Hannappel, Goertz, Ch. Wendel, D. Werthmüller, U. Thoma, K. Fornet-Ponse, W. Meyer, M. Urban, V. Sokhoyan, K. Spieker, G. Reicherz, I. Keshelashvili, R. Ewald, A. Thiel, F. Afzal, D. Walther, and K.-T. Brinkmann

Subjects
Excitation function, Physics, Nuclear and High Energy Physics, Meson, 010308 nuclear & particles physics, media_common.quotation_subject, Nuclear Theory, FOS: Physical sciences, Observable, Polarization (waves), 01 natural sciences, Helicity, Asymmetry, Nuclear physics, Deuterium, 0103 physical sciences, ddc:530, High Energy Physics::Experiment, Neutron, Nuclear Experiment (nucl-ex), 010306 general physics, Nuclear Experiment, media_common
Abstract

Photoproduction of $\eta$ mesons from neutrons} \abstract{Results from measurements of the photoproduction of $\eta$ mesons from quasifree protons and neutrons are summarized. The experiments were performed with the CBELSA/TAPS detector at the electron accelerator ELSA in Bonn using the $\eta\to3\pi^{0}\to6\gamma$ decay. A liquid deuterium target was used for the measurement of total cross sections and angular distributions. The results confirm earlier measurements from Bonn and the MAMI facility in Mainz about the existence of a narrow structure in the excitation function of $\gamma n\rightarrow n\eta$. The current angular distributions show a forward-backward asymmetry, which was previously not seen, but was predicted by model calculations including an additional narrow $P_{11}$ state. Furthermore, data obtained with a longitudinally polarized, deuterated butanol target and a circularly polarized photon beam were analyzed to determine the double polarization observable $E$. Both data sets together were also used to extract the helicity dependent cross sections $\sigma_{1/2}$ and $\sigma_{3/2}$. The narrow structure in the excitation function of $\gamma n\rightarrow n\eta$ appears associated with the helicity-1/2 component of the reaction.

Published
2017
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23. Experimental constraints on the ω–nucleus real potential

Author

D. Elsner, Frank Frommberger, Ph. Hoffmeister, Matthew Lang, V. Kleber, R. Schmitz, T. Seifen, Yu. A. Beloglazov, Wolfgang Hillert, Jens Hartmann, D. Piontek, I. V. Lopatin, T. Rostomyan, V. Metag, A. Wilson, B. Krusche, J. Hannappel, M. Gottschall, R. Ewald, K. Makonyi, H. Schmieden, D. E. Bayadilov, D. Kaiser, I. Jaegle, U. Wiedner, K.-T. Brinkmann, H. van Pee, A. Thiel, E. Gutz, Yasser Maghrbi, A. B. Gridnev, Mariana Nanova, D. Walther, U. Thoma, M. Grüner, Ch. Honisch, Ch. Hammann, Ch. Schmidt, J. Müller, K. Fornet-Ponse, Friedemann Zenke, V. Crede, S. Friedrich, P. Drexler, S. Kammer, A. Winnebeck, Steffen Schaepe, F. Dietz, H. Eberhardt, Ch. Wendel, Th. Challand, Ch. Funke, Janus Weil, I. Keshelashvili, D. Hammann, Satoru Hirenzaki, T. Odenthal, T. Dahlke, Hideko Nagahiro, Friedrich Klein, B. Bantes, S. Böse, H. Kalinowsky, and R. Beck

Subjects
Physics, education.field_of_study, Nuclear and High Energy Physics, Meson, Hadron, Population, Nuclear Theory, Carbon-12, Elementary particle, lcsh:QC1-999, Pion, Bound state, Atomic physics, Nucleon, education, Nuclear Experiment, lcsh:Physics
Abstract

In a search for $\omega$ mesic states, the production of $\omega$-mesons in coincidence with forward going protons has been studied in photon induced reactions on $^{12}$C for incident photon energies of 1250 - 3100 MeV. The $\pi^0 \gamma$ pairs from decays of bound or quasi-free $\omega$-mesons have been measured with the CBELSA/TAPS detector system in coincidence with protons registered in the MiniTAPS forward array. Structures in the total energy distribution of the $\pi^0 \gamma$ pairs, which would indicate the population and decay of bound $\omega~^{11}$B states, are not observed. The $\pi^0 \gamma$ cross section of 0.3 nb/MeV/sr observed in the bound state energy regime between -100 and 0 MeV may be accounted for by yield leaking into the bound state regime because of the large in-medium width of the $\omega$-meson. A comparison of the measured total energy distribution with calculations suggests the real part $V_0$ of the $\omega~^{11}$B potential to be small and only weakly attractive with $V_0(\rho=\rho_0) = -15\pm$ 35(stat) $\pm$20(syst) MeV in contrast to some theoretical predictions of attractive potentials with a depth of 100 - 150 MeV., Comment: 13 pages, 8 figures

Published
2014
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24. Measurement of Excitation Spectra in the C12(p,d) Reaction near the η′ Emission Threshold

Author

Helmut Weick, Y. Higashi, H. Fujioka, Satoru Hirenzaki, J. Zhao, A. Prochazka, E. Widmann, Ken Suzuki, S. Friedrich, Nasser Kalantar-Nayestanaki, R. Knöbel, X. Xu, S. Pietri, Herbert A. Simon, V. Metag, J. Gellanki, K. Itahashi, Imrich Szarka, C. Rappold, Christine Hornung, J. S. Winfield, Isao Tanihata, Rituparna Kanungo, E. Haettner, Daisuke Jido, M.N. Harakeh, Satoru Terashima, Moritz P. Reiter, J. L. Rodriguez-Sanchez, Mariana Nanova, Yasumoto Tanaka, M. Iwasaki, H. Yamakami, T. Nishi, Bao-Hua Sun, Hideko Nagahiro, Yassid Ayyad, E. Gutz, I. G. Mukha, Hooi Jin Ong, Tomofumi Nagae, Yuni N. Watanabe, N. Ikeno, K.-T. Brinkmann, Y. Igarashi, Maya Takechi, Hans Geissel, Branislav Sitar, N. Kurz, C. Guo, Ryugo S. Hayano, C. Scheidenberger, J. Benlliure, and Peter Strmen

Subjects
Physics, Spectrometer, Proton, 010308 nuclear & particles physics, Nuclear Theory, General Physics and Astronomy, chemistry.chemical_element, 01 natural sciences, Spectral line, Synchrotron, law.invention, chemistry, Deuterium, law, 0103 physical sciences, Bound state, Atomic physics, Nuclear Experiment, 010306 general physics, Carbon, Beam (structure)
Abstract

Excitation spectra of ^{11}C are measured in the ^{12}C(p,d) reaction near the η^{'} emission threshold. A proton beam extracted from the synchrotron SIS-18 at GSI with an incident energy of 2.5 GeV impinges on a carbon target. The momenta of deuterons emitted at 0° are precisely measured with the fragment separator (FRS) operated as a spectrometer. In contrast to theoretical predictions on the possible existence of deeply bound η^{'}-mesic states in carbon nuclei, no distinct structures are observed associated with the formation of bound states. The spectra are analyzed to set stringent constraints on the formation cross section and on the hitherto barely known η^{'}-nucleus interaction.

Published
2016

25. Triangle singularity in the γp → pπ0η reaction ??

Author

Mariana Nanova and Volker Metag

Subjects
Physics, 010308 nuclear & particles physics, QC1-999, Detector, Resonance, 01 natural sciences, Near threshold, Singularity, 0103 physical sciences, Pi, Gravitational singularity, Decay chain, Atomic physics, Nuclear Experiment, 010306 general physics
Abstract

The γp → pπ0η reaction has been studied with the CBELSA/TAPS detector system to search for experimental evidence for triangle singularities. Kinematically these singularities exist in the decay chain Δ* → ηΔ(1232) → ηπ0 p but do not show an experimental effect because of the weakness of the π0 − η interaction at low \sqrt s near threshold far below the a0(980) resonance.

Published
2019

26. Spectroscopy of η′ Mesic Nuclei with (p, d) Reaction

Author

Satoru Hirenzaki, Yoshiki Tanaka, Takahiro Nishi, Mariana Nanova, Satoshi Itoh, Kenta Itahashi, Haruhiko Outa, Volker Metag, Ryugo S. Hayano, Ken Suzuki, Hideko Nagahiro, Kota Okochi, Daisuke Jido, Helmut Weick, Hiroyuki Fujioka, Hans Geissel, Stefan Friedrich, and Takatoshi Suzuki

Subjects
Physics, Chiral symmetry, Spectrometer, Proton, Meson, Nuclear Theory, FOS: Physical sciences, Atomic and Molecular Physics, and Optics, Nuclear physics, High Energy Physics::Experiment, Nuclear Experiment (nucl-ex), Absorption (electromagnetic radiation), Spectroscopy, Nuclear Experiment, Beam (structure), Nuclear density
Abstract

We are going to perform an inclusive spectroscopy experiment of eta' mesic nuclei with the 12C(p,d) reaction to study in-medium properties of the eta' meson. In nuclear medium, the eta' meson mass may be reduced due to partial restoration of chiral symmetry. In case of sufficiently large mass reduction and small absorption width of eta' at normal nuclear density, peak structures of eta' mesic states in 11C will be observed near the eta' emission threshold even in an inclusive spectrum. The experiment will be carried out at GSI with proton beam supplied by SIS using FRS as a spectrometer. The detail of the experiment is described., Comment: 4 pages, 2 figures, to appear in the proceedings of FB20 (20th International IUPAP Conference on Few-Body Problems in Physics), 20-25 August 2012, Fukuoka, Japan

Published
2013

27. Determination of the eta '-nucleus optical potential

Author

Ch. Hammann, Friedemann Zenke, Ch. Honisch, Ch. Schmidt, R. Ewald, P. Drexler, A. Winnebeck, Yasser Maghrbi, E. Ya. Paryev, J. Müller, R. Beck, H. Eberhardt, Jens Hartmann, S. Friedrich, T. Seifen, I. Keshelashvili, Friedrich Klein, D. Walther, U. Thoma, A. Thiel, T. Dahlke, H. Schmieden, Matthew Lang, D. E. Bayadilov, A. B. Gridnev, Mariana Nanova, V. Metag, V. Kleber, Ch. Wendel, I. Jaegle, Eberhard Klempt, K.-T. Brinkmann, Wolfgang Hillert, D. Kaiser, J. Hannappel, Yu. A. Beloglazov, D. Piontek, D. Elsner, I. V. Lopatin, Ph. Hoffmeister, S. Böse, B. Krusche, H. Kalinowsky, S. Kammer, F. Dietz, Th. Challand, Ch. Funke, U. Wiedner, K. Fornet-Ponse, T. Odenthal, D. Hammann, K. Makonyi, H. van Pee, Steffen Schaepe, A. Wilson, Frank Frommberger, M. Grüner, V. Crede, M. Gottschall, E. Gutz, B. Bantes, and R. Schmitz

Subjects
Physics, Excitation function, Nuclear and High Energy Physics, Photon, Meson, 010308 nuclear & particles physics, Hadron, Nuclear Theory, Elementary particle, Electron, Nuclear matter, 01 natural sciences, 0103 physical sciences, Bound state, High Energy Physics::Experiment, Atomic physics, 010306 general physics, Nuclear Experiment
Abstract

The excitation function and momentum distribution of $\eta^\prime$ mesons have been measured in photon induced reactions on $^{12}{}$C in the energy range of 1250-2600 MeV. The experiment was performed with tagged photon beams from the ELSA electron accelerator using the Crystal Barrel and TAPS detectors. The data are compared to model calculations to extract information on the sign and magnitude of the real part of the $\eta^\prime$-nucleus potential. Within the model, the comparison indicates an attractive potential of -($37 \pm 10(stat)\pm10(syst)$) MeV depth at normal nuclear matter density. Since the modulus of this depth is larger than the modulus of the imaginary part of the $\eta^\prime$-nucleus potential of -($10\pm2.5$) MeV, determined by transparency ratio measurements, a search for resolved $\eta^\prime$-bound states appears promising., Comment: 13 pages, 6 figures

Published
2013

28. Momentum dependence of the imaginary part of the $\omega$- and $\eta^\prime$-nucleus optical potential

Author

K. Makonyi, J. Hannappel, Ch. Funke, B. Krusche, H. van Pee, Ulrich Wiedner, Volker Metag, H. Eberhardt, T. Seifen, R. Schmitz, F. Kalischewski, Matthew Lang, T. Triffterer, Y. Wunderlich, E. Gutz, I. Keshelashvili, V. Crede, C. Sowa, Lilian Witthauer, D. Schaab, K. Koop, Friedrich Klein, Suvadeep Bose, F. Afzal, Reinhard Beck, D. Elsner, Ph. Hoffmeister, H. Schmieden, D. E. Bayadilov, D. Kaiser, M. Urban, Mariana Nanova, Ch. Wendel, Wolfgang Hillert, Frank Frommberger, M. Gottschall, V. Sokhoyan, U. Thoma, D. Werthmüller, M. Grüner, B. Bantes, Alastair J. Wilson, T. C. Jude, Jens Hartmann, Matthew L. Becker, D. Piontek, H. G. Zaunick, K. Spieker, D. Walther, J. Müller, A. Thiel, Ch. Hammann, P. Drexler, J. Müllers, Ch. Honisch, Ch. Schmidt, S. Friedrich, Francesco Messi, K.-T. Brinkmann, and T. Rostomyan

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Photon, Meson, 010308 nuclear & particles physics, High Energy Physics::Phenomenology, Nuclear Theory, 01 natural sciences, Omega, Momentum, 0103 physical sciences, Bound state, Production (computer science), ddc:530, High Energy Physics::Experiment, Absorption (logic), 010306 general physics, Nuclear Experiment, Glauber
Abstract

The photoproduction of $\omega$ and $\eta^\prime$ mesons off carbon and niobium nuclei has been measured as a function of the meson momentum for incident photon energies of 1.2-2.9 GeV at the electron accelerator ELSA. The mesons have been identified via the $\omega \rightarrow \pi^0 \gamma \rightarrow 3 \gamma$ and $\eta^\prime\rightarrow \pi^0 \pi^0\eta \rightarrow 6 \gamma$ decays, respectively, registered with the CBELSA/TAPS detector system. From the measured meson momentum distributions the momentum dependence of the transparency ratio has been determined for both mesons. Within a Glauber analysis the in-medium $\omega$ and $\eta^\prime$ widths and the corresponding absorption cross sections have been deduced as a function of the meson momentum. The results are compared to recent theoretical predictions for the in-medium $\omega$ width and $\eta^\prime$-N absorption cross sections. The energy dependence of the imaginary part of the $\omega$- and $\eta^\prime$-nucleus optical potential has been extracted. The finer binning of the present data compared to the existing data allows a more reliable extrapolation towards the production threshold. The modulus of the imaginary part of the $\eta^\prime$ nucleus potential is found to be about three times smaller than recently determined values of the real part of the $\eta^\prime$-nucleus potential, which makes the $\eta^\prime$ meson a suitable candidate for the search for meson-nucleus bound states. For the $\omega$ meson, the modulus of the imaginary part near threshold is comparable to the modulus of the real part of the potential. As a consequence, only broad structures can be expected which makes the observation of $\omega$ mesic states very difficult experimentally., Comment: 10 pages, 8 figures

Published
2016

29. Polarised Photon Beams for the BGO-OD Experiment at ELSA

Author

P. Levi Sandri, S. Friedrich, B.-E. Reitz, V. Ganenko, D. Elsner, Francesco Messi, R. Jahn, T. C. Jude, F. Ghio, K.-T. Brinkmann, V. G. Nedorezov, D. P. Watts, M. Becker, D. Moricciani, A. Bella, D. Walther, P. Pedroni, V. Vegna, R. Joosten, A. M. Lapik, H. Schmieden, D. E. Bayadilov, P. Bielefeldt, A. B. Gridnev, Mariana Nanova, S. Boese, T. Zimmermann, A. Stugelev, V. De Leo, E. Gutz, V. Metag, Wolfgang Hillert, S. Alef, P. Hartmann, B. Krusche, Giuseppe Mandaglio, G. Gervino, T. Rostomyan, M. Romaniuk, A. Braghieri, G. Scheluchin, G. Giardina, J. Hannappel, I. V. Lopatin, H. Dutz, A. Fantini, V. Tarakanov, P. L. Cole, N. V. Rudnev, Reinhard Beck, O. Freyermuth, Hans-Georg Zaunick, V. V. Sumachev, A. Ignatov, C. Schaerf, D. Hammann, Francesca Curciarello, K. Koop, R. Messi, Frank Frommberger, A. N. Mushkarenkov, D. Novinskiy, S. Goertz, Frank Klein, and R. Di Salvo

Subjects
Physics, Nuclear physics, Elastic scattering, law, Bremsstrahlung, Polarimeter, Particle accelerator, Electron, Nuclear Experiment, Polarization (waves), Nucleon, Electromagnetic radiation, law.invention
Abstract

The new BGO-OD experiment at the electron accelerator ELSA, of the University of Bonn, is designed to study the reaction dynamics of nucleon excitations in meson photoproduction. It consists of a central BGO calorimeter with a magnetic spectrometer in forward direction. The physics programme includes the measurement of polarisation observables using linearly and circularly polarised photon beams. Linear polarisation is obtained by coherent bremsstrahlung off a diamond crystal, and circular polarisation is obtained via bremsstrahlung from longitudinally polarised electrons. The degree of linear polarisation is determined from the bremsstrahlung spectrum itself. To determine the polarisation of the circularly polarised photon beam, the polarisation of the electron beam is measured by a Moller polarimeter. As a preliminary consistency check, the (linear) polarisation observable, Σ, was compared to world data for π^0 and η photoproduction. To determine the degree of circular polarisation, a Moller polarimeter was setup and first measurements of the electron beam polarisation performed.

Published
2016

30. Determination of the ω- and η′-nucleus optical potential

Author

Mariana Nanova and Volker Metag

Subjects
Excitation function, Physics, Meson, 010308 nuclear & particles physics, QC1-999, Nuclear Theory, 01 natural sciences, Momentum, Cross section (physics), Distribution (mathematics), Excited state, 0103 physical sciences, Bound state, High Energy Physics::Experiment, Atomic physics, 010306 general physics, Nuclear Experiment, Sign (mathematics)
Abstract

The ω and η ′-nucleus interaction has been studied in photoproduction reactions off C and Nb targets, using the CBELSA/TAPS detector system. Transparency ratio measurements provide information on the inelastic cross section and in-medium width of mesons and thereby on the imaginary part of the meson-nucleus potential. The real part of the optical potential can be deduced from measurements of the excitation function and momentum distribution which are sensitive to the sign and depth of the potential. Data taken on a C and Nb target have been analysed to determine the real and the imaginary part of the ω - and η ′-nucleus optical potential. The momentum dependence of the imaginary part of both mesons is presented and discussed. The results are compared to previous experimental results and to model calculations assuming different scenarios. The data are consistent with a weakly attractive potential for both mesons. The relatively small in-medium width of the η ′ meson encourages the search for η ′ bound states.

Published
2016

31. Commissioning and initial experimental program of the BGO-OD experiment at ELSA

Author

D. Elsner, K. Koop, V. G. Nedorezov, D. Geffers, Wolfgang Hillert, R. Jahn, H. Dutz, H. Schmieden, D. Moricciani, D. E. Bayadilov, R. Messi, T. C. Jude, G. Scheluchin, Friedrich Klein, T. Rostomyan, A. B. Gridnev, A. Ignatov, Mariana Nanova, M. Becker, S. Böse, V. Tarakanov, G. Gervino, P. Levi Sandri, D. Walther, J. Knaust, D. P. Watts, E. Gutz, P. Bielefeldt, Reinhard Beck, S. Friedrich, A. Braghieri, A. M. Lapik, N. Rudnev, Francesco Messi, B.-E. Reitz, A. Stugelev, V. Ganenko, S. Görtz, Hans-Georg Zaunick, Patrick Bauer, F. Ghio, V. V. Sumachev, C. Schaerf, I. V. Lopatin, D. Hammann, Volker Metag, K.-T. Brinkmann, S. Alef, T. Zimmermann, V. Vegna, P. Cole, R. Joosten, P. Pedroni, K. Kohl, A. Fantini, B. Krusche, Giuseppe Mandaglio, M. Romaniuk, O. Freyermuth, A. Bella, J. Hannappel, D. Novinskiy, A. Mushkarenkov, R. Di Salvo, and Frank Frommberger

Subjects
Photon, Meson, QC1-999, Hadron, Nuclear Theory, Elementary particle, Astrophysics, radiation detection, 01 natural sciences, Particle detector, Nuclear physics, Hadron Physics, 0103 physical sciences, Nuclear Physics, Hadron Physics, radiation detection, 010306 general physics, Nuclear Experiment, Nuclear Physics, Physics, 010308 nuclear & particles physics, Settore FIS/04, Detector, High Energy Physics::Phenomenology, Hyperon, Baryon, High Energy Physics::Experiment
Abstract

BGO-OD is a new meson photoproduction experiment at the ELSA facility of Bonn University. It aims at the investigation of non strange and strange baryon excitations, and is especially designed to be able to detect weekly bound meson-baryon type structures. The setup for the BGO-OD experiment is presented, the characteristics of the photon beam and the detector performances are shown and the initial experimental program is discussed.

Published
2016

32. Double-polarization observable G in neutral-pion photoproduction off the proton

Author

U. Thoma, V. Crede, F. Afzal, Reinhard Beck, D. Elsner, P. Klassen, H. Dutz, K.-T. Brinkmann, S. Kammer, S. Runkel, H. Eberhardt, D. Walther, I. Keshelashvili, Ch. Honisch, Ch. Hammann, K. Fornet-Ponse, Ch. Schmidt, Ch. Funke, B. Krusche, Ch. Wendel, M. Grüner, E. Gutz, Jens Hartmann, S. Böse, A. Winnebeck, G. Reicherz, A. V. Anisovich, P. Mahlberg, H. Kalinowsky, K. Spieker, M. Bichow, Friedrich Klein, S. Friedrich, J. Müllers, Eberhard Klempt, Volker Metag, A. V. Sarantsev, Matthew Lang, W. Meyer, St. Goertz, M. Urban, Frank Frommberger, D. Kaiser, M. Dieterle, V. A. Nikonov, F. Kalischewski, B. Bantes, V. Sokhoyan, K. Koop, R. Ewald, H. Schmieden, D. E. Bayadilov, A. Thiel, A. B. Gridnev, Mariana Nanova, M. Kube, M. Gottschall, Wolfgang Hillert, J. Hannappel, Ph. Hoffmeister, V. Kleber, T. Seifen, Alastair J. Wilson, T. C. Jude, D. Piontek, I. V. Lopatin, Lilian Witthauer, D. Hammann, K. Makonyi, S. Reeve, H. van Pee, and J. Müller

Subjects
Physics, Nuclear and High Energy Physics, Photon, Proton, 010308 nuclear & particles physics, Nuclear Theory, Bremsstrahlung, Diamond, FOS: Physical sciences, Observable, Photon energy, engineering.material, Polarization (waves), 01 natural sciences, Nuclear physics, Pion, 0103 physical sciences, engineering, ddc:530, Nuclear Experiment (nucl-ex), 010306 general physics, Nuclear Experiment
Abstract

This paper reports on a measurement of the double-polarization observable G in $\pi^0$ photoproduction off the proton using the CBELSA/TAPS experiment at the ELSA accelerator in Bonn. The observable G is determined from reactions of linearly-polarized photons with longitudinally-polarized protons. The polarized photons are produced by bremsstrahlung off a properly oriented diamond radiator. A frozen spin butanol target provides the polarized protons. The data cover the photon energy range from 617 to 1325 MeV and a wide angular range. The experimental results for G are compared to predictions by the Bonn-Gatchina (BnGa), J\"ulich-Bonn (J\"uBo), MAID and SAID partial wave analyses. Implications of the new data for the pion photoproduction multipoles are discussed.

Published
2016
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33. Search for η ′ mesic nuclei by missing-mass spectroscopy of the12C(p, d) reaction

Author

Satoru Terashima, R. Knoebel, Imrich Szarka, C. Rappold, Y. Higashi, C. Guo, J. Zhao, Yuni N. Watanabe, Moritz P. Reiter, S. Pietri, Nikolaus Kurz, J. Gellanki, Kenta Itahashi, Satoru Hirenzaki, Nasser Kalantar-Nayestanaki, J. Benlliure, H. Yamakami, Eberhard Widmann, I. G. Mukha, Maya Takechi, Y. Igarashi, Hooi Jin Ong, Peter Strmen, Branislav Sitar, X. Xu, Masahiko Iwasaki, Yoshiki Tanaka, Muhsin N. Harakeh, José L. Sánchez, Mariana Nanova, A. Prochazka, Tomofumi Nagae, Daisuke Jido, Kai-Thomas Brinkmann, Christoph Scheidenberger, E. Gutz, Haik Simon, Emma Haettner, Christine Hornung, Yassid Ayyad, Ken Suzuki, Volker Metag, Helmut Weick, Bao-Hua Sun, Hideko Nagahiro, J. S. Winfield, Hans Geissel, Stefan Friedrich, Ryugo S. Hayano, Takahiro Nishi, Isao Tanihata, Rituparna Kanungo, N. Ikeno, and Hiroyuki Fujioka

Subjects
deuteron, QC1-999, excited state: energy spectrum, threshold: production, 2.5 GeV, Mass spectrometry, Proton energy, 01 natural sciences, Nuclear physics, mesic atom, 0103 physical sciences, Nuclear Experiment, 010306 general physics, Spectroscopy, Physics, cross section, 010308 nuclear & particles physics, carbon, formation, Cross section (geometry), Deuterium, Atomic physics, missing-mass, eta(958): production, experimental results
Abstract

14th International Workshop on Meson Production, Properties and Interaction, Cracow, Poland, 2 Jun 2016 - 7 Jun 2016; The European physical journal / Web of Conferences Web of Conferences : proceedings proceedings 130, 02010 (2016). doi:10.1051/epjconf/201613002010, We performed a missing-mass spectroscopy experiment of the ^12C(p, d) reaction at 2.5 GeV proton energy in order to search for eta' mesic nuclei. An excitation-energy spectrum of ^11C was obtained around the eta' production threshold. As no significant peak structure was observed in the spectrum, upper limits of the formation cross section of eta' mesic nuclei have been determined. Preliminary results of the experiment as well as future prospects are given., Published by EDP Sciences, Les Ulis

Published
2016

34. Strangeness Photoproduction at the BGO-OD Experiment

Author

V. G. Nedorezov, Frank Frommberger, V. Metag, A. Ignatov, Hans-Georg Zaunick, V. Tarakanov, T. Zimmermann, N. V. Rudnev, D. Hammann, D. Moricciani, P. Bielefeldt, Wolfgang Hillert, P. Pedroni, A. N. Mushkarenkov, D. P. Watts, V. Vegna, O. Freyermuth, D. Novinskiy, D. Elsner, Francesca Curciarello, S. Goertz, V. De Leo, B. Krusche, Giuseppe Mandaglio, R. Messi, M. Romaniuk, H. Dutz, A. Braghieri, B.-E. Reitz, P. Levi Sandri, A. Bella, V. Ganenko, Reinhard Beck, P. Hartmann, Frank Klein, R. Di Salvo, T. Rostomyan, G. Scheluchin, E. Gutz, A. Fantini, D. Walther, S. Friedrich, F. Ghio, Francesco Messi, V. V. Sumachev, S. Boese, P. L. Cole, R. Joosten, S. Alef, G. Giardina, R. Jahn, K. Koop, J. Hannappel, T. C. Jude, M. Becker, I. V. Lopatin, A. Stugelev, K.-T. Brinkmann, A. M. Lapik, G. Gervino, H. Schmieden, D. E. Bayadilov, A. B. Gridnev, and Mariana Nanova

Subjects
Meson, Nuclear Theory, FOS: Physical sciences, Electron, Strangeness, Tracking (particle physics), nucl-ex, 01 natural sciences, Nuclear physics, photoproduction, dynamically generated resonance, strangeness, BGO-OD, 0103 physical sciences, Nuclear Experiment (nucl-ex), 010306 general physics, Nuclear Experiment, Physics, Settore FIS/01, Calorimeter (particle physics), Spectrometer, 010308 nuclear & particles physics, photoproduction, dynamically generated resonance, strangeness, BGO-OD, High Energy Physics::Experiment, Nucleon, Beam (structure)
Abstract

BGO-OD is a newly commissioned experiment to investigate the internal structure of the nucleon, using an energy tagged bremsstrahlung photon beam at the ELSA electron facility. The setup consists of a highly segmented BGO calorimeter surrounding the target, with a particle tracking magnetic spectrometer at forward angles. BGO-OD is ideal for investigating meson photoproduction. The extensive physics programme for open strangeness photoproduction is introduced, and preliminary analysis presented., 6 pages, 4 figures. Proceedings for the 10th International Workshop on the Physics of Excited Nucleons (NSTAR2015)

Published
2016

35. Determination of the real part of the η ′ -Nb optical potential

Author

J. Müllers, Y. Wunderlich, Matthew Lang, J. Hannappel, Alastair J. Wilson, T. C. Jude, M. Becker, Ulrich Wiedner, U. Thoma, R. Schmitz, T. Triffterer, E. Gutz, D. Elsner, V. Crede, V. Metag, Ph. Hoffmeister, Suvadeep Bose, Christian Schmidt, A. Thiel, K. Spieker, B. Krusche, Friedrich Klein, Ch. Hammann, T. Rostomyan, K.-T. Brinkmann, Wolfgang Hillert, D. Walther, K. Koop, M. Urban, D. Schaab, E. Ya. Paryev, D. Piontek, Jörg H. Müller, Jens Hartmann, F. Afzal, H. Schmieden, D. E. Bayadilov, Mariana Nanova, K. Makonyi, H. van Pee, Hans-Georg Zaunick, S. Friedrich, Lilian Witthauer, Francesco Messi, Ch. Honisch, F. Kalischewski, Reinhard Beck, Frank Frommberger, Ch. Wendel, C. Sowa, D. Werthmüller, M. Grüner, I. Keshelashvili, and T. Seifen

Subjects
Excitation function, Physics, Meson, 010308 nuclear & particles physics, Nuclear Theory, Bremsstrahlung, Particle accelerator, Nuclear matter, 01 natural sciences, law.invention, Nuclear physics, Momentum, law, Excited state, 0103 physical sciences, Bound state, High Energy Physics::Experiment, ddc:530, Atomic physics, 010306 general physics, Nuclear Experiment
Abstract

The excitation function and momentum distribution of {\eta}' mesons have been measured in photoproduction off 93^Nb in the energy range of 1.2-2.9 GeV. The experiment has been performed with the combined Crystal Barrel and MiniTAPS detector system, using tagged photon beams from the ELSA electron accelerator. Information on the sign and magnitude of the real part of the {\eta}'-Nb potential has been extracted from a comparison of the data with model calculations. An attractive potential of -(41 \pm 10(stat) \pm 15(syst)) MeV depth at normal nuclear matter density is deduced within model uncertainties. This value is consistent with the potential depth of -(37 \pm 10(stat) \pm 10(syst)) MeV obtained in an earlier measurement for a light nucleus (carbon). This relatively shallow {\eta}'-nucleus potential will make the search for {\eta}'-nucleus bound states more difficult., Comment: 9 pages, 6 figures

Published
2016

36. Anomaly in the KS0Σ+ photoproduction cross section off the proton at the K⁎ threshold

Author

Volker Metag, Wolfgang Hillert, S. Shende, A. Suele, D. Walther, S. Kammer, Ch. Funke, Frank Frommberger, J. Hannappel, H. van Pee, D. Elsner, B. Krusche, D. Menze, R. W. Novotny, Ph. Hoffmeister, O. Bartholomy, B. Schoch, H. Schmieden, U. Thoma, D. E. Bayadilov, A. B. Gridnev, E. Gutz, A. Roy, Mariana Nanova, T. Szczepanek, V. Sokhoyan, Eberhard Klempt, Yu. A. Beloglazov, Ch. Wendel, R. Beck, V. V. Sumachev, Frank Klein, J. Junkersfeld, K. T Brinkmann, H. Kalinowsky, Matthew Lang, S. Schadmand, M. Ostrick, V. Kleber, R. Varma, L. M. Pant, H. Dutz, V. Crede, T. Mertens, Herbert Löhner, R. Ewald, B. Bantes, D. V. Novinski, D. Trnka, Ch. Schmidt, O. Jahn, K. Fornet-Ponse, I. Jaegle, Friedrich Klein, I. V. Lopatin, T. C. Jude, and J. G. Messchendorp

Subjects
Physics, Nuclear physics, Baryon, Nuclear and High Energy Physics, Cross section (physics), Proton, Meson, Hadron, Elementary particle, Strangeness, Nucleon
Abstract

The γ + p → K 0 + Σ + photoproduction reaction is investigated in the energy region from threshold to E γ = 2250 MeV . The differential cross section exhibits increasing forward-peaking with energy, but only up to the K ⁎ threshold. Beyond, it suddenly returns to a flat distribution with the forward cross section dropping by a factor of four. In the total cross section a pronounced structure is observed between the K ⁎ Λ and K ⁎ Σ thresholds.

Published
2012

37. Transparency ratio in γA→η′A′ and the in-medium η′ width

Author

B. Krusche, I. Horn, V. Metag, A. Radkov, S. Lugert, O. Bartholomy, D. Menze, Angels Ramos, Eberhard Klempt, S. Höffgen, K.-T. Brinkmann, T. Szczepanek, Ch. Wendel, I. Jaegle, A. Süle, V. V. Sumachev, J. Junkersfeld, K. Essig, C. Morales, M. Fuchs, H. Dutz, Frank Klein, Yu. A. Beloglazov, A. Ehmanns, E. Gutz, Ch. Funke, M. Konrad, Lalit Mohan Pant, M. Ostrick, H. Kalinowsky, M. Pfeiffer, Friedrich Klein, K. Makonyi, R. Ewald, I. V. Lopatin, T. Mertens, Herbert Löhner, H. van Pee, V. Crede, B. Kopf, D. Trnka, J. Langheinrich, J. G. Messchendorp, D. Elsner, U. Thoma, Ankhi Roy, R. W. Novotny, J. Lotz, D. Walther, Ph. Hoffmeister, B. Schoch, Ch. Schmidt, Eulogi Oset, H. Schmieden, D. E. Bayadilov, A. B. Gridnev, Mariana Nanova, I. Fabry, S. Schadmand, R. Gregor, and R. Varma

Subjects
Physics, Nuclear and High Energy Physics, Photon, Proton, Meson, 010308 nuclear & particles physics, Scattering, Nuclear Theory, Niobium, chemistry.chemical_element, Rest frame, 7. Clean energy, 01 natural sciences, Momentum, Nuclear physics, Cross section (physics), chemistry, 0103 physical sciences, High Energy Physics::Experiment, Atomic physics, Nuclear Experiment, 010306 general physics
Abstract

The photoproduction of η ′ -mesons off different nuclei has been measured with the CBELSA/TAPS detector system for incident photon energies between 1500–2200 MeV. The transparency ratio has been deduced and compared to theoretical calculations describing the propagation of η ′ -mesons in nuclei. The comparison indicates a width of the η ′ -meson of the order of Γ = 15 – 25 MeV at ρ = ρ 0 for an average momentum p η ′ = 1050 MeV / c , at which the η ′ -meson is produced in the nuclear rest frame. The inelastic η ′ N cross section is estimated to be 3–10 mb. Parameterizing the photoproduction cross section of η ′ -mesons by σ ( A ) = σ 0 A α , a value of α = 0.84 ± 0.03 has been deduced.

Published
2012

38. Erratum to: High-statistics study of the reaction $\gamma p\rightarrow p2\pi^{0}$

Author

V. Metag, S. Lugert, Eberhard Klempt, T. Seifen, M. Kotulla, Alastair J. Wilson, Frank Klein, M. Ostrick, D. Walther, S. Kammer, Friedrich Klein, T. Mertens, H. Dutz, V. A. Nikonov, Ch. Funke, Herbert Löhner, J. G. Messchendorp, Lalit Mohan Pant, V. Crede, I. Horn, Frank Frommberger, S. Shende, A. Thiel, Ankhi Roy, Ch. Schmidt, V. Sokhoyan, R. Ewald, B. Krusche, H. Pee, O. Bartholomy, M. Pfeiffer, T. Szczepanek, E. Gutz, B. Bantes, H. Kalinowsky, Michael Fuchs, Yu. A. Beloglazov, D. Piontek, J. C. S. Bacelar, A. V. Sarantsev, B. Metsch, D. Trnka, I. V. Lopatin, Ch. Wendel, Matthew Lang, V. V. Sumachev, A. V. Anisovich, I. Jaegle, V. Kleber, R. Gregor, R. Varma, J. Junkersfeld, D. Elsner, R. W. Novotny, Ph. Hoffmeister, U. Thoma, R. Castelijns, H. Schmieden, D. E. Bayadilov, A. B. Gridnev, Mariana Nanova, A. Süle, Wolfgang Hillert, D. Novinsky, and R. Beck

Subjects
Physics, Baryon, Nuclear and High Energy Physics, Meson, Isospin, Partial wave analysis, Bremsstrahlung, Dalitz plot, Photon energy, Atomic physics, Nucleon
Abstract

The photoproduction of 2π$^{0}$ mesons off protons was studied with the Crystal Barrel/TAPS experiment at the electron accelerator ELSA in Bonn. The energy of photons produced in a radiator was tagged in the energy range from 600 MeV to 2.5 GeV. Differential and total cross sections and pπ$^{0}$ π$^{0}$ Dalitz plots are presented. Part of the data was taken with a diamond radiator producing linearly polarized photons, and beam asymmetries were derived. Properties of nucleon and Δ resonances contributing to the pπ$^{0}$ π$^{0}$ final state were determined within the Bonn-Gatchina (BnGa) partial-wave analysis. The data presented here allow us to determine branching ratios of nucleon and Δ resonances for their decays into pπ$^{0}$ π$^{0}$ via several intermediate states. Most prominent are decays proceeding via Δ(1232)π, N(1440)1/2$^{+}$ π, N(1520)3/2$^{−}$ π, N(1680)5/2$^{+}$ π, but also pf$_{0}$(500), pf$_{0}$(980), and pf$_{2}$(1270) contribute to the reaction.

Published
2015

39. Photoproduction of meson pairs: First measurement of the polarization observable Is

Author

Matthew Lang, T. Mertens, Herbert Löhner, A. Suele, Michael Fuchs, V. Crede, D. Piontek, D. Walther, M. Pfeiffer, I. V. Lopatin, A. Thiel, V. Metag, Ch. Schmidt, H. Dutz, V. Sokhoyan, J. G. Messchendorp, M. Kotulla, J. C. S. Bacelar, Friedrich Klein, R. Beck, I. Jaegle, Winston Roberts, M. Ostrick, R. Gregor, R. Ewald, R. Castelijns, S. Schadmand, Ch. Weinheimer, H. Schmieden, R. Varma, D. E. Bayadilov, A. B. Gridnev, Mariana Nanova, D. Trnka, D. Elsner, T. Szczepanek, V. Kleber, R. W. Novotny, Ph. Hoffmeister, S. Kammer, B. Schoch, Ch. Funke, Lalit Mohan Pant, S. Lugert, Wolfgang Hillert, Eberhard Klempt, Ankhi Roy, V. A. Nikonov, D. Menze, I. Horn, A. V. Anisovich, Ch. Wendel, B. Bantes, V. V. Sumachev, Yu. A. Beloglazov, A. V. Sarantsev, H. Kalinowsky, B. Krusche, E. Gutz, D. V. Novinski, S. Shende, U. Thoma, H. van Pee, O. Bartholomy, J. Junkersfeld, Frank Frommberger, and Frank Klein

Subjects
Physics, Nuclear and High Energy Physics, Photon, Meson, Proton, Linear polarization, media_common.quotation_subject, Partial wave analysis, FOS: Physical sciences, Observable, Polarization (waves), Asymmetry, Nuclear physics, High Energy Physics::Experiment, Nuclear Experiment (nucl-ex), Nuclear Experiment, media_common
Abstract

The polarization observable I^s, a feature exclusive to the acoplanar kinematics of multi-meson final states produced via linearly polarized photons, has been measured for the first time. Results for the reaction g p -> p pi0 eta are presented for incoming photon energies between 970 MeV and 1650 MeV along with the beam asymmetry I^c. The comparably large asymmetries demonstrate a high sensitivity of I^s to the dynamics of the reaction. Fits using Bonn-Gatchina partial wave analysis demonstrate that the new polarization observables carry significant information on the contributing partial waves., 11 pages, 6 figures, v2 to appear in Phys. Lett. B

Published
2010

40. High-statistics study of the reaction γp → p2π0

Author

S. Kammer, Ch. Funke, M. Kotulla, V. Crede, T. Szczepanek, E. Gutz, Alastair J. Wilson, H. Schmieden, Yu. A. Beloglazov, J. C. S. Bacelar, A. V. Sarantsev, D. E. Bayadilov, A. B. Gridnev, Mariana Nanova, Frank Frommberger, V. Sokhoyan, V. Metag, H. Kalinowsky, H. Dutz, A. V. Anisovich, J. G. Messchendorp, U. Thoma, O. Bartholomy, Friedrich Klein, V. A. Nikonov, M. Pfeiffer, Lalit Mohan Pant, M. Ostrick, J. Junkersfeld, T. Seifen, I. Horn, S. Lugert, Ch. Schmidt, Ch. Wendel, V. V. Sumachev, Eberhard Klempt, T. Mertens, Frank Klein, Herbert Löhner, Michael Fuchs, A. Thiel, D. Piontek, B. Metsch, Ankhi Roy, I. V. Lopatin, H. van Pee, B. Krusche, S. Shende, B. Bantes, Wolfgang Hillert, D. Elsner, R. W. Novotny, Ph. Hoffmeister, I. Jaegle, D. Walther, R. Ewald, R. Varma, V. Kleber, Matthew Lang, R. Gregor, D. Novinsky, R. Beck, D. Trnka, R. Castelijns, and A. Süle

Subjects
Nuclear physics, Physics, Nuclear and High Energy Physics, Range (particle radiation), Photon, Meson, law, Linear polarization, Partial wave analysis, Particle accelerator, Nucleon, Beam (structure), law.invention
Abstract

The photoproduction of 2$\pi^0$ mesons off protons was studied with the Crystal Barrel/TAPS experiment at the electron accelerator ELSA in Bonn. The energy of photons produced in a radiator was tagged in the energy range from 600\,MeV to 2.5\,GeV. Differential and total cross sections and $p\pi^0\pi^0$ Dalitz plots are presented. Part of the data was taken with a diamond radiator producing linearly polarized photons, and beam asymmetries were derived. Properties of nucleon and $\Delta$ resonances contributing to the $p\pi^0\pi^0$ final state were determined within the BnGa partial wave analysis. The data presented here allow us to determine branching ratios of nucleon and $\Delta$ resonances for their decays into $p\pi^0\pi^0$ via several intermediate states. Most prominent are decays proceeding via $\Delta(1232)\pi$, $N(1440)1/2^+\pi$, $N(1520)3/2^-\pi$, $N(1680)5/2^+\pi$, but also $pf_0(500)$, $pf_0(980)$, and $pf_2(1270)$ contribute to the reaction.

Published
2015

41. Erratum: Modification of theω-Meson Lifetime in Nuclear Matter [Phys. Rev. Lett.100, 192302 (2008)]

Author

M. Kotulla, A. Ehmanns, I. Jaegle, Ulrich Mosel, Gisela Anton, V. Metag, V. Crede, S. Hoeffgen, I. Fabry, R. W. Gothe, Yu. A. Beloglazov, T. Mertens, J. C. S. Bacelar, M. Konrad, S. Shende, J. G. Messchendorp, D. E. Bayadilov, E. Gutz, H. Dutz, J. Lotz, A. B. Gridnev, Mariana Nanova, J. Hoessl, O. Bartholomy, Michael Fuchs, D. Trnka, J. Langheinrich, R. Gregor, I. V. Lopatin, D. Elsner, R. W. Novotny, Ph. Hoffmeister, R. Castelijns, R. Ewald, K. Essig, S. Schadmand, S. Lugert, Eberhard Klempt, P. Muehlich, J. Junkersfeld, H. Loehner, Fritz Klein, I. Horn, D. Menze, B. Kopf, Ch. Funke, B. Krusche, H. Kalinowsky, R. Bogendoerfer, and Frank Klein

Subjects
Nuclear physics, Physics, Particle physics, Meson production, Meson, General Physics and Astronomy, Nuclear matter, Omega
Published
2015

42. Spectroscopy of η′-nucleus bound states at GSI and FAIR — very preliminary results and future prospects

Author

Yuni N. Watanabe, I. G. Mukha, Moritz P. Reiter, C. Guo, Mariana Nanova, M. Iwasaki, Helmut Weick, S. Pietri, J. Zhao, Kai-Thomas Brinkmann, Yasumoto Tanaka, R. Kanungo, K. Itahashi, C. Scheidenberger, R. Knoebel, J. S. Winfield, Y. Higashi, Volker Metag, Hans Geissel, J. Benlliure, Peter Strmen, Christine Hornung, Imrich Szarka, C. Rappold, H. Yamakami, Hooi Jin Ong, Stefan Friedrich, Daisuke Jido, E. Gutz, N. Ikeno, Nasser Kalantar-Nayestanaki, Ken Suzuki, Y. Igarashi, J. L. Rodriguez-Sanchez, Yassid Ayyad, Eberhard Widmann, H. Fujioka, Satoru Hirenzaki, Ryugo S. Hayano, A. Prochazka, J. Gellanki, Tomofumi Nagae, X. Xu, Bao-Hua Sun, E. Haettner, Hideko Nagahiro, M.N. Harakeh, S. Terashima, Takahiro Nishi, Herbert A. Simon, Branislav Sitar, N. Kurz, M. Takechi, Isao Tanihata, and Research unit Nuclear & Hadron Physics

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Chiral symmetry, Partial restoration of chiral symmetry, Nuclear Theory, nucl-th, 81V05, U[A] (1) anomaly, Condensed Matter Physics, nucl-ex, Atomic and Molecular Physics, and Optics, η′ mesic nuclei, medicine.anatomical_structure, Bound state, medicine, Physical and Theoretical Chemistry, Anomaly (physics), Spectroscopy, Nuclear Experiment, Nucleus
Abstract

The possible existence of \eta'-nucleus bound states has been put forward through theoretical and experimental studies. It is strongly related to the \eta' mass at finite density, which is expected to be reduced because of the interplay between the $U_A(1)$ anomaly and partial restoration of chiral symmetry. The investigation of the C(p,d) reaction at GSI and FAIR, as well as an overview of the experimental program at GSI and future plans at FAIR are discussed., Comment: 7 pages, 3 figures; talk at the International Conference on Exotic Atoms and Related Topics (EXA2014), Vienna, Austria, 15-19 September 2014. in Hyperfine Interactions (2015)

Published
2015

43. Three-Body Nature ofN*andΔ*Resonances from Sequential Decay Chains

Author

Frank Klein, V. Sokhoyan, A. Wilson, E. Gutz, M. Pfeiffer, S. Shende, J. Junkersfeld, J. G. Messchendorp, R. Beck, D. V. Novinski, Ch. Schmidt, M. Kotulla, D. Walther, V. A. Nikonov, R. Castelijns, Matthew Lang, Wolfgang Hillert, A. Thiel, A. V. Anisovich, I. Horn, S. Lugert, H. Kalinowsky, Cbelsa, U. Thoma, Eberhard Klempt, B. Bantes, V. Kleber, D. Elsner, Volker Metag, H. van Pee, R. Gregor, R. Varma, T. Mertens, Friedrich Klein, Herbert Löhner, R. W. Novotny, Yu. A. Beloglazov, B. Krusche, A. Roy, A. V. Sarantsev, Ph. Hoffmeister, O. Bartholomy, L. M. Pant, H. Dutz, S. Kammer, Bernard Metsch, Frank Frommberger, D. Piontek, Ch. Wendel, Ch. Funke, I. V. Lopatin, V. V. Sumachev, H. Schmieden, V. Crede, D. E. Bayadilov, A. B. Gridnev, Mariana Nanova, A. Süle, I. Jaegle, M. Ostrick, D. Trnka, J. C. S. Bacelar, R. Ewald, T. Szczepanek, and M. Fuchs

Subjects
Physics, Partial wave analysis, Nuclear Theory, General Physics and Astronomy, Dalitz plot, Delta baryon, Particle decay, Pion, Isobar, High Energy Physics::Experiment, Decay chain, Atomic physics, Nuclear Experiment, Nucleon
Abstract

The N pi(0)pi(0) decays of positive-parity N* and Delta* resonances at about 2 GeV are studied at ELSA by photoproduction of two neutral pions off protons. The data reveal clear evidence for several intermediate resonances: Delta(1232), N(1520)3/2(-), and N(1680)5/2(+), with spin parities J(P) = 3/2(+), 3/2(-), and 5/2(+). The partial wave analysis (within the Bonn-Gatchina approach) identifies N(1440)1/2(+) and the N(pi pi)s (wave) (abbreviated as N sigma here) as further isobars and assigns the final states to the formation of nucleon and Delta resonances and to nonresonant contributions. We observe the know Delta(1232)pi decays of Delta(1910)1/2(+), Delta(1920)3/2(+), Delta(1905)5/2(+), Delta(1950)7/2(+), and of the corresponding spin-parity series in the nucleon sector, N(1880)1/2(+), N(1900)3/2(+), N(2000)5/2(+), and N(1990)7/2(+). For the nucleon resonances, these decay modes are reported here for the first time. Further new decay modes proceed via N(1440)1/2(pi)(+), N(1520)3/2(pi)(-) , N(1680)5/2(pi)(+), and N sigma. The latter decay modes are observed in the decay of N* resonances and at most weakly in Delta(*) decays. It is argued that these decay modes provide evidence for a 3-quark nature of N* resonances rather than a quark-diquark structure.

Published
2015

44. Photoproduction of omega mesons off protons and neutrons

Author

A. Süle, S. Höffgren, O. Bartholomy, M. Kotulla, Ankhi Roy, M. Konrad, Friedrich Klein, M. Ostrick, S. Schadmand, Matthew Lang, H. Dutz, M. Pfeiffer, J. C. S. Bacelar, V. Kleber, S. Shende, J. Junkersfeld, H. Schmieden, D. E. Bayadilov, V. Crede, H. Kalinowsky, R. Ewald, A. B. Gridnev, Mariana Nanova, I. Jaegle, A. V. Anisovich, Ch. Schmidt, T. Szczepanek, D. Menze, H. van Pee, S. Kammer, Frank Klein, R. Varma, F. Dietz, A. Wilson, I. V. Lopatin, T. Mertens, Herbert Löhner, U. Thoma, V. Shklyar, Ch. Wendel, Lalit Mohan Pant, Frank Frommberger, C. Funke, R. Beck, D. Walter, V. V. Sumachev, J. G. Messchendorp, R. W. Gothe, R. Castelijns, R. Gregor, D. Trnka, E. Gutz, V. Metag, B. Bantes, T. Rostomyan, V. A. Nikonov, I. Horn, S. Lugert, Eberhard Klempt, Y. A. Belogazov, D. Elsner, R. W. Novotny, Ph. Hoffmeister, B. Schoch, Wolfgang Hillert, B. Krusche, D. V. Novinski, and Research unit Nuclear & Hadron Physics

Subjects
Nuclear reaction, Physics, TAPS, Nuclear and High Energy Physics, Proton, Meson, Astrophysics::High Energy Astrophysical Phenomena, Hadron, Nuclear Theory, WIDTH, Photon energy, DEUTERON, Nuclear physics, Deuterium, NUCLEAR MEDIUM, Neutron, High Energy Physics::Experiment, PHI-PHOTOPRODUCTION, SPECTROMETER, Atomic physics, Nucleon, Nuclear Experiment, MATTER
Abstract

Omega photoproduction off hydrogen and deuterium has been studied with the tagged photon beam of the ELSA accelerator in Bonn for photon energies up to 2.0 GeV. The omega meson has been identified via the omega -> pi(0) gamma -> gamma gamma gamma decay mode, using the combined setup of the Crystal Barrel/TAPS detector systems. Both inclusive and exclusive analyses have been carried out. Differential and total cross-sections have been derived for omega mesons produced off free protons and off protons and neutrons bound in deuterium. The cross-section for the production off the bound neutron is found to be a factor of a parts per thousand 1.3 larger than the one off the bound proton in the incident beam energy region 1.2 GeV

Published
2015

45. Experimental access to Transition Distribution Amplitudes with the P̄ANDA experiment at FAIR

Author

M. C. Mora Espí, Pawel Marciniewski, K. Makonyi, Yupeng Yan, S. Wronka, D. Pietreanu, Shaji Kumar, N. Belikov, D. I. Glazier, A. Gillitzer, K. Khanchai, Ajay Kumar Rai, M. Steinen, D. Calvo, Yury Tikhonov, A. A. Derevschikov, T. A. Pocheptsov, R.A. Salmin, P. Balanutsa, B. J. Liu, P. N. Deepak, A. E. Blinov, S. Lange, S. Ryzhikov, G. Kalicy, Arpit Parmar, P. Musiol, G. D. Alexeev, D. P. Watts, Lennart Isaksson, Tobias Stockmanns, E. Gutz, P. F. Dalpiaz, Zhi Liu, D. Marchand, S. Grieser, A. Gerhardt, D. Kangh, L. Fava, A. A. Festchenko, Harphool Kumawat, I. Zimmermann, M. Albrecht, B. Krusche, A. Sanchez Lorente, E. A. Strokovsky, M. A. Pasyuk, J. Ritman, P. C. Vinodkumar, T. Quagli, M.G. Sapozhnikov, Ashok Kumar, Herbert Koch, V. I. Astakhov, V. Serdyuk, K. M. von Würtemberg, D. Münchow, Hans-Georg Zaunick, S. Marcello, M. Ullrich, A. Mustafa, Paola Gianotti, T. Kuske, Michaela Thiel, Kamal K. Seth, S. Schlimme, C. Schwarz, M. Savrie, B. Ketzer, Jerzy Smyrski, E. Etzelmüller, A. G. Fedunov, H. Sohlbach, K. Malgorzata, Victor Bobrovnikov, R.Sh. Teshev, L. Ayut, V.M. Abazov, B. Spruck, B. Kamys, D. Mülhheim, Krzysztof Swientek, S. Schadmand, M. V. Korzihik, Zbigniew Rudy, Matei Eugen Vasile, T. Wasem, J. Schwiening, D. Lehmann, M. Patsyuk, Karin Schönning, W. Czyzycki, M. Zühlsdorf, V. N. Goryachev, A. G. Zorin, A. Davidenko, W. Lauth, B. Fröhlich, A. Amoroso, V. Lucherini, P. Schakel, Grzegorz Korcyl, G.A. Mustafaev, Smbat Grigoryan, Ajit Kumar Mohanty, Grzegorz Filo, R. Veenstra, P. Wüstner, J. Marton, Boris Batyunya, L. Ferrero, A. N. Skachkova, Edward Lisowski, I. Garzia, D. Bremer, T. Eissner, D. Lin, Y.M. Goncharenko, Soumen Paul, A.A. Efremov, Dipanwita Dutta, Alberto Rotondi, M. Michel, B. Slowinski, A. Arefiev, Philip Woods, I. Augustin, Yan Liang, A. Karavdina, M. Greco, P. Rosier, Antoni Szczurek, N. Saito, K. Föhl, T. Schröder, B. Singh, Mariana Nanova, Andreas Herten, Oleg V. Missevitch, S.A. Zaporozhets, K.-T. Brinkmann, Sukanta Dash, A. Filippi, A. Trzcinski, Marek Idzik, M. O. Distler, J. Schumann, C. Sowa, I. Konorov, J. C. van der Weele, Mathias Fink, A. E. Yakutin, B. Kopf, E. Atomssa, A. Pitka, R. Karabowicz, H. H. Leithoff, Angelo Rivetti, S. Pornrad, S. Diehl, M. Maggiora, B. Kröck, R. Duchat, O. Levitskaya, Gianluigi Boca, Krzysztof Korcyl, Gianangelo Bracco, Harald Kleines, F. Nerling, L. Caldeira Balkeståhl, S. Coli, E. Perevalova, T. Gessler, Klaus Peters, A. Magiera, Vassili Kachanov, M. Hawryluk, S. Ong, R. Varma, X. Shen, T. Czyzewski, M. Domagala, S. Godre, M. Zyzak, J. Pettersson, F. Uhlig, F. De Mori, P.J.J. Lemmens, Alexander D. Vasiliev, Mohammed Al-Turany, Q. Hu, Andrzej Kupsc, R. Schmitz, P. Mahlberg, P. De Remigis, C. Schnier, S. Lusso, R. Dosdall, L. Zotti, J. Van de Wiele, A. Britting, S. Fissum, Zhigang Li, Jozef Zlomanczuk, Amiran Tomaradze, S. Spataro, U. Müller, R. Valente, V. Uzhinsky, Giulio Stancari, G. S. Shabratova, I. Keshelashvili, S. Jowzaee, Harald Merkel, C. Guaraldo, S. Li, Christian Schmidt, M. Steinacher, V. Kozlov, Yu.N. Rogov, A. Bianconi, T. Held, V. Datar, Andrei Fedorov, H. Orth, T. Weber, A. Kozela, Piotr Salabura, M. Destefanis, Andrea Lavagno, M. Kuhlmann, B. Ma, J. Pychy, Piotr Lebiedowicz, L. Capozza, Dominik Kwiatkowski, Andrew Levin, A. Wilms, Germán Mazza, Matthias Richter, Wojciech Krzemien, Sean A Dobbs, J. Pochodzalla, I. Shein, H. Ohm, Paolo Montagna, Paul Alois Buhler, Y. Naryshkin, Hans Calén, A. Apostolou, S. Orfanitski, V. Grishin, A. Kashchuk, V. Kormilitsin, Tomasz Fiutowski, M. Mingnore, M. Krebs, A. Dolgolenko, E. Fioravanti, P.-E. Tegnér, A. Chlopik, A. Gromliuk, Andreas Lehrach, I. Georgadze, B. Czech, B. Zwieglinski, Kurt Hansen, W. Schäfer, C. Motzko, R. Kunne, P. Genova, J. Lühning, A. Psyzniak, S. Bianco, H. Smit, Nicola Bianchi, Felice Iazzi, J. Rieke, M. Fritsch, R. Dzhygadlo, O. Corell, E. Pace, S. I. Manaenkov, V. Chandratre, S. Sosio, A. Olshevskiy, T. Johansson, S. Sanchez, Concettina Sfienti, R. F. Parodi, D. Walther, T. Saito, E. Köhler, Zhi Sun, Markus Büscher, P. Kulessa, Magnus Wolke, I. Kisel, V. Tokmenin, Alexander Vodopyanov, J.H. Zhao, C. Wang, M. Kube, M. Kavatsyuk, T. Hennino, Johann Zmeskal, V. Varentsov, C. Morales Morales, S. Esch, R. Kliemt, G. Schepers, S. Poslavskiy, Alessandro Drago, Dan Pantea, M. Imre, W. Eyrich, D. Melnychuk, M.P. Bussa, Dirk Grunwald, I. Lehmann, D. Rodríguez Piñeiro, Kjell Fransson, A. P. Onuchin, Valery Dormenev, M. Rossbach, F. E. Maas, Giuseppe Giraudo, M. Pelizäus, D. P. Mohanta, H. Deppe, C. Rosenbaum, M. Cardinali, A. G. Denig, A. Boukharov, V. Abramov, A. Hayrapetyan, K. Pysz, Vladimir Blinov, A. K. Hergemöller, A. Ryazantsev, K. Kalita, P. Wintz, Raghunath Sahoo, V. Akishina, P. A. Semenov, V. Balanutsa, Mikael Lundin, M. M. Macri, Anne-Laure Martin, A. Karmokov, U. Cahit, A. Demekhin, G. Rosner, W. Erni, S. Plueger, S. Leiber, Michael Werner, L. Schmitt, S. Costanza, Bent Schröder, R. Arora, D. Deermann, M. Leyhe, S.A. Kononov, S. Belostotski, Ulrich Wiedner, Maria Krawczyk, L. V. Malinina, M. Tiemens, Yu.M. Mel'nik, Ch. Schmidt, O. Merle, U. Thoma, M. Babai, A. Semenov, R. Maier, Ankhi Roy, Michael Düren, L. V. Nogach, E. Widmann, A. Zhadanov, Valentino Rigato, Stanisław Kistryn, P. Fedorets, K. Suzuki, D. A. Morozov, Franco Bradamante, Torbjörn Bäck, L. Busso, C. Le Galliard, Bhavin Patel, Alessandro Bressan, K. Chinorat, M. Wojciechowski, A. Lehmann, A.F. Makarov, A. Galoyan, P. Wieczorek, T. Holtmann, Bernd Voss, Aleksandra Wrońska, J. S. Díaz, M. Hoek, D. Veretennikov, F. H. Heinsius, P. Brandys, F. Balestra, H. Flemming, F. Lisowski, H. Younis, Paweł Moskal, G. Maniscalco, P. Jasinski, V. K. Rodionov, J. G. Messchendorp, R. Schnell, O. Miklukho, D. Prasuhn, M. Zambrana, M. Kümmel, L. Cao, I. Marishev, A. Bersani, Bo Cederwall, K. Götzen, L. Lavezzi, S. Vejdani, N. G. Minaev, Herbert Löhner, V. Metag, R. W. Novotny, E. Tomasi-Gustafsson, N. B. Skachkov, A. Cebulla, Bartosz Mindur, V. Chernetsky, B. Seitz, Daniel M. Kaplan, E. K. Koshurnikov, B. Ramstein, A. Kulkarni, B. J. Roy, T. Sefzick, D. Khaneft, D. Branford, A. A. Piskun, Reinhard Beck, S. Bleser, Yu. Yu. Lobanov, R. Siudak, V. I. Lobanov, E. A. Kravchenko, S. Bukreeva, A. Samartsev, U. Thöring, F. Feldbauer, Ting Xiao, Patrick Achenbach, Hongwei Liu, Johannes Peter Wessels, D. Bettoni, Yu.I. Davydov, V. I. Dormenev, Genady Gavrilov, Ch. Wendel, M. Yu. Barabanov, Kirill M. Semenov-Tian-Shansky, R. Birsa, T. Bel, Günter Kemmerling, A. Khoukaz, V. Carassiti, B. Galnander, Jifeng Hu, M. Bragadireanu, I. A. Kuyanov, Bruce Yabsley, Andrey V. Izotov, O. Noll, J. Kunkel, A. Dbeyssi, K. Suvorov, Vivekanand Jha, Wolfgang Kuhn, Hasko Stenzel, O. Malyshev, A. A. Sokolov, U. Kurilla, G. Kuhl, D. Kaiser, P. Strzempek, A. Goerres, J. Biernat, D. G. Ireland, H. Xu, M. K. Suleimanov, G. Sterzenbach, E. Prencipe, A. Ortiz, N. I. Zhuravlev, A. Täschner, A. Gerasimov, T. Triffterer, M. Deiseroth, A. Wilson, Marek Palka, M. Lindemulder, A. Y. Barnyakov, V.Kh. Dodokhov, D. Nicmorus, Andrey Uzunian, A. Ehret, R. Nellen, Ch. Hammann, M. Steinke, V. L. Malyshev, P. Drexler, Richard Wheadon, A. Cotta Ramusino, P. Sarin, Riccardo Introzzi, H. Clement, I. Kulakov, M. Zuehlsdorf, M. Galuska, S. Kliczewski, G.B. Pontecorvo, D. Przyborowski, Mihai Caprini, V. V. Mochalov, M. Jadhav, M. Mikirtychyants, M. Traxler, Frank Goldenbaum, Research unit Nuclear & Hadron Physics, The PANDA Collaboration, Null, Singh, B. P, Erni, W., Keshelashvili, I., Krusche, B., Steinacher, M., Liu, B., Liu, H., Liu, Z., Shen, X., Wang, C., Zhao, J., Albrecht, M., Fink, M., Heinsius, F. H., Held, T., Holtmann, T., Koch, H., Kopf, B., Kümmel, M., Kuhl, G., Kuhlmann, M., Leyhe, M., Mikirtychyants, M., Musiol, P., Mustafa, A., Pelizäus, M., Pychy, J., Richter, M., Schnier, C., Schröder, T., Sowa, C., Steinke, M., Triffterer, T., Wiedner, U., Beck, R., Hammann, C., Kaiser, D., Ketzer, B., Kube, M., Mahlberg, P., Rossbach, M., Schmidt, C., Schmitz, R., Thoma, U., Walther, D., Wendel, C., Wilson, A., Bianconi, A., Bragadireanu, M., Caprini, M., Pantea, D., Pietreanu, D., Vasile, M. E., Patel, B., Kaplan, D., Brandys, P., Czyzewski, T., Czyzycki, W., Domagala, M., Hawryluk, M., Filo, G., Krawczyk, M., Kwiatkowski, D., Lisowski, E., Lisowski, F., Fiutowski, T., Idzik, M., Mindur, B., Przyborowski, D., Swientek, K., Czech, B., Kliczewski, S., Korcyl, K., Kozela, A., Kulessa, P., Lebiedowicz, P., Malgorzata, K., Pysz, K., Schäfer, W., Siudak, R., Szczurek, A., Biernat, J., Jowzaee, S., Kamys, B., Kistryn, S., Korcyl, G., Krzemien, W., Magiera, A., Moskal, P., Palka, M., Psyzniak, A., Rudy, Z., Salabura, P., Smyrski, J., Strzempek, P., Wrońska, A., Augustin, I., Lehmann, I., Nicmorus, D., Schepers, G., Schmitt, L., Al Turany, M., Cahit, U., Capozza, L., Dbeyssi, A., Deppe, H., Dzhygadlo, R., Ehret, A., Flemming, H., Gerhardt, A., Götzen, K., Karabowicz, R., Kliemt, R., Kunkel, J., Kurilla, U., Lehmann, D., Lühning, J., Maas, F., Morales Morales, C., Mora Espí, M. C., Nerling, F., Orth, H., Peters, K., Rodríguez Piñeiro, D., Saito, N., Saito, T., Sánchez Lorente, A., Schmidt, C. J., Schwarz, C., Schwiening, J., Traxler, M., Valente, R., Voss, B., Wieczorek, P., Wilms, A., Zühlsdorf, M., Abazov, V. M., Alexeev, G., Arefiev, A., Astakhov, V. I., Barabanov, M. Y. u., Batyunya, B. V., Davydov, Y. u. I., Dodokhov, V. K. h., Efremov, A. A., Fedunov, A. G., Festchenko, A. A., Galoyan, A. S., Grigoryan, S., Karmokov, A., Koshurnikov, E. K., Lobanov, V. I., Lobanov, Y. u. Y. u., Makarov, A. F., Malinina, L. V., Malyshev, V. L., Mustafaev, G. A., Olshevskiy, A., Pasyuk, M. A., Perevalova, E. A., Piskun, A. A., Pocheptsov, T. A., Pontecorvo, G., Rodionov, V. K., Rogov, Y. u. N., Salmin, R. A., Samartsev, A. G., Sapozhnikov, M. G., Shabratova, G. S., Skachkov, N. B., Skachkova, A. N., Strokovsky, E. A., Suleimanov, M. K., Teshev, R. S. h., Tokmenin, V. V., Uzhinsky, V. V., Vodopyanov, A. S., Zaporozhets, S. A., Zhuravlev, N. I., Zorin, A. G., Branford, D., Glazier, D., Watts, D., Woods, P., Britting, A., Eyrich, W., Lehmann, A., Uhlig, F., Dobbs, S., Seth, K., Tomaradze, A., Xiao, T., Bettoni, D., Carassiti, V., Cotta Ramusino, A., Dalpiaz, P., Drago, A., Fioravanti, E., Garzia, I., Savriè, M., Stancari, G., Akishina, V., Kisel, I., Kulakov, I., Zyzak, M., Arora, R., Bel, T., Gromliuk, A., Kalicy, G., Krebs, M., Patsyuk, M., Zuehlsdorf, M., Bianchi, N., Gianotti, P., Guaraldo, C., Lucherini, V., Pace, E., Bersani, A., Bracco, G., Macri, M., Parodi, R. F., Bianco, S., Bremer, D., Brinkmann, K. T., Diehl, S., Dormenev, V., Drexler, P., Düren, M., Eissner, T., Etzelmüller, E., Föhl, K., Galuska, M., Gessler, T., Gutz, E., Hayrapetyan, A., Hu, J., Kröck, B., Kühn, W., Kuske, T., Lange, S., Liang, Y., Merle, O., Metag, V., Mülhheim, D., Münchow, D., Nanova, M., Novotny, R., Pitka, A., Quagli, T., Rieke, J., Rosenbaum, C., Schnell, R., Spruck, B., Stenzel, H., Thöring, U., Ullrich, M., Wasem, T., Werner, M., Zaunick, H. G., Ireland, D., Rosner, G., Seitz, B., Deepak, P. N., Kulkarni, A. V., Apostolou, A., Babai, M., Kavatsyuk, M., Lemmens, P., Lindemulder, M., Löhner, H., Messchendorp, J., Schakel, P., Smit, H., van der Weele, J. C., Tiemens, M., Veenstra, R., Vejdani, S., Kalita, K., Mohanta, D. P., Kumar, A., Roy, A., Sahoo, R., Sohlbach, H., Büscher, M., Cao, L., Cebulla, A., Deermann, D., Dosdall, R., Esch, S., Georgadze, I., Gillitzer, A., Goerres, A., Goldenbaum, F., Grunwald, D., Herten, A., Hu, Q., Kemmerling, G., Kleines, H., Kozlov, V., Lehrach, A., Leiber, S., Maier, R., Nellen, R., Ohm, H., Orfanitski, S., Prasuhn, D., Prencipe, E., Ritman, J., Schadmand, S., Schumann, J., Sefzick, T., Serdyuk, V., Sterzenbach, G., Stockmanns, T., Wintz, P., Wüstner, P., Xu, H., Li, S., Li, Z., Sun, Z., Rigato, V., Fissum, S., Hansen, K., Isaksson, L., Lundin, M., Schröder, B., Achenbach, P., Bleser, S., Cardinali, M., Corell, O., Deiseroth, M., Denig, A., Distler, M., Feldbauer, F., Fritsch, M., Jasinski, P., Hoek, M., Kangh, D., Karavdina, A., Lauth, W., Leithoff, H., Merkel, H., Michel, M., Motzko, C., Müller, U., Noll, O., Plueger, S., Pochodzalla, J., Sanchez, S., Schlimme, S., Sfienti, C., Steinen, M., Thiel, M., Weber, T., Zambrana, M., Dormenev, V. I., Fedorov, A. A., Korzihik, M. V., Missevitch, O. V., Balanutsa, P., Balanutsa, V., Chernetsky, V., Demekhin, A., Dolgolenko, A., Fedorets, P., Gerasimov, A., Goryachev, V., Varentsov, V., Boukharov, A., Malyshev, O., Marishev, I., Semenov, A., Konorov, I., Paul, S., Grieser, S., Hergemöller, A. K., Khoukaz, A., Köhler, E., Täschner, A., Wessels, J., Dash, S., Jadhav, M., Kumar, S., Sarin, P., Varma, R., Chandratre, V. B., Datar, V., Dutta, D., Jha, V., Kumawat, H., Mohanty, A. K., Roy, B., Yan, Y., Chinorat, K., Khanchai, K., Ayut, L., Pornrad, S., Barnyakov, A. Y., Blinov, A. E., Blinov, V. E., Bobrovnikov, V. S., Kononov, S. A., Kravchenko, E. A., Kuyanov, I. A., Onuchin, A. P., Sokolov, A. A., Tikhonov, Y. A., Atomssa, E., Hennino, T., Imre, M., Kunne, R., Le Galliard, C., Ma, B., Marchand, D., Ong, S., Ramstein, B., Rosier, P., Tomasi Gustafsson, E., Van de Wiele, J., Boca, G., Costanza, S., Genova, P., Lavezzi, L., Montagna, P., Rotondi, A., Abramov, V., Belikov, N., Bukreeva, S., Davidenko, A., Derevschikov, A., Goncharenko, Y., Grishin, V., Kachanov, V., Kormilitsin, V., Melnik, Y., Levin, A., Minaev, N., Mochalov, V., Morozov, D., Nogach, L., Poslavskiy, S., Ryazantsev, A., Ryzhikov, S., Semenov, P., Shein, I., Uzunian, A., Vasiliev, A., Yakutin, A., Yabsley, B., Bäck, T., Cederwall, B., Makónyi, K., Tegnér, P. E., von Würtemberg, K. M., Belostotski, S., Gavrilov, G., Izotov, A., Kashchuk, A., Levitskaya, O., Manaenkov, S., Miklukho, O., Naryshkin, Y., Suvorov, K., Veretennikov, D., Zhadanov, A., Rai, A. K., Godre, S. S., Duchat, R., Amoroso, A., Bussa, M. 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Subjects
Particle physics, (P)Over-Baranda, Nuclear and High Energy Physics, Electroproduction, Hadron, Annihilation, FOS: Physical sciences, 7. Clean energy, 01 natural sciences, Particle identification, Nucleon, NO, Nuclear physics, High Energy Physics - Experiment (hep-ex), High Energy Physics - Phenomenology (hep-ph), Factorization, 0103 physical sciences, Fysik, Invariant mass, ddc:530, Meson Production, Monte-Carlo, Nuclear Experiment (nucl-ex), 010306 general physics, Nuclear Experiment, Physics, Quantum chromodynamics, 010308 nuclear & particles physics, Perturbative QCD, Qcd, Physical Sciences, Exclusive Processes, High Energy Physics::Experiment, Pi(0), Cross-Sections, Energy (signal processing)
Abstract

Baryon-to-meson Transition Distribution Amplitudes (TDAs) encoding valuable new information on hadron structure appear as building blocks in the collinear factorized description for several types of hard exclusive reactions. In this paper, we address the possibility of accessing nucleon-to-pion ($��N$) TDAs from $\bar{p}p \to e^+e^- ��^0$ reaction with the future PANDA detector at the FAIR facility. At high center of mass energy and high invariant mass squared of the lepton pair $q^2$, the amplitude of the signal channel $\bar{p}p \to e^+e^- ��^0$ admits a QCD factorized description in terms of $��N$ TDAs and nucleon Distribution Amplitudes (DAs) in the forward and backward kinematic regimes. Assuming the validity of this factorized description, we perform feasibility studies for measuring $\bar{p}p \to e^+e^- ��^0$ with the PANDA detector. Detailed simulations on signal reconstruction efficiency as well as on rejection of the most severe background channel, i.e. $\bar{p}p \to ��^+��^- ��^0$ were performed for the center of mass energy squared $s = 5$ GeV$^2$ and $s = 10$ GeV$^2$, in the kinematic regions $3.0 < q^2 < 4.3$ GeV$^2$ and $5 < q^2 < 9$ GeV$^2$, respectively, with a neutral pion scattered in the forward or backward cone $| \cos��_{��^0}| > 0.5 $ in the proton-antiproton center of mass frame. Results of the simulation show that the particle identification capabilities of the PANDA detector will allow to achieve a background rejection factor of $5\cdot 10^7$ ($1\cdot 10^7$) at low (high) $q^2$ for $s=5$ GeV$^2$, and of $1\cdot 10^8$ ($6\cdot 10^6$) at low (high) $q^2$ for $s=10$ GeV$^2$, while keeping the signal reconstruction efficiency at around $40\%$. At both energies, a clean lepton signal can be reconstructed with the expected statistics corresponding to $2$ fb$^{-1}$ of integrated luminosity. (.../...), 19 pages, 7 figures (some multiple), 2 tables (each double), preprint of an article for epj - v2

Published
2015

46. In-medium properties of mesons

Author

Mariana Nanova, Kai-Thomas Brinkmann, and Volker Metag

Subjects
Excitation function, Physics, Particle physics, Meson, Proton, 010308 nuclear & particles physics, QC1-999, Nuclear Theory, Hadron, Nuclear matter, 01 natural sciences, Nuclear physics, 0103 physical sciences, Bound state, High Energy Physics::Experiment, Nuclear Experiment, 010306 general physics, Nucleon, Crystal Ball
Abstract

In the project B.4 , the modification of meson properties (mass, width) in a nuclear medium has been studied in photoproduction of mesons off nuclear targets. This work has been motivated by theoretical expectations of in-medium modifications of hadrons based on the conjecture of a partial restoration of chiral symmetry in a strongly interacting medium. It has been shown that these in-medium changes can be discussed in a compact form in terms of an optical potential describing the meson-nucleus interaction. Experimental approaches to determine the real and imaginary part of the meson-nucleus potential have been developed. The experiments have been performed with the Crystal Barrel/TAPS detector at the electron accelerator ELSA (Bonn) and the Crystal Ball/TAPS detector at MAMI (Mainz). Measuring the excitation function and momentum distribution for photo production of ω and η′ mesons, the real parts of the ω and η′ -nucleus potential, given by the in-medium mass shift, have been determined. For the η′ meson a lowering of the mass at normal nuclear matter density by -(39±7(stat)±15(syst)) MeV is observed, while for the ω meson a slightly smaller mass shift is found, however, with much larger uncertainties, not excluding a zero mass shift. The imaginary part of the potentials has been extracted from the measurement of the transparency ratio which compares the meson production cross section per nucleon within a nucleus to the production cross section off the free proton. For the η′ meson the imaginary part of the potential is found to be smaller than the real part. In case of the ω meson the opposite is observed. This makes the η′ meson a good candidate for the search for meson-nucleus bound states while no resolved ω mesic states can be expected. The results are compared with theoretical predictions. An outlook on future experiments is given.

Published
2017

47. First results on the experimental search for η′-mesic nuclei with the12C(p, d) reaction

Author

K. Itahashi, C. Guo, Peter Strmen, Branislav Sitar, S. Friedrich, Helmut Weick, J. Gellanki, R. Kanungo, N. Kurz, H. Yamakami, H. Fujioka, Daisuke Jido, Nasser Kalantar-Nayestanaki, S. Pietri, M.N. Harakeh, Satoru Hirenzaki, S. Terashima, C. Scheidenberger, M. Iwasaki, J. Zhao, Moritz P. Reiter, X. Xu, V. Metag, J. L. Rodriguez-Sanchez, I. G. Mukha, N. Ikeno, J. Benlliure, T. Nishi, Yassid Ayyad, Herbert A. Simon, Yuni N. Watanabe, E. Haettner, R. Knöbel, Ryugo S. Hayano, E. Gutz, Yasumoto Tanaka, Christine Hornung, Imrich Szarka, C. Rappold, Hans Geissel, Y. Higashi, K.-T. Brinkmann, Y. Igarashi, A. Prochazka, J. S. Winfield, Tomofumi Nagae, Bao-Hua Sun, M. Takechi, Hideko Nagahiro, Ken Suzuki, Isao Tanihata, E. Widmann, Hooi Jin Ong, and Mariana Nanova

Subjects
Physics, 010308 nuclear & particles physics, 0103 physical sciences, Resolution (electron density), General Physics and Astronomy, Order (group theory), Atomic physics, 010306 general physics, Spectroscopy, 01 natural sciences, Prime (order theory), Excitation
Abstract

We performed a missing-mass spectroscopy experiment of the 12C(p, d) reaction in order to search for η′-mesic nuclei. Excitation spectrum of 11C around the η′-meson production threshold was successfully obtained with a high-statistical sensitivity and sufficiently good energy resolution. Since no peak structure associated with the formation of η′-mesic nuclei was observed, we set constraints on the formation cross sections of η′-mesic states and on the η′-nucleus interaction.

Published
2017

48. N(1520)3/2−Helicity Amplitudes from an Energy-Independent Multipole Analysis Based on New Polarization Data on Photoproduction of Neutral Pions

Author

Ph. Thämer, Ch. Honisch, Ch. Schmidt, J. Hannappel, A. V. Anisovich, V. A. Nikonov, A. V. Sarantsev, H. Schmieden, Alastair J. Wilson, T. C. Jude, Ulrich Wiedner, D. E. Bayadilov, Lilian Witthauer, A. B. Gridnev, Mariana Nanova, M. Kube, A. Thiel, A. Käser, U. Thoma, K. Makonyi, Francesco Messi, K.-Th. Brinkmann, M. Grüner, Ch. Hammann, Matthew Lang, K. Fornet-Ponse, H. van Pee, K. Koop, M. Becker, Yu. A. Beloglazov, S. Böse, H. Kalinowsky, G. Reicherz, A. Berlin, E. Gutz, D. V. Novinski, Friedrich Klein, F. Kalischewski, A. Winnebeck, P. Klassen, M. Urban, T. Rostomyan, M. Gottschall, D. Elsner, D. Walther, V. Sokhoyan, W. Meyer, V. Metag, T. Seifen, R. W. Novotny, Ph. Hoffmeister, Ch. Funke, B. Krusche, Friedrich, Eberhard Klempt, B. Roth, M. Bichow, Reinhard Beck, Wolfgang Hillert, M. Dieterle, Y. Wunderlich, Ch. Wendel, Frank Frommberger, D. Piontek, I. V. Lopatin, H. Dutz, H. Eberhardt, V. Crede, I. Keshelashvili, Jörg H. Müller, Jens Hartmann, D. Kaiser, R. Schmitz, C. Rosenbaum, O. Jahn, V. Hannen, and J. Herick

Subjects
Physics, 010308 nuclear & particles physics, Linear polarization, Partial wave analysis, General Physics and Astronomy, Electron, Polarization (waves), 01 natural sciences, Helicity, Nuclear physics, Amplitude, Pion, 0103 physical sciences, Nuclear Experiment, 010306 general physics, Multipole expansion
Abstract

New data on the polarization observables T, P, and H for the reaction γp→pπ0 are reported. The results are extracted from azimuthal asymmetries when a transversely polarized butanol target and a linearly polarized photon beam are used. The data were taken at the Bonn electron stretcher accelerator ELSA using the CBELSA/TAPS detector. These and earlier data are used to perform a truncated energy-independent partial wave analysis in sliced-energy bins. This energy-independent analysis is compared to the results from energy-dependent partial wave analyses.

Published
2014

49. Spectroscopy of $\eta '$ mesic nuclei using $(p,d)$ reaction

Author

Haruhiko Outa, Kenta Itahashi, Ryugo S. Hayano, Natsumi Ikeno, M. Iwasaki, Y. Higashi, Yuni N. Watanabe, Tomofumi Nagae, Helmut Weick, Takahiro Nishi, Daisuke Jido, Ken Suzuki, Satoru Hirenzaki, Hans Geissel, Yuusuke Igarashi, H. Yamakami, Yoshiki Tanaka, Takatoshi Suzuki, Hideko Nagahiro, Mariana Nanova, Kai-Thomas Brinkmann, Volker Metag, Stephan Friedrich, and Hiroyuki Fujioka

Subjects
Chemistry, Analytical chemistry, Spectroscopy
Published
2014

50. Spectroscopy of η′ mesic nuclei via semi-exclusive measurement at FAIR

Author

Haruhiko Outa, Ryugo S. Hayano, Yoshiki Tanaka, Satoru Hirenzaki, Helmut Weick, Satoshi Itoh, Daisuke Jido, Hiroyuki Fujioka, Kenta Itahashi, Kota Okochi, Hans Geissel, Stefan Friedrich, Yuni N. Watanabe, Takahiro Nishi, Mariana Nanova, Kai-Thomas Brinkmann, Volker Metag, Ken Suzuki, Hideko Nagahiro, and Takatoshi Suzuki

Subjects
Nuclear physics, Physics, Series (mathematics), Meson, Mass reduction, QC1-999, Bound state, Atomic physics, Spectroscopy, Absorption (electromagnetic radiation)
Abstract

In order to investigate a possible mass reduction of an η ′ meson at finite density, a series of missing-mass spectroscopy experiments of η ′-nucleus bound states with the 12 C(p,d ) reaction is planned at GSI and FAIR. A semi-exclusive measurement with the tagging of protons from η ′ two-body absorption (η ′NN → NN ) will be a key feature in an experiment with Super-FRS at FAIR.

Published
2014

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