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1. Corrigendum to 'Isoscalar single-pion production in the region of Roper and d⁎(2380) resonances' [Phys. Lett. B 774 (2017) 599]

Author

P. Adlarson, W. Augustyniak, W. Bardan, M. Bashkanov, F.S. Bergmann, M. Berłowski, H. Bhatt, A. Bondar, M. Büscher, H. Calén, I. Ciepał, H. Clement, E. Czerwiński, K. Demmich, R. Engels, A. Erven, W. Erven, W. Eyrich, P. Fedorets, K. Föhl, K. Fransson, F. Goldenbaum, A. Goswami, K. Grigoryev, C.-O. Gullström, L. Heijkenskjöld, V. Hejny, N. Hüsken, L. Jarczyk, T. Johansson, B. Kamys, G. Kemmerling, G. Khatri, A. Khoukaz, O. Khreptak, D.A. Kirillov, S. Kistryn, H. Kleines, B. Kłos, W. Krzemień, P. Kulessa, A. Kupść, A. Kuzmin, K. Lalwani, D. Lersch, B. Lorentz, A. Magiera, R. Maier, P. Marciniewski, B. Mariański, H.-P. Morsch, P. Moskal, H. Ohm, W. Parol, E. Perez del Rio, N.M. Piskunov, D. Prasuhn, D. Pszczel, K. Pysz, A. Pyszniak, J. Ritman, A. Roy, Z. Rudy, O. Rundel, S. Sawant, S. Schadmand, I. Schätti-Ozerianska, T. Sefzick, V. Serdyuk, B. Shwartz, K. Sitterberg, T. Skorodko, M. Skurzok, J. Smyrski, V. Sopov, R. Stassen, J. Stepaniak, E. Stephan, G. Sterzenbach, H. Stockhorst, H. Ströher, A. Szczurek, A. Trzciński, R. Varma, M. Wolke, A. Wrońska, P. Wüstner, A. Yamamoto, J. Zabierowski, M.J. Zieliński, J. Złomańczuk, P. Żuprański, and M. Żurek

Subjects
Physics, QC1-999
Published
2020
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2. Importance of d-wave contributions in the charge symmetry breaking reaction dd→4Heπ0

Author

P. Adlarson, W. Augustyniak, W. Bardan, M. Bashkanov, F.S. Bergmann, M. Berłowski, A. Bondar, M. Büscher, H. Calén, I. Ciepał, H. Clement, E. Czerwiński, K. Demmich, R. Engels, A. Erven, W. Erven, W. Eyrich, P. Fedorets, K. Föhl, K. Fransson, F. Goldenbaum, A. Goswami, K. Grigoryev, C.-O. Gullström, C. Hanhart, L. Heijkenskjöld, V. Hejny, N. Hüsken, L. Jarczyk, T. Johansson, B. Kamys, G. Kemmerling, G. Khatri, A. Khoukaz, O. Khreptak, D.A. Kirillov, S. Kistryn, H. Kleines, B. Kłos, W. Krzemień, P. Kulessa, A. Kupść, A. Kuzmin, K. Lalwani, D. Lersch, B. Lorentz, A. Magiera, R. Maier, P. Marciniewski, B. Mariański, H.-P. Morsch, P. Moskal, H. Ohm, W. Parol, E. Perez del Rio, N.M. Piskunov, D. Prasuhn, D. Pszczel, K. Pysz, A. Pyszniak, J. Ritman, A. Roy, Z. Rudy, O. Rundel, S. Sawant, S. Schadmand, I. Schätti-Ozerianska, T. Sefzick, V. Serdyuk, B. Shwartz, K. Sitterberg, T. Skorodko, M. Skurzok, J. Smyrski, V. Sopov, R. Stassen, J. Stepaniak, E. Stephan, G. Sterzenbach, H. Stockhorst, H. Ströher, A. Szczurek, A. Trzciński, M. Wolke, A. Wrońska, P. Wüstner, A. Yamamoto, J. Zabierowski, M.J. Zieliński, J. Złomańczuk, P. Żuprański, and M. Żurek

Subjects
Physics, QC1-999
Abstract

This letter reports a first quantitative analysis of the contribution of higher partial waves in the charge symmetry breaking reaction dd→4Heπ0 using the WASA-at-COSY detector setup at an excess energy of Q=60MeV. The determined differential cross section can be parametrized as dσ/dΩ=a+bcos2⁡θ⁎, where θ⁎ is the production angle of the pion in the center-of-mass coordinate system, and the results for the parameters are a=(1.55±0.46(stat)+0.32−0.8(syst))pb/sr and b=(13.1±2.1(stat)−2.7+1.0(syst))pb/sr. The data are compatible with vanishing p-waves and a sizable d-wave contribution. This finding should strongly constrain the contribution of the Δ isobar to the dd→4Heπ0 reaction and is, therefore, crucial for a quantitative understanding of quark mass effects in nuclear production reactions. Keywords: Charge symmetry breaking, Deuteron–deuteron interactions, Pion production

Published
2018
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3. Isoscalar single-pion production in the region of Roper and d⁎(2380) resonances

Author

P. Adlarson, W. Augustyniak, W. Bardan, M. Bashkanov, F.S. Bergmann, M. Berłowski, H. Bhatt, A. Bondar, M. Büscher, H. Calén, I. Ciepał, H. Clement, E. Czerwiński, K. Demmich, R. Engels, A. Erven, W. Erven, W. Eyrich, P. Fedorets, K. Föhl, K. Fransson, F. Goldenbaum, A. Goswami, K. Grigoryev, C.-O. Gullström, L. Heijkenskjöld, V. Hejny, N. Hüsken, L. Jarczyk, T. Johansson, B. Kamys, G. Kemmerling, G. Khatri, A. Khoukaz, O. Khreptak, D.A. Kirillov, S. Kistryn, H. Kleines, B. Kłos, W. Krzemień, P. Kulessa, A. Kupść, A. Kuzmin, K. Lalwani, D. Lersch, B. Lorentz, A. Magiera, R. Maier, P. Marciniewski, B. Mariański, H.-P. Morsch, P. Moskal, H. Ohm, W. Parol, E. Perez del Rio, N.M. Piskunov, D. Prasuhn, D. Pszczel, K. Pysz, A. Pyszniak, J. Ritman, A. Roy, Z. Rudy, O. Rundel, S. Sawant, S. Schadmand, I. Schätti-Ozerianska, T. Sefzick, V. Serdyuk, B. Shwartz, K. Sitterberg, T. Skorodko, M. Skurzok, J. Smyrski, V. Sopov, R. Stassen, J. Stepaniak, E. Stephan, G. Sterzenbach, H. Stockhorst, H. Ströher, A. Szczurek, A. Trzciński, R. Varma, M. Wolke, A. Wrońska, P. Wüstner, A. Yamamoto, J. Zabierowski, M.J. Zieliński, J. Złomańczuk, P. Żuprański, and M. Żurek

Subjects
Single-pion production, Isoscalar part, Roper resonance, Dibaryon resonance, Physics, QC1-999
Abstract

Exclusive measurements of the quasi-free pn→ppπ− and pp→ppπ0 reactions have been performed by means of pd collisions at Tp=1.2 GeV using the WASA detector setup at COSY. Total and differential cross sections have been obtained covering the energy region Tp=0.95–1.3 GeV (s=2.3–2.46 GeV), which includes the regions of Δ(1232), N⁎(1440) and d⁎(2380) resonance excitations. From these measurements the isoscalar single-pion production has been extracted, for which data existed so far only below Tp=1 GeV. We observe a substantial increase of this cross section around 1 GeV, which can be related to the Roper resonance N⁎(1440), the strength of which shows up isolated from the Δ resonance in the isoscalar (Nπ)I=0 invariant-mass spectrum. No evidence for a decay of the dibaryon resonance d⁎(2380) into the isoscalar (NNπ)I=0 channel is found. An upper limit of 180 μb (90% C.L.) corresponding to a branching ratio of 9% has been deduced.

Published
2017
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4. Measurement of the ω→π+π−π0 Dalitz plot distribution

Author

P. Adlarson, W. Augustyniak, W. Bardan, M. Bashkanov, F.S. Bergmann, M. Berłowski, H. Bhatt, A. Bondar, M. Büscher, H. Calén, I. Ciepał, H. Clement, E. Czerwiński, K. Demmich, R. Engels, A. Erven, W. Erven, W. Eyrich, P. Fedorets, K. Föhl, K. Fransson, F. Goldenbaum, A. Goswami, K. Grigoryev, C.-O. Gullström, L. Heijkenskjöld, V. Hejny, N. Hüsken, L. Jarczyk, T. Johansson, B. Kamys, G. Kemmerling, F.A. Khan, G. Khatri, A. Khoukaz, O. Khreptak, D.A. Kirillov, S. Kistryn, H. Kleines, B. Kłos, W. Krzemień, P. Kulessa, A. Kupść, A. Kuzmin, K. Lalwani, D. Lersch, B. Lorentz, A. Magiera, R. Maier, P. Marciniewski, B. Mariański, H.-P. Morsch, P. Moskal, H. Ohm, E. Perez del Rio, N.M. Piskunov, D. Prasuhn, D. Pszczel, K. Pysz, A. Pyszniak, J. Ritman, A. Roy, Z. Rudy, O. Rundel, S. Sawant, S. Schadmand, I. Schätti-Ozerianska, T. Sefzick, V. Serdyuk, B. Shwartz, K. Sitterberg, T. Skorodko, M. Skurzok, J. Smyrski, V. Sopov, R. Stassen, J. Stepaniak, E. Stephan, G. Sterzenbach, H. Stockhorst, H. Ströher, A. Szczurek, A. Trzciński, R. Varma, M. Wolke, A. Wrońska, P. Wüstner, A. Yamamoto, J. Zabierowski, M.J. Zieliński, J. Złomańczuk, P. Żuprański, and M. Żurek

Subjects
Decays of other mesons, Meson–meson interactions, Light mesons, Physics, QC1-999
Abstract

Using the production reactions pd→He3ω and pp→ppω, the Dalitz plot distribution for the ω→π+π−π0 decay is studied with the WASA detector at COSY, based on a combined data sample of (4.408±0.042)×104 events. The Dalitz plot density is parametrised by a product of the P-wave phase space and a polynomial expansion in the normalised polar Dalitz plot variables Z and ϕ. For the first time, a deviation from pure P-wave phase space is observed with a significance of 4.1σ. The deviation is parametrised by a linear term 1+2αZ, with α determined to be +0.147±0.036, consistent with the expectations of ρ-meson-type final-state interactions of the P-wave pion pairs.

Published
2017
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5. Search for an isospin I=3 dibaryon

Author

P. Adlarson, W. Augustyniak, W. Bardan, M. Bashkanov, F.S. Bergmann, M. Berłowski, H. Bhatt, A. Bondar, M. Büscher, H. Calén, I. Ciepał, H. Clement, E. Czerwiński, K. Demmich, R. Engels, A. Erven, W. Erven, W. Eyrich, P. Fedorets, K. Föhl, K. Fransson, F. Goldenbaum, A. Goswami, K. Grigoryev, C.-O. Gullström, L. Heijkenskjöld, V. Hejny, N. Hüsken, L. Jarczyk, T. Johansson, B. Kamys, G. Kemmerling, F.A. Khan, G. Khatri, A. Khoukaz, O. Khreptak, D.A. Kirillov, S. Kistryn, H. Kleines, B. Kłos, W. Krzemień, P. Kulessa, A. Kupść, A. Kuzmin, K. Lalwani, D. Lersch, B. Lorentz, A. Magiera, R. Maier, P. Marciniewski, B. Mariański, H.-P. Morsch, P. Moskal, H. Ohm, E. Perez del Rio, N.M. Piskunov, D. Prasuhn, D. Pszczel, K. Pysz, A. Pyszniak, J. Ritman, A. Roy, Z. Rudy, O. Rundel, S. Sawant, S. Schadmand, I. Schätti-Ozerianska, T. Sefzick, V. Serdyuk, B. Shwartz, K. Sitterberg, T. Skorodko, M. Skurzok, J. Smyrski, V. Sopov, R. Stassen, J. Stepaniak, E. Stephan, G. Sterzenbach, H. Stockhorst, H. Ströher, A. Szczurek, A. Trzciński, R. Varma, M. Wolke, A. Wrońska, P. Wüstner, A. Yamamoto, J. Zabierowski, M.J. Zieliński, A. Zink, J. Złomańczuk, P. Żuprański, and M. Żurek

Subjects
Physics, QC1-999
Abstract

Various theoretical calculations based on QCD or hadronic interactions predict that in addition to the recently observed dibaryon resonance d⁎(2380) with I(JP)=0(3+) there should also exist a dibaryon resonance with mirrored quantum numbers I(JP)=3(0+). We report here on a search for such a NN-decoupled state in data on the pp→ppπ+π+π−π− reaction. Since no clear-cut evidence has been found, we give upper limits for the production cross section of such a resonance in the mass range 2280–2500 MeV. Keywords: Dibaryons, Four-pion production

Published
2016
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6. Search for η-mesic He4 in the dd→He3nπ0 and dd→He3pπ− reactions with the WASA-at-COSY facility

Author

M. Bashkanov, A. Erven, K. Sitterberg, B. Lorentz, Frank Goldenbaum, A. Trzcinski, D. Lersch, H. Ströher, C.-O. Gullström, Markus Büscher, Jozef Zlomanczuk, Günter Kemmerling, A.E. Bondar, K. Grigoryev, H. Bhatt, R. Stassen, H. P. Morsch, Marcin Zieliński, A. Kuzmin, P. Adlarson, L. Jarczyk, T. Johansson, Rudolf Maier, H. Ohm, W. Eyrich, Aleksandra Wrońska, E. Perez del Rio, M. Berłowski, J. Zabierowski, A. Magiera, G. Sterzenbach, A. Goswami, P. Żuprański, B. Kłos, Di. Kirillov, K. Demmich, N. Hüsken, B. Mariański, P. Kulessa, V. Sopov, A. Pyszniak, W. Augustyniak, Zbigniew Rudy, Antoni Szczurek, K. Pysz, P. Fedorets, H. Clement, W. Erven, D. Pszczel, Hans Calén, Izabela Ciepał, O. Khreptak, T. Skorodko, Eryk Czerwiński, F. S. Bergmann, Magnus Wolke, S. Schadmand, T. Sefzick, Oleksandr Rundel, Magdalena Skurzok, Kjell Fransson, I. Schätti-Ozerianska, Harald Kleines, H. Stockhorst, N. G. Kelkar, K. Föhl, Stanisław Kistryn, J. Stepaniak, E. Stephan, W. Bardan, N.M. Piskunov, M. Żurek, Paweł Moskal, Pawel Marciniewski, Lena Heijkenskjöld, K. Lalwani, Wojciech Krzemien, G. Khatri, S. Sawant, Akira Yamamoto, A. Kupść, R. Engels, D. Prasuhn, J. Ritman, Ankhi Roy, V. Serdyuk, Jerzy Smyrski, B. Kamys, P. Wüstner, R. Varma, V. Hejny, B.A. Shwartz, and A. Khoukaz

Subjects
Excitation function, Physics, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Scattering, 01 natural sciences, Momentum, Deuterium, Isospin, 0103 physical sciences, Bound state, Atomic physics, 010306 general physics, Nucleon, Excitation
Abstract

The search for He 4 - η bound states was performed with the WASA-at-COSY facility via the measurement of the excitation function for the d d → He 3 n π 0 and d d → He 3 p π − processes. The deuteron beam momentum was varied continuously between 2.127 GeV/c and 2.422 GeV/c, corresponding to the excess energy for the d d → He 4 η reaction ranging from Q = − 70 MeV to Q = 30 MeV . The luminosity was determined based on the d d → He 3 n reaction and the quasi-free proton–proton scattering via d d → p p n s p e c t a t o r n s p e c t a t o r reactions. The excitation functions, determined independently for the measured reactions, do not reveal a structure which could be interpreted as a narrow mesic nucleus. Therefore, the upper limits of the total cross sections for the bound state production and decay in d d → ( He 4 - η ) b o u n d → He 3 n π 0 and d d → ( He 4 - η ) b o u n d → He 3 p π − processes were determined taking into account the isospin relation between the both of the considered channels. The results of the analysis depend on the assumptions of the N ⁎ (1535) momentum distribution in the anticipated mesic- He 4 . Assuming, as in the previous works, that this is identical with the distribution of nucleons bound with 20 MeV in He 4 , we determined that (for the mesic bound state width in the range from 5 MeV to 50 MeV) the upper limits at 90% confidence level are about 3 nb and about 6 nb for n π 0 and p π − channels, respectively. However, based on the recent theoretical findings of the N ⁎ (1535) momentum distribution in the N ⁎ - He 3 nucleus bound by 3.6 MeV, we find that the WASA-at-COSY detector acceptance decreases and hence the corresponding upper limits are 5 nb and 10 nb for n π 0 and p π − channels respectively.

Published
2017

7. Examination of the production of an isotensor dibaryon in the pp→ppπ+π− reaction

Author

Zbigniew Rudy, Akira Yamamoto, O. Khreptak, A. Khoukaz, Eryk Czerwiński, B. Kamys, P. Żuprański, K. Fransson, Harald Kleines, Oleksandr Rundel, R. Engels, D. Lersch, P. Wüstner, H. P. Morsch, H. Clement, Hans Calén, E. Stephan, Jozef Zlomanczuk, T. Sefzick, W. Erven, A.E. Bondar, W. Eyrich, Wiktor Parol, Markus Büscher, M. Bashkanov, N. Hüsken, Pawel Marciniewski, A. Erven, Paweł Moskal, K. Pysz, M. Berłowski, D. Pszczel, A. Magiera, P. Fedorets, J. Ritman, T. Skorodko, Izabela Ciepał, A. Goswami, Di. Kirillov, B. Mariański, V. Serdyuk, H. Ströher, Stanisław Kistryn, P. Kulessa, Jerzy Smyrski, V. Hejny, K. Föhl, I. Schätti-Ozerianska, A. Trzcinski, S. Schadmand, Hans Stockhorst, B. Shwartz, J. Stepaniak, N.M. Piskunov, Lena Heijkenskjöld, W. Augustyniak, D. Prasuhn, V. Sopov, Rolf Stassen, G. Sterzenbach, B. Lorentz, Wojciech Krzemien, W. Bardan, Günter Kemmerling, J. Zabierowski, Antoni Szczurek, Aleksandra Wrońska, Ankhi Roy, E. Perez del Rio, M. Żurek, Marcin Zieliński, R. Maier, K. Grigoryev, L. Jarczyk, S. Sawant, F. S. Bergmann, Magnus Wolke, K. Demmich, K. Lalwani, A. Kupść, T. Johansson, B. Kłos, P. Adlarson, Magdalena Skurzok, H. Ohm, and Frank Goldenbaum

Subjects
Nuclear physics, Physics, Cross section (physics), Pion, Meson, 010308 nuclear & particles physics, Isospin, 0103 physical sciences, 010306 general physics, 7. Clean energy, 01 natural sciences, Resonance (particle physics)
Abstract

The quasifree pp → ppπ+π− reaction has been measured by means of pd collisions at Tp = 1.2 GeV using the WASA detector setup at COSY enabling exclusive and kinematically complete measurements. Total and differential cross sections have been extracted for the energy region Tp = 1.08–1.36 GeV (√s = 2.35–2.46 GeV) covering thus the regions of N∗(1440) and (1232)(1232) resonance excitations. Calculations describing these excitations by t-channel meson exchange as well as isospin relations based on the pp → ppπ0π0 data underpredict substantially the measured total cross section. The calculations are also at variance with specific experimental differential cross sections. An isotensor N dibaryon resonance with I (J P ) = 2(1+) produced associatedly with a pion is able to overcome these deficiencies. Such a dibaryon was predicted by Dyson and Xuong [Phys. Rev. Lett. 13, 815 (1964)] and more recently calculated by A. Gal and H. Garcilazo [Nucl. Phys. A 928, 73 (2014)].

Published
2019

8. Search for an isospin I= 3 dibaryon

Author

A.E. Bondar, Izabela Ciepał, O. Khreptak, Hans Stockhorst, Pawel Marciniewski, Rolf Stassen, Frank Goldenbaum, M. Berłowski, A. Magiera, J. Stepaniak, Jozef Zlomanczuk, J. Ritman, T. Skorodko, W. Erven, Di. Kirillov, Oleksandr Rundel, A. Zink, Paweł Moskal, V. Serdyuk, H. Bhatt, W. Eyrich, P. Kulessa, H. P. Morsch, T. Sefzick, Jerzy Smyrski, B. Kamys, P. Żuprański, P. Wüstner, D. Lersch, E. Stephan, M. Żurek, C.-O. Gullström, N. Hüsken, Markus Büscher, Günter Kemmerling, S. Schadmand, Zbigniew Rudy, N.M. Piskunov, A. Pyszniak, W. Augustyniak, A. Kuzmin, Hans Calén, M. Bashkanov, Eryk Czerwiński, K. Pysz, P. Fedorets, H. Clement, G. Khatri, Ferdous Khan, Kjell Fransson, Rudolf Maier, V. Hejny, A. Erven, Stanisław Kistryn, Harald Kleines, Akira Yamamoto, A. Kupść, K. Sitterberg, W. Bardan, Lena Heijkenskjöld, D. Prasuhn, B.A. Shwartz, A. Khoukaz, R. Varma, G. Sterzenbach, B. Lorentz, Ralf Engels, J. Zabierowski, Ankhi Roy, K. Föhl, Antoni Szczurek, H. Ströher, A. Trzcinski, Wojciech Krzemien, V. Sopov, D. Pszczel, I. Schätti-Ozerianska, Marcin Zieliński, P. Adlarson, H. Ohm, B. Mariański, Aleksandra Wrońska, E. Perez del Rio, Magdalena Skurzok, F. S. Bergmann, Magnus Wolke, K. Grigoryev, L. Jarczyk, A. Goswami, K. Demmich, T. Johansson, B. Kłos, K. Lalwani, and S. Sawant

Subjects
Nuclear and High Energy Physics, Particle physics, Pion-Production, Gev/C, Nuclear Theory, Hadron, FOS: Physical sciences, 01 natural sciences, Pp Collisions, High Energy Physics - Experiment, Subatomär fysik, Nuclear physics, High Energy Physics - Experiment (hep-ex), dibaryons, Subatomic Physics, 0103 physical sciences, ddc:530, Nuclear Experiment (nucl-ex), Nuclear Experiment, 010306 general physics, Proton-Proton Interactions, Physics, Quantum chromodynamics, States, Decomposition, Four-pion production, Dibaryons, 010308 nuclear & particles physics, Resonance, Quantum number, lcsh:QC1-999, Energies, Delta, Resonances, Isospin, four-pion production, 24 Gev-C, Beam energy, lcsh:Physics
Abstract

Various theoretical calculations based on QCD or hadronic interactions predict that in addition to the recently observed dibaryon resonance d⁎(2380) with I(JP)=0(3+) there should also exist a dibaryon resonance with mirrored quantum numbers I(JP)=3(0+). We report here on a search for such a NN-decoupled state in data on the pp→ppπ+π+π−π− reaction. Since no clear-cut evidence has been found, we give upper limits for the production cross section of such a resonance in the mass range 2280–2500 MeV., This work has been supported by DFG (CL 214/3-1), STFC (ST/L00478X/1) and by the Polish National Science Center through grants Nos. DEC-2013/11/N/ST2/04152 and 2011/03/B/ST2/01847

Published
2016

9. Corrigendum to 'Isoscalar single-pion production in the region of Roper and d⁎(2380) resonances' [Phys. Lett. B 774 (2017) 599]

Author

A. Khoukaz, K. Grigoryev, P. Fedorets, P. Żuprański, P. Wüstner, R. Stassen, W. Eyrich, Wiktor Parol, B. Kamys, A. Bondar, Hans Calén, C.-O. Gullström, Aleksandra Wrońska, H. Clement, E. Perez del Rio, Kjell Fransson, A. Trzciński, M. Bashkanov, A. Pyszniak, W. Augustyniak, Izabela Ciepał, Magnus Wolke, V. Serdyuk, A. Magiera, Zbigniew Rudy, A. Yamamoto, H. Kleines, A. Kupść, Eryk Czerwiński, H.-P. Morsch, Pawel Marciniewski, A. Roy, Marcin Zieliński, H. Ohm, H. Stockhorst, K. Pysz, L. Jarczyk, G. Sterzenbach, P. Kulessa, Stanisław Kistryn, N.M. Piskunov, B. Shwartz, K. Sitterberg, B. Lorentz, K. Lalwani, K. Demmich, R. Varma, J. Ritman, W. Bardan, Lena Heijkenskjöld, G. Khatri, Paweł Moskal, D.A. Kirillov, Jerzy Smyrski, T. Sefzick, M. Büscher, F. Goldenbaum, G. Kemmerling, R. Maier, T. Johansson, B. Kłos, A. Kuzmin, D. Prasuhn, S. Sawant, F.S. Bergmann, A. Goswami, T. Skorodko, V. Hejny, N. Hüsken, J. Stepaniak, Himani Bhatt, S. Schadmand, D. Lersch, B. Mariański, V. Sopov, P. Adlarson, Oleksandr Rundel, Magdalena Skurzok, M. Berłowski, D. Pszczel, H. Ströher, R. Engels, I. Schätti-Ozerianska, W. Erven, J. Zabierowski, Wojciech Krzemien, E. Stephan, A. Szczurek, K. Föhl, A. Erven, M. Żurek, O. Khreptak, and Jozef Zlomanczuk

Subjects
Physics, Nuclear physics, Nuclear and High Energy Physics, Pion, Isoscalar, ddc:530, lcsh:Physics, lcsh:QC1-999
Published
2020

10. Isotensor Dibaryon in the pp→ppπ+π− Reaction?

Author

A. Magiera, Stanisław Kistryn, O. Khreptak, H. Clement, A. Bondar, B. Shwartz, J. Stepaniak, Lena Heijkenskjöld, D. Prasuhn, K. Lalwani, H. Ohm, D. Lersch, W. Erven, T. Johansson, Jozef Zlomanczuk, H. P. Morsch, G. Sterzenbach, B. Lorentz, Ralf Engels, Pawel Marciniewski, B. Kłos, Wiktor Parol, A. Khoukaz, D. Pszczel, K. Föhl, H. Ströher, Izabela Ciepał, F. S. Bergmann, K. Pysz, P. Fedorets, W. Augustyniak, J. Ritman, V. Serdyuk, S. Sawant, Frank Goldenbaum, Jerzy Smyrski, Aleksandra Wrońska, E. Perez del Rio, Hans Stockhorst, Magnus Wolke, V. Hejny, M. Bashkanov, I. Schätti-Ozerianska, T. Sefzick, S. Schadmand, Akira Yamamoto, A. Kupść, A. Trzcinski, Marcin Zieliński, Rolf Stassen, A. Erven, Di. Kirillov, P. Żuprański, B. Kamys, Markus Büscher, W. Eyrich, Günter Kemmerling, P. Wüstner, N. Hüsken, Hans Calén, P. Adlarson, K. Grigoryev, Kjell Fransson, Magdalena Skurzok, M. Żurek, Paweł Moskal, L. Jarczyk, M. Berłowski, Wojciech Krzemien, R. Maier, A. Goswami, K. Demmich, T. Skorodko, B. Mariański, J. Zabierowski, Antoni Szczurek, Zbigniew Rudy, Eryk Czerwiński, Harald Kleines, V. Sopov, W. Bardan, Oleksandr Rundel, E. Stephan, P. Kulessa, N.M. Piskunov, and Ankhi Roy

Subjects
Nuclear physics, Physics, Cross section (physics), Pion, Meson, 010308 nuclear & particles physics, Excited state, 0103 physical sciences, General Physics and Astronomy, 010306 general physics, 01 natural sciences, Resonance (particle physics), Energy (signal processing)
Abstract

Exclusive measurements of the quasifree pp→ppπ^{+}π^{-} reaction have been carried out at WASA@COSY by means of pd collisions at T_{p}=1.2 GeV. Total and differential cross sections have been extracted covering the energy region T_{p}=1.08-1.36 GeV, which is the region of N^{*}(1440) and Δ(1232)Δ(1232) resonance excitations. Calculations describing these excitations by t-channel meson exchange are at variance with the measured differential cross sections and underpredict substantially the experimental total cross section. An isotensor ΔN dibaryon resonance with I(J^{P})=2(1^{+}) produced associatedly with a pion is able to overcome these deficiencies.

Published
2018

11. Importance of -wave Contributions in the Charge Symmetry Breaking Reaction

Author

D. Lersch, O. Khreptak, M. Bashkanov, K. Grigoryev, A. Erven, K. Sitterberg, K. Föhl, Izabela Ciepał, H. Ströher, Oleksandr Rundel, A. Magiera, V. Sopov, T. Johansson, B. Kłos, Jozef Zlomanczuk, A. Trzcinski, L. Jarczyk, B.A. Shwartz, A. Khoukaz, Hans Stockhorst, G. Khatri, E. Stephan, Rolf Stassen, G. Sterzenbach, Marcin Zieliński, S. Sawant, B. Lorentz, N.M. Piskunov, A. Kuzmin, A. Goswami, J. Zabierowski, K. Demmich, C.-O. Gullström, Markus Büscher, Antoni Szczurek, W. Bardan, S. Schadmand, D. Pszczel, Rudolf Maier, Ankhi Roy, P. Kulessa, P. Adlarson, J. Stepaniak, W. Erven, Wiktor Parol, Zbigniew Rudy, I. Schätti-Ozerianska, K. Lalwani, Magdalena Skurzok, Eryk Czerwiński, B. Mariański, Aleksandra Wrońska, K. Pysz, P. Fedorets, Harald Kleines, E. Perez del Rio, Hans Calén, B. Kamys, P. Wüstner, F. S. Bergmann, Wojciech Krzemien, Magnus Wolke, M. Berłowski, H. P. Morsch, H. Ohm, Kjell Fransson, H. Clement, Frank Goldenbaum, T. Skorodko, T. Sefzick, Pawel Marciniewski, P. Żuprański, M. Żurek, J. Ritman, V. Serdyuk, Jerzy Smyrski, Ralf Engels, Günter Kemmerling, W. Eyrich, N. Hüsken, Christoph Hanhart, Stanisław Kistryn, Lena Heijkenskjöld, D. Prasuhn, A. Pyszniak, W. Augustyniak, Paweł Moskal, V. Hejny, Akira Yamamoto, A. Kupść, Di. Kirillov, and A.E. Bondar

Subjects
Physics, Quark, Nuclear and High Energy Physics, Meson, 010308 nuclear & particles physics, Spontaneous symmetry breaking, Hadron, Charge (physics), 01 natural sciences, Nuclear physics, Pion, 0103 physical sciences, Isobar, Symmetry breaking, Atomic physics, 010306 general physics
Abstract

This letter reports a first quantitative analysis of the contribution of higher partial waves in the charge symmetry breaking reaction dd→4Heπ0 using the WASA-at-COSY detector setup at an excess energy of Q=60MeV. The determined differential cross section can be parametrized as dσ/dΩ=a+bcos2⁡θ⁎, where θ⁎ is the production angle of the pion in the center-of-mass coordinate system, and the results for the parameters are a=(1.55±0.46(stat)+0.32−0.8(syst))pb/sr and b=(13.1±2.1(stat)−2.7+1.0(syst))pb/sr. The data are compatible with vanishing p-waves and a sizable d-wave contribution. This finding should strongly constrain the contribution of the Δ isobar to the dd→4Heπ0 reaction and is, therefore, crucial for a quantitative understanding of quark mass effects in nuclear production reactions.

Published
2018

12. Isotensor Dibaryon in the pp→ppπ^{+}π^{-} Reaction?

Author

P, Adlarson, W, Augustyniak, W, Bardan, M, Bashkanov, F S, Bergmann, M, Berłowski, A, Bondar, M, Büscher, H, Calén, I, Ciepał, H, Clement, E, Czerwiński, K, Demmich, R, Engels, A, Erven, W, Erven, W, Eyrich, P, Fedorets, K, Föhl, K, Fransson, F, Goldenbaum, A, Goswami, K, Grigoryev, L, Heijkenskjöld, V, Hejny, N, Hüsken, L, Jarczyk, T, Johansson, B, Kamys, G, Kemmerling, A, Khoukaz, O, Khreptak, D A, Kirillov, S, Kistryn, H, Kleines, B, Kłos, W, Krzemień, P, Kulessa, A, Kupść, K, Lalwani, D, Lersch, B, Lorentz, A, Magiera, R, Maier, P, Marciniewski, B, Mariański, H-P, Morsch, P, Moskal, H, Ohm, W, Parol, E, Perez Del Rio, N M, Piskunov, D, Prasuhn, D, Pszczel, K, Pysz, J, Ritman, A, Roy, Z, Rudy, O, Rundel, S, Sawant, S, Schadmand, I, Schätti-Ozerianska, T, Sefzick, V, Serdyuk, B, Shwartz, T, Skorodko, M, Skurzok, J, Smyrski, V, Sopov, R, Stassen, J, Stepaniak, E, Stephan, G, Sterzenbach, H, Stockhorst, H, Ströher, A, Szczurek, A, Trzciński, M, Wolke, A, Wrońska, P, Wüstner, A, Yamamoto, J, Zabierowski, M J, Zieliński, J, Złomańczuk, P, Żuprański, and M, Żurek

Abstract

Exclusive measurements of the quasifree pp→ppπ^{+}π^{-} reaction have been carried out at WASA@COSY by means of pd collisions at T_{p}=1.2 GeV. Total and differential cross sections have been extracted covering the energy region T_{p}=1.08-1.36 GeV, which is the region of N^{*}(1440) and Δ(1232)Δ(1232) resonance excitations. Calculations describing these excitations by t-channel meson exchange are at variance with the measured differential cross sections and underpredict substantially the experimental total cross section. An isotensor ΔN dibaryon resonance with I(J^{P})=2(1^{+}) produced associatedly with a pion is able to overcome these deficiencies.

Published
2018

13. Spin dependence of {\eta} meson production in proton-proton collisions close to threshold

Author

M. Bashkanov, Günter Kemmerling, A. Erven, I. Schätti-Ozerianska, K. Sitterberg, G. Sterzenbach, W. Eyrich, A. Magiera, B. Lorentz, H. P. Morsch, O. Khreptak, Ralf Engels, N. Hüsken, Paweł Moskal, Zbigniew Rudy, Marcin Zieliński, Eryk Czerwiński, C.-O. Gullström, Markus Büscher, Harald Kleines, Ankhi Roy, W. Bardan, Aleksandra Wrońska, Hans Calén, E. Perez del Rio, T. Sefzick, Stanisław Kistryn, J. Zabierowski, K. Pysz, V. Hejny, Akira Yamamoto, Kjell Fransson, Lena Heijkenskjöld, D. Prasuhn, Antoni Szczurek, A. Khoukaz, Magdalena Skurzok, B. Mariański, K. Grigoryev, Jozef Zlomanczuk, Wojciech Krzemien, V. Sopov, Andrzej Kupsc, Patrik Adlarson, Frank Goldenbaum, Pawel Marciniewski, Damian Pszczel, B. Shwartz, J. Stepaniak, P. Zupranski, D. Lersch, J. Ritman, A. Trzcinski, G. Khatri, P. Fedorets, W. Augustyniak, Tord Johansson, L. Jarczyk, W. Erven, V. Serdyuk, Steven D. Bass, H. Ohm, H. Clement, M. Berłowski, K. Föhl, K. Lalwani, A. Bondar, H. Stroeher, Maria Zurek, Jerzy Smyrski, B. Kamys, P. Wüstner, B. Kłos, T. Skorodko, S. Schadmand, K. Demmich, A. Pyszniak, S. Sawant, Di. Kirillov, A. Kuzmin, F. S. Bergmann, Magnus Wolke, Izabela Ciepał, A. Goswami, Hans Stockhorst, Rolf Stassen, Rudolf Maier, P. Kulessa, Wiktor Parol, Oleksandr Rundel, E. Stephan, and N.M. Piskunov

Subjects
Nuclear Theory, General Physics and Astronomy, 01 natural sciences, High Energy Physics - Experiment, Nuclear physics, 0103 physical sciences, ddc:530, FACILITY, NEAR-THRESHOLD, 010306 general physics, NUCLEON, Nuclear Experiment, Nuclear theory, Physics, QUASI-FREE, 010308 nuclear & particles physics, Eta meson, Detector, COSY, Polarization (waves), Near threshold, High Energy Physics - Phenomenology, Physics::Accelerator Physics, Axial symmetry, Nucleon
Abstract

Taking advantage of the high acceptance and axial symmetry of the WASA-at-COSY detector, and the high degree of the polarized proton beam of COSY, the reaction pp{\to} pp{\eta} has been measured close to threshold to explore the analyzing power Ay. The angular distribution of Ay is determined with the precision improved by more than one order of magnitude with respect to previous results allowing a first accurate comparison with theoretical predictions. The determined analyzing power is consistent with zero for an excess energy of Q = 15 MeV signaling s wave production with no evidence for higher partial waves. At Q = 72 MeV the data reveals strong interference of P s and P p partial waves and cancellation of (P p) and Ss*Sd contributions. These results rule out the presently available theoretical predictions for the production mechanism of the {\eta} meson., Comment: Accepted for publication in Phys. Rev. Lett

Published
2017

14. Studies of discrete symmetries in a purely leptonic system using the Jagiellonian Positron Emission Tomograph

Author

Daria Kamińska, Paweł Moskal, Sz. Niedźwiecki, M. Pawlik-Niedńwiecka, Wojciech Krzemien, Beatrix C. Hiesmayr, Tomasz Bednarski, Jerzy Smyrski, Muhsin Mohammed, O. Khreptak, Kamil Dulski, Anna Wieczorek, Wojciech Wiślicki, Bożena Zgardzińska, Aleksander Gajos, Ewelina Kubicz, N. Krawczyk, D. Alfs, Catalina Curceanu, Piotr Białas, Marek Gorgol, Paweł Kowalski, Michał Silarski, N. Gupta-Sharma, Grzegorz Korcyl, Zbigniew Rudy, Bartosz Głowacz, Eryk Czerwiński, Bożena Jasińska, Lech Raczyński, and Marcin Zieliński

Subjects
Quark, Physics, Particle physics, Photon, Annihilation, QC1-999, Elementary particle, 01 natural sciences, 030218 nuclear medicine & medical imaging, Positronium, Nuclear physics, 03 medical and health sciences, 0302 clinical medicine, Positron, Antimatter, 0103 physical sciences, High Energy Physics::Experiment, 010306 general physics, Lepton
Abstract

Discrete symmetries such as parity (P), charge-conjugation (C) and time reversal (T) are of fundamental importance in physics and cosmology. Breaking of charge conjugation symmetry (C) and its combination with parity (CP) constitute necessary conditions for the existence of the asymmetry between matter and antimatter in the observed Universe. The presently known sources of discrete symmetries violations can account for only a tiny fraction of the excess of matter over antimatter. So far CP and T symmetries violations were observed only for systems involving quarks and they were never reported for the purely leptonic objects. In this article we describe briefly an experimental proposal for the test of discrete symmetries in the decays of positronium atom which is made exclusively of leptons. The experiments are conducted by means of the Jagiellonian Positron Emission Tomograph (J-PET) which is constructed from strips of plastic scintillators enabling registration of photons from the positronium annihilation. J-PET tomograph together with the positronium target system enable to measure expectation values for the discrete symmetries odd operators constructed from (i) spin vector of the ortho-positronium atom, (ii) momentum vectors of photons originating from the decay of positronium, and (iii) linear polarization direction of annihilation photons. Linearly polarized positronium will be produced in the highly porous aerogel or polymer targets, exploiting longitudinally polarized positrons emitted by the sodium 22 Na isotope. Information about the polarization vector of orthopositronium will be available on the event by event basis and will be reconstructed from the known position of the positron source and the reconstructed position of the orthopositronium annihilation. In 2016 the first tests and calibration runs are planned, and the data collection with high statistics will commence in the year 2017.

Published
2016

15. Production and interaction of the η meson with nucleons and nuclei

Author

O. Khreptak, Magdalena Skurzok, Iryna Ozyrianska-Schätti, Wojciech Krzemien, Paweł Moskal, Oleksandr Rundel, and Marcin Zieliński

Subjects
Physics, Particle physics, Proton, 010308 nuclear & particles physics, QC1-999, Eta meson, Nuclear Theory, FOS: Physical sciences, 01 natural sciences, 0103 physical sciences, High Energy Physics::Experiment, Nuclear Experiment (nucl-ex), 010306 general physics, Nucleon, Nuclear Experiment, Order of magnitude
Abstract

We report on the status of the search for eta-mesic nuclei and the studies of the interaction of the eta meson with nucleons. Recently we have completed the analysis of the new WASA-at-COSY data on the production of the eta meson with polarized proton beam. New results on the analyzing power for the pp->ppeta reaction with more than an order of magnitude improved precision shed a new light on the production mechanism of the eta meson in nucleon-nucleon collisions. Also, the latest results of the search for eta-mesic nuclei are discussed., 4 pages, presented at 14th International Workshop on Meson Production, Properties and Interaction KRAK\'OW, POLAND (MESON 2016), accepted for publication in EPJ

Published
2016

16. Search for the $\eta $-mesic Helium in Proton--Deuteron Reaction

Author

Magdalena Skurzok, Paweł Moskal, Oleksandr Rundel, and O. Khreptak

Subjects
Nuclear physics, Physics, chemistry, Proton, Deuterium, 010308 nuclear & particles physics, 0103 physical sciences, General Physics and Astronomy, chemistry.chemical_element, 010306 general physics, 01 natural sciences, Helium
Published
2017

17. Searching forη-mesic Helium with WASA-at-COSY facility

Author

O. Khreptak, Paweł Moskal, Wojciech Krzemien, Oleksandr Rundel, and Magdalena Skurzok

Subjects
Physics, 010308 nuclear & particles physics, QC1-999, chemistry.chemical_element, 01 natural sciences, Engineering physics, Nuclear physics, chemistry, 0103 physical sciences, Bound state, 010306 general physics, Beam (structure), Helium
Abstract

The search for the 4 He-η and 3 He-η bound states was performed with the WASA-at-COSY facility using a ramped beam technique in 2008, 2010 and 2014, respectively. The 2008 and 2010 data analyses has already been completed and resulted in the upper limits for the total cross sections for the η -mesic 4 He production in dd → 3 Henπ 0 and dd → 3 Hepπ − processes. No narrow structure which could be interpreted as a bound state was observed. The experiment carried out in 2014 collected the largest data sample for 3 He-η in the world. The data analysis is in progress. This article presents results of the 2010 data analysis and preliminary results of the 2014 data analysis.

Published
2016

18. J-PET detector system for studies of the electron-positron annihilations

Author

Bartosz Głowacz, Beatrix C. Hiesmayr, Bożena Jasińska, Muhsin Mohammed, Lech Raczyński, Aleksander Gajos, O. Khreptak, Wojciech Wiślicki, N. Gupta-Sharma, Daria Kamińska, Bożena Zgardzińska, Tomasz Bednarski, Piotr Białas, Paweł Kowalski, Kamil Dulski, Grzegorz Korcyl, Sz. Niedźwiecki, Marek Gorgol, Ewelina Kubicz, Paweł Moskal, Zbigniew Rudy, Marcin Zieliński, Monika Pawlik-Niedźwiecka, W. Krzmień, Michał Silarski, Eryk Czerwiński, Catalina Curceanu, Anna Wieczorek, D. Alfs, and N. Krawczyk

Subjects
Physics, Antiparticle, Photon, Physics::Instrumentation and Detectors, QC1-999, Physics::Medical Physics, Detector, Scintillator, 01 natural sciences, Particle detector, 030218 nuclear medicine & medical imaging, Nuclear physics, 03 medical and health sciences, 0302 clinical medicine, Positron, Antimatter, 0103 physical sciences, High Energy Physics::Experiment, Positron emission, 010306 general physics
Abstract

Jagiellonian Positron Emission Tomograph (J-PET) has been recently constructed at the Jagiellonian University as a prototype of a cost-effective scanner for the metabolic imaging of the whole human body. J-PET detector is optimized for the measurement of momentum and polarization of photons from the electron-positron annihilations. It is built out of strips of plastic scintillators, forming three cylindrical layers. As detector of gamma quanta it will be used for studies of discrete symmetries and multiparticle entanglement of photons originating from the decays of ortho-positronium atoms.

Published
2016

19. Isotensor Dibaryon in the pp→ppπ^{+}π^{-} Reaction?

Author

Adlarson P, Augustyniak W, Bardan W, Bashkanov M, Bergmann FS, Berłowski M, Bondar A, Büscher M, Calén H, Ciepał I, Clement H, Czerwiński E, Demmich K, Engels R, Erven A, Erven W, Eyrich W, Fedorets P, Föhl K, Fransson K, Goldenbaum F, Goswami A, Grigoryev K, Heijkenskjöld L, Hejny V, Hüsken N, Jarczyk L, Johansson T, Kamys B, Kemmerling G, Khoukaz A, Khreptak O, Kirillov DA, Kistryn S, Kleines H, Kłos B, Krzemień W, Kulessa P, Kupść A, Lalwani K, Lersch D, Lorentz B, Magiera A, Maier R, Marciniewski P, Mariański B, Morsch HP, Moskal P, Ohm H, Parol W, Perez Del Rio E, Piskunov NM, Prasuhn D, Pszczel D, Pysz K, Ritman J, Roy A, Rudy Z, Rundel O, Sawant S, Schadmand S, Schätti-Ozerianska I, Sefzick T, Serdyuk V, Shwartz B, Skorodko T, Skurzok M, Smyrski J, Sopov V, Stassen R, Stepaniak J, Stephan E, Sterzenbach G, Stockhorst H, Ströher H, Szczurek A, Trzciński A, Wolke M, Wrońska A, Wüstner P, Yamamoto A, Zabierowski J, Zieliński MJ, Złomańczuk J, Żuprański P, and Żurek M

Abstract

Exclusive measurements of the quasifree pp→ppπ^{+}π^{-} reaction have been carried out at WASA@COSY by means of pd collisions at T_{p}=1.2  GeV. Total and differential cross sections have been extracted covering the energy region T_{p}=1.08-1.36  GeV, which is the region of N^{*}(1440) and Δ(1232)Δ(1232) resonance excitations. Calculations describing these excitations by t-channel meson exchange are at variance with the measured differential cross sections and underpredict substantially the experimental total cross section. An isotensor ΔN dibaryon resonance with I(J^{P})=2(1^{+}) produced associatedly with a pion is able to overcome these deficiencies.

Published
2018
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20. Spin Dependence of η Meson Production in Proton-Proton Collisions Close to Threshold.

Author

Adlarson P, Augustyniak W, Bardan W, Bashkanov M, Bass SD, Bergmann FS, Berłowski M, Bondar A, Büscher M, Calén H, Ciepał I, Clement H, Czerwiński E, Demmich K, Engels R, Erven A, Erven W, Eyrich W, Fedorets P, Föhl K, Fransson K, Goldenbaum F, Goswami A, Grigoryev K, Gullström CO, Heijkenskjöld L, Hejny V, Hüsken N, Jarczyk L, Johansson T, Kamys B, Kemmerling G, Khatri G, Khoukaz A, Khreptak O, Kirillov DA, Kistryn S, Kleines H, Kłos B, Krzemień W, Kulessa P, Kupść A, Kuzmin A, Lalwani K, Lersch D, Lorentz B, Magiera A, Maier R, Marciniewski P, Mariański B, Morsch HP, Moskal P, Ohm H, Parol W, Perez Del Rio E, Piskunov NM, Prasuhn D, Pszczel D, Pysz K, Pyszniak A, Ritman J, Roy A, Rudy Z, Rundel O, Sawant S, Schadmand S, Schätti-Ozerianska I, Sefzick T, Serdyuk V, Shwartz B, Sitterberg K, Skorodko T, Skurzok M, Smyrski J, Sopov V, Stassen R, Stepaniak J, Stephan E, Sterzenbach G, Stockhorst H, Ströher H, Szczurek A, Trzciński A, Wolke M, Wrońska A, Wüstner P, Yamamoto A, Zabierowski J, Zieliński MJ, Złomańczuk J, Żuprański P, and Żurek M

Abstract

Taking advantage of the high acceptance and axial symmetry of the WASA-at-COSY detector, and the high polarization degree of the proton beam of COSY, the reaction p[over →]p→ppη has been measured close to threshold to explore the analyzing power A_{y}. The angular distribution of A_{y} is determined with the precision improved by more than 1 order of magnitude with respect to previous results, allowing a first accurate comparison with theoretical predictions. The determined analyzing power is consistent with zero for an excess energy of Q=15  MeV, signaling s-wave production with no evidence for higher partial waves. At Q=72  MeV the data reveal strong interference of Ps and Pp partial waves and cancellation of (Pp)^{2} and Ss^{*}Sd contributions. These results rule out the presently available theoretical predictions for the production mechanism of the η meson.

Published
2018
Full Text
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