Standard

Search for η-mesic He4 in the dd→He3nπ0 and dd→He3pπ− reactions with the WASA-at-COSY facility. / The WASA-at-COSY Collaboration.

In: Nuclear Physics A, Vol. 959, 01.03.2017, p. 102-115.

Research output: Contribution to journal › Article › peer-review

Harvard

The WASA-at-COSY Collaboration 2017, 'Search for η-mesic He4 in the dd→He3nπ0 and dd→He3pπ− reactions with the WASA-at-COSY facility', Nuclear Physics A, vol. 959, pp. 102-115. https://doi.org/10.1016/j.nuclphysa.2017.01.001

APA

The WASA-at-COSY Collaboration (2017). Search for η-mesic He4 in the dd→He3nπ0 and dd→He3pπ− reactions with the WASA-at-COSY facility. Nuclear Physics A, 959, 102-115. https://doi.org/10.1016/j.nuclphysa.2017.01.001

Vancouver

The WASA-at-COSY Collaboration. Search for η-mesic He4 in the dd→He3nπ0 and dd→He3pπ− reactions with the WASA-at-COSY facility. Nuclear Physics A. 2017 Mar 1;959:102-115. doi: 10.1016/j.nuclphysa.2017.01.001

Author

The WASA-at-COSY Collaboration. / Search for η-mesic He4 in the dd→He3nπ0 and dd→He3pπ− reactions with the WASA-at-COSY facility. In: Nuclear Physics A. 2017 ; Vol. 959. pp. 102-115.

BibTeX

@article{06d5363eae184710ab85ec39eba40619,
title = "Search for η-mesic He4 in the dd→He3nπ0 and dd→He3pπ− reactions with the WASA-at-COSY facility",
abstract = "The search for He4-η bound states was performed with the WASA-at-COSY facility via the measurement of the excitation function for the dd→He3nπ0 and dd→He3pπ− 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 dd→He4η reaction ranging from Q=−70 MeV to Q=30 MeV. The luminosity was determined based on the dd→He3n reaction and the quasi-free proton–proton scattering via dd→ppnspectatornspectator 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 dd→(He4-η)bound→He3nπ0 and dd→(He4-η)bound→He3pπ− 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-He4. Assuming, as in the previous works, that this is identical with the distribution of nucleons bound with 20 MeV in He4, 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 nπ0 and pπ− channels, respectively. However, based on the recent theoretical findings of the N⁎(1535) momentum distribution in the N⁎-He3 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 nπ0 and pπ− channels respectively.",
keywords = "η meson, η-Mesic nuclei, eta meson, NUCLEI, NEAR-THRESHOLD, DETECTOR, QUASI-BOUND STATES, eta-Mesic nuclei, SYSTEMS, SCATTERING",
author = "{The WASA-at-COSY Collaboration} and P. Adlarson and W. Augustyniak and W. Bardan and M. Bashkanov and Bergmann, {F. S.} and M. Ber{\l}owski and H. Bhatt and A. Bondar and M. B{\"i}¿½scher and H. Cal{\"i}¿½n and I. Ciepa{\l} and H. Clement and E. Czerwi{\'n}ski and K. Demmich and R. Engels and A. Erven and W. Erven and W. Eyrich and P. Fedorets and K. F{\"i}¿½hl and K. Fransson and F. Goldenbaum and A. Goswami and K. Grigoryev and Gullstr{\"i}¿½m, {C. O.} and L. Heijkenskj{\"i}¿½ld and V. Hejny and N. H{\"i}¿½sken and L. Jarczyk and T. Johansson and B. Kamys and Kelkar, {N. G.} and G. Kemmerling and G. Khatri and A. Khoukaz and O. Khreptak and Kirillov, {D. A.} and S. Kistryn and H. Kleines and B. K{\l}os and W. Krzemie{\'n} and P. Kulessa and A. Kup{\'s}{\'c} and A. Kuzmin and K. Lalwani and D. Lersch and B. Lorentz and A. Magiera and R. Maier and B. Shwartz",
note = "Publisher Copyright: {\textcopyright} 2017",
year = "2017",
month = mar,
day = "1",
doi = "10.1016/j.nuclphysa.2017.01.001",
language = "English",
volume = "959",
pages = "102--115",
journal = "Nuclear Physics A",
issn = "0375-9474",
publisher = "Elsevier",

}

RIS

TY - JOUR

T1 - Search for η-mesic He4 in the dd→He3nπ0 and dd→He3pπ− reactions with the WASA-at-COSY facility

AU - The WASA-at-COSY Collaboration

AU - Adlarson, P.

AU - Augustyniak, W.

AU - Bardan, W.

AU - Bashkanov, M.

AU - Bergmann, F. S.

AU - Berłowski, M.

AU - Bhatt, H.

AU - Bondar, A.

AU - B�scher, M.

AU - Cal�n, H.

AU - Ciepał, I.

AU - Clement, H.

AU - Czerwiński, E.

AU - Demmich, K.

AU - Engels, R.

AU - Erven, A.

AU - Erven, W.

AU - Eyrich, W.

AU - Fedorets, P.

AU - F�hl, K.

AU - Fransson, K.

AU - Goldenbaum, F.

AU - Goswami, A.

AU - Grigoryev, K.

AU - Gullstr�m, C. O.

AU - Heijkenskj�ld, L.

AU - Hejny, V.

AU - H�sken, N.

AU - Jarczyk, L.

AU - Johansson, T.

AU - Kamys, B.

AU - Kelkar, N. G.

AU - Kemmerling, G.

AU - Khatri, G.

AU - Khoukaz, A.

AU - Khreptak, O.

AU - Kirillov, D. A.

AU - Kistryn, S.

AU - Kleines, H.

AU - Kłos, B.

AU - Krzemień, W.

AU - Kulessa, P.

AU - Kupść, A.

AU - Kuzmin, A.

AU - Lalwani, K.

AU - Lersch, D.

AU - Lorentz, B.

AU - Magiera, A.

AU - Maier, R.

AU - Shwartz, B.

N1 - Publisher Copyright: © 2017

PY - 2017/3/1

Y1 - 2017/3/1

N2 - The search for He4-η bound states was performed with the WASA-at-COSY facility via the measurement of the excitation function for the dd→He3nπ0 and dd→He3pπ− 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 dd→He4η reaction ranging from Q=−70 MeV to Q=30 MeV. The luminosity was determined based on the dd→He3n reaction and the quasi-free proton–proton scattering via dd→ppnspectatornspectator 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 dd→(He4-η)bound→He3nπ0 and dd→(He4-η)bound→He3pπ− 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-He4. Assuming, as in the previous works, that this is identical with the distribution of nucleons bound with 20 MeV in He4, 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 nπ0 and pπ− channels, respectively. However, based on the recent theoretical findings of the N⁎(1535) momentum distribution in the N⁎-He3 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 nπ0 and pπ− channels respectively.

AB - The search for He4-η bound states was performed with the WASA-at-COSY facility via the measurement of the excitation function for the dd→He3nπ0 and dd→He3pπ− 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 dd→He4η reaction ranging from Q=−70 MeV to Q=30 MeV. The luminosity was determined based on the dd→He3n reaction and the quasi-free proton–proton scattering via dd→ppnspectatornspectator 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 dd→(He4-η)bound→He3nπ0 and dd→(He4-η)bound→He3pπ− 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-He4. Assuming, as in the previous works, that this is identical with the distribution of nucleons bound with 20 MeV in He4, 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 nπ0 and pπ− channels, respectively. However, based on the recent theoretical findings of the N⁎(1535) momentum distribution in the N⁎-He3 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 nπ0 and pπ− channels respectively.

KW - η meson

KW - η-Mesic nuclei

KW - eta meson

KW - NUCLEI

KW - NEAR-THRESHOLD

KW - DETECTOR

KW - QUASI-BOUND STATES

KW - eta-Mesic nuclei

KW - SYSTEMS

KW - SCATTERING

UR - http://www.scopus.com/inward/record.url?scp=85009200807&partnerID=8YFLogxK

U2 - 10.1016/j.nuclphysa.2017.01.001

DO - 10.1016/j.nuclphysa.2017.01.001

M3 - Article

AN - SCOPUS:85009200807

VL - 959

SP - 102

EP - 115

JO - Nuclear Physics A

JF - Nuclear Physics A

SN - 0375-9474

ER -

ID: 12692864