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The η′-carbon potential at low meson momenta

Nanova, M. ; Friedrich, S. ; Metag, V. ; Paryev, E. Ya ; Afzal, F. N. ; Bayadilov, D. ; Bantes, B. ; Beck, R. ; Böse, S. and Brinkmann, K. T. , et al. (2018) In European Physical Journal A 54(10).
Abstract


The production of η′ mesons in coincidence with forward-going protons has been studied in photon-induced reactions on
12
C and on a liquid hydrogen (LH
2
) target for incoming photon energies of 1.3–2.6 GeV at the electron accelerator ELSA. The η′ mesons have been identified via the η′ → π
0
... (More)


The production of η′ mesons in coincidence with forward-going protons has been studied in photon-induced reactions on
12
C and on a liquid hydrogen (LH
2
) target for incoming photon energies of 1.3–2.6 GeV at the electron accelerator ELSA. The η′ mesons have been identified via the η′ → π
0
π
0
η → 6γ decay registered with the CBELSA/TAPS detector system. Coincident protons have been identified in the MiniTAPS BaF
2
array at polar angles of 2°≤ θ
p
≤ 11°. Under these kinematic constraints the η′ mesons are produced with relatively low kinetic energy (≈ 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 η′-carbon potential at low meson momenta by comparing with collision model calculations of the η′ kinetic energy distribution and excitation function. Fitting the latter data for η′ mesons going backwards in the center-of-mass system yields a potential depth of V = −(44 ± 16(stat) ± 15(syst)) MeV, consistent with earlier determinations of the potential depth in inclusive measurements for average η′ momenta of ≈ 1.1 GeV/c. Within the experimental uncertainties, there is no indication of a momentum dependence of the η′-carbon potential. The LH
2
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 η′ photoproduction off the free proton.

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publishing date
type
Contribution to journal
publication status
published
in
European Physical Journal A
volume
54
issue
10
article number
182
publisher
Springer
external identifiers
  • scopus:85062604714
ISSN
1434-6001
DOI
10.1140/epja/i2018-12639-6
language
English
LU publication?
no
id
1d651eee-d725-4ab8-a5da-85e357d2e52d
date added to LUP
2019-03-16 14:34:24
date last changed
2020-12-29 03:58:22
@article{1d651eee-d725-4ab8-a5da-85e357d2e52d,
  abstract     = {<p><br>
                                                         The production of η′ mesons in coincidence with forward-going protons has been studied in photon-induced reactions on                             <br>
                            <sup>12</sup><br>
                                                         C and on a liquid hydrogen (LH                             <br>
                            <sub>2</sub><br>
                                                         ) target for incoming photon energies of 1.3–2.6 GeV at the electron accelerator ELSA. The η′ mesons have been identified via the η′ → π                             <br>
                            <sup>0</sup><br>
                                                         π                             <br>
                            <sup>0</sup><br>
                                                         η → 6γ decay registered with the CBELSA/TAPS detector system. Coincident protons have been identified in the MiniTAPS BaF                             <br>
                            <sub>2</sub><br>
                                                          array at polar angles of 2°≤ θ                             <br>
                            <sub>p</sub><br>
                                                          ≤ 11°. Under these kinematic constraints the η′ mesons are produced with relatively low kinetic energy (≈ 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 η′-carbon potential at low meson momenta by comparing with collision model calculations of the η′ kinetic energy distribution and excitation function. Fitting the latter data for η′ mesons going backwards in the center-of-mass system yields a potential depth of V = −(44 ± 16(stat) ± 15(syst)) MeV, consistent with earlier determinations of the potential depth in inclusive measurements for average η′ momenta of ≈ 1.1 GeV/c. Within the experimental uncertainties, there is no indication of a momentum dependence of the η′-carbon potential. The LH                             <br>
                            <sub>2</sub><br>
                                                          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 η′ photoproduction off the free proton.                         <br>
                        </p>},
  author       = {Nanova, M. and Friedrich, S. and Metag, V. and Paryev, E. Ya and Afzal, F. N. and Bayadilov, D. and Bantes, B. and Beck, R. and Böse, S. and Brinkmann, K. T. and Crede, V. and Drexler, P. and Eberhardt, H. and Elsner, D. and Frommberger, F. and Funke, Ch and Gottschall, M. and Grüner, M. and Gutz, E. and Hammann, Ch and Hannappel, J. and Hartmann, J. and Hillert, W. and Hoffmeister, Ph and Honisch, Ch and Jude, T. and Kaiser, D. and Kalischewski, F. and Keshelashvili, I. and Klein, F. and Koop, K. and Krusche, B. and Makonyi, K. and Messi, F. and Müller, J. and Müllers, J. and Piontek, D. and Rostomyan, T. and Schaab, D. and Schmidt, Ch and Schmieden, H. and Schmitz, R. and Seifen, T. and Sokhoyan, V. and Sowa, C. and Spieker, K. and Thoma, U. and Triffterer, T. and Urban, M. and Van Pee, H.},
  issn         = {1434-6001},
  language     = {eng},
  month        = {01},
  number       = {10},
  publisher    = {Springer},
  series       = {European Physical Journal A},
  title        = {The η′-carbon potential at low meson momenta},
  url          = {http://dx.doi.org/10.1140/epja/i2018-12639-6},
  doi          = {10.1140/epja/i2018-12639-6},
  volume       = {54},
  year         = {2018},
}