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Momentum dependence of the imaginary part of the ω - and η -nucleus optical potential

The CBELSA/TAPS Collaboration, CBELSA/TAPS Collaboration ; Friedrich, S. ; Nanova, M. ; Metag, V. ; Afzal, F. N. ; Bayadilov, D. ; Bantes, B. ; Beck, R. ; Becker, M. LU and Böse, S. , et al. (2016) In European Physical Journal A 52(9).
Abstract

The photoproduction of ω and η mesons off carbon and niobium nuclei has been measured as a function of the meson momentum for incident photon energies of 1.2-2.9GeV at the electron accelerator ELSA. The mesons have been identified via the ω → π0 γ → 3 γ and η → π0η → 6 γ 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 ω and η 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 ω width and... (More)

The photoproduction of ω and η mesons off carbon and niobium nuclei has been measured as a function of the meson momentum for incident photon energies of 1.2-2.9GeV at the electron accelerator ELSA. The mesons have been identified via the ω → π0 γ → 3 γ and η → π0η → 6 γ 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 ω and η 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 ω width and η-N absorption cross sections. The energy dependence of the imaginary part of the ω- and η-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 η-nucleus potential is found to be about three times smaller than recently determined values of the real part of the η-nucleus potential, which makes the η meson a suitable candidate for the search for meson-nucleus bound states. For the ω 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 ω mesic states very difficult experimentally.

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publishing date
type
Contribution to journal
publication status
published
in
European Physical Journal A
volume
52
issue
9
article number
297
publisher
Springer
external identifiers
  • scopus:84990841526
ISSN
1434-6001
DOI
10.1140/epja/i2016-16297-4
language
English
LU publication?
no
id
5c5d5876-6b5d-40f2-a92a-646715e2318c
date added to LUP
2019-03-11 13:24:22
date last changed
2020-11-22 06:11:06
@article{5c5d5876-6b5d-40f2-a92a-646715e2318c,
  abstract     = {<p>The photoproduction of ω and η mesons off carbon and niobium nuclei has been measured as a function of the meson momentum for incident photon energies of 1.2-2.9GeV at the electron accelerator ELSA. The mesons have been identified via the ω → π<sup>0</sup> γ → 3 γ and η → π<sup>0</sup>η → 6 γ 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 ω and η 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 ω width and η-N absorption cross sections. The energy dependence of the imaginary part of the ω- and η-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 η-nucleus potential is found to be about three times smaller than recently determined values of the real part of the η-nucleus potential, which makes the η meson a suitable candidate for the search for meson-nucleus bound states. For the ω 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 ω mesic states very difficult experimentally.</p>},
  author       = {The CBELSA/TAPS Collaboration, CBELSA/TAPS Collaboration and Friedrich, S. and Nanova, M. and Metag, V. and Afzal, F. N. and Bayadilov, D. and Bantes, B. and Beck, R. and Becker, M. 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 Lang, M. and Makonyi, K. and Messi, F. and Müller, J. and Müllers, J. and Piontek, D. M. 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 Thiel, A. and Walther, D. and Wilson, A.},
  issn         = {1434-6001},
  language     = {eng},
  month        = {09},
  number       = {9},
  publisher    = {Springer},
  series       = {European Physical Journal A},
  title        = {Momentum dependence of the imaginary part of the ω - and η -nucleus optical potential},
  url          = {http://dx.doi.org/10.1140/epja/i2016-16297-4},
  doi          = {10.1140/epja/i2016-16297-4},
  volume       = {52},
  year         = {2016},
}