Measurement of the np -> np pi(0)pi(0) reaction in search for the recently observed d* (2380) resonance

WASA-At-COSY Collaboration, P. Adlarsona, W. Augustyniak, W. Bardan, M. Bashkanov, F. S. Bergmann, M. Berlowski, H. Bhatt, A. Bondar, M. Buescher, H. Calen, I. Ciepal, H. Clement*, D. Coderre, E. Czerwinski, K. Demmich, E. Doroshkevich, R. Engels, A. Erven, W. ErvenW. Eyrich, P. Fedorets, K. Foehl, K. Fransson, F. Goldenbaum, P. Goslawski, A. Goswami, K. Grigoryev, C. -O. Gullstrom, F. Hauenstein, L. Heijkenskjold, V. Hejny, B. Hoistad, N. Huesken, L. Jarczyk, T. Johansson, B. Kamys, G. Kemmerling, F. A. Khan, A. Khoukaz, D. A. Kirillov, S. Kistryn, H. Kleines, B. Klos, W. Krzemien, P. Kulessa, A. Kupsc, A. Kuzmin, K. Lalwani, D. Lersch, B. Lorentz

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

Exclusive measurements of the quasi-free np --> np pi(0)pi(0) reaction have been performed by means of dp collisions at T-d = 2.27 GeV using the WASA detector setup at COSY. Total and differential cross sections have been obtained covering the energy region root s = (2.35-2.46) GeV, which includes the region of the ABC effect and its associated d* (2380) resonance. Adding the d* resonance amplitude to that for the conventional processes leads to a reasonable description of the data. The observed resonance effect in the total cross section is in agreement with the predictions of Faldt and Wilkin as well with those of Albadajedo and Oset. The ABC effect, i.e. the low-mass enhancement in the pi(0)pi(0)-invariant mass spectrum, is found to be very modest - if present at all, which might pose a problem to some of its interpretations. (C) 2015 The Authors. Published by Elsevier B.V.

Original languageEnglish
Pages (from-to)325-332
Number of pages8
JournalPhysics Letters B
Volume743
DOIs
Publication statusPublished - 9 Apr 2015

Keywords

  • Two-pion production
  • ABC effect and resonance structure
  • Dibaryon resonance
  • PROTON-PROTON COLLISIONS
  • NUCLEON-NUCLEON COLLISIONS
  • TOTAL CROSS-SECTIONS
  • PI(0)PI(0) PRODUCTION
  • 2-PION PRODUCTION
  • ROPER RESONANCE
  • PION PRODUCTION
  • EXCITATION
  • DIBARYON
  • PP

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