Role of the Δ Resonance in the Population of a Four-Nucleon State in the 56Fe → 54Fe Reaction at Relativistic Energies

Research output: Contribution to journalArticle


The Fe54 nucleus was populated from a 56Fe beam impinging on a Be target with an energy of E/A=500 MeV. The internal decay via γ-ray emission of the 10+ metastable state was observed. As the structure of this isomeric state has to involve at least four unpaired nucleons, it cannot be populated in a simple two-neutron removal reaction from the 56Fe ground state. The isomeric state was produced in the low-momentum (-energy) tail of the parallel momentum (energy) distribution of 54Fe, suggesting that it was populated via the decay of the Δ0 resonance into a proton. This process allows the population of four-nucleon states, such as the observed isomer. Therefore, it is concluded that the observation of this 10+ metastable state in 54Fe is a consequence of the quark structure of the nucleons.


  • Zs Podolyák
  • C. M. Shand
  • Natasa Lalovic
  • J. Gerl
  • T. Alexander
  • P. Boutachkov
  • M. L. Cortés
  • M. Górska
  • I. Kojouharov
  • N. Kurz
  • C. Louchart
  • E. Merchán
  • C. Michelagnoli
  • R. M. Pérez-Vidal
  • S. Pietri
  • D. Ralet
  • M. Reese
  • H. Schaffner
  • Ch Stahl
  • H. Weick
  • F. Ameil
  • G. De Angelis
  • T. Arici
  • R. Carroll
  • Zs Dombrádi
  • A. Gadea
  • M. Lettmann
  • C. Lizarazo
  • D. Mahboub
  • H. Pai
  • Z. Patel
  • N. Pietralla
  • P. H. Regan
  • O. Wieland
  • E. Wilson
  • B. Birkenbach
  • B. Bruyneel
  • I. Burrows
  • L. Charles
  • E. Clément
  • F. C L Crespi
  • D. M. Cullen
  • P. Désesquelles
  • J. Eberth
  • V. González
  • T. Habermann
  • L. Harkness-Brennan
  • H. Hess
  • D. S. Judson
  • A. Jungclaus
  • W. Korten
  • M. Labiche
  • A. Maj
  • D. Mengoni
  • D. R. Napoli
  • A. Pullia
  • B. Quintana
  • G. Rainovski
  • P. Reiter
  • M. D. Salsac
  • E. Sanchis
  • J. J. Valiente Dóbon
External organisations
  • Technical University of Darmstadt
  • University of Cologne
  • Daresbury Laboratory
  • University of Strasbourg
  • University of Liverpool
  • University of Valencia
  • Justus Liebig University Giessen
  • INFN Section of Milano
  • University of Manchester
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Subatomic Physics


  • isomer decay, gamma-ray spectroscopy, relativistic projectile fragmentation
Original languageEnglish
Article number222302
Number of pages5
JournalPhysical Review Letters
Issue number22
Publication statusPublished - 2016 Nov 23
Publication categoryResearch

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Related research output

Natasa Lalovic, 2017 May, Lund: Lund University, Faculty of Science, Department of Physics, Division of Nuclear Physics. 169 p.

Research output: ThesisDoctoral Thesis (compilation)

Zs. Podolyák, C. M. Shand, Natasa Lalovic, J Gerl & Dirk Rudolph, 2017, The 26th International Nuclear Physics Conference. Trieste: Proceedings of Science, Vol. (INPC2016). 8 p. 231. (Proceedings of Science).

Research output: Chapter in Book/Report/Conference proceedingPaper in conference proceeding

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Related projects

Natasa Lalovic, Dirk Rudolph & Pavel Golubev

Swedish Research Council, Kungliga Fysiografiska Sällskapet i Lund


Project: DissertationIndividual research project, International collaboration

Dirk Rudolph, Pavel Golubev & Luis Sarmiento Pico

Crafoord Foundation, Swedish Research Council, Kungliga Fysiografiska Sällskapet i Lund


Project: ResearchInternational collaboration

Dirk Rudolph, Claes Fahlander, Pavel Golubev, Luis Sarmiento Pico, Daniel Cox, Yuliia Hrabar, Anton Såmark-Roth, Ulrika Forsberg, Christian Lorenz, Natasa Lalovic, Natasa Lalovic, Ulrika Forsberg, Jnaneswari Gellanki, Robert Hoischen, Emma Johansson, Lise-Lotte Andersson, Rickard du Rietz, Jörgen Ekman & Corina Andreoiu

Swedish Research Council


Project: ResearchInternational collaboration

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Related activities

Rudolph, D. (Chair)

Activity: Consultancy, expert advice and membershipsMember of board/committee/council etc

Rudolph, D. (Member)

Activity: Consultancy, expert advice and membershipsMember of board/committee/council etc

View all (2)