Direct Observation of a <span class="aps-inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>ρ</mi></math></span> Decay of the <span class="aps-inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi mathvariant="italic">D</mi></mrow><mrow><mn>13</mn></mrow></msub></mrow><mo>(</mo><mn>1520</mn><mo>)</mo></math></span> Baryon Resonance

W. Langgärtner; J. Ahrens; R. Beck; V. Hejny; M. Kotulla; B. Krusche; V. Kuhr; R. Leukel; J. D. McGregor; J. G. Messchendorp; V. Metag; R. Novotny; V. Olmos de Léon; R. O. Owens; F. Rambo; S. Schadmand; A. Schmidt; U. Siodlaczek; H. Ströher; J. Weiß; F. Wissmann; M. Wolf

doi:10.1103/PhysRevLett.87.052001

Direct Observation of a $ρ$ Decay of the $D_{13} (1520)$ Baryon Resonance

W. Langgärtner, J. Ahrens, R. Beck, V. Hejny, M. Kotulla, B. Krusche, V. Kuhr, R. Leukel, J. D. McGregor, J. G. Messchendorp, V. Metag, R. Novotny, V. Olmos de Léon, R. O. Owens, F. Rambo, S. Schadmand, A. Schmidt, U. Siodlaczek, H. Ströher, J. Weiß, F. Wissmann, and M. Wolf

Phys. Rev. Lett. 87, 052001 – Published 11 July 2001

Abstract

The reaction $γ p \to π^{+} π^{0} n$ has been measured at MAMI for photon energies up to 820 MeV. Invariant mass spectra of the particles in the final state $(π^{+} n)$ , $(π^{0} n)$ , $(π^{+} π^{0})$ have been determined for several bins of incident photon energy. Differences in $π^{+} π^{0}$ and simultaneously measured $π^{0} π^{0}$ invariant mass distributions are assigned to a $ρ$ branch of the $D_{13} (1520)$ nucleon resonance.

Received 30 October 2000

DOI:https://doi.org/10.1103/PhysRevLett.87.052001

Authors & Affiliations

W. Langgärtner¹, J. Ahrens², R. Beck², V. Hejny^1,*, M. Kotulla¹, B. Krusche⁶, V. Kuhr⁵, R. Leukel², J. D. McGregor⁴, J. G. Messchendorp¹, V. Metag¹, R. Novotny¹, V. Olmos de Léon², R. O. Owens⁴, F. Rambo⁵, S. Schadmand¹, A. Schmidt², U. Siodlaczek³, H. Ströher^1,†, J. Weiß¹, F. Wissmann⁵, and M. Wolf¹

¹II. Physikalisches Institut, Universität Gießen, D-35392 Gießen, Germany
²Institut für Kernphysik, Johannes-Gutenberg-Universität Mainz, D-55099 Mainz, Germany
³Physikalisches Institut, Universität Tübingen, D-72076 Tübingen, Germany
⁴Department of Physics and Astronomy, University of Glasgow, Glasgow, G128QQ, United Kingdom
⁵II. Physikalisches Institut, Universität Göttingen, D-37073 Göttingen, Germany
⁶Department of Physics and Astronomy, University of Basel, CH-4056 Basel, Switzerland

^*Present address: Institut für Kernphysik, Forschungszentrum Jülich, D-52425 Jülich, Germany.
^†Present address: Institut für Kernphysik, Forschungszentrum Jülich, D-52425 Jülich, Germany.