ABC Effect and Resonance Structure in the Double-Pionic Fusion to 3He

E. Perez del Rio; M. Bashkanov; H. Clement; E. Doroshkevich; A. Pricking; T. Skorodko; G. J. Wagner

doi:10.1051/epjconf/20123709029

EPJ

a
b
c
d
e
ap
st
h
plus
ds
pv
ti
qt
am
n

Proceedings

Open Access

EPJ Web of Conferences 37, 09029 (2012)
https://doi.org/10.1051/epjconf/20123709029

ABC Effect and Resonance Structure in the Double-Pionic Fusion to ³He

E. Perez del Rio¹^,2, M. Bashkanov¹^,2, H. Clement¹^,2^a, E. Doroshkevich¹^,2, A. Pricking¹^,2, T. Skorodko¹^,2 and G. J. Wagner¹^,2 for the WASA-at-COSY Collaboration

¹ Physikalisches Institut, Univ. Tübingen, Auf der Morgenstelle 14, D-72076 Tübingen, Germany
² Kepler Center for Astro and Particle Physics, Univ. Tübingen, Auf der Morgenstelle 14, D-72076 Tübingen

^a e-mail: clement@pit.physik.uni-tuebingen.de

Abstract

Historically the double-pionic fusion to ³He is the reaction, where the ABC effect (low-mass enhancement of the ππ-invariant mass spectrum) was observed for the first time more than 50 years ago. Meanwhile exclusive and kinematically complete high-statistics measurements with WASA at COSY revealed a strict correlation between the ABC effect and a narrow resonance structure with I(J^P) = 0(3⁺) in the total cross section of the most basic double-pionic fusion, the pn → dπ⁰π⁰ reaction. In order to investigate the situation in the double-pionic fusion to ³He the energy dependence of the ABC effect in the fusion to ³He has been measured by fixed energy measurements of the type pd →³Heππ as well as by quasifree and coherent measurements of the type dd →³He n ππ.

© Owned by the authors, published by EDP Sciences, 2012

This is an Open Access article distributed under the terms of the Creative Commons Attribution License 2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.