Large {sigma} Channel Low-Mass Enhancement in Exclusively Measured Double Pionic Fusion to 3He
- Physikalisches Institut, Universitaet Tuebingen, Auf der Morgenstelle 14, D-72076 Tuebingen (Germany)
The pd {yields} 3He {pi}0{pi}0 and pd {yields} 3He {pi}+{pi}- reactions have been measured exclusively at CELSIUS using the WASA 4{pi} detector with pellet target system. For the double-pionic fusion to 3He data have been taken at Tp = 0.893 GeV, where the maximum of the socalled ABC effect is expected. A very large low-mass enhancement is observed in the {pi}0{pi}0 invariant mass spectrum M{pi}0{pi}0, whereas only a moderate low-mass enhancement is seen in M{pi}+{pi}- raising thus the question of isospin invariance in this region. With both channels summed up the data agree well to previous inclusive measurements regarding the low-mass enhancement. However, they do not exhibit the high-mass enhancement seen in the inclusive measurements and predicted by theoretical calculations based on a {delta}{delta} process, which produces a double-hump structure in the M{pi}{pi} spectra.
- OSTI ID:
- 20873338
- Journal Information:
- AIP Conference Proceedings, Vol. 842, Issue 1; Conference: 17. international conference on particles and nuclei, Santa Fe, NM (United States), 23-30 Oct 2005; Other Information: DOI: 10.1063/1.2220293; (c) 2006 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
- Country of Publication:
- United States
- Language:
- English
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