Reanalysis of data on a{sub 0}(1450) and a{sub 0}(980)
- Queen Mary, University of London, London E1 4NS (United Kingdom)
Four sets of data determining parameters of a{sub 0}(1450) and a{sub 0}(980) are reanalyzed. These are Crystal Barrel data for pp annihilation at rest to {eta}{pi}{sup 0}{pi}{sup 0} in (i) liquid hydrogen and (ii) gas, and to (iii) K{sub L}{sup 0}{pi}{sup {+-}}K{sup {+-}} and (iv) {omega}{pi}{sup +}{pi}{sup -}{pi}{sup 0} (mostly {omega}{rho}{pi}). Dispersive corrections due to opening of inelastic thresholds are treated fully. This stabilizes parameters of a{sub 0}(1450) substantially. The mass of its peak is 1448{+-}13(stat){+-}25(syst) MeV and its mean full width at half maximum is 192{+-}9{+-}9 MeV. The pole position is M-i{gamma}/2=1432{+-}13{+-}25-i(98{+-}5{+-}5) MeV. At the peak, {eta}{pi}, {omega}{rho} and a{sub 0}(980){sigma} decay intensities are in the ratios 1 ratio 9.2{+-}0.8{+-}1.3 ratio 3.1{+-}0.2{+-}0.9. There is no evidence for a separate a{sub 0} near 1300 MeV claimed by Obelix. Parameters of a{sub 0}(980) are updated to M=987.4{+-}1.0{+-}3.0 MeV, g{sup 2}({eta}{pi})=0.164{+-}0.007{+-}0.010 GeV{sup 2}, g{sup 2}(KK)/g{sup 2}({eta}{pi})=1.05{+-}0.07{+-}0.05. Its dominant second-sheet pole in the KK channel is at (989{+-}1{+-}5)-i(40{+-}2{+-}4) MeV. Finally, the nature of the prominent J{sup PC}=0{sup -+}{yields}{omega}{rho} signal in {omega}{rho}{pi} data is also clarified.
- OSTI ID:
- 21254292
- Journal Information:
- Physical Review. D, Particles Fields, Vol. 78, Issue 7; Other Information: DOI: 10.1103/PhysRevD.78.074023; (c) 2008 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2821
- Country of Publication:
- United States
- Language:
- English
Similar Records
Mechanisms of the reaction {pi}{sup {minus}}p{r_arrow}a{sub 0}{sup 0}(980)n{r_arrow}{pi}{sup 0}{eta}n at high energies
Strong and radiative decays of the scalars f{sub 0}(980) and a{sub 0}(980) in a hadronic molecule approach