The decays χ_c1→J/ψμ^+μ^- and χ_c2→J/ψμ^+μ^- are observed and used to study the resonance parameters of the χ_c1 and χ_c2 mesons. The masses of these states are measured to be m(χ_c1)=3510.71±0.04(stat)±0.09(syst) MeV and m(χ_c2)=3556.10±0.06(stat)±0.11(syst) MeV, where the knowledge of the momentum scale for charged particles dominates the systematic uncertainty. The momentum-scale uncertainties largely cancel in the mass difference m(χ_c2)-m(χ_c1)=45.39±0.07(stat)±0.03(syst) MeV. The natural width of the χ_c2 meson is measured to be Γ(χ_c2)=2.10±0.20(stat)±0.02(syst) MeV. These results are in good agreement with and have comparable precision to the current world averages.
χ_c1 and χ_c2 Resonance Parameters with the Decays χ_c1,c2→J/ψμ^+μ^-
Veltri, M;
2017
Abstract
The decays χ_c1→J/ψμ^+μ^- and χ_c2→J/ψμ^+μ^- are observed and used to study the resonance parameters of the χ_c1 and χ_c2 mesons. The masses of these states are measured to be m(χ_c1)=3510.71±0.04(stat)±0.09(syst) MeV and m(χ_c2)=3556.10±0.06(stat)±0.11(syst) MeV, where the knowledge of the momentum scale for charged particles dominates the systematic uncertainty. The momentum-scale uncertainties largely cancel in the mass difference m(χ_c2)-m(χ_c1)=45.39±0.07(stat)±0.03(syst) MeV. The natural width of the χ_c2 meson is measured to be Γ(χ_c2)=2.10±0.20(stat)±0.02(syst) MeV. These results are in good agreement with and have comparable precision to the current world averages.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
