We present a study of the X(3872) lineshape in the decay B→X(3872)K→D0D∗0K using a data sample of 772×10^6 BB pairs collected at the Υ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e− collider. The peak near the threshold in the D0D∗0 invariant mass spectrum is fitted using a relativistic Breit-Wigner lineshape. We determine the mass and width parameters to be m=3873.71 (+0.56/−0.50)(stat)±0.13(syst) MeV/c2 and Γ0=5.2(+2.2/−1.5)(stat)±0.4(syst) MeV, respectively. The branching fraction is found to be B(B+→X(3872)K+)×B(X(3872)→D0D∗0)=(0.97(+0.21/−0.18)(stat)±0.10(syst))×10^−4. The signal from B0 decays is observed for the first time with 5.2σ significance, and the ratio of branching fractions between charged and neutral B decays is measured to be B(B0→X(3872)K0)/B(B+→X(3872)K+)=1.34(+0.47/−0.40)(stat)(+0.10/−0.12)(syst). The peak is also studied using a Flatté lineshape. We determine the lower limit on the DD∗ coupling constant g to be 0.075 at 95% credibility in the parameter region where the ratio of g to the mass difference from the D0D∗0 threshold is equal to −15.11 GeV^−1, as measured by LHCb.
Study of the lineshape of X(3872) using B decays to D0D¯*0K
Tenchini, F.;
2023-01-01
Abstract
We present a study of the X(3872) lineshape in the decay B→X(3872)K→D0D∗0K using a data sample of 772×10^6 BB pairs collected at the Υ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e− collider. The peak near the threshold in the D0D∗0 invariant mass spectrum is fitted using a relativistic Breit-Wigner lineshape. We determine the mass and width parameters to be m=3873.71 (+0.56/−0.50)(stat)±0.13(syst) MeV/c2 and Γ0=5.2(+2.2/−1.5)(stat)±0.4(syst) MeV, respectively. The branching fraction is found to be B(B+→X(3872)K+)×B(X(3872)→D0D∗0)=(0.97(+0.21/−0.18)(stat)±0.10(syst))×10^−4. The signal from B0 decays is observed for the first time with 5.2σ significance, and the ratio of branching fractions between charged and neutral B decays is measured to be B(B0→X(3872)K0)/B(B+→X(3872)K+)=1.34(+0.47/−0.40)(stat)(+0.10/−0.12)(syst). The peak is also studied using a Flatté lineshape. We determine the lower limit on the DD∗ coupling constant g to be 0.075 at 95% credibility in the parameter region where the ratio of g to the mass difference from the D0D∗0 threshold is equal to −15.11 GeV^−1, as measured by LHCb.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.