Search for π π$\overline{π}$π β’(4459) 0 and π π$\overline{π}$π (4338) 0 in Ο(1π,2π) Inclusive Decays at Belle
Using data samples of 102 million Οβ‘(1β’π) events and 158 million Οβ‘(2β’π) events collected by the Belle detector at the KEKB asymmetric-energy π+β’πβ collider, we search for [π’β’πβ’π β’π$\overline{π}$ ] pentaquark states decaying to π½/πβ’Ξ. Using the first observations of Οβ‘(1β’π,2β’π) inclusive decays to π½/πβ’Ξ, we find evidence of the π π$\overline{π}$π β’(4459) 0 state with a local significance of 3.3 standard deviations, including statistical and systematic uncertainties. We measure the mass and width of the π π$\overline{π}$π β’(4459) 0 to be (4471.7Β±4.8Β±0.6) MeV/π 2 and (22 Β±13 Β±3) MeV, respectively. The branching fractions for π π$\overline{π}$π β’(4459) 0 production are measured to be β¬β‘[Οβ‘(1β’π)βπ π$\overline{π}$π β’(4459)0/ $\overline{π}$ π$\overline{π}$π β’(4459) 0 +anything]=(3.5Β±2.0Β±0.2)Γ10 β6 and β¬β‘[Οβ‘(2β’π)βπ π$\overline{π}$π β’(4459) 0 /$\overline{π}$ π$\overline{π}$π β’(4459) 0 +anything]=(2.9Β±1.7Β±0.4)Γ10 β6 . The inclusive branching fractions of Οβ‘(1β’π,2β’π) βπ½/πβ’Ξ/$\overline{Ξ}$ are measured to be β¬β‘[Οβ‘(1β’π) βπ½/πβ’Ξ/$\overline{Ξ}$ +anything] =(36.9 Β±5.3 Β±2.4) Γ10 β6 and β¬β‘[Οβ‘(2β’π) βπ½/πβ’Ξ/$\overline{Ξ}$ +anything] =(22.3 Β±5.7 Β±3.1) Γ10 β6 . We measure the visible cross section πβ‘(π+β’πββπ½/πβ’Ξ/ $\overline{Ξ}$ +anything)=(90Β±14Β±6) fb for the continuum production at βπ =10.52 GeV. In all cases, the first uncertainties are statistical and the second are systematic.