Search for P_{cc[over ¯]s}(4459)^{0} and P_{cc[over ¯]s}(4338)^{0} in ϒ(1S,2S) Inclusive Decays at Belle

Using data samples of 102 million ϒ(1S) events and 158 million ϒ(2S) events collected by the Belle detector at the KEKB asymmetric-energy e+e- collider, we search for [udscc¯] pentaquark states decaying to J/ψΛ. Using the first observations of ϒ(1S,2S) inclusive decays to J/ψΛ, we find evidence of the Pcc¯s(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 Pcc¯s(4459)0 to be (4471.7±4.8±0.6) MeV/c2 and (22±13±3) MeV, respectively. The branching fractions for Pcc¯s(4459)0 production are measured to be B[ϒ(1S)→Pcc¯s(4459)0/P¯cc¯s(4459)0+anything]=(3.5±2.0±0.2)×10-6 and B[ϒ(2S)→Pcc¯s(4459)0/P¯cc¯s(4459)0+anything]=(2.9±1.7±0.4)×10-6. The inclusive branching fractions of ϒ(1S,2S)→J/ψΛ/Λ¯ are measured to be B[ϒ(1S)→J/ψΛ/Λ¯+anything]=(36.9±5.3±2.4)×10-6 and B[ϒ(2S)→J/ψΛ/Λ¯+anything]=(22.3±5.7±3.1)×10-6. We measure the visible cross section σ(e+e-→J/ψΛ/Λ¯+anything)=(90±14±6) fb for the continuum production at s=10.52 GeV. In all cases, the first uncertainties are statistical and the second are systematic.