Evidence for a vector charmoniumlike state in e + e − → D + s D ∗ s 2 ( 2573 ) − + c . c .

Abstract

We report the measurement of e + e − → D + s D ∗ s 2 ( 2573 ) − + c . c . via initial-state radiation using a data sample of an integrated luminosity of 921.9

fb − 1 collected with the Belle detector at the Υ ( 4 S ) and nearby. We find evidence for an enhancement with a 3.4 σ significance in the invariant mass of D + s D ∗ s 2 ( 2573 ) − + c . c . The measured mass and width are ( 4619.8 + 8.9 − 8.0 ( stat . ) ± 2.3 ( syst . ) )

MeV / c 2 and ( 47.0 + 31.3 − 14.8 ( stat . ) ± 4.6 ( syst . ) )

MeV , respectively. The mass, width, and quantum numbers of this enhancement are consistent with the charmoniumlike state at 4626

MeV / c 2 recently reported by Belle in e + e − → D + s D s 1 ( 2536 ) − + c . c . The product of the e + e − → D + s D ∗ s 2 ( 2573 ) − + c . c . cross section and the branching fraction of D ∗ s 2 ( 2573 ) − → ¯ D 0 K − is measured from D + s D ∗ s 2 ( 2573 ) − threshold to 5.6 GeV.