Observation of a narrow resonance of mass2.46GeV/c2decaying toD

Abstract

Using 13.5 fb Ϫ1 of e ϩ e Ϫ annihilation data collected with the CLEO II detector, we have observed a narrow resonance decaying to D s * ϩ 0 with a mass near 2.46 GeV/c 2. The search for such a state was motivated by the recent discovery by the BaBar Collaboration of a narrow state at 2.32 GeV/c 2 , the D sJ * (2317) ϩ , that decays to D s ϩ 0. Reconstructing the D s ϩ 0 and D s * ϩ 0 final states in CLEO data, we observe peaks in both of the corresponding reconstructed mass difference distributions, ⌬M (D s 0)ϭM (D s 0)ϪM (D s) and ⌬M (D s * 0)ϭM (D s * 0)ϪM (D s *), both of them at values near 350 MeV/c 2. We interpret these peaks as signatures of two distinct states, the D sJ * (2317) ϩ plus a new state, designated as the D sJ (2463) ϩ. Because of the similar ⌬M values, each of these states represents a source of background for the other if photons are lost, ignored or added. A quantitative accounting of these reflections confirms that both states exist. We have measured the mean mass differences ͗⌬M (D s 0)͘ϭ350.0Ϯ1.2 (stat)Ϯ1.0 (syst) MeV/c 2 for the D sJ * (2317) ϩ state, and ͗⌬M (D s * 0)͘ϭ351.2Ϯ1.7 (stat)Ϯ1.0 (syst) MeV/c 2 for the new D sJ (2463) ϩ state. We have also searched, but find no evidence, for decays of the two states via the channels D s * ϩ ␥, D s ϩ ␥, and D s ϩ ϩ Ϫ. The observations of the two states at 2.32 and 2.46 GeV/c 2 , in the D s ϩ 0 and D s * ϩ 0 decay channels, respectively, are consistent with their interpretations as cs mesons with an orbital angular momentum Lϭ1 and spin and parity J P ϭ0 ϩ and 1 ϩ .

Reanalysis of lattice QCD spectra leading to the D s0 ∗ (2317) and D s1 ∗ (2460)

“…The scalar D * s0 (2317) and axial D s1 (2460) mesons were experimentally found slightly below KD and KD * thresholds [1][2][3][4]. These are one of the few shallow bound states in the meson sector, and therefore deserve special attention.…”

NonleptonicB→D(*)DsJ(*)decays and the natur

“…Within the charmed-strange sector, the BABAR Collaboration found, in the inclusive D þ s 0 invariant mass distribution from e þ e À annihilation data, the narrow state D Ã s0 ð2317Þ [1]. The CLEO Collaboration, aiming to confirm the previous state, observed its doublet partner D s1 ð2460Þ in the D Ãþ s 0 final state [2]. However, the properties of these states were not well known until the Belle Collaboration observed the B ! "…”

An Effective Theory approach to $\bar{B}_s$ mesons involving $SU(3)$ heavy meson symmetry and constituent quark-model states

“…[1], where the B ( * ) K interaction is studied incorporating a constituent quark model (CQM) state, i.e., a P-wave bs component interacting with the previous channels. The importance of including the effect of two-meson threhsolds was revealed after the discovery of the D * s0 (2317) and D s1 (2560) resonances [2,3], with a mass and width much lower than previous quark model and lattice QCD calculations. Both states were found around 100 MeV below naive quark model predictions, and below the DK and D * K thresholds respectively.…”