Line shape ofψ(3770)ine+e−→DD¯

Abstract

Interference phenomena observed in the c ð3770Þ resonance region in the reactions e þ e À ! D " D are analyzed. To avoid ambiguities in the determination of the c ð3770Þ resonance parameters, when analyzing data between the D " D and D " D thresholds, the amplitudes satisfying the elastic unitarity requirement should be used. In the lack of information on the P wave of D " D elastic scattering, the c ð3770Þ parameters, determined by fitting the e þ e À ! D " D data, can essentially depend on the model used for the total contribution of the resonance and background. The selection of the models can be toughened by comparing their predictions with the relevant data on the shape of the c ð3770Þ peak in the non-D "D channels e þ e À ! c0 , J=c , , etc.

Line-shape and poles of the ψ(3770)

“…a dip structure, is explained by the interference with the DD kinematical background which is higher for larger relative momentum. The same dip is reproduced in [11], using DD background only, in [14], where in addition, the continuum of light hadrons is removed, and in Refs. [15] and [16], using Fano resonances.…”

“…In Refs. [11,12] fits were computed taking into account not only the D D interference but also the tail of the ψ(2S). Such inclusion is natural since the ψ(3770) should be a mixed state |1 3 D 1 -|2 3 S 1 .…”

“…i) As a last comment, we compare our result with the approach of Refs. [11,12]. Interestingly, in Ref.…”

Can the $$\psi (4040)$$ ψ ( 4040 ) explain the peak associated with Y(4008)?

“…By studying the mix propagator (see Refs. [47,48] for some formal equation), we tested how the spectral function of ψ(4040) changes when taking into account the processes ψ(4040) → D D * → ψ(4160) → D D * → ψ(4040) (this is so because ψ(4160) also couples to D D * ; analogous processes with D D and D * D * are possible). The spectral function of ψ(4040) turns out to be only slightly affected in the region of interest, thus the results here presented would hold also in the enlarged scenario in which morecc states are considered.…”

The cross section of the process $e^+e^- \to p\bar{p}$ in the vicinity of charmonium $ψ(3770)$ including three-gluon and $D$-meson loop contributions

“…For example it leads to a specific peak shape of the cross section of the process e + e − → D D in the vicinity of ψ(3770) state mass. One of the strong conjecture to interpret this fact is to suppose the presence of a ψ(2S) resonance with mass close to the ψ(3770) [18]. We however do not dive into this complicated consideration since D-meson loop contribution appears to be small in our case and one can limit oneself with single two quark state with spin 1.…”