K-matrix Analysis of $e^+e^-$ Annihilation in the Bottomonium Region

Abstract

We perform the first global and unitary analysis of e + e − → b b cross sections. We analyze exclusive cross sections in the B B, B * B(+c.c.), B * B * , B * s B * s , Υ(nS)π + π − and h b (nP )π + π − channels as well as the total inclusive cross section for b b production. Pole positions and residues are determined for four vector states, which we associate with the Υ(4S), Υ(10750), Υ(5S) (or Υ(10860)), and Υ(6S) (or Υ(11020)). We find strong evidence for the new Υ(10750) recently claimed by Belle, although with parameters not well constrained by the data. Results presented here cast doubt on the validity of branching ratios reported earlier using Breit-Wigner parameterizations or ratios of cross sections. We also compare our results with a selection of theoretical calculations for the vector bottomonium spectrum.

The strong decay of higher vector $$\Upsilon$$(11020) state in the framework of non-relativistic quark model

“…Lately Ref. [3] provides us with a new estimated branching ratio of the ϒ(11020) which is in agreement with us in the ratio of the channel, and the B * s B * s channel. That makes us need more measured data and calculated strong widths and their branching ratio.…”

“…Although the fact that these models take partially different is explicit in the previous, they all arrive at the same conclusion: the ϒ(11020) resonance might be considered a possible candidate for the ϒ(6S) state. 4 The predicted values for the strong decay widths of ϒ(6S) in (MeV) compared with [16-18, 20, 47] in addition to [3] Figure 2 represents the calculated masses of Upsilon states including the mass of ϒ(6S) in GeV, in the frame of the non-relativistic quark model, listed in Table 2 in comparison with the experimental data [4]. The solid horizontal lines represent the theoretical calculations and the symbols are the experimental data.…”

“…(B mesons) [1]. The measurements have exhibited three discrete ϒ resonance states: ϒ(4S), ϒ(10860), and ϒ(11020), also recently have found the ϒ(10750) [2,3] state which is possibly considered the ϒ(3D) state. [4].…”

“…There is no measured data about the strong decay partial widths of the ϒ(11020) state and their branching ratio in the Particle Data Group [4]. Practically just the total decay width is available, but a recent study by (Husken et al) [3] presented a new estimated branching ratio of this state. The overall unanimity is that ϒ(11020) assigns as the S-wave vector bottomonium state ϒ(6S) [13][14][15][16][17][18][19][20][21].…”

Measurement of the e+e− → $$ {B}_s^0{\overline{B}}_s^0X $$ cross section in the energy range from 10.63 to 11.02 GeV using inclusive $$ {D}_s^{+} $$ and D0 production

“…A combined fit of the available measurements was performed in ref. [12] using a coupledchannel approach. For the first time, the decay branching fractions of the Υ(10753), Υ(10860), and Υ(11020) resonances were determined rigorously.…”