Future Physics Programme of BESIII *

Abstract

There has recently been a dramatic renewal of interest in hadron spectroscopy and charm physics. This renaissance has been driven in part by the discovery of a plethora of charmonium-like XYZ states at BESIII and B factories, and the observation of an intriguing proton-antiproton threshold enhancement and the possibly related X(1835) meson state at BESIII, as well as the threshold measurements of charm mesons and charm baryons. We present a detailed survey of the important topics in tau-charm physics and hadron physics that can be further explored at BESIII during the remaining operation period of BEPCII. This survey will help in the optimization of the data-taking plan over the coming years, and provides physics motivation for the possible upgrade of BEPCII to higher luminosity.

Are the Y states around 4.6 GeV from e+e− annihilation higher charmonia?

“…Fortunately, the energy region above 4.6 GeV can be accessed by the running BESIII and BelleII experiments. Very recently, we notice that the BESIII collaboration released their white paper on the future physics programme [50], in which they plan to take data above 4.6 GeV to extend experimental search for more Y states. They simply estimated number of events for BESIII and found it can be comparable to BelleII.…”

“…They simply estimated number of events for BESIII and found it can be comparable to BelleII. However, a more important advantage of BESIII is that its energy resolution is relatively high [50]. It means smaller bin size of energy point can be achieved in BESIII, which is very significant to identify the possible narrow structures existing above 4.6 GeV.…”

Spectrum of p -wave hidden-charm exotic mesons in the diquark model

“…The pattern of observed Y decays to conventional charmonium is itself quite confusing: Referring to Table II, the Y (4230) has been seen to decay to ψ(2S), χ c0 , and h c , while Y (4260) is so far only observed in channels decaying (eventually) to J/ψ; Y (4360) to both J/ψ and ψ(2S); Y (4660) only to ψ(2S); and Y (4390) only to h c . Recent data from BESIII [37] show that Y (4230) and Y (4390) both decay to J/ψ η, which restricts Y (4390) to I = 0.…”

“…each of I = 0 and I = 1. The I = 0 Y (4230) is clearly one of them, while Y (4390) may be considered to carry either I = 0 or I = 1 (although again, recent BESIII J/ψ η data[37] appear to eliminate the latter possibility). The probability P s QQ =0 of coupling to the s QQ = 0 component of a mass eigenstate is given by the square of theX…”

Charmed baryon weak decays with vector mesons

“…On the other hand, one can use the SU(3) F flavor symmetry to relate the amplitudes among different decays [7][8][9]. This becomes possible [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27] as there have been recently many new experimental measurements for charmed baryon decays [3][4][5][6][28][29][30][31][32][33][34][35][36][37]. In addition to the analysis of charmed baryon decays with SU(3) F , the theoretical calculations based on dynamical models have also been done in the literature [38][39][40][41][42][43][44][45][46][47][48][49][50].…”