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.

Inspired by the present experimental status of charmed-strange mesons, we perform a systematic study of the charmed-strange meson family in which we calculate the mass spectra of the charmed-strange meson family by taking a screening effect into account in the Godfrey-Isgur model and investigate the corresponding strong decays via the quark pair creation model. These phenomenological analyses of charmed-strange mesons not only shed light on the features of the observed charmed-strange states, but also provide important information on future experimental search for the missing higher radial and orbital excitations in the charmed-strange meson family, which will be a valuable task in LHCb, the forthcoming Belle H, and PANDA. SONG et al. PHYSICAL REVIEW D 91, 054031 (2015)TABLE I. Experimental information of the observed charmed-strange states. State Mass (MeV) [1] Width (MeV) [1] First observation Observed decay modes D, 1968.49 ±0.33 o ; 2112.3 ±0.5 <1.9 D*A 2317) 2317.8 ± 0.6 <3.8 BABAR [3] D+/r° [3] 0,1(2460) 2459.6 ± 0.6 <3.5 CLEO [4] D*+n° [4] 0,1 (2536) 2535.12 ±0.13 0.92 ± 0.05 ITEP, SERP [23] D*+r P3] 0 : 2(2573) 2571.9 ±0.8 16+| ± 3 [24] CLEO [24] D°K+ [24] DtA2632)" 2632.5 ± 1.7 ± 5 .0 [25] < 17 [25] SELEX [25] D°K+ [25] 0*1 (2700) 2688 ± 4 ± 3 [26] 112 ± 7 ± 3 6 [26] BABAR [26] DK [26] 2708 ± 9+1(( [27] 108 ± 23+|f [27] Belle [27] D°K+ [27] 2710 ± 2f)2 [28] 149 ± 7+52 t28] BABAR [28] D^K [28] 2709.2 ± 1.9 ± 4.5 [29] 115.8 ± 7.3 ± 12.1 [29] LHCb [29] DK [29] O[./(2860) 2856.6 ± 1.5 ± 5 .0 [26] 47 ± 7 ± 10 [26] BABAR [26] DK [26] 2862 ± 2±f [28] 48 ± 3 ± 6 [28] BABAR [28] D^K [28] 2866.1 ± 1.0 ±6.3 [29] 69.9 ± 3.2 ± 6.6 [29] LHCb [29] DK [29] 0 ; 3(2860) 2860.5 ± 2.6 ± 2.5 ± 6.0 [30,31] 53 ± 7 ± 4 ± 6 [30,31] LHCb [30,31] D°K~ [30,31] OJi (2860) 2859 ± 12 ± 6 ± 23 [30,31] 159 ± 2 3 ± 2 7 ± 7 2 [30,31] LHCb [30,31] D°K-[30,31] 0.5/(3040) 3044 ± 8l5 30 [28] 239 ± 3 5^2 6 [28]

Having abundant experimental information of charmed mesons together with the present research status, we systematically study higher radial and orbital excitations in the charmed meson family by analyzing the mass spectrum and by calculating their OZI-allowed two-body decay behaviors. This phenomenological analysis reveals underlying properties of the newly observed charmed states D

Lepton scattering is an established ideal tool for studying inner structure of small particles such as nucleons as well as nuclei. As a future high energy nuclear physics project, an Electron-ion collider in China (EicC) has been proposed. It will be constructed based on an upgraded heavy-ion accelerator, High Intensity heavy-ion Accelerator Facility (HIAF) which is currently under construction, together with a new electron ring. The proposed collider will provide highly polarized electrons (with a polarization of ∼80%) and protons (with a polarization of ∼70%) with variable center of mass energies from 15 to 20 GeV and the luminosity of (2–3) × 1033 cm−2 · s−1. Polarized deuterons and Helium-3, as well as unpolarized ion beams from Carbon to Uranium, will be also available at the EicC.The main foci of the EicC will be precision measurements of the structure of the nucleon in the sea quark region, including 3D tomography of nucleon; the partonic structure of nuclei and the parton interaction with the nuclear environment; the exotic states, especially those with heavy flavor quark contents. In addition, issues fundamental to understanding the origin of mass could be addressed by measurements of heavy quarkonia near-threshold production at the EicC. In order to achieve the above-mentioned physics goals, a hermetical detector system will be constructed with cutting-edge technologies.This document is the result of collective contributions and valuable inputs from experts across the globe. The EicC physics program complements the ongoing scientific programs at the Jefferson Laboratory and the future EIC project in the United States. The success of this project will also advance both nuclear and particle physics as well as accelerator and detector technology in China.

Motivated by the recent observation of the orbital excitation $B(5970)$ by CDF collaboration, we have performed a systematical study of the mass spectrum and strong decay patterns of the higher $B$ and $B_s$ mesons. Hopefully the present investigation may provide valuable clues to further experimental exploration of these intriguing excited heavy mesons.Comment: 13 pages, 11 figures, 10 tables. More discussions and references added. Accepted by Phys. Rev.

Hadron tomography can be investigated by three-dimensional structure functions such as generalized parton distributions (GPDs), transverse-momentum-dependent parton distributions, and generalized distribution amplitudes (GDAs). Here, we extract the GDAs, which are s-t crossed quantities of the GPDs, from cross-section measurements of hadron-pair production process γ Ã γ → π 0 π 0 at KEKB. This work is the first attempt to obtain the GDAs from the actual experimental data. The GDAs are expressed by a number of parameters and they are determined from the data of γ Ã γ → π 0 π 0 by including intermediate scalar-and tensor-meson contributions to the cross section. Our results indicate that the dependence of parton-momentum fraction z in the GDAs is close to the asymptotic one. The timelike gravitational form factors Θ 1 and Θ 2 are obtained from our GDAs, and they are converted to the spacelike ones by the dispersion relation. From the spacelike Θ 1 and Θ 2 , gravitational densities of the pion are calculated. Then, we obtained the mass (energy) radius and the mechanical (pressure and shear force) radius from Θ 2 and Θ 1 , respectively. They are calculated as ffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi hr 2 i mass p ¼ 0.32-0.39 fm, whereas the mechanical radius is larger ffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi ffi hr 2 i mech p ¼ 0.82-0.88 fm. This is the first report on the gravitational radius of a hadron from actual experimental measurements. It is interesting to find the possibility that the gravitational mass and mechanical radii could be different from the experimental charge radius ffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi ffi hr 2 i charge q ¼ 0.672 AE 0.008 fm for the charged pion. For drawing a clear conclusion on the GDAs of hadrons, accurate experimental data are needed, and it should be possible, for example, by future measurements of super-KEKB and international linear collider. Accurate measurements will not only provide important information on hadron tomography but also possibly shed light on gravitational physics in the quark and gluon level.

The Born cross section for the process e þ e − → pp is measured using the initial state radiation technique with an undetected photon. This analysis is based on datasets corresponding to an integrated luminosity of 7.5 fb −1 , collected with the BESIII detector at the BEPCII collider at center of mass energies between 3.773 and 4.600 GeV. The Born cross section for the process e þ e − → pp and the proton effective form factor are determined in the pp invariant mass range between 2.0 and 3.8 GeV=c 2 divided into 30 intervals. The proton form factor ratio (jG E j=jG M j) is measured in 3 intervals of the pp invariant mass between 2.0 and 3.0 GeV=c 2 .