共查询到20条相似文献,搜索用时 140 毫秒
1.
2.
3.
PING Rong-Gang LI Gang WANG Zheng 《理论物理通讯》2007,47(1):89-94
The formalisms of helicity coupling amplitudes for J/ψ→π^+π^-π^0 are presented. A detailed discussion is also given on the barrier factor, Breit Wigner, and density matrix. A Monte Carlo simulation of J/ψ→ρ(770)π→π^+π^-π^0 is carried out. The results show that the p(770) resonance is well reproduced compared with experimental data. 相似文献
4.
The π^+π^ transition of heavy quarkonia in decay ψ(2S) →π^+π^-J/ψ is studied. With the BESII data on the decay ψ(2S) →π^+π^-J/ψ, we update the values of coupling constants (gi) and chromopolarizability (αψ(2s)J/ψ) in this process. 相似文献
5.
6.
ZHAO Shu-Min PANG Xue-Xia LIU Li-Quan LI Yong-Hui 《理论物理通讯》2009,51(6):1101-1106
It is interesting to investigate the OZI-forbidden decays of orthoquarkoknium, J/ψ→γπ^0(γη,γη′), J/ψ→π^+π^-(π^0π^0). At first glance, there is infrared divergence in the above processes. In this work, to clear the mist we use the factorization method with the light cone wavefunction of the final state light meson. We prove straightforwardly that the infrared divergence can be eliminated completely. 相似文献
7.
在北京谱仪(BES)原有模拟程序框架下,建立了适用于J/ψ,ψ‘衰变到VP和PP模式,以及ψ‘→π^ π^-/J/ψ‘衰变到J/ψ衰变到VP和PP模式的事例产生器,考虑了相应的角分布,为J/ψ,ψ‘物理的研究提供了方便,在ψ‘→γη,γη‘,ωπ^0,π^ π^-,K^ K^-等分支比的测量中,这一事例产生器可用于选择效率的确定和本底估计。 相似文献
8.
SHEN Xiao-Yan 《中国物理C(英文版)》2008,32(6):448-451
We reported the observation of Y(2175) in φf0(980) mass spectrum in J/ψ→ηφf0(980) with f0(980)→π+π- and the observation of a broad 1-- resonance of K+K-mass in J/ψ→K+K-π0. The results from the partial wave analyses of Jψ→γπ+π- and γπ0π0, as well as J/ψ→pK-∧. are also presented. 相似文献
9.
Using ~ 14 × 10^6 ψ(2S) and ~ 58 × 10^ J/ ψ data collected at BES Ⅱ/BEPC, the branching fraction of ψ(2S)→Ω-Ω^+ is measured with about 5a statistical significance. The A electric dipole and ∧ decay parameter are studied using the decay J/ψ →∧∧→ ppπ^+π^-. Using (106±3)× 10^6 ψ(2S) decays collected at BESⅢ/BEPC Ⅱ, we have obtained some interesting physics results. The branching fractions of XcJ→π^0π^0, ηη are measured with precision improved. The mass and width of he(l^1P1) state, together with the branching fractions of Br(ψ(2S) →π^0hc) and Br(hc →γηc) are the first measurements. Surprisingly, the decays of Xc1→φφ, ωω, and ωφ are firstly observed in BESⅢ data. 相似文献
10.
Trigger efficiencies at BESⅢ were determined for both the J/ψ and ψ' data taking of 2009. Both dedicated runs and physics datasets are used; efficiencies are presented for Bhabha-scattering events, generic hadronic decay events involving charged tracks, dimuon events and ψ'→π+π-J/ψ, J/ψ→ 1+1- events.The efficiencies are found to lie well above 99% for all relevant physics cases, thus fulfilling the BESⅢ design specifications. 相似文献
11.
用BESⅠ的7.8×106J/ψ数据更为精确地测定了J/ψ→π03(π+π-)和J/ψ→ω2(π+π-)的分支比(Br(J/ψ→π03(π+π-))=(2.52±0.06±0.43)%,Br(J/ψ→π03(π+π-))=(1.31±0.09±0.21)%.同时对4π不变质量谱和ωππ不变质量谱进行研究分析,试图观察是否存在有兴趣的信号. 相似文献
12.
PING Rong-Gang 《中国物理C(英文版)》2010,34(6):626-631
Using ~14×106ψ(2S) and ~58×106J/ψ data collected at BESⅡ/BEPC,the branching fraction of ψ(2S) →Ω+Ωˉ+ is measured with about 5σ statistical significance.The Λ electric dipole and Λ decay parameter are studied using the decay J/ψ→ΛΛ→ ppˉπ+π-.Using(106±3)×106 ψ(2S) decays collected at BESⅢ/BEPCⅡ,we have obtained some interesting physics results.The branching fractions of χcJ →π0π0,ηη are measured with precision improved.The mass and width of hc(11P1) state,together with the branching fractions of Br(ψ(2S) →π0hc) and Br(hc →γηc) are the first measurements.Surprisingly,the decays of χc1 →φφ,ωω,and ωφ are firstly observed in BESⅢ data. 相似文献
13.
利用北京谱仪(BES)上取得的ψ(2S)数据,对ψ(2S)→π+π-J/ψ,J/ψ→1+1-和J/ψ→任意末态两个过程进行了细致的研究,得到J/ψ的轻子道衰变分支比为B(J/ψ→e+e-)=(5.90±0.07±0.16)%和B(J/ψ→μ+μ-)=(5.96±0.08±0.16)%,由此给出Be/Bμ的值为0.990±0.018±0.024.假定Be=Bμ,J/ψ的轻子道衰变分支比为B(J/ψ→1+1-)=(5.93±0.05±0.16)%.上述结果可用来估计强相互作用耦合常数αs和QCD减除参数∧. 相似文献
14.
In this paper the J/ψ→μ^+μ^- reconstruction performance in the CMS experiment at the LHC is studied in detail by using B8→J/ψφ→μμKK events. The reconstruction efficiencies of J/ψ mesons and their decay muons are obtained as a function of the transverse momentum PT and the pseudo-rapidity η. We also study the muon trigger efficiency for this channel with the planned Level-1 trigger and High Level Trigger selection criteria. It was observed that the muon reconstruction efficiency decreases when the two decay muons have a small or large 3D angular separation, which further affects the overall J/ψ reconstruction efficiency. 相似文献
15.
16.
17.
The π+π- transition of heavy quarkonia in decay ψ(2S) ψ(2S)→π+π-J/ψ is studied. With the BESII data on the decay ψ(2S)→π+π-J/ψ, we update the values of coupling constants (gi) and chromopolarizability (аψ(2S)J/ψ) in this process. 相似文献
18.
Using the isospin- and momentum-dependent hadronic transport model IBUU04, the effects of symmetry energy on the π^-/π^+ ratio are studied. Our investigations are based on the calculations of the ^132 Sn+^124Sn semi-central collisions at beam energies of 400/AMeV, 600/A MeV and 800/A MeV. It is found that both the transverse momentum and kinetic energy distributions of the π^-/π^+ ratio are rather sensitive to the symmetry energy, especially around the Coulomb peaks. The position of the Coulomb peak is shown to be nearly independent of beam energy. The sensitivity of the π^-/π^+ ratio to the symmetry energy decreases as the beam energy increases from 600/A MeV to 800/A MeV. 相似文献
19.