BESIII上h1(1380)和Kstar anti-Kstar系统的研究

Study of hadron spectrum could provide information for us to understand Quantum Chrodynamics at low energy scale. However, experimental results of hadron spectrum is limited by statics and detector behavior. According to Particle Data Group(PDG2012), the Strangeonia is a terra incognita. there are only possible seven candidate for 22 predicted strangeonia. As a axial vector, h1(1380) is a possible candidate for 1+- stangeonia, and there are only two experimental results, which have big difference. Without confirmented experimental results for h1(1380), the h1(1380) as a 1P1 stangeonia member maybe premature. Based on data sets collected with BESIII detector,we plan to precise measure mass and width of h1(1380), search for its possible decay mode, and study its mixing with h1(1170). To the end. we try to understand nature of h1(1380).Theory predicts a resonance JPC=1+- h1 with mass around 1800MeV with K* anti-K*, and there is not a candidate in PDG2012, we plan to search for h1 with J/psi-> eta K* anti-K*.and we also study K* anti-K* system in charmonium (eta_c, chi_cJ and psi') strong decay mods.

强子谱学的研究为理解量子色动力学的非微扰性质提供很好的信息，但是由于统计量和探测器性能的限制，目前强子谱学的实验结果还不完善。例如奇异偶素的谱学研究还存在空白，理论预言的22个奇异偶素态，但是实验上只有七个可能候选者。轴矢介子h1(1380)作为1+-奇异偶素的候选者，目前仅有两个差别较大的实验数据，理论工作者还不能完全确定h1(1380)的物理本质。根据BESIII合作组采集的实验数据，我们计划精确测量h1(1380)的共振参数，寻找h1(1380)的未知衰变模式，测量h1(1380)和h1(1170)的混合角度。我们同时计划系统研究粲偶素强衰变中的K* anti-K*系统，在其不变质量谱中寻找可能的共振态。例如理论预言的1+-共振态h1，但是PDG12中没有其实验候选者。通过我们的研究成果，为理论工作者提供实验数据理解h1(1380)介子，理解矢量介子对K* anti-K*的相互作用。

目前奇异偶素谱学实验研究存在较大空白。h1(1380)作为1+-奇异偶素候选者，仅有两个通过K* K的差别较大数据，粒子物理手册将h1(1380)列为待确认的粒子，理论对其物理本质存在疑问。通过chi-cJ -> phi K* K和J/psi -> eta’ K* K精确测量h1(1380)质量和宽度，h1(1380)和h1(1170)混合角。发现h1(1380)-> omega eta新衰变模式，实验数据表明h1(1380)是奇异偶素轴矢介子。理论预言h1(1380)的激发态h1(1780)和X(2100)，质量1800MeV的h1。通过粲偶素衰变末态eta /pi0 K*K*bar的K*K*bar寻找这些h1粒子。实验数据上没有明显的1800MeV的h1信号。psi(3770) -> eta K*K*bar和 chi-cJ-> pi0 K*K*bar的K*K*bar不变质量谱2.0GeV附近存在结构。e+ e- -> K* K*bar产生截面谱2.0GeV反常跳起。通过e+e- -> eta J/psi研究Y粒子强衰变机制，实验数据和理论计算符合，eta J/psi和pi+ pi- J/psi谱形式不一样，表明两者的产生机制不一样。通过e+e- ->K+K-, phi eta和K+ K- pi0 pi0发现phi(2170) ->K K1(1270)，K K1(1400)，没有发现phi(2170) ->K+ K-, K*K*bar。表明phi(2170)可能是奇异夸克混杂态或多夸克态。