BESIII π~+π~-形状因子测量以及π~+π~-π~0展望（英文）

详细信息    查看全文 | 推荐本文 |

英文篇名：BESIII π~+π~- form factor measurement and perspective of π~+π~-π~0 作者：王亚乾 英文作者：WANG Yaqian;the BESIII Collaboration;Johannes-Gutenberg University; 关键词：缪子反常磁矩 ; 真空极化 ; 初态辐射 英文关键词：muon anomalous magnetic moment g-2;;vacuum polarization;;initial state radiation(ISR) 中文刊名：ZKJD 英文刊名：Journal of University of Science and Technology of China 机构：BESIII合作组;美因茨大学; 出版日期：2016-04-15 出版单位：中国科学技术大学学报 年：2016 期：v.46;No.276 基金：Supported by German Research Foundation DFG under Collaborative Research Center(CRC-1044) 语种：英文; 页：ZKJD201604008 页数：7 CN：04 ISSN：34-1054/N 分类号：48-54

摘要

利用BESIII在3.773GeV获取的2.93fb-1数据,测量了600~900 MeV/c~2区间e~+e~-→π~+π~-的截面.分析主要基于初态辐射的方法,总的系统误差控制在0.9%.通过计算得到的形状因子|F_π|~2与其他两个实验做了比较.两π过程对缪子反常磁矩的贡献为a_μ~(ππ,LO)(600~900 MeV/c~2)=(368.2±2.5_(stat)±3.3_(sys))×10~(-10).
        The cross section is measured of e~+e~-→π~+π~- in the energy range between 600 and 900MeV/c~2 with a 2.93fb~(-1) data set taken at the center-of-mass energy 3.773 GeV at BESIII.The initial state radiation technique is used,and the total systematic uncertainty is estimated to be 0.9%.The squared form factor|F_π|~2 is extracted,and comparisons are made with results from both KLOE and BaBar. The two-pion contribution to the hadronic vacuum polarization contribution to(g-2)_μ is calculated to be a_μ~(ππ,LO)(600~900 MeV/c~2)=(368.2±2.5_(stat)±3.3_(sys))×10~(-10).

引文

[1]DAVIER M,HOECKER A,MALESCU B,et al.Reevaluation of the hadronic contributions to the muon g-2and toα(M2Z)[J].Eur Phys J C,2011,71:1 515.
    [2]GRANGE J,GUARINO V,WINTER P,et al.Muon(g-2)Technical Design Report[EB/OL].(2015-01-27)[2015-11-30].http://arxiv.org/abs/1501.06858.
    [3]BOUCHIAT C,MICHEL L.La résonance dans la diffusion mésonπ-mésonπet le moment magnétique anormal du mésonμ[J].J Phys Radium,196122:121.
    [4]GOURDIN M,DE RAFAEL E.Hadronic contributions to the muon g-factor[J].Nucl Phys B,1969,10(4):667-674.
    [5]BRODSKY S J,DE RAFAEL E.Suggested bosonlepton pair couplings and the anomalous magnetic moment of the muon[J].Phys Rev,1968,168(5):1 620-1 622.
    [6]ALOISIO A,AMBROSINO F,ANTONELLI A,et al.Measurement ofσ(e+e-→π~+π~-γ)and extraction ofσ(e+e-→π~+π~-)below 1 GeV with the KLOE detector[J].Phys Lett B,2005,606(1/2):12-24
    [7]AMBROSIO F,ANTONELLI A,ANTONELLI M,et al.Measurement ofσ(e+e-→π~+π~-γ(γ))and the dipion contribution to the muon anomaly with the KLOE detector[J].Phys Lett B,2009,670(4/5):285-291.
    [8]AMBROSINO F,ARCHILLI F,BELTRAME P,et al.Measurement ofσ(e+e-→π~+π~-)from threshold to0.85GeV2 using initial state radiation with the KLOE detector[J].Phys Lett B,2011,700(2):102-110.
    [9]BABUSCI D,BADONI D,BALWIERZ-PYTKO I,et al.Precision measurement ofσ(e+e-→π~+π~-γ)/σ(e+e-→μ+μ-γ)and determination of theπ~+π~-contribution to the muon anomaly with the KLOE detector[J].Phys Lett B,2013,720(4/5):336-343.
    [10]AUBERT B,KARYOTAKIS Y,LEES J P,et al.Precise measurement of the e+e-→π~+π~-(γ)cross section with the initial state radiation method at BABAR[J].Phys Rev Lett,2009,103:231801.
    [11]ABLIKIM M,ACHASOV M N,AI X C,et al.Measurement of the e+e-→π~+π~-Cross Section between 600and 900MeV Using Initial State Radiation[EB/OL].(2015-11-17)[2015-11-30].http://arxiv.org/abs/1507.08188.
    [12]ABLIKIM M,AN Z H,BAI J Z,et al.Design and construction of the BESIII detector[J].Nucl Instrum Meth A,2010,614(3):345-399.
    [13]CZYZ H,KUHN J H,WAPIENIK A.Four-pion production inτdecays and e+e-annihilation:An update[J].Phys Rev D,2008,77:114005.
    [14]HOECKER A,SPECKMAYER P,STELZER J,et al.TMVA-Toolkit for Multivariate Data Analysis[EB/OL].(2007-03-04)[2015-11-30].http://arxiv.org/abs/physics/0703039.
    [15]AGOSTINELLI S,ALLISON J,AMAKO K,et al.GEANT4-a simulation toolkit[J].Nucl Instrum Meth A,2003,506(3):250-303.
    [16]GOUNARIS G J,SAKURAI J J.Finite-width corrections to the vector-meson-dominance prediction forρ→e+e-[J].Phys Rev Lett,1968,21:244.
    [17]OLIVE K A,AGASHE K,AMSLER C,et al.Review of particle physics[J].Chin Phys C,2014,38(09):090001.
    [18]AKHMETSHIN R R,AKSENOV G A,ANASHKIN E V,et al.Measurement ofφmeson parameters with CMD-2detector at VEPP-2Mcollider[J].Phys Lett B,1995,364(3):199-206.
    [19]AKHMETSHIN R R,AKSENOV G A,ANASHKIN E V,et al.Study of dynamics ofφ→π~+π~-π0decay with CMD-2 detector[J].Phys Lett B,1998,434(3/4):426-436.
    [20]AKHMETSHIN R R,ANASHKIN E V,AULCHENKO V M,et al.Measurement ofωmeson parameters inπ~+π~-π0decay mode with CMD-21[J].Phys Lett B,2000,476(1/2):33-39.
    [21]ACHASOV M N,AULCHENKO V M,BARU S E,et al.The process e+e-→π~+π~-π0in the energy range2E0=1.04~1.38 GeV[J].Phys Lett B,1999,462(3/4):365-370.
    [22]ACHASOV M N,BELOBORODOV K I,BERDYUGIN A V,et al.Measurements of the parameters of theφ(1020)resonance through studies of the processes e+e-→K+K-,KSKL,andπ~+π~-π0[J].Phys Rev D,2001,63:072002.
    [23]ACHASOV M N,AULCHENKO V M,BELOBORODOV K I,et al.Study of the process e+e-→π~+π~-π0in the energy region槡sfrom 0.98to 1.38GeV[J].Phys Rev D,2002,66:032001.
    [24]ACHASOV M N,BELOBORODOV K I,BERDYUGIN A V,et al.Study of the process e+e-→π~+π~-π0in the energy region槡s below 0.98GeV[J].Phys Rev D,2003,68:052006.
    [25]AUBERT B,BARATE R,BOUTIGNY D,et al.Study of the e+e-→π~+π~-π0process using initial state radiation with BABAR[J].Phys Rev D,2004,70:072004.
    [26]ANTONELLI A,BALDINI R,BIAGINI M E,et al.Measurement of the e+e-→π~+π~-π0and e+e-→ωπ~+π~-reactions in the energy interval 1 350~2 400 MeV[J].Z Phys C,1992,56(1):15-19.