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BESIII 物理分析 PowerPoint Presentation
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BESIII 物理分析

BESIII 物理分析

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BESIII 物理分析

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  1. BESIII物理分析

  2. 2004: start BEPCII construction 2008: test run of BEPCII 2009-now: BECPII/BESIII data taking Beam energy: 1.0-2.3 GeV Design Luminosity: 1×1033cm-2s-1 L = 0.5 × 1033/cm2/s (maximum 0.65 × 1033) Optimum energy:1.89 GeV Energy spread:5.16 ×10-4 No. of bunches:93 Bunch length:1.5 cm Total current:0.91 A Circumference:237m

  3. BEPCII能量范围:2.0~4.6GeV

  4. BESIII Collaboration Helmholtz Institute Mainz Johannes Gutenberg-University Mainz 11 >300 physicists 49 institutions from 10 countries

  5. BESIII物理研究内容 Charmonium physics: - Spectroscopy - transitions and decays Light hadron physics: - meson & baryon spectroscopy - glueball & hybrid -two-photon physics - e.m. form factors of nucleon Charm physics: - (semi)leptonic + hadronic decays - decay constant, form factors - CKM matrix: Vcd, Vcs -D0-D0bar mixing and CP violation - rare/forbidden decays Tau physics: - Tau decays near threshold - tau mass scan …and many more

  6. Data samples So far BESIII has collected : • 2009: 225 Million J/ψ • 2009: 106 Million ψ’ • 2010-11: 2.9 fb−1 ψ(3770)(3.5 × CLEO-c 0.818fb−1) • - May 2011: 0.5fb−1 @4010 MeV (one month) for Ds and XYZ spectroscopy • BESIII will also collect:more J/ψ, ψ’, ψ(3770) • data at higher energies (for XYZ searches, R scan and Ds physics)

  7. 目前参与BES研究的人员: 教师:张学尧、王萌、黄性涛、焦健斌、李晓玲 博士研究生:王亚乾、于帅鹏、丁伟民、刘佩莲 • 物理分析课题: • 粲偶素物理: 王亚乾:Ψ(2S) γ + c(2S) 焦健斌:Ψ(2S) 重子对 黄性涛:Ψ(2S) VP 张学尧:(3770)到非DDbar衰变 • 轻强子谱:李晓玲 • 粲物理:王萌、黄性涛、李晓玲、于帅鹏

  8. 经费情况: 张学尧、黄性涛、焦健斌:973计划课题: 焦健斌:基金委青年基金(2010年1月) 王萌: 基金委面上基金(2010年1月) 黄性涛:基金委联合基金(2010年1月) 张学尧:基金委重点项目(参与)(2010年1月) 李晓玲:基金委青年基金(2011年1月) 黄性涛:基金委联合基金重点项目(参与)(2011年1月)

  9. (3770)到非DDbar遍举衰变道的寻找 由国家基金委重点项目支持,参与人员:张学尧、焦健斌、丁伟民 Motivation: • The (3770) was traditionally interpreted as a charmonium state with a mixture of 1D and 2S wave. The potential models predicted that (3770) decays into non-DDbar final states with BF of not more than 1%. • Assuming that there is only one simple (3770) in the range between 3.73 and 3.89 GeV, BES-II has measured the branching fraction of (3770) to non-DDbar B[(3770)non-DDbar] = (14.7±3.2)% • The inconsistency of BES measurement with the prediction of traditional theories implies that • Traditional theories interpreting (3770) need to be improved; • (3770) does decay into non-DDbar final states with substantial branching fraction; • Or, there exists some unknown structure or dynamics in the range from 3.73 to 3.89 GeV, which greatly affect the ψ(3770) decays. Search for (3770) to exclusive non-DDbar decay modes at BES-III will provide some valuable information for better understanding the (3770) non-DDbar puzzle

  10. 承担的任务: • 含重子对的遍举衰变过程(ppbar, bar); • 含的遍举衰变过程(约11个衰变道); • 含的遍举衰变过程(约11个衰变道)。 截面或截面的上限 进展情况: • 含重子对的遍举衰变过程(ppbar, bar):已完成了事例挑选、本底分析,给出了产生截面的初步测量结果; • 含的遍举衰变过程:已完成了事例挑选、本底分析,给出了产生截面的初步测量结果; • 含的遍举衰变过程:已开始事例挑选 Searching c(2S) decays into vector meson pairs 王亚乾(高能所苑长征指导) 谢谢! 进展情况:已发表在PRD上