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Chinese Science Bulletin, Volume 65 , Issue 27 : 2933-2940(2020) https://doi.org/10.1360/TB-2020-1061

Discoveries of the pentaquark states

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  • ReceivedAug 24, 2020
  • AcceptedAug 31, 2020
  • PublishedSep 1, 2020

Abstract


Funded by

国家自然科学基金(11575091)


Author information

高原宁, 北京大学博雅讲座教授、中国科学院院士, 主要从事粒子物理实验研究. 近年来领导 LHCb 国际合作 中国组在强子谱研究上得到重要成果.2015 年首次发现五夸克粒子, 被评选为当年物理学领域的重大进展. 2017 年发现双粲重子, 成果入选 2017 年度“中国科学十大进展”.


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  • Figure 1

    LHCb detector

  • Figure 2

    Λb0J/ψKp event recorded by the LHCb detector

  • Figure 3

    The invariant mass distributions of Λb0J/ψKp decays[13]. (a) Distribution of J/ψp invariant mass; (b) Dalitz plot

  • Figure 4

    Comparisons between the amplitude analysis (red points) and the data (black squares)[13]

  • Figure 5

    Three pentaquarks shown in the inviant mass spectrum ofJ/ψp[15]

  • Table 1   Quarks

    名称

    符号

    电荷a)

    质量(MeV/c2)

    下(down)

    d

    13e

    4.670.17+0.48

    上(up)

    u

    23e

    2.160.26+0.49

    奇异(strange)

    s

    13e

    93 5+11

    粲(charm)

    c

    23e

    (1.27±0.02)×103

    底(bottom)

    b

    13e

    (4.180.02+0.03)×103

    顶(top)

    t

    23e

    (172.76±0.30)×103

    e≈1.602×10–19 C(电子电荷的绝对值)

  • Table 2   Properties of the pentaquarks

    五夸克态

    质量(MeV)

    宽度(MeV)

    统计显著性

    Pc(4450)

    4449.8±1.7(stat)±2.5(syst)

    39±5(stat)±19(syst)

    >12倍标准偏差

    Pc(4380)

    4380±8(stat)±29(syst)

    205±18(stat)±86(syst)

    >9倍标准偏差

qqqq

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