在B^{+}→D_{s}^{+}K^{+}衰变中的D_{s}^{-}值附近观察一个共振结构
R Aaij1, A S W Abdelmotteleb2, C Abellan Beteta3
1Nikhef National Institute for Subatomic Physics, Amsterdam, Netherlands.
Physical review letters
|September 1, 2023
概括
研究人员在B+衰变中发现了一种新粒子,X(3960),可能由魅力和奇怪夸克组成. 这一发现为外来子和夸克相互作用提供了洞察力.
科学领域:
- 粒子物理学 粒子物理学
- 高能物理 高能物理
- 量子色态动力学 量子色态动力学
背景情况:
- B+→Ds+Ds-K+衰变是一个复杂的过程,涉及多个粒子.
- 了解共振贡献对于解释实验数据和推进理论模型至关重要.
- 以前的研究还没有完全分析这个特定的衰变通道内的共振结构.
研究的目的:
- 执行B+→Ds+Ds-K+衰变的第一个振幅分析.
- 调查中间共振贡献,并描述新观察到的结构.
- 为了比较实验结果与对奇特夸克状态的理论预测.
主要方法:
- 利用了来自LHCb探测器在7,8和13 TeV的质子对质子碰撞数据.
- 进行了Ds+Ds-不变质谱的振幅分析.
- 测量了观察到的共振结构的质量,宽度和量子数 (JPC).
主要成果:
- 在Ds+Ds-不变质量谱中观察到一个显著的近值结构,X(3960). (显著性>12个标准偏差).
- 测量了X(3960) 的属性:质量 (3956±5±10 MeV),宽度 (43±13±8 MeV) 和JPC (0++).
- 发现了大约4140 MeV的额外结构的证据,可能是新的共振或合通道效应.
结论:
- X(3960) 结构的属性与理论预测的cc[over ̄]ss[over ̄]四夸克状态相一致.
- 这些发现提供了强有力的证据,证明X ((3960)) 粒子的存在.
- 潜在的第二结构需要进一步调查以确定其性质.
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