论文标题
观察$ j/ψλ$共振与$ b^ - \ to j/ψλ\ bar {p} $衰减中的一个奇怪的pentaquark候选人一致
Observation of a $J/ψΛ$ resonance consistent with a strange pentaquark candidate in $B^-\to J/ψΛ\bar{p}$ decays
论文作者
论文摘要
$ b^ - \至j/ψλ\ bar {p} $衰减的振幅分析使用在7、8和13 TEV的数据样本中选出的约4400个信号候选$ PP $碰撞，该数据样本与LHCB检测器的7、8和13 TEV中，对应于9 fb $^$^^$^$^^ - 1}。观察到与具有陌生性的五夸克候选人一致的$ J/ψλ$系统中的狭窄共振，具有很高的意义。该新状态的质量和宽度为$ 4338.2 \ pm 0.7 \ pm 0.4 $ mev和$ {7.0 \ pm1.2 \ pm1.3} $ mev，其中第一个不确定性是统计的，第二个系统是系统的。旋转被确定为$ 1/2 $，并且首选负均值。由于反应的小$ q $价值，迄今为止，$ b^ - $质量的最精确的单个测量值为$ 5279.44 \ pm0.05 \ pm0.07 $ mev。
An amplitude analysis of $B^-\to J/ψΛ\bar{p}$ decays is performed using about 4400 signal candidates selected on a data sample of $pp$ collisions recorded at center-of-mass energies of 7, 8 and 13 TeV with the LHCb detector, corresponding to an integrated luminosity of 9 fb$^{-1}$. A narrow resonance in the $J/ψΛ$ system, consistent with a pentaquark candidate with strangeness, is observed with high significance. The mass and the width of this new state are measured to be $4338.2\pm 0.7\pm 0.4$MeV and ${7.0\pm1.2\pm1.3}$MeV, where the first uncertainty is statistical and the second systematic. The spin is determined to be $1/2$ and negative parity is preferred. Due to the small $Q$-value of the reaction, the most precise single measurement of the $B^-$ mass to date, $5279.44\pm0.05\pm0.07$MeV, is obtained.
