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arXiv 1212.4191hep-ex
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奇异强子X(3872)是D0 D*0分子吗:X(3872)的Binding Energy的精确测定

Is the Exotic Hadron X(3872) a D0 D*0 Molecule: Precision Determination of the Binding Energy of X(3872)

A. Tomaradze, S. Dobbs, T. Xiao, Kamal K. Seth, G. Bonvicini

摘要:

最近发现的原型“奇异”介子X(3872),其M(X(3872))=3871.68+-0.17 MeV/c^2,其宽度非常窄,γ(X(3872))<1.2 MeV,它是一个束缚D^0和D^*0介子的强子分子。如果这是真的,这将建立一种新的强子,不同于qqbar介子和qqq重子。通过对所提出的分子的结合能进行高精度测量,这是一个重要的实验测试。利用CLEO-c探测器在psi(3770)处获得的818 pb ~(-1)的e ~+e ~-湮没数据,研究了衰变D_0-> KS K ~+ K ~-和D_0(Dbar_0)-> K ~+- pi-+ pi+ pi ~-,从而获得了D_0质量的最高精度测量,M(D_0)=1864.851+-0.020+-0.019+-0.054MeV/c^2,式中,第一个误差是统计误差,第二个误差是系统误差,第三个误差是由于K介子质量的不确定性,即1864.851+-0.061 MeV/c^2,所有误差都以正交方式相加。这导致M(D 0 + D*0)=3871.822+-0.140 MeV/c^2,结合能BE(X(3872))= M(D 0 +D*0)-M(X(3872))= +142+-220 keV。在90%的置信水平下,这导致X(3872)未被高达140 keV的能量束缚,或者被小于420 keV的能量束缚。如果结合,X(3872)有一个非常大的半径;结合能的中心值对应于12 fm的半径,下限为7 fm,对于一个分子来说都是不舒服的大。

英文摘要:

It has been proposed that the recently discovered archetypical "exotic" meson, X(3872), with M(X(3872))=3871.68+-0.17 MeV/c^2, and an extremely narrow width, Gamma(X(3872))<1.2 MeV, is a hadronic molecule of bound D^0 and D^*0 mesons. If true, this would establish a new species of hadrons, distinct from qqbar mesons and qqq baryons. It is put to an important experimental test by making a high precision measurement of the proposed molecule's binding energy. Using 818 pb-1 of e+e- annihilation data taken with the CLEO-c detector at psi(3770), the decays D0 -> KS K+ K- and D^0(Dbar0) -> K+- pi-+ pi+ pi- have been studied to make the highest precision measurement of D0 mass, M(D0)=1864.851+-0.020+-0.019+-0.054 MeV/c^2, where the first error is statistical, the second error is systematic, and the third error is due to uncertainty in kaon masses, or 1864.851+-0.061 MeV/c^2 with all errors added in quadrature. This leads to M(D0 + D*0)=3871.822+-0.140 MeV/c^2, and the binding energy BE(X(3872)) = M(D0+D*0)-M(X(3872)) = +142+-220 keV. At the 90% confidence level this leads to the conclusion that X(3872) is either unbound by as much as 140 keV, or it is bound by less than 420 keV. If bound, X(3872) has a very large radius; the central value of binding energy corresponds to a radius of 12 fm, and the lower limit to 7 fm, both being uncomfortably large for a molecule.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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