The Enrico Fermi Institute, The University of Chicago, Illinois 60637, USA.
Phys Rev Lett. 2011 Nov 11;107(20):201803. doi: 10.1103/PhysRevLett.107.201803. Epub 2011 Nov 9.
The KTeV E799 experiment has conducted a search for the rare decays, K(L)→π(0)π(0)μ(+)μ(-) and K(L)→π(0)π(0)X(0)→π(0)π(0)μ(+)μ(-), where the X(0) is a possible new neutral boson that was reported by the HyperCP experiment with a mass of (214.3 ± 0.5) MeV/c(2). We find no evidence for either decay. We obtain upper limits of Br(K(L)→π(0)π(0)X(0)→π(0)π(0)μ(+)μ(-)) < 1.0 × 10(-10) and Br(K(L)→π(0)π(0)μ(+)μ(-)) < 9.2 × 10(-11) at the 90% confidence level. This result rules out the pseudoscalar X(0) as an explanation of the HyperCP result under the scenario that the dsX(0) coupling is completely real.
KTeV E799 实验对罕见衰变 K(L)→π(0)π(0)μ(+)μ(-)和 K(L)→π(0)π(0)X(0)→π(0)π(0)μ(+)μ(-)进行了搜索，其中 X(0)是 HyperCP 实验报道的一种可能的新中性玻色子，其质量为(214.3 ± 0.5) MeV/c(2)。我们没有发现这两种衰变的任何证据。我们在 90%置信水平下得到了 K(L)→π(0)π(0)X(0)→π(0)π(0)μ(+)μ(-)的上限 Br(K(L)→π(0)π(0)X(0)→π(0)π(0)μ(+)μ(-))<1.0×10(-10)和 K(L)→π(0)π(0)μ(+)μ(-))<9.2×10(-11)。在 dsX(0)耦合完全实的情况下，这个结果排除了赝标量 X(0)作为 HyperCP 结果的解释。
