Tippens W B, Prakhov S, Allgower C E, Bekrenev V, Berger E, Briscoe W J, Clajus M, Comfort J R, Craig K, Efendiev A, Grosnick D, Holstein B R, Huber G M, Isenhower D, Knecht N, Koetke D, Koulbardis A, Kozlenko N, Kruglov S, Lolos G J, Lopatin I, Manley D M, Marusić A, Manweiler R, McDonald S, Nefkens B M, Olmsted J, Papandreou Z, Phaisangittisakul N, Price J W, Pulver M, Ramirez A F, Sadler M E, Shafi A, Spinka H, Stanislaus S, Starostin A, Staudenmaier H M
University of California, Los Angeles, Los Angeles, California 90095-1547.
Phys Rev Lett. 2001 Nov 5;87(19):192001. doi: 10.1103/PhysRevLett.87.192001. Epub 2001 Oct 22.
We have determined the quadratic slope parameter alpha for eta-->3pi(0) to be alpha = -0.031(4) from a 99% pure sample of 10(6)eta-->3pi(0) decays produced in the reaction pi(-)p-->n(eta) close to the eta threshold using the Crystal Ball detector at the AGS. The result is four times more precise than the present world data and disagrees with current chiral perturbation theory calculations by about four standard deviations.
我们利用AGS的晶体球探测器，从π⁻p→n(η)反应中产生的10⁶个η→3π⁰衰变的99%纯样本中，确定了η→3π⁰的二次斜率参数α为α = -0.031(4)，该反应接近η阈值。这个结果比目前的世界数据精确四倍，并且与当前的手征微扰理论计算结果相差约四个标准差。
