The cross section for the pd --> ^3He eta pi0 reaction has been measured at a beam energy of 1450 MeV using the WASA detector at the CELSIUS storage ring and detecting one ^3He and four photons from the decays of the two photons. The data indicate that the production mechanism involves the formation of the Delta(1232) isobar. Although the beam energy does not allow the full peak of this resonance to be seen, the invariant masses of all three pairs of final state particles are well reproduced by a phase space Monte Carlo simulation weighted with the p-wave factor of the square of the pi^0 momentum in the ^3Hepi^0 system.
翻译:Pd -- > +3He eta pi0反应的横截面部分是在1450兆瓦的波束能量中测量的,当时使用了CELSIUS贮存圈的WASA探测器,探测了两枚光子衰变的1×3He和4个光子。数据显示,生产机制涉及德尔塔(1232)等离子体的形成。虽然波束能量无法显示这种共振的完整峰值,但所有三对最后状态粒子的挥发性质量都通过一个相位空间蒙太罗模拟得到很好的再现,该空间在 3Hepi+0 系统中将Pi+#0 动力平方的波系数加权。