First exclusive data for the $pp \to nn\pi^+\pi^+$ reaction have been obtained at CELSIUS with the WASA detector setup at a beam energy of $T_p$ = 1.1 GeV. Total and differential cross sections disagree with theoretical calculations, which predict the $\Delta\Delta$ excitation to be the dominant process at this beam energy. Instead the data require the excitation of a higher-lying $\Delta$ state, most likely the $\Delta(1600)$, to be the leading process.

翻译：CELSIUS公司获得了美元对美元对美元和美元反应的首个独家数据,WASA探测器安装的波束能量为$T_p$=1.1 GEV。总和差异交叉部分与理论计算不一致,理论计算预测,美元对Delta\Delta$的刺激是这一波束能量的主导过程。相反,数据要求引证高基量的$/Delta$状态,很可能是1600美元,作为主导过程。