Theory of {tau} mesonic decays
Theory of {tau} mesonic decays
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{tau}介子衰变理论
DOI：
10.1103/physrevd.55.1436
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发表时间：
1996
影响因子：
5
通讯作者：
B. Li
中科院分区：
文献类型：
--
作者：
B. Li
介绍了对介子衰变的研究。提出了一种产生低能轴向矢量电流的机制。采用VMD对矢量电流进行处理。所有正常宇称和反常宇称(Wess-Zumino-Witten反常)的介子顶点都是从一个有效的介子手征理论得到的。在{tau}轻子的衰变模式中发现了{sub1}占优势：3{pi}，f(1285){pi}。{Rho}和a{sub1}介子对衰变都有贡献{tau}{r_row}K{sup{Asterisk}}K{Nu}，发现矢量电流占主导地位。通过研究e{sup+}e{sup{负}}{r_row}{pi}{sup+}{pi}{sup{负}}来测试CVC。计算了{tau}{r_arrow}{omega}{pi}{nu}和K{bar K}{nu}的支化比。用类似的机制研究了{tau}轻子的{Delta}S=1衰变模式，发现在{tau}{r_row}K{sup{Asterisk}}{pi}{Nu}和K{sup{Asterisk}}{Eta}{Nu}中K{suba}占优势。揭示了{tau}{r_row}K{rho}{nu}的抑制作用。计算了{tau}{r_row}{eta}K{nu}的支化比。作为对这一理论的检验，确定了{pi}{r_row}e{r_row}{nu}和K{r_row}e{r_row}{nu}的形状因子。理论计算结果与数据吻合较好。{版权所有}{ITAL 1997}{ITAL The American Physitive Society}
Studies of {tau} mesonic decays are presented. A mechanism for the axial-vector current at low energies is proposed. The VMD is used to treat the vector current. All the meson vertices of both normal parity and abnormal parity (Wess-Zumino-Witten anomaly) are obtained from an effective chiral theory of mesons. a{sub 1} dominance is found in the decay modes of the {tau} lepton: 3{pi}, f(1285){pi}. Both the {rho} and the a{sub 1} meson contribute to the decay {tau}{r_arrow}K{sup {asterisk}}K{nu}; it is found that the vector current is dominant. CVC is tested by studying e{sup +}e{sup {minus}}{r_arrow}{pi}{sup +}{pi}{sup {minus}}. The branching ratios of {tau}{r_arrow}{omega}{pi}{nu} and K{bar K}{nu} are calculated. In terms of a similar mechanism the {Delta}s=1 decay modes of the {tau} lepton are studied and K{sub a} dominance is found in {tau}{r_arrow}K{sup {asterisk}}{pi}{nu} and K{sup {asterisk}}{eta}{nu}. The suppression of {tau}{r_arrow}K{rho}{nu} is revealed. The branching ratio of {tau}{r_arrow}{eta}K{nu} is computed. As a test of this theory, the form factors of {pi}{r_arrow}e{gamma}{nu} and K{r_arrow}e{gamma}{nu} are determined. The theoretical results agree with data reasonably well. {copyright} {ital 1997} {ital The American Physical Society}