The operators of b→ sγ, b →sl＋l- are usually regarded as being sufficient to describe b →sγγ, b → sl＋l-T with the statement that contributions from diagrams without an effective vertex b --＊ ST to processes...The operators of b→ sγ, b →sl＋l- are usually regarded as being sufficient to describe b →sγγ, b → sl＋l-T with the statement that contributions from diagrams without an effective vertex b --＊ ST to processes b →sγγ and b →sl＋l-T are negligible. In this work we present a comprehensive analysis of the transition b→sγγ and find that 1） Effects due to off-shell quarks in vertex b → sγ on b →sγγ are large; 2） Contributions from diagrams without an effective vertex b →sγ to b →sγγ are not negligible compared with others; 3） These effects cancel each other out exactly, so the operators of b→sγ can safely be used to describe b →sγγ.展开更多
基金Supported by China Postdoctoral Science Foundation (20080440292)
文摘The operators of b→ sγ, b →sl＋l- are usually regarded as being sufficient to describe b →sγγ, b → sl＋l-T with the statement that contributions from diagrams without an effective vertex b --＊ ST to processes b →sγγ and b →sl＋l-T are negligible. In this work we present a comprehensive analysis of the transition b→sγγ and find that 1） Effects due to off-shell quarks in vertex b → sγ on b →sγγ are large; 2） Contributions from diagrams without an effective vertex b →sγ to b →sγγ are not negligible compared with others; 3） These effects cancel each other out exactly, so the operators of b→sγ can safely be used to describe b →sγγ.
