In one context, the value for this phenomenon is called sin(2b)
Gronau and London have developed a way of using isospin triangle relations to remove theoretical uncertainties in the value of this phenomenon caused due to so-called "penguin pollution."  This phenomenon is non-zero if and only if the Jarlskog invariant is non-zero.  In one context, the value for this phenomenon is called sin(2b) ("sine of two beta"), and the existence of this is one of the Sakharov conditions. In the Standard Model, this phenomenon arises due to an imaginary component in the CKM matrix, and this phenomenon was first observed in 1964 in kaon decays by Cronin and Fitch.  FTP, what is this breaking of  a combination of two symmetries of nature?
Gronau and London have developed a way of using isospin triangle relations to remove theoretical uncertainties in the value of this phenomenon caused due to so-called "penguin pollution."  
{CP violation} (accept things like {CP asymmetry})