Jul 22 – 28, 2018
Kellogg Hotel and Conference Center
EST timezone

Progress on the study of electromagnetic corrections to $K\to\pi\pi$ decay

Jul 26, 2018, 12:20 PM
103 (Kellogg Hotel and Conference Center)


Kellogg Hotel and Conference Center

219 S Harrison Rd, East Lansing, MI 48824
Weak Decays and Matrix Elements Weak Decays and Matrix Elements


Prof. Xu Feng (Peking University)


In this talk, we present our progress on the study of the electromagnetic corrections to $K\to\pi\pi$ decay. To provide an accurate Standard-Model determination of direct CP violation at the precision of O(10%), it is important to include the electromagnetic corrections, as such $O(\alpha_e)$ effects could be enhanced 22 times in principle due to the isospin mixing and the $\Delta I=1/2$ rule. On the other hand, the long-range electromagnetic interaction is inconsistent with the Luscher and the Lellouch-Luscher finite-volume formalisms. Different from the traditional infrared regulators introduced as $QED_L$, massive photon or $C^*$ boundary condition, here we propose to use a truncated range as a new infrared regulator, which allows us to use the available finite-volume formalisms directly. To remove the unphysical truncation effects, we then provide the relations to connect the truncated quantities to the physical ones. Some other aspects of the electromagnetic corrections are also discussed.

Primary author

Prof. Xu Feng (Peking University)


Prof. Norman Christ (Columbia University)

Presentation materials