Standard Model Prediction for Direct C P Violation in K →π π Decay
Abstract
We report the first lattice QCD calculation of the complex kaon decay amplitude A0 with physical kinematics, using a 323×64 lattice volume and a single lattice spacing a , with 1 /a =1.3784 (68 ) GeV . We find Re (A0)=4.66 (1.00 )(1.26 )×1 0-7 GeV and Im (A0)=-1.90 (1.23 )(1.08 )×1 0-11 GeV , where the first error is statistical and the second systematic. The first value is in approximate agreement with the experimental result: Re (A0)=3.3201 (18 )×1 0-7 GeV , while the second can be used to compute the direct C P -violating ratio Re (ɛ'/ɛ )=1.38 (5.15 )(4.59 )×1 0-4 , which is 2.1 σ below the experimental value 16.6 (2.3 )×1 0-4. The real part of A0 is C P conserving and serves as a test of our method while the result for Re (ɛ'/ɛ ) provides a new test of the standard model theory of C P violation, one which can be made more accurate with increasing computer capability.
- Publication:
-
Physical Review Letters
- Pub Date:
- November 2015
- DOI:
- 10.1103/PhysRevLett.115.212001
- arXiv:
- arXiv:1505.07863
- Bibcode:
- 2015PhRvL.115u2001B
- Keywords:
-
- 12.38.Gc;
- 11.30.Er;
- 12.15.Hh;
- 13.20.Eb;
- Lattice QCD calculations;
- Charge conjugation parity time reversal and other discrete symmetries;
- Determination of Kobayashi-Maskawa matrix elements;
- Decays of K mesons;
- High Energy Physics - Lattice;
- High Energy Physics - Phenomenology
- E-Print:
- 9 pages, 3 figures. Updated to match published version