The University of Southampton
University of Southampton Institutional Repository

K → (ππ)I=2 decay amplitude from lattice QCD

K → (ππ)I=2 decay amplitude from lattice QCD
K → (ππ)I=2 decay amplitude from lattice QCD
We report on the first realistic ab initio calculation of a hadronic weak decay, that of the amplitude A2 for a kaon to decay into two π mesons with isospin 2. We find Re A2 = (1.436±0.063stat±0.258syst)10-8 GeV in good agreement with the experimental result and for the hitherto unknown imaginary part we find Im A2 = -(6.83±0.51stat±1.30syst)10-13 GeV. Moreover combining our result for Im A2 with experimental values of Re A2, Re A0, and ε'/ε, we obtain the following value for the unknown ratio Im A0/Re A0 within the standard model: Im A0/Re A0 = -1.63(19)stat(20)syst×10-4. One consequence of these results is that the contribution from Im A2 to the direct CP violation parameter ε' (the so-called Electroweak Penguin contribution) is Re(ε'/ε)EWP = -(6.52±0.49stat±1.24syst)×10-4. We explain why this calculation of A2 represents a major milestone for lattice QCD and discuss the exciting prospects for a full quantitative understanding of CP violation in kaon decays.
141601-1-141601-5
Blum, T.
29e11a5b-96d3-4b8d-a17c-ec4b836ceead
Boyle, P.
a12661a4-a1da-4fdc-9207-db20087bfaba
Christ, N.
bafeb9b1-3dd1-4027-8690-1d99257b2c8e
Garron, N.
4652f982-8723-41c1-9bf7-46bc5c54c2db
Goode, E.
29354b98-c117-4ace-9ca4-1d3ad531485f
Izubuchi, T.
4ee5b26a-e913-4a6b-8a2f-80159b3219b2
Jung, C.
c6d7a1c1-b894-4c10-b12f-437062bf40bd
Kelly, C.
c4345b06-5900-4597-9dbc-623dc13e6f8e
Lehner, C.
f5ed25c1-68c1-4a5f-9e01-73233639caae
Lightman, M.
2eb91ad6-e29c-4897-bba2-39663050d0a7
Liu, Q.
9c3579c5-8fa0-402b-ad8e-83f4542b1b05
Lytle, A.
098ff8c3-113f-42fe-bcbd-e8879fa44986
Mawhinney, R.
871ec3e5-7501-4c79-a815-95b147eb1907
Sachrajda, C.
0ed6568b-f52f-4314-8677-4aeeb925d6f7
Soni, A.
7a4196ff-0f6b-429e-af54-d1036e9c433b
Sturm, C.
5ccbb81f-c09b-4b32-9871-fc6b13bfacc4
Blum, T.
29e11a5b-96d3-4b8d-a17c-ec4b836ceead
Boyle, P.
a12661a4-a1da-4fdc-9207-db20087bfaba
Christ, N.
bafeb9b1-3dd1-4027-8690-1d99257b2c8e
Garron, N.
4652f982-8723-41c1-9bf7-46bc5c54c2db
Goode, E.
29354b98-c117-4ace-9ca4-1d3ad531485f
Izubuchi, T.
4ee5b26a-e913-4a6b-8a2f-80159b3219b2
Jung, C.
c6d7a1c1-b894-4c10-b12f-437062bf40bd
Kelly, C.
c4345b06-5900-4597-9dbc-623dc13e6f8e
Lehner, C.
f5ed25c1-68c1-4a5f-9e01-73233639caae
Lightman, M.
2eb91ad6-e29c-4897-bba2-39663050d0a7
Liu, Q.
9c3579c5-8fa0-402b-ad8e-83f4542b1b05
Lytle, A.
098ff8c3-113f-42fe-bcbd-e8879fa44986
Mawhinney, R.
871ec3e5-7501-4c79-a815-95b147eb1907
Sachrajda, C.
0ed6568b-f52f-4314-8677-4aeeb925d6f7
Soni, A.
7a4196ff-0f6b-429e-af54-d1036e9c433b
Sturm, C.
5ccbb81f-c09b-4b32-9871-fc6b13bfacc4

Blum, T., Boyle, P., Christ, N., Garron, N., Goode, E., Izubuchi, T., Jung, C., Kelly, C., Lehner, C., Lightman, M., Liu, Q., Lytle, A., Mawhinney, R., Sachrajda, C., Soni, A. and Sturm, C. (2012) K → (ππ)I=2 decay amplitude from lattice QCD. Physical Review Letters, 108 (14), 141601-1-141601-5. (doi:10.1103/PhysRevLett.108.141601).

Record type: Article

Abstract

We report on the first realistic ab initio calculation of a hadronic weak decay, that of the amplitude A2 for a kaon to decay into two π mesons with isospin 2. We find Re A2 = (1.436±0.063stat±0.258syst)10-8 GeV in good agreement with the experimental result and for the hitherto unknown imaginary part we find Im A2 = -(6.83±0.51stat±1.30syst)10-13 GeV. Moreover combining our result for Im A2 with experimental values of Re A2, Re A0, and ε'/ε, we obtain the following value for the unknown ratio Im A0/Re A0 within the standard model: Im A0/Re A0 = -1.63(19)stat(20)syst×10-4. One consequence of these results is that the contribution from Im A2 to the direct CP violation parameter ε' (the so-called Electroweak Penguin contribution) is Re(ε'/ε)EWP = -(6.52±0.49stat±1.24syst)×10-4. We explain why this calculation of A2 represents a major milestone for lattice QCD and discuss the exciting prospects for a full quantitative understanding of CP violation in kaon decays.

This record has no associated files available for download.

More information

Published date: 6 April 2012
Organisations: Theoretical Partical Physics Group

Identifiers

Local EPrints ID: 339270
URI: http://eprints.soton.ac.uk/id/eprint/339270
PURE UUID: e3bff73a-16a6-47e6-8489-e62cd4f84ee5

Catalogue record

Date deposited: 28 May 2012 13:09
Last modified: 11 Apr 2022 17:58

Export record

Altmetrics

Contributors

Author: T. Blum
Author: P. Boyle
Author: N. Christ
Author: N. Garron
Author: E. Goode
Author: T. Izubuchi
Author: C. Jung
Author: C. Kelly
Author: C. Lehner
Author: M. Lightman
Author: Q. Liu
Author: A. Lytle
Author: R. Mawhinney
Author: C. Sachrajda
Author: A. Soni
Author: C. Sturm

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×