%0 Generic %1 Buras2015Upper %A Buras, Andrzej J. %A Gerard, Jean-Marc %D 2015 %K kaon %T Upper Bounds on epsilon'/epsilon Parameters B\_6^(1/2) and B\_8^(3/2) from Large N QCD and other News %U http://arxiv.org/abs/1507.06326 %X We demonstrate that in the large N approach developed by the authors in collaboration with Bardeen, the parameters B\_6^(1/2) and B\_8^(3/2) parametrizing the K\to\pimatrix elements <Q\_6>\_0 and <Q\_8>\_2 of the dominant QCD and electroweak operators receive both negative O(1/N) corrections such that B\_6^(1/2) < B\_8^(3/2)<1 in agreement with the recent lattice results of the RBC-UKQCD collaboration. We also point out that the pattern of the size of the hadronic matrix elements of all QCD and electroweak penguin operators Q\_i contributing to the Kamplitudes A\_0 and A\_2, obtained by this lattice collaboration, provides further support to our large N approach. In particular, a very precise lattice result for the matrix element <Q\_8>\_0 implies for the corresponding parameter B\_8^(1/2)=1.010.03 to be compared with large N value B\_8^(1/2)=1.10.1. We discuss briefly the implications of these findings for the ratio epsilon'/epsilon. In fact, with the precise value for B\_8^(3/2) from RBC-UKQCD collaboration, our upper bound on B\_6^(1/2) implies epsilon'/epsilon in the SM roughly by a factor of two below its experimental value (16.62.3)10^-4. We also briefly comment on the parameter B\_K and the \Delta I=1/2\$ rule.

@misc{Buras2015Upper, abstract = {We demonstrate that in the large N approach developed by the authors in collaboration with Bardeen, the parameters B\_6^{(1/2)} and B\_8^{(3/2)} parametrizing the K\to\pi\pi matrix elements \<Q\_6\>\_0 and \<Q\_8\>\_2 of the dominant QCD and electroweak operators receive both negative O(1/N) corrections such that B\_6^{(1/2)} \< B\_8^{(3/2)}\<1 in agreement with the recent lattice results of the RBC-UKQCD collaboration. We also point out that the pattern of the size of the hadronic matrix elements of all QCD and electroweak penguin operators Q\_i contributing to the K\to \pi \pi amplitudes A\_0 and A\_2, obtained by this lattice collaboration, provides further support to our large N approach. In particular, a very precise lattice result for the matrix element \<Q\_8\>\_0 implies for the corresponding parameter B\_8^{(1/2)}=1.01\pm 0.03 to be compared with large N value B\_8^{(1/2)}=1.1\pm 0.1. We discuss briefly the implications of these findings for the ratio epsilon'/epsilon. In fact, with the precise value for B\_8^{(3/2)} from RBC-UKQCD collaboration, our upper bound on B\_6^{(1/2)} implies epsilon'/epsilon in the SM roughly by a factor of two below its experimental value (16.6\pm 2.3)\times 10^{-4}. We also briefly comment on the parameter \hat B\_K and the \Delta I=1/2\$ rule.}, added-at = {2019-02-23T22:09:48.000+0100}, archiveprefix = {arXiv}, author = {Buras, Andrzej J. and Gerard, Jean-Marc}, biburl = {https://www.bibsonomy.org/bibtex/25597cd17551b838b360992a104adb631/cmcneile}, citeulike-article-id = {13683492}, citeulike-linkout-0 = {http://arxiv.org/abs/1507.06326}, citeulike-linkout-1 = {http://arxiv.org/pdf/1507.06326}, day = 22, eprint = {1507.06326}, interhash = {2fc398d8944cd31f2cd8d85087521782}, intrahash = {5597cd17551b838b360992a104adb631}, keywords = {kaon}, month = jul, posted-at = {2015-07-24 15:24:23}, priority = {2}, timestamp = {2019-02-23T22:15:27.000+0100}, title = {Upper Bounds on epsilon'/epsilon Parameters B\_6^{(1/2)} and B\_8^{(3/2)} from Large N QCD and other News}, url = {http://arxiv.org/abs/1507.06326}, year = 2015 }