Calculation of BSM Kaon B-parameters using improved staggered quarks in N_f = 2+1 QCD

• Published in: Pos : proceedings of science Vol. 214
• Main Authors: Leem, Jaehoon, Jang, Yong-Chull, Jeong, Hwancheol, Jung, Chulwoo, Kim, Hyung-Jin, Kim, Jangho, Kim, Seonghee, Lee, Weonjong, Pak, Jeonghwan, Park, Sungwoo, Sharpe, Stephen R., Yoon, Boram
• Format: Journal Article
• Language: English
• Published: United States SISSA 21.05.2015
• Subjects: Atomic; ATOMIC AND MOLECULAR PHYSICS; Nuclear and Particle Physics
• ISSN: 1824-8039; 1824-8039

We present updated results for kaon B-parameters for operators arising in models of new physics.We use HYP-smeared staggered quarks on the Nf = 2 + 1 MILC asqtad lattices. During the last year we have added new ensembles, which has necessitated chiral-continuum fitting with more elaborate fitting functions. We have also corrected an error in a two-loop anomalous dimension used to evolve results between different scales. Our results for the beyond-the-Standard-Model B-parameters have total errors of 5–10%. We find that the discrepancy observed last year between our results and those of the RBC/UKQCD and ETM collaborations for some of the B-parameters has been reduced from 4–5σ to 2–3σ.