Continuum Limit of $B_K$ from 2+1 Flavor Domain Wall QCD

التفاصيل البيبلوغرافية
العنوان: Continuum Limit of $B_K$ from 2+1 Flavor Domain Wall QCD
المؤلفون: Aoki, Y., Arthur, R., Blum, T., Boyle, P. A., Brömmel, D., Christ, N. H., Dawson, C., Izubuchi, T., Jung, C., Kelly, C., Kenway, R. D., Lightman, M., Mawhinney, R. D., Ohta, Shigemi, Sachrajda, C. T., Scholz, E. E., Soni, A., Sturm, C., Wennekers, J., Zhou, R.
المصدر: Phys.Rev.D84:014503,2011
سنة النشر: 2010
المجموعة: High Energy Physics - Lattice
High Energy Physics - Phenomenology
مصطلحات موضوعية: High Energy Physics - Lattice, High Energy Physics - Phenomenology
الوصف: We determine the neutral kaon mixing matrix element $B_K$ in the continuum limit with 2+1 flavors of domain wall fermions, using the Iwasaki gauge action at two different lattice spacings. These lattice fermions have near exact chiral symmetry and therefore avoid artificial lattice operator mixing. We introduce a significant improvement to the conventional NPR method in which the bare matrix elements are renormalized non-perturbatively in the RI-MOM scheme and are then converted into the MSbar scheme using continuum perturbation theory. In addition to RI-MOM, we introduce and implement four non-exceptional intermediate momentum schemes that suppress infrared non-perturbative uncertainties in the renormalization procedure. We compute the conversion factors relating the matrix elements in this family of RI-SMOM schemes and MSbar at one-loop order. Comparison of the results obtained using these different intermediate schemes allows for a more reliable estimate of the unknown higher-order contributions and hence for a correspondingly more robust estimate of the systematic error. We also apply a recently proposed approach in which twisted boundary conditions are used to control the Symanzik expansion for off-shell vertex functions leading to a better control of the renormalization in the continuum limit. We control chiral extrapolation errors by considering both the NLO SU(2) chiral effective theory, and an analytic mass expansion. We obtain $B_K^{\msbar}(3 GeV) = 0.529(5)_{stat}(15)_\chi(2)_{FV}(11)_{NPR}$. This corresponds to $\hat{B}_K = 0.749(7)_{stat}(21)_\chi(3)_{FV}(15)_{NPR}$. Adding all sources of error in quadrature we obtain $\hat{B}_K = 0.749(27)_{combined}$, with an overall combined error of 3.6%.
Comment: 65 pages
نوع الوثيقة: Working Paper
DOI: 10.1103/PhysRevD.84.014503
URL الوصول: http://arxiv.org/abs/1012.4178
رقم الأكسشن: edsarx.1012.4178
قاعدة البيانات: arXiv