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Title: $$B^0_{(s)}$$-mixing matrix elements from lattice QCD for the Standard Model and beyond

We calculate—for the first time in three-flavor lattice QCD—the hadronic matrix elements of all five local operators that contribute to neutral B 0- and B s-meson mixing in and beyond the Standard Model. We present a complete error budget for each matrix element and also provide the full set of correlations among the matrix elements. We also present the corresponding bag parameters and their correlations, as well as specific combinations of the mixing matrix elements that enter the expression for the neutral B-meson width difference. We obtain the most precise determination to date of the SU(3)-breaking ratio ξ=1.206(18)(6), where the second error stems from the omission of charm-sea quarks, while the first encompasses all other uncertainties. The threefold reduction in total uncertainty, relative to the 2013 Flavor Lattice Averaging Group results, tightens the constraint from B mixing on the Cabibbo-Kobayashi-Maskawa (CKM) unitarity triangle. Our calculation employs gauge-field ensembles generated by the MILC Collaboration with four lattice spacings and pion masses close to the physical value. We use the asqtad-improved staggered action for the light-valence quarks and the Fermilab method for the bottom quark. We use heavy-light meson chiral perturbation theory modified to include lattice-spacing effects to extrapolate the five matrixmore » elements to the physical point. We combine our results with experimental measurements of the neutral B-meson oscillation frequencies to determine the CKM matrix elements |V td| = 8.00(34)(8)×10 -3, |V ts| = 39.0(1.2)(0.4)×10 -3, and |V td/V ts| = 0.2052(31)(10), which differ from CKM-unitarity expectations by about 2σ. In addition, these results and others from flavor-changing-neutral currents point towards an emerging tension between weak processes that are mediated at the loop and tree levels.« less
 [1] ;  [2] ;  [3] ;  [4] ;  [5] ;  [6] ;  [4] ;  [7] ;  [8] ;  [9] ;  [10] ;  [11] ;  [6] ;  [12] ;  [13] ;  [12] ;  [14] ;  [15] ;  [12] ;  [12]
  1. Univ. of Iowa, Iowa City, IA (United States)
  2. Washington Univ., St. Louis, MO (United States)
  3. The College of William and Mary, Williamsburg, VA (United States)
  4. Univ. of Illinois, Urbana, IL (United States)
  5. Univ. of Utah, Salt Lake City, UT (United States)
  6. Syracuse Univ., Syracuse, NY (United States)
  7. School of the Art Institute of Chicago, Chicago, IL (United States)
  8. Univ. de Granada, Granada (Spain)
  9. Indiana Univ., Bloomington, IN (United States)
  10. American Physical Society, Ridge, NY (United States)
  11. Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Technische Univ. Munchen, Garching (Germany)
  12. Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
  13. Univ. of Colorado, Boulder, CO (United States); Brookhaven National Lab. (BNL), Upton, NY (United States)
  14. Univ. of California, Santa Barbara, CA (United States)
  15. Univ. of Arizona, Tucson, AZ (United States)
Publication Date:
Report Number(s):
FERMILAB-PUB-16-030-T; arXiv:1602.03560; BNL-112445-2016-JA
Journal ID: ISSN 2470-0010; PRVDAQ; 1421164
Grant/Contract Number:
AC02-07CH11359; FG02-91ER40628; FC02-06ER41446; SC0010120; SC0010005; FG02-91ER40661; FG02-13ER42001; FG02-13ER41976; SC0012704; SC00112704
Accepted Manuscript
Journal Name:
Physical Review D
Additional Journal Information:
Journal Volume: 93; Journal Issue: 11; Journal ID: ISSN 2470-0010
American Physical Society (APS)
Research Org:
Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Brookhaven National Lab. (BNL), Upton, NY (United States). RIKEN Research Center
Sponsoring Org:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
Contributing Orgs:
Fermilab Lattice; MILC; Fermilab Lattice and MILC Collaborations
Country of Publication:
United States
OSTI Identifier:
Alternate Identifier(s):
OSTI ID: 1259736; OSTI ID: 1336071