Standard model matrix elements for neutralB-meson mixing and associated decay constants

Abstract

We present results of quenched lattice calculations of the matrix elements relevant for B d −B d and Bs−Bs mixing in the standard model. Results for the corresponding SU (3)-breaking ratios, which can be used to constrain or determine |V td |, are also given. The calculations are performed at two values of the lattice spacing, corresponding to β = 6.0 and β = 6.2, with quarks described by a mean-field-improved Sheikholeslami-Wohlert action. As a by-product, we obtain the leptonic decay constants of B and D mesons. We also present matrix elements relevant for D 0 −D 0 mixing. Our results are summarized in the Introduction.12.38. Gc, 12.15.Hh, 14.40.Nd

Precision measurement ofB(D+→μ+ν)and the pseudoscalar decay constantfEisenstein1, Karliner2, Mehrabyan3 et al. 2008Phys. Rev. D1048600View full textAdd to dashboardCite

“…Other Standard Model based predictions are listed in Table IV. [4] 207 ± 4 1.164 ± 0.011 LQCD (Fermilab+MILC) [7] 201 ± 3 ± 17 1.24 ± 0.02 ± 0.07 QL (QCDSF) [8] 206 ± 6 ± 3 ± 22 1.07 ± 0.02 ± 0.02 QL (Taiwan) [9] 235 ± 8 ± 14 1.13 ± 0.03 ± 0.05 QL (UKQCD) [10] 210 ± 10 +17 −16…”

“…Quenched calculations have also been performed [8,9,10,11], and other methods have been used [12,13,14,15,16,17,18]. The various theoretical predictions of f D + range from 190 MeV to 350 MeV.…”

Measurement ofB(Ds+→l+ν)and the decay constantfAlexander1, Cassel2, Duboscq3 et al. 2009Phys. Rev. D786330View full textAdd to dashboardCite

“…[21] µ + ν (6.38 ± 0.76 ± 0.52) · 10 −3 274 ± 16 ± 12 Average of CLEO and Belle results above, radiatively corrected 261.2 ± 6.9 CLEO [14] µ + ν (6.2 ± 0.8 ± 1.3 ± 1.6) · 10 −3 3.6±0.9 273 ± 19 ± 27 ± 33 BEATRICE [15] µ + ν (8.3 ± 2.3 ± 0.6 ± 2.1) · 10 −3 3.6±0.9 312 ± 43 ± 12 ± 39 ALEPH [16] µ + ν (6.8 ± 1.1 ± 1.8) · 10 −3 3.6±0.9 282 ± 19 ± 40 ALEPH [16] τ + ν (5.8 ± 0.8 ± 1.8) · 10 −2 L3 [17] τ + ν (7.4 ± 2.8 ± 1.6 ± 1.8) · 10 −2 299 ± 57 ± 32 ± 37 OPAL [18] τ + ν (7.0 ± 2.1 ± 2.0) · 10 −2 283 ± 44 ± 41 BaBar [19] µ + ν (6.74 ± 0.83 ± 0. [6] 241 ± 3 208 ± 4 1.162 ± 0.009 Lattice (FNAL+MILC+HPQCD) [5] 249 ± 3 ± 16 201 ± 3 ± 17 1.24 ± 0.01 ± 0.07 QL (QCDSF) [37] 220 ± 6 ± 5 ± 11 206 ± 6 ± 3 ± 22 1.07 ± 0.02 ± 0.02 QL (Taiwan) [38] 266 ± 10 ± 18 235 ± 8 ± 14 1.13 ± 0.03 ± 0.05 QL (UKQCD) [39] 236 ± 8 1.10 ± 0.02 QCD Sum Rules [41] 205 ± 22 177 ± 21 1.16 ± 0.01 ± 0.03 QCD Sum Rules [42] 235 ± 24 203 ± 20 1.15 ± 0.04 Field Correlators [43] 210 ± 10 260 ± 10 1.24 ± 0.03 Quark Model [44] 268 234 1.15 Quark Model [45] 248±27 230±25 1.08±0.01 LFQM (Linear) [46] 211 248 1.18 LFQM (HO) [46] 194 233 1.20 LF-QCD [47] 253 241 1.05 Potential Model [48] 241 238 1.01 Isospin Splittings [49] 262 ± 29 on f D + and f Ds of 230 and 270 MeV, respectively, have been determined using two-point correlation functions by Khodjamirian [36]. Our result for f Ds is higher than most theoretical expectations.…”

Combined analysis of the unitarity triangle and CP violation in the Standard Model

“…I = 2 matrix element of Q 8 . There exists a large set of quenched calculations of Q 8 2 performed with different formulations of the lattice fermion actions (Staggered, Wilson, tree-level improved, tadpole improved) and renormalization techniques (perturbative, boosted perturbative, non-perturbative), at several values of the inverse lattice spacing a −1 = 2 ÷ 3 GeV [30,50], [53]- [55]. All these calculations, usually expressed in terms of B (3/2) 8 , give consistent results within 20% of uncertainty.…”