TY  - JOUR
AU  - Gambino, P.
AU  - Melis, A.
AU  - Simula, S.
PY  - 2017
DA  - 2017//
TI  - Extraction of heavy-quark-expansion parameters from unquenched lattice data on pseudoscalar and vector heavy-light meson masses
T2  - Phys. Rev. D
JO  - Physical Review D
SP  - 014511
EP  - 17pp
VL  - 96
IS  - 1
PB  - Amer Physical Soc
AB  - We present a precise lattice computation of pseudoscalar and vector heavy-light meson masses for heavy-quark masses ranging from the physical charm mass up to similar or equal to 4 times the physical b-quark mass. We employ the gauge configurations generated by the European Twisted Mass Collaboration (ETMC) with N-f = 2 + 1 + 1 dynamical quarks at three values of the lattice spacing (a similar or equal to 0.062; 0.082; 0.089 fm) with pion masses in the range M-pi similar or equal to 210-450 MeV. The heavy-quark mass is simulated directly on the lattice up to similar or equal to 3 times the physical charm mass. The interpolation to the physical b-quark mass is performed using the ETMC ratio method, based on ratios of the meson masses computed at nearby heavy-quark masses, and adopting the kinetic mass scheme. The extrapolation to the physical pion mass and to the continuum limit yields m(b)(kin) (1 GeV) = 4.61(20) GeV, which corresponds to (m) over bar (b) ((m) over bar (b)) 4.26(18) GeV in the (MS) over bar scheme. The lattice data are analyzed in terms of the heavy-quark expansion (HQE) and the matrix elements of dimension-four and dimension-five operators are extracted with a good precision, namely,(Lambda) over bar = 0.552(26) GeV, mu(2)(pi) = 0.321(32) GeV2, and mu(2)(G)(m(b)) = 0.253(25) GeV2. The data also allow for a rough estimate of the dimension-six operator matrix elements. As the HQE parameters play a crucial role in the inclusive determination of the Cabibbo-Kobayashi-Maskawa matrix elements V-ub and V-cb, their precise determination on the lattice may eventually validate and improve the analyses based on fits to the semileptonic moments.
SN  - 2470-0010
UR  - http://arxiv.org/abs/1704.06105
UR  - https://doi.org/10.1103/PhysRevD.96.014511
DO  - 10.1103/PhysRevD.96.014511
LA  - English
N1  - WOS:000406298500005
ID  - Gambino_etal2017
ER  -