Abstract
We present results for the decay constants of the D and Ds mesons computed in lattice QCD with Nf = 2 + 1 dynamical flavours. The simulations are based on RBC/UKQCD’s domain wall ensembles with both physical and unphysical light-quark masses and lattice spacings in the range 0.11-0.07 fm. We employ the domain wall discretisation for all valence quarks.The results in the continuum limit are fD = 208.7(2.8)stat(− 1.8+ 2.1)sysMeV and {f}_{D_s}=246.4{(1.3)}_{mathrm{stat}}{left({}_{-1.9}^{+1.3}right)}_{mathrm{sys}}mathrm{M}mathrm{e}mathrm{V} and {f}_{D_s}={f}_D=1.667{(77)}_{mathrm{stat}}{left({}_{-43}^{+57}right)}_{mathrm{sys}} . Using these results in a Standard Model analysis we compute the predictions |Vcd| = 0.2185(50)exp(− 37+ 35)lat and |Vcs| = 1.011(16)exp(− 9+ 4)lat for the CKM matrix elements.
Highlights
We present results for the decay constants of the D and Ds mesons computed in lattice QCD with Nf = 2 + 1 dynamical flavours
The simulations are based on RBC/UKQCD’s domain wall ensembles with both physical and unphysical light-quark masses and lattice spacings in the range 0.11–0.07 fm
As we will see in section 3.2.2, the difference between treating them as mixed and non-mixed is numerically irrelevant. Two observations in this context which we made in our quenched Domain wall fermions (DWF) studies [34, 35] are crucial for understanding the choice of simulation parameters made here: studying the pseudoscalar heavy-heavy and strange-heavy decay constants we found cut-off effects to be minimal for M5 ≈ 1.6
Summary
This report centres mainly around ensembles with physical light-quark masses in large volumes [37]. As we will see in section 3.2.2, the difference between treating them as mixed and non-mixed is numerically irrelevant Two observations in this context which we made in our quenched DWF studies [34, 35] are crucial for understanding the choice of simulation parameters made here: studying the pseudoscalar heavy-heavy and strange-heavy decay constants we found cut-off effects to be minimal for M5 ≈ 1.6. That we allow for one exception to the bound amh ≤ 0.4 by generating data for amh = 0.45 on ensemble C0 With this we tested whether the reach in the heavy quark mass for DWF with M5 = 1.6 observed in the quenched theory [35] persists in the dynamical case. We exclude any data with amh > 0.4 in the remainder of this paper
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
