$D \rightarrow K, l ν$ Semileptonic Decay Scalar Form Factor and $|V_{cs}|$ from Lattice QCD

Details $D \rightarrow K, l ν$ Semileptonic Decay Scalar Form Factor and $|V_{cs}|$ from Lattice QCD $D \rightarrow K, l ν$ Semileptonic Decay Scalar Form Factor and $|V_{cs}|$ from Lattice QCD

2010-08-26

arxiv.org/abs/1008.4562v2

Phys.Rev.D82:114506,2010

Physics

High Energy Physics

High Energy Physics - Lattice

23 pages, 31 figures, 11 tables. Added a paragraph in sction VII, and updated with PDG 2010 instead of PDG 2008

Scientific paper

10.1103/PhysRevD.82.114506

We present a new study of D semileptonic decays on the lattice which employs the Highly Improved Staggered Quark (HISQ) action for both the charm and the light valence quarks. We work with MILC unquenched $N_f = 2 + 1$ lattices and determine the scalar form factor $f_0(q^2)$ for $D \rightarrow K, l \nu$ semileptonic decays. The form factor is obtained from a scalar current matrix element that does not require any operator matching. We develop a new approach to carrying out chiral/continuum extrapolations of $f_0(q^2)$. The method uses the kinematic "$z$" variable instead of $q^2$ or the kaon energy $E_K$ and is applicable over the entire physical $q^2$ range. We find $f^{D \rightarrow K}_0(0) \equiv f^{D \rightarrow K}_+(0) = 0.747(19)$ in the chiral plus continuum limit and hereby improve the theory error on this quantity by a factor of $\sim$4 compared to previous lattice determinations. Combining the new theory result with recent experimental measurements of the product $f^{D \rightarrow K}_+(0) * |V_{cs}| $ from BaBar and CLEO-c leads to the most precise direct determination of the CKM matrix element $|V_{cs}| $ to date, $|V_{cs}| = 0.961(11)(24)$, where the first error comes from experiment and the second is the lattice QCD theory error. We calculate the ratio $f^{D \rightarrow K}_+(0)/f_{D_s}$ and find $2.986 \pm 0.087$ GeV$^{-1}$ and show that this agrees with experiment.

Affiliated with

Also associated with

No associations

Rating

$D \rightarrow K, l ν$ Semileptonic Decay Scalar Form Factor and $|V_{cs}|$ from Lattice QCD does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with $D \rightarrow K, l ν$ Semileptonic Decay Scalar Form Factor and $|V_{cs}|$ from Lattice QCD, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and $D \rightarrow K, l ν$ Semileptonic Decay Scalar Form Factor and $|V_{cs}|$ from Lattice QCD will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-704345