May 29, 2018 to June 3, 2018
Hyatt Regency Indian Wells Conference Center
US/Pacific timezone

Short-Distance Matrix Elements for $D^0$-Meson Mixing from $N_f=2+1$ Lattice QCD

Jun 1, 2018, 2:00 PM
30m
South Foyer | Ocotillo Room (Hyatt Regency Indian Wells Conference Center)

South Foyer | Ocotillo Room

Hyatt Regency Indian Wells Conference Center

44600 Indian Wells Lane, Indian Wells, CA 92210, USA

Speaker

Dr Chia Cheng Chang (LBL)

Description

We calculate in three-flavor lattice QCD the short-distance hadronic matrix elements of all five $\Delta C=2$ four-fermion operators that contribute to neutral $D$-meson mixing both in and beyond the Standard Model. We use the MILC Collaboration's $N_f = 2+1$ lattice gauge-field configurations generated with asqtad-improved staggered sea quarks. We also employ the asqtad action for the valence light quarks and use the clover action with the Fermilab interpretation for the charm quark. We analyze a large set of ensembles with pions as light as $M_\pi \approx 180$ MeV and lattice spacings as fine as $a\approx0.045$ fm, thereby enabling good control over the extrapolation to the physical pion mass and continuum limit. We obtain for the matrix elements in the $\overline{MS}-NDR$ scheme using the choice of evanescent operators proposed by Beneke $\textit{et al.}$, evaluated at 3 GeV. To illustrate the utility of our matrix-element results, we place bounds on the scale of CP-violating new physics in $D^0$ mixing, finding lower limits of about 10–50 $\times 10^3$ TeV for couplings of $\mathcal{O}(1)$. To enable our results to be employed in more sophisticated or model-specific phenomenological studies, we provide the correlations among our matrix-element results. For convenience, we also present numerical results in the other commonly used scheme of Buras, Misiak, and Urban.
E-mail [email protected]
Collaboration name FNAL/MILC
Funding source DOE

Primary author

Presentation materials