1 / 34

Precision Charmed Meson Spectroscopy and Decay Constants from Chiral Fermions

Precision Charmed Meson Spectroscopy and Decay Constants from Chiral Fermions . Overlap Fermion on 2+1 flavor Domain Wall Fermion Configurations Charmonium and Charmed-strange Meson Spectrum and f Ds. χ QCD Collaboration:

gloria
Download Presentation

Precision Charmed Meson Spectroscopy and Decay Constants from Chiral Fermions

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Precision Charmed Meson Spectroscopy and Decay Constants from Chiral Fermions • Overlap Fermion on 2+1 flavor Domain Wall FermionConfigurations • Charmonium and Charmed-strange Meson Spectrum and fDs χQCDCollaboration: A. Alexandru, S.J. Dong, T. Draper, T. Doi, I. Horvath, B. Joo, F. Lee, A. Li, KFL, R. Lewis, N. Mathur, X. Meng, T. Streuer, H. Thacker, and J.B. Zhang YITP, Feb. 5, 2010

  2. fD and fDs

  3. Overlap Fermion • Some desirable features: • O(a2) error are small (e.g. spectrum). • O(m2a2) errors are small (dispersion relation, hyperfine splitting) can include charm quark • The effective propagator is • Dc = D/(1 – D/2) is chirally symmetric, i.e. {γ5, Dc} = 0. • Dc + m is like in the continuum formalism. • Multi-mass algorithm (30 masses) • Renormalization is relatively simple (e.g. with chiral Ward identity). • Undesirable feature: • Numerically intensive (can be tamed with eigenmode deflation)

  4. 2+1 Flavor DWF Configurations(RBC and UKQCD) • 163 x 32 x 16, a-1 =1.73 GeV (a = 0.114 fm), ml a=0.01, 0.02, 0.03, ms a=0.04 • 243 x 64 x 16, a-1 =1.73 GeV (a = 0.114 fm), ml a=0.005, 0.01, 0.02, 0.03, ms a=0.04 • 323 x 64 x 16, a-1 =2.42 GeV (a = 0.085 fm), ml a=0.004, 0.006, 0.008, ms a=0.03

  5. Overlap on 2+1 Flavor DWF configurations with HYP Smearing • Mixed action • For chirally symmetric valence, it is like partial quenching with one extra parameter in valence-sea mass (Chen, O’Connell, Walker-Loud, arXiv:0706.0035)

  6. Determination of ρ (243 x 64 lattice) from Hyperfine Splitting ρ=1.62 ρ=1.50

  7. Overlap with Deflation

  8. Speed up with deflation and HYP smearing • No critical slowing down • Can calculate for any mass except zero • Multi-mass inversion (30 masses)

  9. 163 x 32 243 x 64

  10. DS Spectrum

  11. 323 x 64, mla = 0.006, a = 0.0814 fm S.J. Dong talk

  12. Hyperfine Splitting of Charmonium (50 config.) Expt: 116.5(1) MeV

  13. Sharpe and Zhang, ‘95

  14. fDs on 323 x 64 lattice at chiral limit

  15. fDs fDs = 266.0 (9.5) MeV

  16. fD

  17. C. Aubin, Lattice ‘09

  18. Z3 Grid Source with Low-Mode Substitution Z3 Grid: noise on 64 grid points separated by 8 lattice spacings on a time slice of 323 x 64 lattice Mesons H+L L H H H L + H+L L

  19. Low-mode substitution for Baryons H+L H H H H H L H+L H+L H L L L + + L L

  20. Proton Correlator and Relative Errors with Low-mode Substituion (12 configurations)

  21. Is a tetraquarkmesonium? 2+1 flavor DWF+Overlap 0 flavor Overlap

  22. f0(1710) f0(1500) a0(1450) K0*(1430) f0(1370) a2(1320) a1(1230) a0(980) f0(980) M (MeV) ρ(770) K0*(800) σ(600) π(137) JPG(I)) 1+ ¯(1) 0¯ ¯(1) 2+ ¯(1) 0+¯(1) 0++(0) 0+(1/2) 1¯+(1)

  23. Why a0(980) is not a state? • The corresponding K0 would be ~ 1100 MeV which is 300 MeV away from both and . • Cannot explain why a0(980) and f0(980) are narrow while σ(600) and κ(800) are broad. • γ γ width of a0(980) and f0(980) are much smaller than expected of states. • Large indicates in f0(980), but cannot be in I=1 a0(980). How to explain the mass degeneracy then?

  24. ms Our results shows scalar mass around 1400-1500 MeV, suggesting a0(1450)is a two quark state.

  25. Scattering states Possible BOUND state σ(600)? Scattering states (Negative scattering length) Further study is needed to check the volume dependence of the observed states.

  26. Volume dependence of spectral weights W0 W1 Volume independence suggests the observed state is an one particle state

  27. f0(1710) f0(1500) a0(1450) K0*(1430) f0(1370) a2(1320) a1(1230) a0(980) f0(980) M (MeV) ρ(770) K0*(800) σ(600) Kπ Mesonium ππMesonium π(137) JPG(I)) 1+ ¯(1) 0¯ ¯(1) 2+ ¯(1) 0+¯(1) 0++(0) 0+(1/2) 1¯+(1)

  28. Scalar Mesons and Glueball glueball

  29. Summary • Chiral fermions (Overlap valence on 2+1 flavor DWF configurations) • Preliminary results on DS spectrum at one sea mass and one lattice spacing. • Preliminary results on hyperfine splitting of charmonium, and fDs at chiral and continuum limits. • Systematic errors (NLO MAPQ PT fitting) • Noise grid source can reduce errors by a factor of 3 to 4. • Need to observe all members of multiplets in addition to to discern tetraquarkmesoniums.

More Related