Dynamical Anisotropic-Clover Lattice Production for Hadronic Physics J. Bulava, J. Foley, C. Morningstar, CMU K. Orginos, College W&M S. Cohen, J. Dudek, R. Edwards, B. Joo, H.-W. Lin, D. Richards, C. Thomas, A. Thomas, JLab S. Wallace, UMD J. Juge, U. of Pacific N. Mathur, Tata Institute M. Peardon, S. Ryan, Trinity College

Physics Focus New generation of experiments: hadron spectroscopy GlueX (JLab/HallD) Panda (GSI/Fair) BES III (Beijing) Spectrum: (Anisotropic-Clover fermions) Excited state baryon resonances (Hall B) Conventional and exotic (hybrid) mesons (Hall D) Ground and excited state form-factors (Hall B) Critical need: Hybrid meson spectrum/photo-coupling Baryon spectrum

Anisotropic Actions Anisotropic Symanzik gauge action: anisotropy =as/at Bare gauge anisotropy °g Anisotropic Clover: 3d-Stout-link smeared U’s (spatial). Choose rs=1. No doublers Bare fermion anisotropy °f Clover coefficients ct and cs (Manke): Consistent with non-perturbative improvement!

Anisotropy Tuning Results Anisotropies Nf=2+1, =3.5, as=0.1227(8)fm, at=0.03506(23)fm Tuning results: arxiv:0803.3960 Scale setting: determine as and ms in arxiv:0810.3588 gg gf 0 MeV 175 MeV 0 MeV 175 MeV

Nf=2+1 Anisotropic Clover: dynamical generation Scaling based on actual (243) runs down to ~230 MeV The entries are #traj, location[M-core-hours](m L) Goal is ~ 11k traj Blue uses NSF resources 323 140MeV only a contingency – not proposed 323 proposed for USQCD, request available INCITE/ESP at ORNL,ANL, possibly multi-year. as=0.1227fm

HMC Improvements Issues for 323x256 1-flavor light clover: problematic (via RHMC) Recent major improvements/changes: 2-flavor Clover mass preconditioned by TWM Switch to BiCG inverter Switch to double precision Tuning Omelyan integrator via Shadow Hamiltonian Roughly factor >2X improvement

ORNL Allocations

ORNL Queues Queue Configuration Bin Cores Wall-Time Max Hrs Aging Boost Days Min Max 1 17001 24.0 10 2 6001 17000 8 3 1025 6000 12.0 4 513 1024 4.0 5 257 512 2.5 6 256 1.5

ORNL Job Sizes

ORNL Running Steps are wait period

Second Lattice Spacing? Ratio method

Discretization effects Isotropic clover action - small discretization effects Quantify discretization effects: Move to as=0.1fm Compare ratio at m¼ ~ 500MeV (about 0.1 above) Cost: 203x192, 5k traj ! ~1M core-hrs Ratio method BMW 2008

Distillation Correlation funcs Smear quark fields Suggests (smooth) low-rank approximation for smearing arxiv:0905.2160

Distillation - mesons Smearing in correlator Correlator Factorizes: operators and perambulators A posteriori evaluation of C(2) after ¿ arxiv:0905.2160

Demonstration for mesons “½” spectrum (T1--) , m¼ = 383MeV, 163£ 128, 450 cfgs Increasing vectors, better resolution 12x12 correlation matrix (derivatives source/sink) ! 5 states 4-th ~ 1.5% statistical error 3rd 2nd 1st 0-th arxiv:0905.2160

Demonstration for baryons arxiv:0905.2160 Nucleon (G1g), m¼ = 383MeV, 163£ 128, 316 cfgs 4x4 correlation matrix ! 2 states Noise/signal: C(t) = a + b/Np ! p ~ 1 Better than naïve scaling 2nd ~ 2.5% statistical error 0-th

Demonstration for two-mesons arxiv:0905.2160 Sump ¼(prel,t)¼(-prel,t) m¼ = 383MeV, 163£ 128, 100 cfgs 5x5 correlation matrix (in p) ! 3 states 2nd 1st 0-th Relative momentum at origin!

Distillation: annihilation diagrams Two-meson creation op Correlator arxiv:0905.2160

Distillation: 3pts Generalized perambulator Supports 3-pt functions tf X arxiv:0905.2160

Prospects Gauge production: Many improvements! Room for more… ORNL: Heavily used: small fraction available for USQCD Access to ANL resources requested Distillation: Looks promising! Framework for multi-particle states Flexible: useful for 2-pt and 3-pt

Distillation – baryons Baryon op Correlator Perambulators arxiv:0905.2160