1996/05/31 by Benjamı́n Grinstein, Benjamin Grinstein, Ira Z. Rothstein +1 · 1 citation
Physics and Astronomy · #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-lat #hep-ph
paper · pdf · doi:10.1016/0370-2693(96)00832-5
published as Phys.Lett. B385 (1996) 265-272 · Version to appear in PLB, with extended discussion and numbers for intermediate values of the pion mass
arxiv created 1996/07/25 · openalex publication_date 1996/09/01 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We investigate the errors due to the use of unphysical values of light quark masses in lattice extractions of αs. A functional form for the pion mass dependence of the quarkonium mass splittings (Δm) is given as an expansion in mπ/(4πfπ) and mπrB, where rB is the quarkonium Bohr radius. We find that, to lowest order,Δm≃ A+B mπ2, where the scale of B is given by fπ2 rB3. To order mπ4 there are four unknown coefficients, however, utilizing multipole and operator product expansions, symmetry arguments eliminate one of the four unknowns. Using the central values for the lattice spacings which were extracted using two different, unphysical values for the pion mass, we find that the errors introduced by extrapolating to the physical regime are comparable to the errors quoted due to other sources. Extrapolation to physical values of the pion mass \it increases the value of αs(MZ), bringing its value closer to the high energy extractions.