Utilities for muon g-2 analyses in lattice QCD.
This module contains a small number of tools useful for analyzing contributions to the muon’s magnetic moment from (lattice) QCD vacuum polarization. The general technique is described in arXiv:1403.1778. The functions or classes include:
moments(G) – compute moments of jj correlator G.
- mom2taylor(G) – convert moments in G into Taylor coefficients
- for q2-expansion.
taylor2mom(G) – convert Taylor expansion coefficients G into moments.
- vacpol(G) – create a Pade approximant for the subtracted
- vacuum polarization (PI-hat) from the jj correlator whose moments (or Taylor coefs) are in G.
- a_mu(pihat, Q) – compute the contribution to the muon’s g-2
- anomaly from function pihat (usually built by vacpol).
- pade_gvar(f,m,n)– general-purpose code for determining Pade approximants
- to a power series whose coefficients are GVars.
- pade_svd(f,m,n) – general-purpose code for determining Pade approximants
- for a power series whose coefficients are floats. Uses SVD regularization to stabilize results when the input data are noisy.