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A (P)HMC algorithm for N_f = 2 + 1 + 1 flavours of twisted mass fermions

T. Chiarappa·R. Frezzotti·C. Urbach
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Abstract

We present a detailed design of a (P)HMC simulation algorithm for N_f = 2 + 1 + 1 maximally twisted Wilson quark flavours. The algorithm retains even/odd and mass-shift preconditionings combined with multiple Molecular Dynamics time scales for both the light mass degenerate, u and d, quarks and the heavy mass non-degenerate, s and c, quarks. Various non-standard aspects of the algorithm are discussed, among which those connected to the use of a polynomial approximation for the inverse (square root of the squared) Dirac matrix in the s and c quark sector.

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T. Chiarappa, R. Frezzotti, C. Urbach. 2005-09-27. A (P)HMC algorithm for N_f = 2 + 1 + 1 flavours of twisted mass fermions. https://arxiv.org/abs/hep-lat/0509154

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