2022/03/15 by Leonardo Chimirri, Chimirri, Leonardo, Rainer Sommer +1
Physics and Astronomy · #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #High-Energy Particle Collisions Research
paper · pdf · doi:10.48550/arxiv.2203.07936
The QCD-coupling is a necessary input in the computation of many observables,\nand the parametric error on input parameters can be a dominant source of\nuncertainty. The coupling can be extracted by comparing high order perturbative\ncomputations and lattice evaluated moments of mesonic two-point functions with\nheavy quarks, which provide a high energy scale for perturbation theory. The\ntruncation of the perturbative series is an important systematic uncertainty.\nWe report on our attempt to study this issue by measuring pseudo-scalar\ntwo-point functions in volumes of L=2 , \fm with twisted-mass Wilson\nfermions in the quenched approximation. We use full twist, the non-perturbative\nclover term and lattice spacings down to a=0.015 ,\fm to tame the\nsizable discretization effects. Our preliminary results indicate that either\nhigher order perturbative corrections or the continuum limit are not under\nsufficient control despite our small lattice spacings and quark masses\nextending beyond 2 ,m\charm.\n