CERN Accelerating science

Published Articles
Report number	arXiv:1706.03821 ; CERN-TH-2017-129 ; DESY-17-088 ; WUB-17-03
Title	The strong coupling from a nonperturbative determination of the $\Lambda$ parameter in three-flavor QCD
Related title	The strong coupling from a nonperturbative determination of the $\Lambda$ parameter in three-flavor QCD
Author(s)	Bruno, Mattia (Brookhaven Natl. Lab.) ; Dalla Brida, Mattia (INFN, Milan Bicocca ; Milan Bicocca U.) ; Fritzsch, Patrick (CERN) ; Korzec, Tomasz (Bergische U., Wuppertal (main)) ; Ramos, Alberto (CERN) ; Schaefer, Stefan (DESY, Zeuthen ; NIC, Zeuthen) ; Simma, Hubert (DESY, Zeuthen ; NIC, Zeuthen) ; Sint, Stefan (Trinity Coll., Dublin) ; Sommer, Rainer (NIC, Zeuthen ; DESY, Zeuthen ; Humboldt U., Berlin)
Collaboration	ALPHA Collaboration
Publication	2017-09-08
Imprint	2017-06-12
Number of pages	6
Note	Correction in the comparison to the LHC value for alpha(1.5TeV) which was given by CMS in the 5-flavor theory. The agreement is improved. Also 1 Reference added and a few typos corrected
In:	Phys. Rev. Lett. 119 (2017) 102001
DOI	10.1103/PhysRevLett.119.102001
Subject category	hep-lat ; Particle Physics - Lattice
Abstract	We present a lattice determination of the $\Lambda$ parameter in three-flavor QCD and the strong coupling at the Z pole mass. Computing the nonperturbative running of the coupling in the range from $0.2\,$GeV to $70\,$GeV, and using experimental input values for the masses and decay constants of the pion and the kaon, we obtain $\Lambda_{\overline{\rm MS}}^{(3)}=341(12)\,$MeV. The nonperturbative running up to very high energies guarantees that systematic effects associated with perturbation theory are well under control. Using the four-loop prediction for $\Lambda_{\overline{\rm MS}}^{(5)}/\Lambda_{\overline{\rm MS}}^{(3)}$ yields $\alpha^{(5)}_{\overline{\rm MS}}(m_{\rm Z}) = 0.11852(84)$.
Copyright/License	arXiv nonexclusive-distrib. 1.0 Publication: © 2017-2025 authors

Corresponding record in: Inspire