Short-distance perturbation theory for the leading logarithm models

1983 ◽  
Vol 217 (2) ◽  
pp. 381-394 ◽  
Author(s):  
Stephen L. Adler
2020 ◽  
Vol 2020 (9) ◽  
Author(s):  
Cesar Ayala ◽  
Xabier Lobregat ◽  
Antonio Pineda

Abstract We give the hyperasymptotic expansion of the energy of a static quark-antiquark pair with a precision that includes the effects of the subleading renormalon. The terminants associated to the first and second renormalon are incorporated in the analysis when necessary. In particular, we determine the normalization of the leading renormalon of the force and, consequently, of the subleading renormalon of the static potential. We obtain $$ {Z}_3^F $$ Z 3 F (nf = 3) = $$ 2{Z}_3^V $$ 2 Z 3 V (nf = 3) = 0.37(17). The precision we reach in strict perturbation theory is next-to-next-to-next-to-leading logarithmic resummed order both for the static potential and for the force. We find that the resummation of large logarithms and the inclusion of the leading terminants associated to the renormalons are compulsory to get accurate determinations of $$ {\Lambda}_{\overline{\mathrm{MS}}} $$ Λ MS ¯ when fitting to short-distance lattice data of the static energy. We obtain $$ {\Lambda}_{\overline{\mathrm{MS}}}^{\left({n}_f=3\right)} $$ Λ MS ¯ n f = 3 = 338(12) MeV and α(Mz) = 0.1181(9). We have also MS found strong consistency checks that the ultrasoft correction to the static energy can be computed at weak coupling in the energy range we have studied.


2013 ◽  
Vol 22 (05) ◽  
pp. 1330012 ◽  
Author(s):  
SINYA AOKI ◽  
JANOS BALOG ◽  
TAKUMI DOI ◽  
TAKASHI INOUE ◽  
PETER WEISZ

We review recent investigations on the short distance behaviors of potentials among baryons, which are formulated through the Nambu–Bethe–Salpeter (NBS) wave function. After explaining the method to define the potentials, we analyze the short distance behavior of the NBS wave functions and the corresponding potentials by combining the operator product expansion (OPE) and a renormalization group (RG) analysis in the perturbation theory (PT) of QCD. These analytic results are compared with numerical results obtained in lattice QCD simulations.


2020 ◽  
Author(s):  
Rainer Sommer ◽  
Nikolai Husung ◽  
Alessandro Nada

1979 ◽  
Vol 57 (10) ◽  
pp. 1699-1707
Author(s):  
C. S. Lam ◽  
G. C. Marleau

We show that when the β and γ functions in the Callan–Symanzik equation are calculated to a finite order in perturbation theory, the solution to the equation may be represented by an infinite series of Feynman diagrams obtained by repeated insertions of the lower order diagrams from which the β and γ functions are calculated. We demonstrate this assertion in two ways, by explicitly calculating these graphs in the leading logarithm approximation, and by proving that this set of diagrams satisfies exactly the Callan–Symanzik equation.


1995 ◽  
Vol 10 (15n16) ◽  
pp. 1159-1168 ◽  
Author(s):  
M.D. SCADRON ◽  
V. ELIAS

We construct a very short-distance weak interaction Δ = ½ Hamiltonian and use it in an old-fashioned perturbation theory to explain both first-order weak [Formula: see text] and [Formula: see text] decays and the second-order weak KL—KS mass difference.


2000 ◽  
Vol 14 (29n31) ◽  
pp. 3783-3790 ◽  
Author(s):  
MARC G. ZACHER ◽  
ROBERT EDER ◽  
ENRICO ARRIGONI ◽  
WERNER HANKE

The single-particle Green's function for a striped t–J model is calculated using cluster a perturbation theory, where short-distance effects are accounted for by exact cluster diagonalization and long-distance effects by perturbation (in the hopping). Both site-centered and bond-centered stripe scenarios have been studied. The data for site-centered stripes quantitatively reproduce salient (ARPES-) features.


2019 ◽  
Vol 7 (2) ◽  
Author(s):  
Markus Diehl ◽  
Jonathan Gaunt ◽  
Peter Plössl ◽  
Andreas Schafer

Double parton distributions (DPDs) receive a short-distance contribution from a single parton splitting to yield the two observed partons. We investigate this mechanism at next-to-leading order (NLO) in perturbation theory. Technically, we compute the two-loop matching of both the position and momentum space DPDs onto ordinary PDFs. This also yields the 1 \to 21→2 splitting functions appearing in the evolution of momentum-space DPDs at NLO. We give results for the unpolarised, colour-singlet DPDs in all partonic channels. These quantities are required for calculations of double parton scattering at full NLO. We discuss various kinematic limits of our results, and we verify that the 1 \to 21→2 splitting functions are consistent with the number and momentum sum rules for DPDs.


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