Spectrality, coupling constant analyticity and the renormalization group
نویسنده
چکیده
Analytic structure in the strong coupling constant that emerges for some observables in QCD after duality averaging of renormalization group improved amplitudes is discussed. It is shown that perturbation theory calculations are justified for the proper observables related to the two-point correlators of hadronic currents the analytic properties of which are well-established. A particular case of gluonic current correlators is discussed in detail. PACS: 11.55.Hx, 12.38.Bx, 13.35.Dx, 02.70.Hm
منابع مشابه
Interacting Fermi liquid in two dimensions at finite temperature Part II: Renormalization
Abstract This is a companion paper to [DR1]. Using the method of continuous renormalization group around the Fermi surface and the results of [DR1], we achieve the proof that a two-dimensional jellium system of interacting Fermions at low temperature T is a Fermi liquid above the BCS temperature Following [S1], this means proving analyticity in the coupling constant λ for |λ|| logT | ≤ K where ...
متن کاملA numerical renormalization group approach for calculating the spectrum of a vibronic system occurring in molecules or impurities in insulators
Theoretically, in order to describe the behavior of a spectrum, a mathematical model whichcould predict the spectrum characteristics is needed. Since in this study a Two-state system has beenused like models which was introduced previously past and could couple with the environment, theformer ideas have been extended in this study. we use the second quantized version for writing thisHamiltonian...
متن کاملThe two dimensional Hubbard Model at half-filling: I. Convergent Contributions
We prove analyticity theorems in the coupling constant for the Hubbard model at half-filling. The model in a single renormalization group slice of index i is proved to be analytic in λ for |λ| ≤ c/i for some constant c, and the skeleton part of the model at temperature T (the sum of all graphs without two point insertions) is proved to be analytic in λ for |λ| ≤ c/| log T |2. These theorems are...
متن کاملThe running coupling from the four-gluon vertex in Landau gauge SU(N) Yang-Mills theory
The running coupling of Yang-Mills theory has been investigated in a number of approaches in recent years [1]. The focus of these studies is the question how to extend our knowledge of the coupling from the perturbative, large momentum region towards small scales of the order of ΛQCD. Perturbation theory alone, plagued by the problem of the Landau pole, is clearly insufficient for this task. In...
متن کاملCan the QCD running coupling have a causal analyticity structure?
Solving the QCD renormalization group equation at the 2-loop and 3-loop orders we obtain explicit expressions for the coupling as a function of the scale in terms of the Lambert W function. We study the nature of the “Landau singularities” in the complex Q2 plane and show that perturbative freezing can lead, in certain cases, to an analyticity structure that is consistent with causality. We ana...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2001