Color Ferromagnetic Vacuum States in {QCD} and Two Loop Energy Densities Bounds on {MIT} Bag Constant in Relation to {QCD}
Dec, 197920 pages
Published in:
- Nucl.Phys.B 169 (1980) 309-328
- Published: 1980
Report number:
- NBI-HE-79-43
Citations per year
Abstract: (Elsevier)
We obtain two-loop energy densities of color ferromagnetic states, which are identified with the QCD ground state, using the β-function calculated to the two-loop approximation and the exact formula for the energy density of such a state. This is used to derive bounds on the MIT bag constant correcting our previous bound in the one-loop approximation. For a constant field color ferromagnetic ansatz state we obtain the bound on the QCD scale parameter Λ P ⩽0.88 GeV when B 1 4 =0.145 GeV . The correction by going from one loop to two loops is only of the order of 20%. Correcting for instanton effects we obtain Λ P ⩽0.46 GeV. Our ϑ 3 vacuum ansatz with two-loop and instanton corrections gives Λ P ⩽0.16 GeV. We stress that the ”perturbative vacuum“, which is identified with the inside bag state, is a somewhat ill-defined concept due to a path dependence in the integral giving the energy density.- QUANTUM CHROMODYNAMICS: VACUUM STATE
- QUARK: COLOR
- MODEL: FERROMAGNET
- ENERGY: DENSITY
- MODEL: BAG
- PERTURBATION THEORY: HIGHER-ORDER
- SCALING
- EFFECT: INSTANTON
- FIELD EQUATIONS: INSTANTON
- NUMERICAL CALCULATIONS
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