scholarly journals Yang-Mills ghost propagator in linear covariant gauges

2019 ◽  
Vol 99 (9) ◽  
Author(s):  
Fabio Siringo
Keyword(s):  
2020 ◽  
Vol 80 (11) ◽  
Author(s):  
Markus Q. Huber ◽  
Christian S. Fischer ◽  
Hèlios Sanchis-Alepuz

AbstractWe provide results for the spectrum of scalar and pseudoscalar glueballs in pure Yang–Mills theory using a parameter-free fully self-contained truncation of Dyson–Schwinger and Bethe–Salpeter equations. The only input, the scale, is fixed by comparison with lattice calculations. We obtain ground state masses of $$1.9\,\text {GeV}$$ 1.9 GeV and $$2.6\,\text {GeV}$$ 2.6 GeV for the scalar and pseudoscalar glueballs, respectively, and $$2.6\,\text {GeV}$$ 2.6 GeV and $$3.9\,\text {GeV}$$ 3.9 GeV for the corresponding first excited states. This is in very good quantitative agreement with available lattice results. Furthermore, we predict masses for the second excited states at $$3.7\,\text {GeV}$$ 3.7 GeV and $$4.3\,\text {GeV}$$ 4.3 GeV . The quality of the results hinges crucially on the self-consistency of the employed input. The masses are independent of a specific choice for the infrared behavior of the ghost propagator providing further evidence that this only reflects a nonperturbative gauge completion.


2014 ◽  
Vol 11 (03) ◽  
pp. 1450018
Author(s):  
Marco de Cesare

The quantization of Yang–Mills theories relies on the gauge-fixing procedure. However, in the non-Abelian case this procedure leads to the well-known Gribov ambiguity. In order to solve the ambiguity a modification of the functional integral formula must be introduced. As a consequence of this, the Green functions get deep modifications in the infrared. We consider, in particular, the SU (N) case and show that in the pure gauge case the ghost propagator is enhanced, while the gluon propagator is suppressed in this limit, therefore the study of the Gribov ambiguity may shed some light on the mass gap problem and on color confinement. We discuss some recent developments on the subject in the case of a curved background. We argue that the concurrent presence of a spacetime curvature and the Gribov ambiguity may introduce further modifications to the Green functions in the infrared.


Author(s):  
Laurent Baulieu ◽  
John Iliopoulos ◽  
Roland Sénéor

A geometrical derivation of Abelian and non- Abelian gauge theories. The Faddeev–Popov quantisation. BRST invariance and ghost fields. General discussion of BRST symmetry. Application to Yang–Mills theories and general relativity. A brief history of gauge theories.


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