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Hamilton approch to Yang-Mills Theory in Coulomb Gauge. H. Reinhardt Tübingen. Collaborators: D. Campagnari, D. Epple, C. Feuchter, M. Leder, M.Quandt, W. Schleifenbaum, P. Watson. related work: D. Zwanziger A.P. Szczepaniak, E. S. Swanson, …. Plan of the talk.
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Hamilton approch to Yang-Mills Theory in Coulomb Gauge H. Reinhardt Tübingen Collaborators: D. Campagnari, D. Epple, C. Feuchter, M. Leder, M.Quandt, W. Schleifenbaum, P. Watson
related work: D. Zwanziger A.P. Szczepaniak, E. S. Swanson, …
Plan of the talk • Hamilton approach to continuum Yang-Mills theory in Coulomb gauge • Variational solution of the YM Schrödinger equation: Dyson- Schwinger equations • Numerical Results • Infrared analysis of the DSE • ghost-gluon and 3-gluon vertex • t Hooft loop • Conclusions
Classical Yang-Mills theory Lagrange function: field strength tensor
Gauß law: Canonical Quantization of Yang-Mills theory
Attempts to solve the Schrödinger equation with gauge invariant wave functionals K. Johnson,… gauge invariant variables Karabali, Kim, Nair strong coupling expansion of the (D=2+1) YM wave functional Greensite gradient expansion projection techniques Kogan, Kovner,... Heineman, Martin, Vautherin Schröder, H.R. more efficient way: resolve Gauß´law explicitly by fixing the gauge
Gauß law: curved space resolution of Gauß´ law Faddeev-Popov Coulomb gauge
YM Hamiltonian in Coulomb gauge Christ and Lee Coulomb term -arises from Gauß´law =neccessary to maintain gauge invariance -provides the confining potential
Importance of the Faddeev-Popov determinant defines the metric in the space of gauge orbits and hence reflects the gauge invariance
metric of the space of gauge orbits: aim: solving the Yang-Mills Schrödinger eq. for the vacuum by the variational principle with suitable ansätze for Dyson-Schwinger equations
QM: particle in a L=0-state variational kernel determined from DSE (gap equation) vacuum wave functional
Dyson-Schwinger Equations ghost form factor d Abelian case d=1 ghost propagator ghost DSE gluon propagator gluon DSE (gap equation) gluon self-energy curvature
Regularization and renormalization: momentum subtraction scheme renormalization constants: In D=2+1 is the only value for which the coupled Schwinger-Dyson equation have a self-consistent solution ultrviolet and infrared asymtotic behaviour of the solutions to the Schwinger Dyson equations is independent of the renormalization constants except for Zwanziger horizon condition
ghost form factor gluon energy and curvature Numerical results (D=3+1)
external static color sources electric field ghost propagator
The color electric flux tube missing: back reaction of the vacuum to the external sources
comparison with lattice d=3 lattice: L. Moyarts, dissertation
D=3+1 Infrared behaviour of lattice GF: not yet conclusive too small lattices, see talk by A. Maas
previous work: A.P. Szczepaniak, E. S. Swanson, Phys. Rev. 65 (2002) 025012 A.P. Szczepaniak, Phys. Rev. 69(2004) 074031 different ansatz for the wave functional did not include the curvature of the space of gauge orbits i.e. the Faddeev- Popov determinant present work: C. Feuchter & H. R. hep-th/0402106, PRD70(2004) hep-th/0408237, PRD71(2005) W. Schleifenbaum, M. Leder, H.R. PRD73(2006) D. Epple, H. R., W. Schleifenbaum, in prepration full inclusion of the curvature measure for the curvature
Importance of the curvature Szczepaniak & Swanson Phys. Rev. D65 (2002) • the c = 0 solution does not produce • a linear confinement potential
Infrared limit = independent of to 2-loop order: Robustness of the infrared limit
ghost dominance in the infrared d=4 Landau gauge functional integral d=3 Coulomb gauge canonical quantization strong coupling Infrared analysis of the DSE vacuum wave functional: generating functional
LG: Lerche, v. Smekal Zwanziger, Alkofer, Fischer,… CG: Schleifenbaum, Leder, H.R. gluon propagator ghost propagator basic assumption:Gribov´s confinment scenario at work horizon condition: ghost DSE (bare ghost-gluon vertex) Landau gauge d=4 sum rule: solution of gluon DSE Coulomb gauge d=3 Coulomb gauge d=2 Analytic solution of DSE in the infrared
ghost gluon vertex D=4 Landau gauge(Taylor): non-renormalization in all orders in g becomes bare for vanishing incoming ghost momentum d=3 Coulomb gauge: similar behaviour renormalization can be ignored
3- gluon vertex Asumption: color structure of the bare vertex single form factor
order parameter of YMT temporal Wilson loop large variety of wave functionals produce the same DSE more sensitive observables than energy Coulomb potential = upper bound for true static quark potential (Zwanziger) confining Coulomb potential (=nessary but) not suffient for confinement Wilson loop difficult to calculate in continuum theory due to path ordering
disorder parameter of YMT spatial ´t Hooft loop ´t Hooft loop ´t Hooft Münster Tomboulis Samuel Bhattacharya et al Del Debbio, Di Giacomo, B. Lucini Chernodub et al. Korthals-Altes, Kovner,.. de Focrand, D´Elia, Pepe, v. Smekal,…. Quandt, H.R., Engelhardt …. Recent review: Greensite
defining eq. center vortex field V(C)-center vortex generator continuum representation: H.R: Phys.Lett.B557(2003) ´t Hooft loop
C gauge dependent but produces gauge invariant results when acting on gauge invariant states
Wilson loop magnetic flux C C ´t Hooft loop electric flux
QM: wave functionals in Coulomb gauge satisfy Gauß´law and hence should be regarded as the gauge invariant wave functional restricted to transverse gauge fields.
representation (correct to 2 loop) H. R. & C.F. PRD71 h(C;p)-geometry of the loop C planar circular loop C with radius R properties of the YM vacuum infrared properties of K(p) determine the large R-behaviour of S(R) ´t Hooft loop in Coulomb gauge
c 0 c=0 produces wave functional which in the infrared approaches the strong coupling limit neglect curvature from gap equation renormalization condition:
Summary and Conclusion • Variational solution of the YM Schrödinger equation in Coulomb gauge • Infrared analysis and numerical solution of the resulting DSE • Quark and gluon confinement • Curvature in gauge orbit space (Fadeev –Popov determinant) is crucial for the confinement properties • Ghost-gluon vertex = IR-finite • 3-gluon vertex= IR-divergent • ´t Hooft loop: perimeter law for a wave functional which in the infrared shows strict ghost dominance • Current projects: • QCD string • Topological susceptibility