Light-Front Holography, Color Confinement, and Supersymmetric Features of QCD

Abstract

Light-Front Quantization provides a physical, frame-independent formalism for hadron dynamics and structure. Observables such as structure functions, transverse momentum distributions, and distribution amplitudes are defined from the hadronic light-front wavefunctions. One obtains new insights into the hadronic spectrum, light-front wavefunctions, and the functional form of the QCD running coupling in the nonperturbative domain using light-front holography -- the duality between the front form and AdS${}_5$, the space of isometries of the conformal group. In addition, superconformal algebra leads to remarkable supersymmetric relations between mesons and baryons of the same parity. The mass scale $\kappa$ underlying confinement and hadron masses can be connected to the parameter ${\Lambda }_{\overline{MS}}$ in the QCD running coupling by matching the nonperturbative dynamics, as described by the effective conformal theory mapped to the light-front and its embedding in AdS space, to the perturbative QCD regime. The result is an effective coupling defined at all momenta. This matching of the high and low momentum transfer regimes determines a scale $Q_0$ which sets the interface between perturbative and nonperturbative hadron dynamics. The use of $Q_0$ to resolve the factorization scale uncertainty for structure functions and distribution amplitudes, in combination with the principle of maximal conformality (PMC) for setting the renormalization scales, can greatly improve the precision of perturbative QCD predictions for collider phenomenology. The absence of vacuum excitations of the front-form vacuum has important consequences for the cosmological constant. I also discuss evidence that the antishadowing of nuclear structure functions is flavor dependent, and why shadowing and antishadowing phenomena may be incompatible with sum rules for nuclear parton distribution functions.

Invited Talk, presented at Light-Cone 2015, Theory and Experiment for Hadrons on the Light-Front, September 21-25, 2015, INFN, Frascati, Italy. arXiv admin note: substantial text overlap with arXiv:1512.05100, arXiv:1511.04142

References in corpus (18)

• Light-Front Holography: A First Approximation to QCD
• Eliminating the Renormalization Scale Ambiguity for Top-Pair Production Using the Principle of Maximum Conformality
• Unified framework for generalized and transverse-momentum dependent parton distributions within a 3Q light-cone picture of the nucleon
• Nuclear PDFs from neutrino deep inelastic scattering
• New limits on intrinsic charm in the nucleon from global analysis of parton distributions
• Baryon Spectrum from Superconformal Quantum Mechanics and its Light-Front Holographic Embedding
• Determination of the effective strong coupling constant alpha_{s,g_1}(Q^2) from CLAS spin structure function data
• Superconformal Baryon-Meson Symmetry and Light-Front Holographic QCD
• Kinematical and Dynamical Aspects of Higher-Spin Bound-State Equations in Holographic QCD
• Effective confining potentials for QCD
• Generalized parton distributions and transverse densities in a light-front quark-diquark model for the nucleons
• Generalization of the Brodsky-Lepage-Mackenzie optimization within the $\{\beta \}$-expansion and the Principle of Maximal Conformality
• On the Interface between Perturbative and Nonperturbative QCD
• The Light-Front Schrödinger Equation and Determination of the Perturbative QCD Scale from Color Confinement
• Dynamic versus Static Hadronic Structure Functions
• Recursion relations for multi-gluon off-shell amplitudes on the light-front and Wilson lines
• Dynamic versus Static Structure Functions and Novel Diffractive Effects in QCD
• Applications of Basis Light-Front Quantization to QED

Cited by in corpus (6)

• The Large Hadron-Electron Collider at the HL-LHC
• Dynamics of the quark-antiquark interaction and the universality of Regge trajectories
• Hadron Spectroscopy and Dynamics from Light-Front Holography and Superconformal Algebra
• Color Confinement and Spatial Dimensions in the Complex-sedenion Space
• Hadron and Nuclear Physics on the Light Front
• Deviation pattern approach for optimizing perturbative terms of QCD renormalization group invariant observables