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Title: Hadron Spectroscopy and Dynamics from Light-Front Holography and Superconformal Algebra

QCD is not supersymmetrical in the traditional sense – the QCD Lagrangian is based on quark and gluonic fields, not squarks nor gluinos. However, its hadronic eigensolutions conform to a representation of superconformal algebra, reflecting the underlying conformal symmetry of chiral QCD and its Pauli matrix representation. The eigensolutions of superconformal algebra provide a unified Regge spectroscopy of meson, baryon, and tetraquarks of the same parity and twist as equal-mass members of the same 4-plet representation with a universal Regge slope. The pion $$q\bar{q}$$ eigenstate has zero mass for m q = 0. The superconformal relations also can be extended to heavy-light quark mesons and baryons. The combined approach of light-front holography and superconformal algebra also provides insight into the origin of the QCD mass scale and color confinement. A key observation is the remarkable dAFF principle which shows how a mass scale can appear in the Hamiltonian and the equations of motion while retaining the conformal symmetry of the action. When one applies the dAFF procedure to chiral QCD, a mass scale κ appears which determines universal Regge slopes, hadron masses in the absence of the Higgs coupling, and the mass parameter underlying the Gaussian functional form of the nonperturbative QCD running coupling: α s(Q 2) ∝ exp-Q 2/4κ 2, in agreement with the effective charge determined from measurements of the Bjorken sum rule. The mass scale κ underlying hadron masses can be connected to the parameter Λ $$\overline{MS}$$ in the QCD running coupling by matching its predicted nonperturbative form to the perturbative QCD regime. The result is an effective coupling α s(Q 2) defined at all momenta. In conclusion, one also obtains empirically viable predictions for spacelike and timelike hadronic form factors, structure functions, distribution amplitudes, and transverse momentum distributions.
Authors:
 [1]
  1. Stanford Univ., Stanford, CA (United States). SLAC National Accelerator Lab
Publication Date:
Report Number(s):
SLAC-PUB-17201
Journal ID: ISSN 0177-7963
Grant/Contract Number:
AC02-76SF00515
Type:
Accepted Manuscript
Journal Name:
Few-Body Systems
Additional Journal Information:
Journal Volume: 59; Journal Issue: 5; Conference: NSTAR 2017, The 11th International Workshop on the Physics of Excited Nucleons, Univ. of South Carolina, Columbia, SC (United States), 20-23 Aug 2017; Journal ID: ISSN 0177-7963
Publisher:
Springer
Research Org:
SLAC National Accelerator Lab., Menlo Park, CA (United States)
Sponsoring Org:
USDOE Office of Science (SC)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
OSTI Identifier:
1443973