Spin effects in the pion holographic light-front wavefunction

Light front field theory: An advanced PrimerWe present an elementary introduction to quantum field theory formulated in terms of Dirac's light front variables. In addition to general principles and methods, a few more specific topics and approaches based on the author's work will be discussed. Most of the discussion deals with massive two-dimensional models formulated in a finite spatial volume starting with a detailed comparison between quantization of massive free fields in the usual field theory and the light front (LF) quantization. We discuss basic properties such as relativistic invariance and causality. After the LF treatment of the soluble Federbush model, a LF approach to spontaneous symmetry breaking is explained and a simple gauge theory - the massive Schwinger model in various gauges is studied. A LF version of bosonization and the massive Thirring model are also discussed. A special chapter is devoted to the method of discretized light cone quantization and its application to calculations of the properties of quantum solitons. The problem of LF zero modes is illustrated with the example of the two-dimensional Yukawa model. Hamiltonian perturbation theory in the LF formulation is derived and applied to a few simple processes to demonstrate its advantages. As a byproduct, it is shown that the LF theory cannot be obtained as a "light-like" limit of the usual field theory quantized on an initial space-like surface. A simple LF formulation of the Higgs mechanism is then given. Since our intention was to provide a treatment of the light front quantization accessible to postgradual students, an effort was made to discuss most of the topics pedagogically and a number of technical details and derivations are contained in the appendices.

Download Full-text

QCD near the light front

10.31274/rtd-180813-10549 ◽

1996 ◽

Author(s):

Thomas John Fields

Keyword(s):

Light Front

Download Full-text

Spin Resonance

10.1093/oso/9780198807308.003.0003 ◽

2018 ◽

Author(s):

M. M. Glazov

Keyword(s):

Magnetic Resonance ◽

Nuclear Spin ◽

Electromagnetic Waves ◽

Zeeman Splitting ◽

Resonant Absorption ◽

Magnetic Interactions ◽

Spin Effects ◽

Crystalline Environment ◽

Spin Resonance ◽

Optically Detected

This chapter is devoted to one of key phenomena in the field of spin physics, namely, resonant absorption of electromagnetic waves under conditions where the Zeeman splitting of spin levels in magnetic field is equal to photon energy. This method is particularly important for identification of nuclear spin effects, because resonance spectra provide fingerprints of different involved spin species and make it possible to distinguish different nuclear isotopes. As discussed in this chapter the nuclear magnetic resonance provides also an access to local magnetic fields acting on nuclear spins. These fields are caused by the magnetic interactions between the nuclei and by the quadrupole splittings of nuclear spin states in anisotropic crystalline environment. Manifestations of spin resonance in optical responses of semiconductors–that is, optically detected magnetic resonance–are discussed.

Download Full-text

Spin effects in the effective field theory approach to Post-Minkowskian conservative dynamics

Journal of High Energy Physics ◽

10.1007/jhep06(2021)012 ◽

2021 ◽

Vol 2021 (6) ◽

Author(s):

Zhengwen Liu ◽

Rafael A. Porto ◽

Zixin Yang

Keyword(s):

Field Theory ◽

Effective Field Theory ◽

Scattering Problem ◽

Finite Size ◽

Effective Field ◽

Compact Objects ◽

Scattering Data ◽

Theory Approach ◽

Spin Effects ◽

Radial Action

Abstract Building upon the worldline effective field theory (EFT) formalism for spinning bodies developed for the Post-Newtonian regime, we generalize the EFT approach to Post-Minkowskian (PM) dynamics to include rotational degrees of freedom in a manifestly covariant framework. We introduce a systematic procedure to compute the total change in momentum and spin in the gravitational scattering of compact objects. For the special case of spins aligned with the orbital angular momentum, we show how to construct the radial action for elliptic-like orbits using the Boundary-to-Bound correspondence. As a paradigmatic example, we solve the scattering problem to next-to-leading PM order with linear and bilinear spin effects and arbitrary initial conditions, incorporating for the first time finite-size corrections. We obtain the aligned-spin radial action from the resulting scattering data, and derive the periastron advance and binding energy for circular orbits. We also provide the (square of the) center-of-mass momentum to $$ \mathcal{O}\left({G}^2\right) $$ O G 2 , which may be used to reconstruct a Hamiltonian. Our results are in perfect agreement with the existent literature, while at the same time extend the knowledge of the PM dynamics of compact binaries at quadratic order in spins.

Download Full-text