English
Related papers

Related papers: Spin 1/2 and Invariant Coefficients

200 papers

It is shown that Maxwell's equation cannot be put into a spinor form that is equivalent to Dirac's equation. First of all, the spinor \psi in the representation \vec{F} = \psi \vec{u} \bar{\psi} of the electromagnetic field bivector depends…

Mathematical Physics · Physics 2007-05-23 Andre Gsponer

A simple translation between a standard representation of $\mathfrak{sl}_2\mathbb{C}$ and the complex-quaternions ($\mathbb{H}\otimes_\mathbb{R}\mathbb{C}$) is established and exploited to construct a novel hyper-complex description of the…

Quantum Physics · Physics 2026-04-21 James Henry Atwater , David Lambert , Yuri Rostovtsev

The space-time symmetry group of a model of a relativistic spin 1/2 elementary particle, which satisfies Dirac's equation when quantized, is analyzed. It is shown that this group, larger than the Poincare group, also contains space-time…

High Energy Physics - Theory · Physics 2009-11-11 Martin Rivas

Dirac's equation for a massless particle is conformal invariant, and accordingly has an so(4,2)invariance algebra. It is known that although Dirac's equation for a massive spin 1/2 particle is not conformal invariant, it too has an so(4,2)…

High Energy Physics - Theory · Physics 2007-05-23 A. J. Bracken

20-component Petras theory of 1/2-spin particle with anomalous magnetic momentum in presence of external electromagnetic and gravitational fields is investigated. The gravitation field is described as space-time curvature. Correctness of…

High Energy Physics - Theory · Physics 2007-05-23 A. A. Bogush , V. V. Kisel , N. G. Tokarevskaya , V. M. Red'kov

The spin coherent state path integral describing the dynamics of a spin-1/2-system in a magnetic field of arbitrary time-dependence is considered. Defining the path integral as the limit of a Wiener regularized expression, the semiclassical…

Quantum Physics · Physics 2008-11-26 Adrian Alscher , Hermann Grabert

This paper sets out to establish a comparative study between classes of spin- and velocity-dependent potentials for spin-1/2 and spin-1 matter currents/sources in the non-relativistic regime. Both (neutral massive) scalar and vector…

High Energy Physics - Theory · Physics 2017-01-03 P. C. Malta , L. P. R. Ospedal , K. Veiga , J. A. Helayël-Neto

Using an approach based on the Casimir operators of the de Sitter group, the conformal invariant equations for a fundamental spin-2 field are obtained, and their consistency discussed. It is shown that, only when the spin-2 field is…

General Relativity and Quantum Cosmology · Physics 2013-08-29 C. S. O. Mayor , G. Otalora , J. G. Pereira

A generalization of the Lagrangian introduced earlier in [2011 {\it J. Phys. G} ${\bf 37}$ 105001] for a classical color spinning particle interacting with background non-Abelian gauge and fermion fields for purpose of considering a change…

High Energy Physics - Theory · Physics 2011-12-12 Yuri A. Markov , Margarita A. Markova , Alexey A. Shishmarev , Alexander N. Vall

We show that the Lagrangian of the free spin-5/2 field in the spinor-tensor representation with the auxiliary spinor field depends on the three arbitrary parameters. The first two parameters are associated with the spin-3/2 and -1/2 sector…

High Energy Physics - Phenomenology · Physics 2014-11-20 V. Shklyar , H. Lenske , U. Mosel

The relativistic Wigner function for spin 1/2 particles is the subject of active research due to diverse applications. However, further progress is hindered by the fabulous complexity of the integro-differential equations of motion. We…

Quantum Physics · Physics 2012-08-23 Renan Cabrera , Denys I. Bondar , Herschel A. Rabitz

We construct a matrix-valued spin-dependent distribution function (MVSD) for massive spin-1/2 fermions and study its properties under Lorentz transformations. Such transformations result in a Wigner rotation in spin space and in a…

Nuclear Theory · Physics 2022-12-21 Xin-Li Sheng , Qun Wang , Dirk H. Rischke

A generalized vector particle theory with the use of an extended set of Lorentz group irredicible representations, including scalar, two 4-vectors, and antisymmetric 2-rang tensor, is investigated. Initial equations depend upon four complex…

High Energy Physics - Theory · Physics 2007-05-23 V. V. Kisel , N. G. Tokarevskaya , A. A. Bogush , V. M. Red'kov

We show that Dirac 4-spinors admit an entirely equivalent formulation in terms of 2-spinors defined over the split-quaternions. In this formalism, a Lorentz transformation is represented as a $2 \times 2$ unitary matrix over the…

General Physics · Physics 2015-02-24 Francesco Antonuccio

The dielectric permeability tensor for spin polarized plasmas derived in terms of the spin-1/2 quantum kinetic model in six-dimensional phase space in Part I of this work is applied for study of spectra of high-frequency transverse and…

Plasma Physics · Physics 2017-03-08 Pavel A. Andreev

We investigate the role played by particular field representations of an intermediate massive spin-1 boson in the context of spin-dependent interparticle potentials between fermionic sources in the limit of low momentum transfer. The…

High Energy Physics - Theory · Physics 2016-07-26 F. A. Gomes Ferreira , P. C. Malta , L. P. R. Ospedal , J. A. Helayël-Neto

We give a brief overview of the kinetic theory for spin-1/2 fermions in Wigner function formulism. The chiral and spin kinetic equations can be derived from equations for Wigner functions. A general Wigner function has 16 components which…

High Energy Physics - Phenomenology · Physics 2021-02-03 Jian-Hua Gao , Zuo-Tang Liang , Qun Wang

We give an informal summary of ongoing work which uses tools distilled from the theory of fibre bundles to classify and connect invariant fields associated with spin motion in storage rings. We mention four major theorems. One ties…

Accelerator Physics · Physics 2016-03-23 Klaus Heinemann , Desmond P. Barber , James A. Ellison , Mathias Vogt

In this paper we describe the transformation properties of quantum entanglement encoded in a pair of spin 1/2 particles described via Dirac bispinors. Due to the intrinsic parity-spin internal structure of the bispinors, the joint state is…

Quantum Physics · Physics 2018-10-04 Victor A. S. V. Bittencourt , Alex E. Bernardini , Massimo Blasone

The spin supplementary conditions are constraints on spin degrees of freedom in classical relativity which restricts physical degrees of freedom to rotations. It is argued that the equivalent constraints in quantum field theory are the…

High Energy Physics - Theory · Physics 2023-07-11 Jung-Wook Kim , Jan Steinhoff