scholarly journals ELKO and Dirac spinors seen from torsion

2014 ◽  
Vol 23 (14) ◽  
pp. 1444001 ◽  
Author(s):  
Luca Fabbri ◽  
Stefano Vignolo
Keyword(s):  
Particle Physics ◽  
Point Of View ◽  
Dirac Spinor ◽  
Spinor Fields ◽  
Algebraic Properties ◽  
Geometrical Character ◽  
Dynamical Features ◽  
Dirac Spinors

In this paper, the recently-introduced ELKO and the well-known Dirac spinor fields will be compared. However, instead of comparing them under the point of view of their algebraic properties or their dynamical features, we will proceed by investigating the analogies and similarities in terms of their geometrical character viewed from the perspective of torsion. The paper will be concluded by sketching some consequences for the application to cosmology and particle physics.

scholarly journals Geometry, Zitterbewegung, quantization

2019 ◽  
Vol 16 (09) ◽  
pp. 1950146 ◽  
Author(s):  
Luca Fabbri
Keyword(s):  
Explicit Form ◽  
Dirac Spinor ◽  
Internal Dynamics ◽  
Spinor Fields ◽  
Field Quantization ◽  
The Way

In the most general geometric background, we study the Dirac spinor fields with particular emphasis given to the explicit form of their gauge momentum and the way in which this can be inverted so as to give the expression of the corresponding velocity; we study how Zitterbewegung affects the motion of particles, focusing on the internal dynamics involving the chiral parts; we discuss the connections to field quantization, sketching in what way anomalous terms may be gotten eventually.

scholarly journals Neutrinoless Double-Beta Decay

2012 ◽  
Vol 2012 ◽  
pp. 1-38 ◽  
Author(s):  
Andrea Giuliani ◽  
Alfredo Poves
Keyword(s):  
Beta Decay ◽  
Particle Physics ◽  
Nuclear Physics ◽  
Experimental Situation ◽  
Neutrinoless Double Beta Decay ◽  
Majorana Neutrino ◽  
Double Beta Decay ◽  
Point Of View ◽  
The Status ◽  
Majorana Neutrino Mass

This paper introduces the neutrinoless double-beta decay (the rarest nuclear weak process) and describes the status of the research for this transition, both from the point of view of theoretical nuclear physics and in terms of the present and future experimental scenarios. Implications of this phenomenon on crucial aspects of particle physics are briefly discussed. The calculations of the nuclear matrix elements in case of mass mechanisms are reviewed, and a range for these quantities is proposed for the most appealing candidates. After introducing general experimental concepts—such as the choice of the best candidates, the different proposed technological approaches, and the sensitivity—we make the point on the experimental situation. Searches running or in preparation are described, providing an organic presentation which picks up similarities and differences. A critical comparison of the adopted technologies and of their physics reach (in terms of sensitivity to the effective Majorana neutrino mass) is performed. As a conclusion, we try to envisage what we expect round the corner and at a longer time scale.

Quantum numbers for Dirac spinor fields on a curved space-time

1979 ◽  
Vol 20 (2) ◽  
pp. 409-413 ◽  
Author(s):  
R. G. McLenaghan ◽  
Ph. Spindel
Keyword(s):  
Space Time ◽  
Dirac Spinor ◽  
Curved Space ◽  
Spinor Fields ◽  
Quantum Numbers

scholarly journals FROM DIRAC ACTION TO ELKO ACTION

2009 ◽  
Vol 24 (16n17) ◽  
pp. 3227-3242 ◽  
Author(s):  
J. M. HOFF DA SILVA ◽  
ROLDÃO DA ROCHA
Keyword(s):  
Dark Matter ◽  
Standard Model ◽  
Natural Extension ◽  
Dirac Spinor ◽  
Spinor Fields ◽  
The Standard Model ◽  
Mass Dimension ◽  
Fermionic Fields ◽  
Elko Spinor Fields ◽  
First Time

A fundamental action, representing a mass dimension-transmuting operator between Dirac and ELKO spinor fields, is performed on the Dirac Lagrangian, in order to lead it into the ELKO Lagrangian. Such a dynamical transformation can be seen as a natural extension of the Standard Model that incorporates dark matter fields. The action of the mass dimension-transmuting operator on a Dirac spinor field, that defines and introduces such a mapping, is shown to be a composition of the Dirac operator and the nonunitary transformation that maps Dirac spinor fields into ELKO spinor fields, defined in J. Math. Phys.48, 123517 (2007). This paper gives allowance for ELKO, as a candidate to describe dark matter, to be incorporated in the Standard Model. It is intended to present for the first time, up to our knowledge, the dynamical character of a mapping between Dirac and ELKO spinor fields, transmuting the mass dimension of spin one-half fermionic fields from 3/2 to 1 and from 1 to 3/2.

scholarly journals The No Alternatives Argument

2019 ◽  
pp. 67-80
Author(s):  
Jan Sprenger ◽  
Stephan Hartmann
Keyword(s):  
Empirical Evidence ◽  
Particle Physics ◽  
Scientific Theory ◽  
Point Of View ◽  
Scientific Theories ◽  
Empirical Theory ◽  
Degree Of Belief ◽  
Feasible Alternative ◽  
Theory Confirmation ◽  
Degree Of Confirmation

Convincing scientific theories are often hard to find, especially when empirical evidence is scarce (e.g., in particle physics). Once scientists have found a theory, they often believe that there are not many distinct alternatives to it. Is this belief justified? We model how the failure to find a feasible alternative can increase the degree of belief in a scientific theory—in other words, we establish the validity of the No Alternatives Argument and the possibility of non-empirical theory confirmation from a Bayesian point of view. Then we evaluate scope and limits of this argument (e.g., by calculating the degree of confirmation it provides) and relate it to other argument forms such as Inference to the Best Explanation (IBE) or “There is No Alternative” (TINA).

scholarly journals ELKO SPINOR FIELDS: LAGRANGIANS FOR GRAVITY DERIVED FROM SUPERGRAVITY

2009 ◽  
Vol 06 (03) ◽  
pp. 461-477 ◽  
Author(s):  
ROLDÃO DA ROCHA ◽  
J. M. HOFF DA SILVA
Keyword(s):  
Spinor Field ◽  
Sufficient Conditions ◽  
Dirac Spinor ◽  
Weyl Spinor ◽  
Conjugation Operator ◽  
Spinor Fields ◽  
Mass Dimension ◽  
Majorana Spinor ◽  
Dimension One ◽  
Elko Spinor Fields

Dual-helicity eigenspinors of the charge conjugation operator (ELKO spinor fields) belong — together with Majorana spinor fields — to a wider class of spinor fields, the so-called flagpole spinor fields, corresponding to the class-(5), according to Lounesto spinor field classification based on the relations and values taken by their associated bilinear covariants. There exists only six such disjoint classes: the first three corresponding to Dirac spinor fields, and the other three respectively corresponding to flagpole, flag-dipole and Weyl spinor fields. Using the mapping from ELKO spinor fields to the three classes Dirac spinor fields, it is shown that the Einstein–Hilbert, the Einstein–Palatini, and the Holst actions can be derived from the Quadratic Spinor Lagrangian (QSL), as the prime Lagrangian for supergravity. The Holst action is related to the Ashtekar's quantum gravity formulation. To each one of these classes, there corresponds a unique kind of action for a covariant gravity theory. Furthermore we consider the necessary and sufficient conditions to map Dirac spinor fields (DSFs) to ELKO, in order to naturally extend the Standard Model to spinor fields possessing mass dimension one. As ELKO is a prime candidate to describe dark matter and can be obtained from the DSFs, via a mapping explicitly constructed that does not preserve spinor field classes, we prove that — in particular — the Einstein–Hilbert, Einstein–Palatini, and Holst actions can be derived from the QSL, as a fundamental Lagrangian for supergravity, via ELKO spinor fields. The geometric meaning of the mass dimension-transmuting operator — leading ELKO Lagrangian into the Dirac Lagrangian — is also pointed out, together with its relationship to the instanton Hopf fibration.

Gravitational interactions in the Dirac spinor fields and possible structure of local space-time of fermions

2021 ◽  
pp. 129-135
Author(s):  
V.G. Krechet ◽  
◽  
V.B. Oshurko ◽  
A.E. Baidin ◽  
◽  
...  
Keyword(s):  
General Relativity ◽  
Magnetic Moment ◽  
Spinor Field ◽  
Space Time ◽  
Spin Interaction ◽  
Internal Space ◽  
Dirac Spinor ◽  
Geometric Properties ◽  
Spinor Fields ◽  
Local Space

In the framework of general relativity, possible effects of the gravitational interactions in the Dirac spinor field are considered. It is shown that these interactions manifest locally as contact spin-spin interaction of the gravitational and spinor fields. This interaction leads to the classical rotation of particles with spin ħ /2. As a result, it leads to appearance of local internal space-time with specific geometric properties for each particle. New effect of an increase of the mass of spinor particles due to this interaction is found. Also, an explanation of the existence of a magnetic moment in Dirac spinor particles as a result of a local electro-spin-spin interaction has been proposed.

First steps in classical field theory

2021 ◽  
pp. 435-448
Author(s):  
Andrew M. Steane
Keyword(s):  
Field Theory ◽  
Yukawa Potential ◽  
Classical Field Theory ◽  
Classical Field ◽  
Dirac Spinor ◽  
Dirac Equations ◽  
Flat Spacetime ◽  
Spinor Fields ◽  
The Relationship ◽  
Conserved Currents

Classical field theory, as it is applied to the most simple scalar, vector and spinor fields in flat spacetime, is described. The Klein-Gordan, Weyl and Dirac equations are obtained, and some features of their solutions are discussed. The Yukawa potential, the plane wave solutions, and the conserved currents are obtained. Spinors are introduced, both through physical pictures (flagpole and flag) and algebraic defintions (complex vectors). The relationship between spinors and four-vectors is given, and related to the Lie groups SU(2) and SO(3). The Dirac spinor is introduced.

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