scholarly journals The Self-Energy of the Electron and the Mass Difference of Nucleons

1949 ◽  
Vol 2 (1) ◽  
pp. 30-31 ◽  
Author(s):  
S. Sakata ◽  
O. Hara
Keyword(s):  
Mass Difference ◽  
The Self ◽  
Self Energy

ON THE POSSIBLE EXISTENCE OF A DERIVATIVE COUPLING IN QUANTUM ELECTRODYNAMICS

1959 ◽  
Vol 37 (12) ◽  
pp. 1339-1343
Author(s):  
F. A. Kaempffer
Keyword(s):  
Cross Section ◽  
Quantum Electrodynamics ◽  
Mass Difference ◽  
Large Mass ◽  
The Self ◽  
Nucleon Mass ◽  
Muon Scattering ◽  
Derivative Coupling ◽  
Self Energy ◽  
Classical Analogue

Within the framework of quantum electrodynamics there exists the possibility of a derivative coupling between source and photon field, referred to as eΛ-charge, which has no classical analogue. For calculations the usual graph technique can be used, provided the factor eγμ contributed by each vertex in a conventional graph is replaced by ieΛkμ, where Λ is a length characteristic of the new interaction. Using as cutoff the nucleon mass M one finds for a bare source of electronic mass m the self-energy in second order to be Λm/m ≈ 200, if Λ−1 ≈ 60 M. It is argued that the large mass difference between muon and electron may be due to this effect, assuming muon and electron to differ only in that the muon has eΛ-charge whereas the electron has not. An estimate is made of the muon–muon scattering cross section caused by the presence of eΛ-charge on the muon, and it is found that the existence of this derivative coupling may have escaped observation.

STRONG SU(2) BREAKING AND MASS SPLITTINGS IN PSEUDOSCALAR MESONS

1996 ◽  
Vol 11 (29) ◽  
pp. 5245-5259 ◽  
Author(s):  
A. N. MITRA
Keyword(s):  
Mass Difference ◽  
Dynamical Symmetry ◽  
Quark Condensate ◽  
Low Energy ◽  
The Self ◽  
Quark Loop ◽  
Self Energy ◽  
A Value ◽  
Pseudoscalar Mesons ◽  
Vector Exchange

The mass splittings within the SU(2) multiplets of pseudoscalar mesons (π, K, D, B) are used as a laboratory to determine the mass difference between d and u quarks (current), through the simplest (two-point) quark-loop diagrams for the self-energies of the corresponding hadrons, together with the associated quark-condensate diagrams within the loops. The second-order e.m. correction is also calculated with a photon line joining the two opposite quark lines in the self-energy loop. The basic ingredient is a hadron–quark-vertex function generated from a vector-exchange-like (chirally invariant) four-fermion Lagrangian (with current quarks) under dynamical symmetry breaking (DχSB), precalibrated to spectroscopy and other important low-energy amplitudes. The results which are expressed as proportional to the u−d mass difference δc, but are otherwise free from any adjustable parameters, reproduce in a rather accurate way all the SU(2) mass differences (from kaon to bottom) with δc = 4.0 MeV, when all the three self-energy diagrams are included. The pion receives only e.m. contributions with a value 5.24 MeV.

scholarly journals Opacity from Loops in AdS

2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Alexandria Costantino ◽  
Sylvain Fichet
Keyword(s):  
Imaginary Part ◽  
Quantum Dynamics ◽  
Model Building ◽  
Asymptotic Properties ◽  
The Self ◽  
Effective Theory ◽  
Self Energy ◽  
Higher Dimensional ◽  
Timelike Region ◽  
Spectral Representations

Abstract We investigate how quantum dynamics affects the propagation of a scalar field in Lorentzian AdS. We work in momentum space, in which the propagator admits two spectral representations (denoted “conformal” and “momentum”) in addition to a closed-form one, and all have a simple split structure. Focusing on scalar bubbles, we compute the imaginary part of the self-energy ImΠ in the three representations, which involves the evaluation of seemingly very different objects. We explicitly prove their equivalence in any dimension, and derive some elementary and asymptotic properties of ImΠ.Using a WKB-like approach in the timelike region, we evaluate the propagator dressed with the imaginary part of the self-energy. We find that the dressing from loops exponentially dampens the propagator when one of the endpoints is in the IR region, rendering this region opaque to propagation. This suppression may have implications for field-theoretical model-building in AdS. We argue that in the effective theory (EFT) paradigm, opacity of the IR region induced by higher dimensional operators censors the region of EFT breakdown. This confirms earlier expectations from the literature. Specializing to AdS5, we determine a universal contribution to opacity from gravity.

scholarly journals Classical gravitational self-energy from double copy

2020 ◽  
Vol 2020 (11) ◽  
Author(s):  
Gabriel Luz Almeida ◽  
Stefano Foffa ◽  
Riccardo Sturani
Keyword(s):  
Gravitational Field ◽  
Binary System ◽  
The Self ◽  
Gravitational Coupling ◽  
Leading Order ◽  
Body System ◽  
Self Energy ◽  
Composite Systems ◽  
Body Dynamics ◽  
Double Copy

Abstract We apply the classical double copy to the calculation of self-energy of composite systems with multipolar coupling to gravitational field, obtaining next-to-leading order results in the gravitational coupling GN by generalizing color to kinematics replacement rules known in literature. When applied to the multipolar description of the two-body system, the self-energy diagrams studied in this work correspond to tail processes, whose physical interpretation is of radiation being emitted by the non-relativistic source, scattered by the curvature generated by the binary system and then re-absorbed by the same source. These processes contribute to the conservative two-body dynamics and the present work represents a decisive step towards the systematic use of double copy within the multipolar post-Minkowskian expansion.

scholarly journals The self-energy of a confined quark

1983 ◽  
Vol 131 (4-6) ◽  
pp. 445-449 ◽  
Author(s):  
S. Goldhaber ◽  
T.H. Hansson ◽  
R.L. Jaffe
Keyword(s):  
The Self ◽  
Self Energy

A NEW HAMILTONIAN OF INTERACTION FOR FERMIONS

2005 ◽  
Vol 19 (13n14) ◽  
pp. 669-681 ◽  
Author(s):  
ANDREI DOLOCAN ◽  
VOICU OCTAVIAN DOLOCAN ◽  
VOICU DOLOCAN
Keyword(s):  
Interaction Energy ◽  
The Self ◽  
Lagrangian Formalism ◽  
Expectation Values ◽  
Boson System ◽  
Self Energy ◽  
Fermion Gas

Using the Lagrangian formalism we attempt to introduce a new Hamiltonian for fermions. On this basis we have evaluated the expectation values for the interaction energy between fermions via bosons. The interaction energy between two fermions via phonons becomes attractive in a degenerate fermion-gas. The interaction energy between two fermions via photons appears to be attractive in certain conditions. The self-energy of the fermion + boson system, e.g. polaron and polariton, was evaluated.

THEORY OF THE INTERACTION BETWEEN THE LATTICE VIBRATIONS AND THE ROTATIONAL MOTION IN SOLID HYDROGEN

1966 ◽  
Vol 44 (2) ◽  
pp. 313-335 ◽  
Author(s):  
J. Van Kranendonk ◽  
V. F. Sears
Keyword(s):  
Rotational Motion ◽  
Zero Point ◽  
Solid Hydrogen ◽  
The Self ◽  
Intermolecular Potential ◽  
Lattice Vibrations ◽  
Energy Effect ◽  
Self Energy ◽  
Blowing Up ◽  
Point Lattice

The effects of the interaction between the rotational motion of the molecules in solid hydrogen and the lattice vibrations, resulting from the anisotropic van der Waals forces, have been investigated theoretically. For the radial part of the anisotropic intermolecular potential an exp–6 model has been adopted. First, the effect of the lattice vibrations, and of the anistropic blowing up of the crystal by the zero-point lattice vibrations, is discussed. The effective anisotropic interaction resulting from averaging the instantaneous interaction over the lattice vibrations is calculated by assuming a Gaussian distribution for the modulation of the relative intermolecular separations by the lattice vibrations. Secondly, the displacement of the rotational levels due to the self-energy of the molecules in the lattice is calculated both classically and quantum mechanically, and the resulting shifts in the frequencies of the rotational transitions in solid hydrogen are given. Finally, the splitting of the rotational levels due to the anisotropy of the self-energy effect is calculated. The theory is applied to the calculation of the asymmetry of the S0(0) triplet in the rotational Raman spectrum of solid parahydrogen, and of the specific heat anomaly in solid hydrogen at low ortho-concentrations.

Sign in / Sign up

Export Citation Format

Share Document