Search results for "Particle physics"
showing 10 items of 6826 documents
Resonance Dipole-Dipole Interaction Between Two Accelerated Atoms in the Presence of a Reflecting Plane Boundary
2018
We study the resonant dipole-dipole interaction energy between two uniformly accelerated identical atoms, one excited and the other in the ground state, prepared in a correlated {\em Bell-type} state, and interacting with the scalar field or the electromagnetic field nearby a perfectly reflecting plate. We suppose the two atoms moving with the same uniform acceleration, parallel to the plane boundary, and that their separation is constant during the motion. We separate the contributions of vacuum fluctuations and radiation reaction field to the resonance energy shift of the two-atom system, and show that Unruh thermal fluctuations do not affect the resonance interaction, which is exclusivel…
Multicenter solutions in Eddington-inspired Born-Infeld gravity
2020
We find multicenter (Majumdar-Papapetrou type) solutions of Eddington-inspired Born-Infeld gravity coupled to electromagnetic fields governed by a Born-Infeld-like Lagrangian. We construct the general solution for an arbitrary number of centers in equilibrium and then discuss the properties of their one-particle configurations, including the existence of bounces and the regularity (geodesic completeness) of these spacetimes. Our method can be used to construct multicenter solutions in other theories of gravity.
Van der Waals and resonance interactions between accelerated atoms in vacuum and the Unruh effect
2017
We discuss different physical effects related to the uniform acceleration of atoms in vacuum, in the framework of quantum electrodynamics. We first investigate the van der Waals/Casimir-Polder dispersion and resonance interactions between two uniformly accelerated atoms in vacuum. We show that the atomic acceleration significantly affects the van der Waals force, yielding a different scaling of the interaction with the interatomic distance and an explicit time dependence of the interaction energy. We argue how these results could allow for an indirect detection of the Unruh effect through dispersion interactions between atoms. We then consider the resonance interaction between two accelerat…
Motion of an electric charge in a terrestrial laboratory.
1995
The equation of motion for a charge in an electromagnetic field is written in the Fermi coordinates of an observer moving with a constant acceleration g=9.8 m/${\mathrm{s}}^{2}$ (${10}^{\mathrm{\ensuremath{-}}18}$ ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$ in units such that c=1). This is involved in the equation of motion not only as a Newtonian term g\ensuremath{\rightarrow}, but also as a relativistic correction of the form ``-2(g\ensuremath{\rightarrow}\ensuremath{\cdot}v\ensuremath{\rightarrow})v\ensuremath{\rightarrow}.'' We have studied the effect of this term under the conditions of an accelerator of particles. To this end, we have considered a constant and uniform magnetic field, a…
Virtual Compton Scattering and polarizabilities
1999
Abstract Virtual Compton Scattering (VCS) off the proton below pion threshold allows access to generalized polarizabilities of the proton. These observables measure the response of the nucleon to low energy electromagnetic field perturbations. This paper presents a comparison with Real Compton Scattering and also results for the first dedicated VCS experiment performed at the Mainz Microtron MAMI with high resolution spectrometers at Q2 = 0.33 GeV2.
Long-range potentials and electromagnetic polarizabilities
1976
The long-range spin and velocity independent forces of electromagnetic origin which act between any two systems are studied for those cases in which no forces of this type exist to order e 2 . It is shown that they are uniquely determined by the charge, magnetic moment, and polarizabilities of both systems, not only to the dominant order r − n , but also to the next one r −( n +1) . These potentials provide the link between Compton scattering polarizabilities (response to real photons) and classically defined polarizabilities (response to static electromagnetic field). The two definitions are shown to be equivalent for neutral spinless systems; the problems arising for a neutral particle wi…
On the Mechanism of Low Frequency Bioelectromagnetism
2008
Results of investigations using simple physical models were presented. It is shown that physically exist small models that intensified low frequency electromagnetic field (EM). There are individual modes with definite symmetry. In the model cases we need some small background field for generations but in biological systems maybe there is some stabilizations factor. Experimental results and their biophysical aspects were discussed.
Vacuum fluctuations and radiation reaction contributions to the resonance dipole-dipole interaction between two atoms near a reflecting boundary
2018
We investigate the resonance dipole-dipole interaction energy between two identical atoms, one in the ground state and the other in the excited state, interacting with the electromagnetic field in the presence of a perfectly reflecting plane boundary. The atoms are prepared in a correlated (symmetric or anti-symmetric) Bell-type state. Following a procedure due to Dalibard et. al. [J. Dalibard et. al., J. Phys. (Paris) {\bf 43}, 1617 (1982); {\bf 45}, 637 (1984)], we separate the contributions of vacuum fluctuations and radiation reaction (source) field to the resonance interaction energy between the two atoms, and show that only the source field contributes to the interatomic interaction, …
Compton Scattering Program Studying Nucleon Polarizabilities
2017
The A2 collaboration at the Mainz Microtron has undertaken a program of Compton scattering experiments with the goal of extracting the proton and, in the future, neutron polarizabilities. These are fundamental parameters that describe the response of the nucleon to an electromagnetic field. An extraction of these parameters will provide a crucial test of QCD theories. This talk presented the concept and status of this program, including some preliminary results.
First operation of the superconducting Darmstadt linear electron accelerator as an energy recovery linac
2020
The superconducting Darmstadt linear electron accelerator (S-DALINAC) has been operated as an energy recovery linac (ERL) for the first time. The S-DALINAC is a recirculating superconducting radio-frequency (SRF) accelerator and had been upgraded with an additional recirculation beamline. It features a path length adjustment system that provides a freedom of choice of 360\ifmmode^\circ\else\textdegree\fi{} for the rf phase difference between the electron bunches recirculated through the new beamline and the phase of the accelerating ${\mathrm{TM}}_{010}$ mode of the oscillating electromagnetic field in the SRF cavities of the accelerator. A choice of around 180\ifmmode^\circ\else\textdegree…