Search results for "electrodynamics"

showing 10 items of 820 documents

Coulomb effects in three-body reactions with two charged particles

1978

We present the details of a novel approach to the treatment of Coulomb effects in atomic and nuclear reactions of the three-body type in which two of the particles are charged. Based on three-body integral equations the formalism allows the practical calculation of elastic, inelastic, rearrangement, and breakup processes with full inclusion of the Coulomb repulsion or attraction in a mathematically correct way. No restrictions need to be made concerning the form of the short-range interactions between the three pairs. A particular virtue of our method lies in the fact that it corroborates, and gives precise meaning to, the intuitively anticipated conception of how to describe such reactions.

PhysicsMany-body problemElastic scatteringNuclear and High Energy PhysicsFaddeev equationsClassical mechanicsQuantum electrodynamicsElectric fieldCoulombInelastic scatteringIntegral equationCharged particlePhysical Review C
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Random polarisations of the dipoles

2012

We extend the dipole formalism for massless and massive partons to random polarisations of the external partons. The dipole formalism was originally formulated for spin-summed matrix elements and later extended to individual helicity eigenstates. For efficiency reasons one wants to replace the spin sum by a smooth integration over additional variables. This requires the extension of the dipole formalism to random polarisations. In this paper we derive the modified subtraction terms. We only modify the real subtraction terms, the integrated subtraction terms do not require any modifications.

PhysicsMassless particleNuclear and High Energy PhysicsFormalism (philosophy of mathematics)DipoleHigh Energy Physics - PhenomenologyHigh Energy Physics - Phenomenology (hep-ph)Quantum electrodynamicsSubtractionFOS: Physical sciencesPartonHelicityEigenvalues and eigenvectors
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O(αs)corrections to the correlator of finite mass baryon currents

2000

We present analytical next-to-leading order results for the correlator of baryonic currents at the three-loop level with one finite mass quark. We obtain the massless and the HQET limit of the correlator from the general formula as particular cases. We also give explicit expressions for the moments of the spectral density.

PhysicsMassless particleQuantum chromodynamicsBaryonQuarkNuclear and High Energy PhysicsParticle physicsQuantum electrodynamicsHigh Energy Physics::PhenomenologyHyperonSpectral densityLimit (mathematics)Spectral methodPhysical Review D
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Solution of self-consistent equations for the N3LO nuclear energy density functional in spherical symmetry. The program hosphe (v1.02)

2010

Abstract We present solution of self-consistent equations for the N 3 LO nuclear energy density functional. We derive general expressions for the mean fields expressed as differential operators depending on densities and for the densities expressed in terms of derivatives of wave functions. These expressions are then specified to the case of spherical symmetry. We also present the computer program hosphe (v1.02), which solves the self-consistent equations by using the expansion of single-particle wave functions on the spherical harmonic oscillator basis. Program summary Program title: HOSPHE (v1.02) Catalogue identifier: AEGK_v1_0 Program summary URL: http://cpc.cs.qub.ac.uk/summaries/AEGK_…

PhysicsMathematical analysisGeneral Physics and AstronomySpherical harmonicsCPU timeDifferential operatorsymbols.namesakeHardware and ArchitectureQuantum electrodynamicsSelf-consistent mean fieldsymbolsNeutronCircular symmetryWave functionHamiltonian (quantum mechanics)Computer Physics Communications
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Dissipative soliton interactions inside a fiber laser cavity

2005

We report our recent numerical and experimental observations of dissipative soliton interactions inside a fiber laser cavity. A bound state, formed from two pulses, may have a group velocity which differs from that of a single soliton. As a result, they can collide inside the cavity. This results in a variety of outcomes. Numerical simulations are based either on a continuous model or on a parameter-managed model of the cubic-quintic Ginzburg-Landau equation. Each of the models provides explanations for our experimental observations. © 2005 Elsevier Inc. All rights reserved.

PhysicsMathematical modelContinuous modellingNumerical analysisAtomic and Molecular Physics and OpticsElectronic Optical and Magnetic Materialslaw.inventionDissipative solitonClassical mechanicsControl and Systems EngineeringlawQuantum electrodynamicsOptical cavityBound stateGroup velocitySolitonElectrical and Electronic EngineeringNonlinear Sciences::Pattern Formation and SolitonsInstrumentationOptical Fiber Technology
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Maximum Principle and Application to Nuclear Magnetic Resonance and Magnetic Resonance Imaging

2018

In this section we state the Pontryagin maximum principle and we outline the proof. We adopt the presentation from Lee and Markus [64] where the result is presented into two theorems.

PhysicsMaximum principlemedicine.diagnostic_testSection (archaeology)Quantum electrodynamicsmedicineMagnetic resonance imagingState (functional analysis)Pontryagin's minimum principle
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A Coherent Master Equation for active mode locking in lasers

2015

We present the derivation of a new master equation for active mode locking in lasers that fully takes into account the coherent effects of the light matter interaction through a peculiar adiabatic elimination technique. The coherent effects included in our model could be relevant to describe properly mode-locked semiconductor lasers where the standard Haus’ Master Equation predictions show some discrepancy with respect to the experimental results and can be included in the modelling of other mode locking techniques too.

PhysicsMaxwell-Bloch equationsmode lockingcoherent effects in mode locking; Maxwell-Bloch equations; mode locking; semiconductor lasers;Active modesemiconductor lasersLaserSemiconductor laser theorylaw.inventionMode-lockingcoherent effects in mode lockingModulationlawQuantum mechanicsElectric fieldQuantum electrodynamicsMaster equationAdiabatic process
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QQ-onia package: a numerical solution to the Schrodinger radial equation for heavy quarkonium

2008

30 pages, 3 figures.-- ISI article identifier:000265158700009.-- ArXiv pre-print avaible at: http://arxiv.org/abs/0805.2704

PhysicsMesonbusiness.industrySpectrum (functional analysis)High Energy Physics::PhenomenologyFOS: Physical sciencesGeneral Physics and AstronomyFísicaQuarkoniumSquare (algebra)High Energy Physics - Phenomenologysymbols.namesakeHigh Energy Physics - Phenomenology (hep-ph)SoftwareHardware and ArchitectureSimple (abstract algebra)Quantum electrodynamicsWave function at the originHeavy quarkonium potentialsymbolsbusinessSchrödinger's catSpin-½
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Quantum Stochastic Resonance in a Micromaser

1998

We demonstrate that quantum stochastic resonance allows for the noise-controlled synchronization of quantum jumps between the metastable states of the quantized radiation field in a micromaser. Under readily accessible experimental conditions optimal synchronization is achieved at a finite temperature $T\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}500\mathrm{mK}$ of the environment.

PhysicsMetastabilityQuantum mechanicsRadiation fieldQuantum electrodynamicsSynchronization (computer science)General Physics and AstronomyStochastic resonance (sensory neurobiology)QuantumImaging phantomPhysical Review Letters
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On the momentum dependence ofJ/? suppression

1988

The formation of deconfined matter in high energy collisions is expected to result in reducedJ/ψ production. The finite space-time extension of any quark-gluon plasma thus produced leads to a rather characteristic dependence ofJ/ψ suppression on the longitudinal and transverse momentum of theJ/ψ. We study in particular the longitudinal momentum dependence and discuss its implications for nuclear collision experiments.

PhysicsMomentumNuclear physicsHigh energyNuclear collisionPhysics and Astronomy (miscellaneous)High Energy Physics::LatticeQuantum electrodynamicsTransverse momentumPlasmaNuclear ExperimentEngineering (miscellaneous)Zeitschrift f�r Physik C Particles and Fields
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