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Showing 1 to 20 of 40 for “"self-energy"”.
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Massive quark self-energy in cavity QCD
The greatest obstacle in calculating the self-energy Feynman diagram is that it is, in principle, linearly divergent. So far the self-energy of a massive quark in cavity quantum chromodynamics has only been calculated for the lowest cavity mode ls1/2. The methods used so far, have been based on the …
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The gluon self-energy in cavity quantum chromodynamics
… In this cavity regularization method, the energy shift is expressed as the integral of a divergent spectral function, from which the divergence may be extracted by analogy to the free space expression. It is shown for the case of the self-energy of a gluon in a cavity that no new …
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Improving the Dispersive Optical Model toward a Dispersive Self-energy Method
… optical potential and the irreducible nucleon self-energy from Green's function theory is improved, providing a tighter link between nuclear reactions and nuclear structure. In particular, since the self-energy is inherently nonlocal, an explicitly nonlocal term is incorporated in the real part …
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The weakly coupled polaron
… and the phonon-cross-exchange diagrams in the self-energy, a vertex correction has been made to the lowest order diagram. The real part and the imaginary part of the self-energy are obtained. The dispersion relationship obtained by this approximation gives the ground state energy which is lower …
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Feynman Diagram Models of Daughter Regge Trajectories
… and a generalized model that includes propagator self-energy insertions are considered. It is found that, in the simple model, the second boson daughter and the first fermion daughter are fixed (as a function of the squared momentum transfer t or u) double poles in complex J-plane. When …
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Transport theory for scalar quarks and gluons
… for a theory of scalar quarks and gluons with self-interactions. Special care has been taken in particular in understanding how the transport equation, taken on its own, leads to a Boltzmann-like equation when considered in the quasiparticle approximation. Through the analysis of all …
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On the dynamic structure factor for the electron gas
… transfer case (q > qc). We proved that the self-energy correction appearing in the pertinent Green functions of S(q,q0 ) vanishes. Those theoretical results indicate that the first peak in the fine structure of S(q,q 0 ) observed in experiments for large q (~ 1.5 qf) neither comes from a …
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Infrared absorption by localized polarons in the silver halides
… illumination of the crystals with light whose energy exceeded the indirect band gap, was measured from 33 to 2000 cm-1 at temperatures from. 90 K to 40 0 K. The induced far infrared absorption was shown to be in agreement with the predictions of an extension of the theory of Buimistrov and …
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Electron tunneling into superconducting mercury films below one degree Kelvin
… The effective phonon spectrum and the complex energy gap function for mercury are thereby derived. Values for the electron self energy function, the electron renormalization function, Coulomb pseudopotentia1, and the electron-phonon interaction constant are also determined.
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The anomalous magnetic moment of baryons in cavity QCD
… with the new divergences this brings into the self-energy insert diagrams. The results of this work show that no improvement on the simple SU(3) model is made by including these corrections. These calculations point to a smaller value of αs than that which is usually used.
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Pion electromagnetic form factor in the Kroll-Lee-Zumino model at zero and finite temperature
… data. A calculation of the vertex and self energy functions in the Matsubara formalism at finite temperature do not agree with the results of the Gale & Kapusta calculations. The resulting prediction for the radius is found to increase with temperature, consistent vith ideas about …
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Transceiver design for wireless energy harvesting cooperative networks
In this thesis, the RF energy harvesting technique is studied in the cooperative wireless network, and different optimization studies are investigated. First, an energy-efficient optimization is considered in the cooperative system with the time switching relaying and power splitting relaying …
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Generalization of the BTK Theory to the Case of Finite Quasiparticle Lifetimes
… the interactions. For this purpose, appropriate self-energy expressions and wave functions are inserted into the strong coupling version of the Bogoliubov equations and subsequently, the coherence factors are computed. By applying the suitable boundary conditions to the case of a …
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Feynman-Dyson perturbation theory applied to model linear polyenes
… the inclusion of time-independent second-order self-energy insertions. The results of calculations on polyenes show that consideration of this approach is warranted, as the contribution of the second- order terms is significant. The computer program, written during the course of the research …
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Raman Scattering From the Superconductor Niobium-Diselenide
… one each of A and E symmetry. These are close in energy to the energy gap 2(DELTA), as measured by far infrared transmission. The Raman activity of the gap excitations is believed to be caused by coupling to the Raman active CDW phonon modes. Such coupling is shown directly by the changes in the …
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Electroweak Calculations In The Presence Of Nonperturbative Qcd Effects
… component of the QCD nonperturbative quark self-energy is calculated, leading to a gauge independent dynamical component for the quark mass.;Insertion of this nonperturbative order parameter into lowest-order electroweak quark self-energies is shown to satisfy on-mass-shell gauge parameter …
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Power-law liquid in high-temperature superconductors
… liquid, a state of matter with a power-law self-energy $\Sigma^{\pr\pr}\sim(\omega^{2}+\pi^{2}T^{2})^{\alpha}$. The scaling exponent decreases from $\alpha\sim1$ in the overdoped Fermi-liquid state to $\alpha\lesssim\frac{1}{2}$ in the optimal and underdoped regime. We find that broad scale …
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A microscopic theory of tunneling
… interactions appear in this formalism as self-energy corrections to the extended-basis electronic wave functions, The position of the impurity relative to the junction-region determines both the sign and magnitude of these corrections, Therefore, the asymmetries in the tunnel …
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Ab initio calculations of phonon properties and spectra in condensed matter
… factors, phonon contributions the electron self–energy and spectral function, vibrational free energy, thermal expansion, and heat capacity.
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