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Showing 1 to 17 of 17 for “"Feynman diagrams"”.
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Two-gluon exchange graphs in cavity QCD to order αs2
… and to evaluate the two-gluon exchange diagrams, which are second order in as. Two distinct Feynman diagrams exist, of which each consists of twenty-four timeordered diagrams. All the possible time-ordered diagrams are calculated here. A similar calculation of only the first six …
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Perturbative quantum chromodynamics in a cavity
… 4th order perturbation theory we calculate the Feynman diagrams corresponding to configuration mixing-and two gluon annihilation. The results are inserted into the MIT bag model and compared with hadron spectra.
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Symbolic computation of electron-proton to slepton-squark scattering cross sections based on a left-right supersymmetric extension of the standard model
… of the standard model is presented. The Feynman diagrams for the neutralino-quark-squark and chargino-quark-squark are written down, and the production of sleptons and squarks resulting from the t-channel exchange of neutralinos and charginos in electron-proton scattering is analyzed. The …
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Canonical quantization and quantum chromodynamics in a cavity
… Based on this formalism, we calculate, in the Feynman gauge, all non-divergent Feynman diagrams of second order in the strong coupling constant g. Explicit values of the matrix elements are given for low-lying quark and gluon cavity modes.
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Perturbative QCD in exclusive processes
… that symbolically generates and evaluates all Feynman diagrams required for scattering amplitude for exclusive processes is tested, corrected, extended, and brought to operational status. The sensitivity of perturbative QCD predictions for the nucleon form factors, ψ → pp̅, and 𝛾𝛾 → pp̅, to the …
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Hadronic productions of a Higgs boson in association with two jets at next-to-leading order
… and the four-gluon φ-MHV amplitude using Feynman diagrams. For the φ-MHV amplitude we also use the unitarity-boostrap method to calculate the rational pieces. We then implement these, and analytic results from previous calculations, into MCFM. Using this program we are able to perform some …
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Finite-temperature quantum field theory and the structure functions of the nucleon
… in the propagation of particles when considering Feynman diagrams containing internal lines in next-to-leading-order calculations. These features are incorporated through the use of Fermi-Dirac and Bose-Einstein distributions for quarks and gluons, respectively. Stimulated emission factors for …
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Renormalization of cavity field theories
A major obstacle to calculating Feynman diagrams in field theories, confined to a cavity, has always been the divergent loop diagrams. So far, only the quantum chromodynamic and electrodynamic self-energies of a ls1/2 quark, confined to a static spherical cavity, have been accurately calculated. …
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A multireference coupled-cluster method using a single-reference formalism.
… (CCSDTQ) are qraphically derived using Feynman diagrams. These equations are programmed and an iterative reduced linear equation method is used to solve these equations. A few points on the potential curves for the dissociation of some model systems with a single bond (LiH and Li₂) are …
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The (Semi-)Classical Vibrational Echo
… analogs of quantum mechanical double-sided Feynman diagrams. We have investigated the role of resonant coupling on the quantum mechanical vibrational echo at zero temperature and have analytically taken the classical limit of this expression to investigate the effect of resonance on …
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Aspects of finite temperature field theories in Ads/CFT
… that this is indeed the case and that Yang-Mills Feynman diagrams with vortices can be identified with contributions from boundaries of moduli space on the string theory side. Finally, I consider the shear viscosity to entropy density ratio in conformal field theories dual to Einstein gravity with …
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Aspects of twistors and tractors in field theory
… theory in three dimensions. The Feynman diagrams of this action will construct perturbation theory around solutions of the Bogomolny equations in much the same way that MHV diagrams describe perturbation theory around the self--dual Yang Mills equations in four dimensions. We also …
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Early Seeds and Cosmic Skies: Quantum Origins of the Universe and Insights from Large-Scale Structure
… This leads to simplified calculations with fewer Feynman diagrams and only one propagator. Part III jumps forward a couple of billion years, and we study the clustering of dark matter and galaxies in the mildly nonlinear regime using its Effective Field Theory. Specifically, we develop the …
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Resonant Raman scattering in graphene
… analysis into simple rules for constructing Feynman diagrams for processes to leading order and we thereby enumerate the 2D and D modes. Using expressions for the terms to leading order obtained from our theoretical treatment we proceed to evaluate the Raman matrix element [4] for the Raman …
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Nonequilibrium green function approach to elastic and inelastic spin-charge transport in topological insulator-based heterostructures and magnetic tunnel junctions
… formalism resummation of the corresponding Feynman diagrams, including the self-consistent second Born approximation with and without bubble diagrams ( GW-like), to find the effect of coupling on I-V characteristics and STT in MTJs. Particularly, I investigated if the electron-magnon …
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Two-particle level diagrammatic approaches for strongly correlated systems
This thesis presents the development of new numerical methods for the treatment of strongly correlated electron systems based on self-consistent approaches at both the one and the two-particle level such as the parquet formalism. The parquet formalism was solved for the first time on a …
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On Different Parametrizations of Feynman Integrals
… insights on the mathematical structures of Feynman integrals.</p> <p>We start by presenting phenomenological calculations relevant for the experimental analyses at the Large Hadron Collider. We use the resummation of soft gluon emission corrections to study the associated production of a top …