The Experts below are selected from a list of 150 Experts worldwide ranked by ideXlab platform
Massimo Capone - One of the best experts on this subject based on the ideXlab platform.
-
Single-boson exchange decomposition of the Vertex Function
Physical Review B, 2019Co-Authors: Friedrich Krien, A. Valli, Massimo CaponeAbstract:We present a decomposition of the two-particle Vertex Function of the single-band Anderson impurity model which imparts a physical interpretation of the Vertex in terms of the exchange of bosons of three flavors. We evaluate the various components of the Vertex for an impurity model corresponding to the half-filled Hubbard model within dynamical mean-field theory. For small values of the interaction almost the entire information encoded in the Vertex Function corresponds to single-boson exchange processes, which can be represented in terms of the Hedin three-leg Vertex and the screened interaction. Also for larger interaction, the single-boson exchange still captures scatterings between electrons and the dominant low-energy fluctuations and provides a unified description of the Vertex asymptotics. The proposed decomposition of the Vertex does not require the matrix inversion of the Bethe-Salpeter equation. Therefore, it represents a computationally lighter and hence more practical alternative to the parquet decomposition.
M Gomshi A Nobary - One of the best experts on this subject based on the ideXlab platform.
-
soft end point and mass corrections to the eta g g Vertex Function
arXiv: High Energy Physics - Phenomenology, 2008Co-Authors: S S Agaev, M Gomshi A NobaryAbstract:Power-suppressed corrections arising from end-point integration regions to the space-like Vertex Function of the massive eta'-meson virtual gluon transition eta' - g*g* are computed. Calculations are performed within the standard hard-scattering approach (HSA) and the running coupling method supplemented by the infrared renormalon calculus. Contributions to the Vertex Function from the quark and gluon contents of the eta' -meson are taken into account and the Borel resummed expressions for F_{eta' g*g*}(Q2,\omega ,\eta), as well as for F_{eta' g g*}}(Q^{2},\omega =\pm 1,\eta) and F_{eta' g*g*}(Q^{2},\omega =0,\eta) are obtained. It is demonstrated that the power-suppressed corrections \sim (\Lambda ^{2}/Q^{2})^{n}, in the explored range of the total gluon virtuality 1
Vertex Function relative to the results found in the framework of the standard HSA with a fixed coupling. Modifications generated by the eta ' -meson mass effects are discussed. -
Soft end-point and mass corrections to the eta' g*g* Vertex Function
The European Physical Journal C, 2008Co-Authors: S S Agaev, M Gomshi A NobaryAbstract:Power-suppressed corrections arising from end-point integration regions to the space-like Vertex Function of the massive eta'-meson virtual gluon transition eta' - g*g* are computed. Calculations are performed within the standard hard-scattering approach (HSA) and the running coupling method supplemented by the infrared renormalon calculus. Contributions to the Vertex Function from the quark and gluon contents of the eta' -meson are taken into account and the Borel resummed expressions for F_{eta' g*g*}(Q2,\omega ,\eta), as well as for F_{eta' g g*}}(Q^{2},\omega =\pm 1,\eta) and F_{eta' g*g*}(Q^{2},\omega =0,\eta) are obtained. It is demonstrated that the power-suppressed corrections \sim (\Lambda ^{2}/Q^{2})^{n}, in the explored range of the total gluon virtuality 1
Dirk Kreimer - One of the best experts on this subject based on the ideXlab platform.
-
New representation of the two-loop crossed Vertex Function
Nuclear Physics B, 1997Co-Authors: Alexander Frink, Ulrich Kilian, Dirk KreimerAbstract:We calculate the two-loop Vertex Function for the crossed topology, and for arbitrary masses and external momenta. We derive a double integral representation, suitable for a numerical evaluation by a Gaussian quadrature. Real and imaginary parts of the diagram can be calculated separately.
Friedrich Krien - One of the best experts on this subject based on the ideXlab platform.
-
Single-boson exchange decomposition of the Vertex Function
Physical Review B, 2019Co-Authors: Friedrich Krien, A. Valli, Massimo CaponeAbstract:We present a decomposition of the two-particle Vertex Function of the single-band Anderson impurity model which imparts a physical interpretation of the Vertex in terms of the exchange of bosons of three flavors. We evaluate the various components of the Vertex for an impurity model corresponding to the half-filled Hubbard model within dynamical mean-field theory. For small values of the interaction almost the entire information encoded in the Vertex Function corresponds to single-boson exchange processes, which can be represented in terms of the Hedin three-leg Vertex and the screened interaction. Also for larger interaction, the single-boson exchange still captures scatterings between electrons and the dominant low-energy fluctuations and provides a unified description of the Vertex asymptotics. The proposed decomposition of the Vertex does not require the matrix inversion of the Bethe-Salpeter equation. Therefore, it represents a computationally lighter and hence more practical alternative to the parquet decomposition.
S S Agaev - One of the best experts on this subject based on the ideXlab platform.
-
soft end point and mass corrections to the eta g g Vertex Function
arXiv: High Energy Physics - Phenomenology, 2008Co-Authors: S S Agaev, M Gomshi A NobaryAbstract:Power-suppressed corrections arising from end-point integration regions to the space-like Vertex Function of the massive eta'-meson virtual gluon transition eta' - g*g* are computed. Calculations are performed within the standard hard-scattering approach (HSA) and the running coupling method supplemented by the infrared renormalon calculus. Contributions to the Vertex Function from the quark and gluon contents of the eta' -meson are taken into account and the Borel resummed expressions for F_{eta' g*g*}(Q2,\omega ,\eta), as well as for F_{eta' g g*}}(Q^{2},\omega =\pm 1,\eta) and F_{eta' g*g*}(Q^{2},\omega =0,\eta) are obtained. It is demonstrated that the power-suppressed corrections \sim (\Lambda ^{2}/Q^{2})^{n}, in the explored range of the total gluon virtuality 1
Vertex Function relative to the results found in the framework of the standard HSA with a fixed coupling. Modifications generated by the eta ' -meson mass effects are discussed. -
Soft end-point and mass corrections to the eta' g*g* Vertex Function
The European Physical Journal C, 2008Co-Authors: S S Agaev, M Gomshi A NobaryAbstract:Power-suppressed corrections arising from end-point integration regions to the space-like Vertex Function of the massive eta'-meson virtual gluon transition eta' - g*g* are computed. Calculations are performed within the standard hard-scattering approach (HSA) and the running coupling method supplemented by the infrared renormalon calculus. Contributions to the Vertex Function from the quark and gluon contents of the eta' -meson are taken into account and the Borel resummed expressions for F_{eta' g*g*}(Q2,\omega ,\eta), as well as for F_{eta' g g*}}(Q^{2},\omega =\pm 1,\eta) and F_{eta' g*g*}(Q^{2},\omega =0,\eta) are obtained. It is demonstrated that the power-suppressed corrections \sim (\Lambda ^{2}/Q^{2})^{n}, in the explored range of the total gluon virtuality 1
