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Showing 1 to 20 of 31 for “"sum rules"”.
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Applications of QCD sum rules at finite temperature
QCD Sum Rules is one of the most successful quantum field theory frameworks to extract hadronic information from QCD analytically. This technique is based on the Operator Product Expansion (OPE) and Cauchy's Theorem in the complex energy plane. OPE factorizes the short and long distance …
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Light Quark Masses from QCD Finite Energy Sum Rules
… from Lattice QCD, or analytically using QCD sum rules. The latter makes use of the complex squared energy plane, and Cauchy’s theorem for the correlator of axial-vector divergences. This procedure relates a QCD expression containing the quark masses, with an hadronic expression in terms of …
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Perturbative Check of the Action and Energy Lattice Sum Rules
Lattice sum rules are checked using lattice perturbation theory. The action sum rule gives a relation between the quark-antiquark potential, its logarithmic derivative with respect to distance and the expectation value of the action; the energy sum rule expresses the potential as the sum of the …
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Pions and vector mesons at finite temperature from QCD sum rules
The temperature corrections to the current algebra Gell-Mann, Oakes and Renner(GMOR) relation in SU(2) X SU(2), the temperature behaviour of the pion mass and the q2 and T dependence of the ρππ vertex function in the space-like region are investigated.
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In-Medium QCD Sum Rules for omega Meson, Nucleon and D Meson
… medium are investigated within the scope of QCD sum rules. This is exemplified for the cases of the omega meson, the nucleon and the D meson. By virtue of the sum rules, integrated spectral densities of these hadrons are linked to properties of the QCD ground state, quantified in condensates. For …
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Determination of the charm- and beauty-quark masses from QCD sum rules
Ratios of Laplace QCD sum rules are used in order to determine the on-shell charm- and beauty-quark masses. After confronting the experimental data in the charmonium and bottonium systems with theory, we obtain mc = 1.46 ± 0.07 GeV and mb = 4.70 ± 0.07 GeV. The error is due to the uncertainties in …
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Sum rules and constraints on passive systems - a general approach and applications to electromagnetic scattering
… due to passivity. A general approach to derive sum rules and physical limitations on passive systems is presented. The sum rules relate the dynamical behaviour of a system to its static and/or high-frequency properties. This is beneficial, since static properties are in general easier to …
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The mass of the strange quark
Sum rules in QCD are discussed and finite energy and Laplace transform sum rules are used to determine the strange-quark mass. We use improved QCD input and experimental data to obtain for the invariant mass: mₛ= 266 ± 29 MeV, or for the running mass at 1 GeV: mₛ(1 GeV) = 194 ± 4 MeV.
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Hadronic matter: from vacuum to extreme temperature in the presence of magnetic fields
… themes. First, we work with Finite Energy QCD Sum Rules (FESR) approach in the vacuum. We tackle the problem of quark-hadron duality violation (DV), using the vector and axial-vector hadronic spectral function from tau-decay. A pinched integration kernel is introduce in the FESR in order to …
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Integral Identities for Passive Systems and Spherical Waves in Scattering and Antenna Problems
Sum rules and physical limitations within electromagnetic theory and antenna theory have received significant attention in the last few years. However, the derivations are often relying on application specific and sometimes unsupported assumptions, and therefore a mathematically rigorous and …
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Interacting Ultracold Alkali Atomic Fermion Gases and Radio-Frequency Spectroscopy
… interactions constrain the rf spectrum through sum rules. We self-consistently generate the spin correlation functions for 6Li within Hartree-Fock-BCS approximation. Our calculation reproduces the mean field shift observed in experiments for normal gases, and confirms that a second peak detected …
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Group theory predictions for B --> M₁M₂M₃
… B --> [pi][pi] isospin triangle. We also derive sum rules for isospin triangle. We also derive sum rules for B --> MMM, which give approximate SU(2) relations among branching ratios and CP asymmetries.
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Octet and decuplet baryon masses at finite temperature
… in the framework of finite energy QCD sum rules. In all cases it is found that the mass stays fairly constant over a range of temperatures, increasing sharply near the critical temperature for deconfinement Tc.
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Quantum field theories on the light front
… than the usual time-ordered product. The Feynman rules for these S-matrix elements are identical to the old rules in the case of the self-interacting scalar theory, but they differ by noncovariant terms for the interacting Dirac theory. A formal proof of the equivalence of the S-m3trix in the new …
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Physics beyond the standard model: moduli stabilisation and neutrino physics
… running on neutrino mixing angles and various sum rules, in models where tri-bimaximal mixing is exactly achieved at high energy scale. We find the RG corrections to neutrino sum rules to be typically small for the case of hierarchical neutrinos.<br/><br/>Another aspect of physics beyond the …
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Measurement of Generalized GDH Integrand for the Neutron and 3He at Low Q2
… in the non-perturbative regime. Dispersive sum rules, based on universal principles, provide a data-driven approach to study the nucleon structure without model-dependencies. Among those sum rules, the well known Gerasimov-Drell-Hearn (GDH) sum rule relates the anomalous magnetic moment to a …
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Numerical investigation of highly inelastic reactions in a φ3 ladder model
… the convergence of Campbell and Chang's sum rules for exclusive spectra. The applicability of this method depends critically on this convergence and it is our intention to test this question in a simple nontrivial model. This seems worthwhile since a final decision cannot be reached from …
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B → K∗µ+µ− and Form Factors for Semi-Leptonic and Radiative B Decays
… of the full form factors, calculated in QCD sum rules on the light-cone (LCSR), and QCD factorisation. Those with reduced dependence on hadronic quantities and sensitivity to NP are identified. In the first few years of data–taking at the LHC, the focus will be on quantities which are simple to …
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