S-Matrix Elements in General Renormalization Schemes
Starting from the Lehmann-Symanzik-Zimmermann reduction theorem, we provide a general procedure to extract S-matrix elements from Green functions in arbitrary renormalization schemes.
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arXiv subjects
Mingxing Luo
Publications and source records attributed to Mingxing Luo.
Two-loop Renormalization Group Equations in General Gauge Field Theories
The complete set of two-loop renormalization group equations in general gauge field theories is presented. This includes the βfunctions of parameters with and without a mass dimension.
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Precision Determination of Heavy Quark Masses and the Strong Coupling Constant
We present a new QCD sum rule with high sensitivity to the continuum regions of charm and bottom quark pair production. Combining this sum rule with existing ones yields very stable results for the MS-bar quark masses, m_c(m_c) and m_b(m_b). We introduce a phenomenological parametrization of the continuum interpolating smoothly between the pseudoscalar threshold and asymptotic quark regions. Comparison of our approach with recent BES data allows for a robust theoretical error estimate. The parametric uncertainty due to alpha_s is reduced by performing a simultaneous fit to the most precise sum rules and other high precision observables. This includes a new evaluation of the lifetime of the tau lepton, tau_tau, serving as a strong constraint on alpha_s. Our results are m_c(m_c) = 1.289 +0.040 -0.045 GeV, m_b(m_b) = 4.207 +0.030 -0.031 GeV (with a correlation of 29%), and alpha_s(M_Z) [tau_tau] = 0.1221 +0.0026 -0.0023.
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QCD Sum Rules and the Determination of Fundamental Parameters
We present a new QCD sum rule with high sensitivity to the continuum regions of charm and bottom quark pair production. Combining this sum rule with existing ones yields very stable results for the msbar quark masses, m_c(m_c)$ and m_b (m_b). Comparison of our approach with experimental data allows for a robust theoretical error estimate. We have also provided a new evaluation of the lifetime of the tau lepton, serving as a strong constraint on alpha_s.
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Renormalization Group Equations in Gauge Theories with Multiple U(1) Groups
Two-loop renormalization group equations in gauge theories with multiple U(1) groups are presented. Instead of normalizing the abelian gauge fields in canonical forms, we retain kinetic-mixing terms and treat the mixing coefficients as free parameters. The beta- and gamma-functions are then obtained in a straightforward manner.
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Two-loop Renormalization Group Equations in the Standard Model
Two-loop renormalization group equations in the standard model are re-calculated. A new coefficient is found in the beta-function of the quartic coupling and a class of gauge invariants are found to be absent in the beta-functions of hadronic Yukawa couplings. The two-loop beta-function of the Higgs mass parameter is presented in complete form.
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Vertex Operators of Open String States in the Intersecting D-brane World
Starting with a new bosonization scheme for the βγCFT of the super-conformal ghosts, vertex operators are constructed for massless open string states in the intersecting D-brane world. These vertex operators satisfy all requirements for a consistent RNS formulation of superstring theories, so GSO projections can be properly taken.
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Hadronic Loop Corrections to the Muon Anomalous Magnetic Moment
The dominant theoretical uncertainties in both, the anomalous magnetic moment of the muon and the value of the electromagnetic coupling at the Z scale arise from their hadronic contributions. Since these will ultimately dominate the experimental errors, we study the correlation between them, as well as with other fundamental parameters. To this end we present analytical formulas for the QCD contribution from higher energies and from heavy quarks. Including these correlations affects the Higgs boson mass extracted from precision data.
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