相关论文: Singlet Polarization Functions at O(\alpha_s^2)
We re-examine the characteristic polarization angle sweep of rotation-powered pulsars and calculate the expected deviations from this sweep caused by aberrational effects and by polar-cap current flow. We find that in addition to the…
A new manifestation of interlayer coherence in strongly polarized double layer quantum Hall systems with total filling factor $\nu=1$ in the presence of a small or zero tunneling is theoretically predicted. It is shown that moving (for…
We compute the imaginary part of the heavy quark contribution to the photon polarization tensor, i.e. the quarkonium spectral function in the vector channel, at next-to-leading order in thermal QCD. Matching our result, which is valid…
We discuss the recent derivation of the three-loop ${\cal O}(\alpha\alpha_s)$ contribution to the Higgs boson production cross section via gluon fusion arising from diagrams with light quarks, using an effective theory approach. We show…
We review recent developments in the theory and phenomenology of polarized structure functions. We summarize recent experimental data on the proton and deuteron structure function $g_1$, and their impact on the understanding of polarized…
We review the analysis of polarized structure function data using perturbative QCD at next-to-leading order. We use the most recent experimental data to obtain updated results for polarized parton distributions, first moments and the strong…
We use a semiclassical approximation to derive the partition function for an arbitrary potential in one-dimensional Quantum Statistical Mechanics, which we view as an example of finite temperature scalar Field Theory at a point. We rely on…
Recent analytical and numerical results for the three-loop polarization function allow to present a phenomenological analysis of the cross section for massive quark production in electron positron annihilation to order $\alpha_s^2$.…
The analytic expressions for the production cross sections of polarized bottom and top quarks in $e^+e^-$ annihilation are explicitly derived at the one-loop order of strong interactions. Chirality-violating mass effects will reduce the…
We compute the three-loop relation between the pole and the minimally subtracted quark mass allowing for virtual effects from a second massive quark. We also consider the analogue effects for the on-shell wave function renormalization…
We suggest a phenomenological theory of the polarization conversions effect, an excitonic analog of the first-order spatial dispersion phenomena which is, however, observed in the photoluminescence rather than in the passing light. The…
In a previous paper we showed how higher-order strong-field-QED processes in long laser pulses can be approximated by multiplying sequences of "strong-field Mueller matrices". We obtained expressions that are valid for arbitrary field shape…
We analytically compute the dominant contributions to the \beta-functions for the top-Yukawa coupling, the strong coupling and the Higgs self-coupling as well as the anomalous dimensions of the scalar, gluon and quark fields in the unbroken…
An alternate method is described to extract the quark contribution to the spin of the nucleon directly from the first moment of the deuteron structure function, $g^d_1$. It is obtained without recourse to the use of input on the nucleon…
Top quark polarization in $e^+e^-$ annihilation into $t\bar t$ is calculated for linearly polarized beams. The Green function formalism is applied to this reaction near threshold. The Lippmann--Schwinger equations for the $S$-wave and…
Counterparts of the Dyson-Schwinger equations for scalar QED in an external electromagnetic field are derived. Exact structure and diagrammatic interpretation of the corresponding mass and polarization operators are obtained. It is shown…
Polarization observables in top quark decays are sensitive probes of possible new physics contributions to the interactions of the heavy third generation quarks. Within an effective theory approach such new physics contributions can be…
The coupling of a pseudo-scalar Higgs boson to gluons is mediated through a heavy quark loop. In the limit of large quark mass, it is described by an effective Lagrangian that only admits light degrees of freedom. In this effective theory,…
Correlators of singlet and octet axial currents, as well as anomaly and pseudoscalar densities have been studied using QCD sum rules. Several of these sum rules are used to determine the couplings f^8_eta, f^0_eta, f^8_etaprime and…
We demonstrate two effects that occur in all diffusive superconducting-magnetic heterostructures with rotating magnetization: the reappearance of singlet $|0,0>$ correlations deep in the magnetic material and a cascade of $s=1$, $m=0, \pm…