Adrian Signer

Vector Boson Pair Production in Hadronic Collisions at Order alpha(s): Lepton Correlations and Anomalous Couplings

We present cross sections for the production of electroweak vector boson pairs, WW, WZ, and ZZ, in

The bottom quark mass from sum rules at next-to-next-to-leading order

p\overline{p}

Top quark production near threshold and the top quark mass

and pp collisions, at next-to-leading order in

Heavy quark pair production near threshold with potential non-relativistic QCD

{\ensuremath{\alpha}}_{s}.

Effective Theory Approach to Unstable Particle Production

We treat the leptonic decays of the bosons in the narrow-width approximation, but retain all spin information via decay angle correlations. We also include the effects of WWZ and

Effective theory calculation of resonant high-energy scattering.

\mathrm{WW}\ensuremath{\gamma}

Renormalization group improved sum rule analysis for the bottom-quark mass.

anomalous couplings.

Four-fermion production near the W pair-production threshold

Abstract We determine the bottom MS quark mass m b and the quark mass in the potential subtraction scheme from moments of the b b production cross section and from the mass of the Upsilon 1S state at next-to-next-to-leading order in a reorganized perturbative expansion that sums Coulomb exchange to all orders. We find m b ( m b )=(4.25±0.08) GeV and m b, PS (2 GeV )=(4.59±0.08) GeV for the potential-subtracted mass at the scale 2 GeV, adopting a conservative error estimate.

Production-decay interferences at NLO in QCD for

Abstract We consider top-anti-top production near threshold in e + e − collisions, resumming Coulomb-enhanced corrections at next-to-next-to-leading order (NNLO). We also sum potentially large logarithms of the small top quark velocity at the next-to-leading logarithmic level using the renormalization group. The NNLO correction to the cross section is large, and it leads to a significant modification of the peak position and normalization. We demonstrate that an accurate top quark mass determination is feasible if one abandons the conventional pole mass scheme and if one uses a subtracted potential and the corresponding mass definition. Significant uncertainties in the normalization of the t t cross section, however, remain.

t

Abstract We study the effect of the resummation of logarithms for t t ¯ production near threshold and inclusive electromagnetic decays of heavy quarkonium. This analysis is complete at next-to-next-to-leading order and includes the full resummation of logarithms at next-to-leading-logarithmic accuracy and some partial contributions at next-to-next-to-leading logarithmic accuracy. Compared with fixed-order computations at next-to-next-to-leading order the scale dependence and convergence of the perturbative series is greatly improved for both the position of the peak and the normalization of the total cross section. Nevertheless, we identify a possible source of large scale dependence in the result. At present we estimate the remaining theoretical uncertainty of the normalization of the total cross section to be of the order of 10% and for the position of the peak of the order of 100 MeV.