André Hoang

Univ.-Prof. Dr. André H. Hoang

Fakultät für Physik
Universität Wien
Boltzmanngasse 5
1090 Wien

Tel.: +43-1-4277-51559

e-mail: andre.hoang@univie.ac.at

Web: http://wwwth.mppmu.mpg.de/members/ahoang/

Top-antitop production cross-section at threshold. A complete NNLL resummation of ultrasoft logarithms (right plot) decreases substantially the renormalization scale dependence compared to earlier predictions (left plot).

Phenomenological collider physics aims at increased precision in predictions to allow to disentangle potential deviations from Standard Model predictions and to provide the theoretical tools to discover and measure new elementary particles and interactions to resolve the physics that stands behind the Standard Model. At this time the LHC is the collider facility with the highest energy reach. However, doing precise measurements and drawing conclusions concerning the above aims is difficult due to the effects of the strong interactions. Therefore an important test of all new theoretical developments is to also analyse experimental data from electron-positron colliders such as LEP and the B factories, which also allows for applications at future experiments such as the International Linear Collider.
In recent years effective field theory (EFT) methods have been applied for collider physics observables by an increasing number of research groups. EFT methods allow for a efficient theoretical description when the dynamics is governed by vastly different energy scales. Among these are new, modern versions of nonrelativistic QCD (NRQCD) for heavy quarkonium production and soft-collinear effective theory (SCET), a powerful theory for the systematic description of so-called jets, collimated clusters of energetic hadrons appearing in particle collisions. Among the results obtained by the research group of Hoang are: (i) A derivation of a factorization theorem for the production of massive quark initiated jets in the dijet limit, (ii) a rigorous relation between the observable invariant mass distribution and the Lagrangian mass, (iii) the description of massless quark event shapes such as thrust at next-to-next-to-next-to-leading order, (iv) a description of top and bottom pair production at threshold at next-to-next-to-leading order including for top quarks a systematic treatment of electroweak and finite lifetime effects.