Heavy quark mass determinations with sum rules and jets
2016389 pages
Supervisor:
Thesis: PhD - André H. Hoang
- Wien U.,
- Vienna U.
- Published: 2016
Citations per year
Abstract: (Wien U.)
In this thesis I discuss the charm, bottom and top quark mass determinations.
In the first part, I present new determinations of the {} charm and bottom quark masses using relativistic QCD sum rules at \,.
For the charm quark mass extraction we use the moments of the vector and the pseudoscalar current correlators where
we take into account the available experimental measurements from collisions and
lattice simulation results, respectively.
For the bottom quark mass determination we use the vector current correlator for which we compute the corresponding experimental moments including a modeling uncertainty associated to the continuum region where no data is available.
Our analysis of the theoretical uncertainties is based on
independent variations of the renormalization scales for the mass and the strong coupling. In addition we apply a convergence test to discard the perturbative series for which the convergence behavior is significantly worse than the average convergence rate.
As the final result we obtain GeV and
GeV from
the vector correlator analyses.
In the second part, I present a complete theoretical description of the entire thrust distribution
for boosted heavy quark initiated jets in colliders.
The results are given in terms of various factorization theorems in the dijet limit within a
variable flavor number scheme (VFNS) for final state jets. In this limit we use Soft-Collinear Effective Theory (SCET), including mass modes, in order to factorize the cross section and to sum large logarithms at order.
When the invariant mass of the massive jet is close to the heavy quark mass we match onto a
boosted Heavy Quark Effective Theory (bHQET) to sum up a new class of large logarithms along with the treatment of finite
width effects.
In this regime one cannot use the mass for the heavy quark, as it would break the power counting of bHQET. We solve this issue by switching to a more suitable short-distance scheme for the mass, which we call the MSR scheme. Finally we also apply a VFNS to the gap subtractions, used to define a scheme for the leading power correction in which the leading renormalon of the soft function is removed.
At the end, we show the perturbative convergence of the resulting thrust distributions for stable and unstable top and bottom quark production and discuss the sensitivity of the peak region of the distributions to the heavy quark masses.
Our hadron-level results can be used to find a numerical relation between the top (bottom) mass parameters in parton-shower Monte Carlo generators and the well defined short-distance schemes for quark masses in QCD.- Physik der Elementarteilchen und Felder: Allgemeines
- Theoretische Physik: Sonstiges
- Elementarteilchenphysik
- QCD
- Sum Rules
- Lattice QCD
- perturbation theory
- charm mass
- bottom mass
- top mass
References(260)
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