相关论文: Do quark masses run?
Reliable values of quark and lepton masses are important for model building at a fundamental energy scale, such as the Fermi scale M_Z \approx 91.2 GeV and the would-be GUT scale \Lambda_GUT \sim 2 \times 10^16 GeV. Using the latest data…
In this contribution I will highlight the new challenges for top quark physics at LHC Run II, focusing in particular on the interplay between precision studies on the top quark and searches for new physics. A new strategy to search for…
Importance of studies of $b$ quark decays and experimental status of various measurements are discussed.
Far above threshold the production process e^+e^-to t t-bar can be analyzed using effective field theories. In this talk we consider the invariant mass distribution of top-jets and report about our computation of the two-loop heavy quark…
We consider the possibility of extracting the bottom quark mass from LEP data. The inclusive decay rate for $\zbb +\cdots$ is obtained at order $\as$ by summing up the one-loop two-parton decay rate to the tree-level three-parton rate. We…
We present a detailed description of our calculation of next-to-leading order QCD corrections to heavy quark production in e^+ e^- collisions including mass effects. In particular, we study the observables $R_3^{b\ql}$ and $D_2^{b\ql}$ in…
The influence of the top quark mass on mixing processes and precise electroweak measurements is described. Experimental observation of the top quark in proton-antiproton collisions is discussed, and some brief remarks are made about…
Experimental results on c- and b-quark fragmentation are reviewed. The discussion is concentrated on measurements of heavy-quark fragmentation functions and fragmentation fractions. Measurements of various heavy-quark fragmentation ratios…
In this contribution we discuss conceptual issues of current mass measurements performed at the Tevatron. In addition we propose an alternative method which is theoretically much cleaner and to a large extend free from the problems…
The LHC provides new opportunities to improve our understanding of the b quark using high statistics data samples and the 14 TeV center-of-mass energy. The prospects to measure the cross section for inclusive b production in events…
The top quark mass measurements are based either on a direct kinematic reconstruction of the top quark decay products or on indirect measurements, where an observable sensitive to the top quark mass, such as the production cross section, is…
We consider the production of heavy quark jets at the $Z$-pole at the next-to-leading order (NLO) using the {\it Cambridge jet-algorithm}. We study the effects of the quark mass in two- and three-jet observables and the uncertainty due to…
The determination of quark masses has been transformed in the past few years by accurate results from realistic lattice QCD. This has meant a range of new methods for both b and c quarks which I will describe along with results from…
The ATLAS and CMS Collaborations have performed a variety of measurements of the top quark mass, taking advantage of the abundant production of top quarks at the LHC. The most recent measurements are reported here, based on data collected…
The meaning and the extraction of heavy quark masses are discussed. A simple production model is presented which incorporates the running of the heavy quark mass into perturbative calculations. The model offers the possibilities of (i)…
Theoretical issues are discussed for the measurement of the top-mass using jets, including perturbative and non-perturbative effects that relate experimental observables to the Lagrangian mass, and appropriate choices for mass schemes. Full…
We present a next-to-leading-order calculation of the production of a Z boson with two jets, one or more of which contains a heavy quark (Q=c,b). We show that the cross section with only one heavy-quark jet is larger than that with two…
Measurements involving top quarks provide important tests of QCD. A selected set of top quark measurements in CMS including the strong coupling constant, top quark pole mass, constraints on parton distribution functions, top quark pair…
In this contribution I review the physics of top quarks at a future Linear Collider. Main emphasis is put on the process e+ e- to ttbar close to threshold. Different physical observables, their sensitivity to the basic parameters and their…
We illustrate the utility of jet mass distributions as probes of new physics at the LHC, focusing on a heavy vector-quark doublet that mixes with the top as a concrete example. For 1 TeV vector-quark masses, we find that signals with…