Search results for "Top quark condensate"
showing 10 items of 26 documents
Heavy quark impact factor and the single bottom production at the LHC
2014
Grigorios Chachamis Instituto de Fisica Corpuscular, Universitat de Valencia – Consejo Superior de Investigaciones Cientificas, Parc Cientific, E-46980 Paterna (Valencia), Spain E-mail: grigorios.chachamis@ific.uv.es Michal Deak∗ Instituto de Fisica Corpuscular, Universitat de Valencia – Consejo Superior de Investigaciones Cientificas, Parc Cientific, E-46980 Paterna (Valencia), Spain E-mail: michal.deak@ific.uv.es
Dynamical Symmetry Breaking in Warped Compactifications
2001
We study dynamical electroweak symmetry breaking in the Randall-Sundrum scenario. We show that one extra dimension is enough to give the correct pattern of electroweak symmetry breaking in a simple model with gauge bosons and the right-handed top quark in the bulk. The top quark mass is also in agreement with experiment. Furthermore, we propose an extended scenario with all Standard Model gauge bosons and fermions propagating in the bulk, which naturally accommodates the fermion mass hierarchies. No new fields or interactions beyond the observed in the Standard Model are required.
Electroweak and finite width corrections to top quark decays into transverse and longitudinal $ W $-bosons
2002
We calculate the electroweak and finite width corrections to the decay of an unpolarized top quark into a bottom quark and a $ W $-gauge boson where the helicities of the $ W $ are specified as longitudinal, transverse-plus and transverse-minus. Together with the $ O(\alpha_s) $ corrections these corrections may become relevant for the determination of the mass of the top quark through angular decay measurements.
IMPLICATIONS OF A LARGE $Ht \bar{t}$-COUPLING FOR THREE-BODY DECAYS OF HIGGS BOSON AND TOP QUARK
1991
The three-body decays a heavy Higgs [Formula: see text], [Formula: see text] and of a heavy top t → bW+ H are studied in the context of the Standard Model. The common feature of these decay channels is the relative big coupling constant of the Higgs particle to the top quark. Indeed within a certain range of the masses M H , mt we find that branching ratios of the order O(10-3) are possible for the decays [Formula: see text] and t → bW+ H. The decay with [Formula: see text] as a function of M H and mt is investigated below the 2mt threshold (Mtt < 2mt) and is found to have an interesting behaviour just near this threshold.
Measurement of the top quark mass in thelepton+jetsfinal state with the matrix element method
2006
We present a measurement of the top quark mass with the Matrix Element method in the lepton+jets final state. As the energy scale for calorimeter jets represents the dominant source of systematic uncertainty, the Matrix Element likelihood is extended by an additional parameter, which is defined as a global multiplicative factor applied to the standard energy scale. The top quark mass is obtained from a fit that yields the combined statistical and systematic jet energy scale uncertainty.
CORRELATIONS BETWEEN ε′/ε AND HEAVY TOP
1991
The paper reviews new theoretical developments for the CP-parameter ε′/ε and its intimate connection with the mass of a heavy top quark. It presents an extensive list of results and their implications for experiments.
Top quark decay in the Aligned two-Higgs-doublet Model
2015
AbstractWe compute the one loop right and left anomalous tensor couplings (gR and gL, respectively) for the top quark, in the aligned two-Higgs-doublet model. They are the magnetic-like couplings in the most general parameterization of the tbW vertex. We find that the aligned two-Higgs doublet model, that includes as particular cases some of the most studied extensions of the Higgs sector, as Type I and II 2HDM, introduces new electroweak contributions and provides theoretical predictions that are very sensitive to both new scalar masses and the neutral scalar mixing angle. The model can account for new CP violation effects via the introduction of complex alignment parameters that have impo…
Combination of searches for anomalous top quark couplings with 5.4 fb−1 of pp¯ collisions
2012
We present measurements of the tWb coupling form factors using information from electroweak single top quark production and from the helicity of W bosons from top quark decays in t (t) over bar events. We set upper limits on anomalous tWb coupling form factors using data collected with the DO detector at the Tevatron p (p) over bar collider corresponding to an integrated luminosity of 5.4 fb(-1).
NN Interaction in Chiral Constituent Quark Models
2003
We review the actual state in the description of the nucleon-nucleon (NN) interaction by means of chiral constituent quark models. We present a series of relevant features that are nicely explained within the quark model framework.
The non-perturbative unquenched quark model
2017
In recent years states in the quarkonium spectrum not expected in the naive quark model have appeared and created a lot of interest. In the theoretical side the study of the effect of meson-meson thresholds in the spectrum have been performed in different approximations. In a quark model framework, and in the spirit of the Cornell model, when a meson-meson threshold is included, the coupling to all the quark-antiquark states have to be considered. In practice only the closest states are included perturbatively. In this contribution we will present a framework in which we couple quark-antiquark states with meson-meson states non-perturbatively, taking into account effectively the coupling to…