Related papers: Sfermion Precision Measurements at a Linear Collid…
A fermion can be chiral or vectorlike with respect to a given symmetry, depending on its coupling to the corresponding gauge boson. Vectorlike fermions have a distinct property that their left-handed and right-handed components behave in…
Lepton collider experiments can search for light technipions in final states made striking by the presence of an energetic photon: $e+e- \to \photon\technipion$. To date, searches have focused on either production through anomalous coupling…
In this paper we study non-commutative (NC) QED signatures at photon colliders through pair production of charged leptons $(\ell^+ \ell^-)$ and charged scalars $(H^+ H^-)$. The NC corrections for the fermion pair production can be easily…
We report two measurements of the top quark mass M_top using the CDF II detector at the Fermilab Tevatron in a 318 pb^-1 data sample observed in the lepton + jets final state. One method uses an event-based likelihood technique resulting in…
Supersymmetric particles at the multi-TeV scale will escape direct detection at planned future colliders. However, such particles induce non-decoupling corrections in processes involving the accessible superparticles through violations of…
The smallness and hierarchy of the fermion parameters could be explained in theories with extra dimensions where doublets and singlets are localized at slightly separated points. Scattering cross sections for collisions of such fermions…
Several proposals exist for energy-frontier facilities after the HL-LHC. In this contribution I review the potential of these facilities to perform key measurements of top quark properties and interacions. Top quark precision physics at a…
A search for pair production of the lightest supersymmetric partner of the top quark is performed in the lepton+jets channel using 0.9 fb-1 of data collected by the D0 experiment. Kinematic differences between scalar top quark pair…
At a prospective e+e- Linear Collider (LC) a very precise determination of the top quark mass with an accuracy of $\delta m_t <= 100 MeV$ will be possible. This is to be compared with the envisaged accuracy of $\delta m_t = 1-2 GeV$ at the…
We propose a neutrino lepton collider where the neutrino beam is generated from TeV scale muon decays. Such a device would allow for a precise measurement of the W mass based on single W production: nu l to W. Although it is challenging to…
The scattering of fermions in the background field of a topological soliton of the modified $(2 + 1)$-dimensional $\mathbb{CP}^{1}$ model is studied here both analytically and numerically. Unlike the original $\mathbb{CP}^{1}$ model, the…
The expected experimental precision of the rates and asymmetries in the Future Circular Collider with electron positron beams (FCC-ee) in the centre of the mass energy range 88-365GeV considered for construction in CERN, will be better by a…
We consider lepton pair production at a hadron collider in a class of effective theories with the relevant operators being four-fermion contact interaction. Despite the nonrenormalizable nature of the interaction, we explicitly demonstrate…
I present a systematic study of all possible four leptons final states from $\gamma\gamma$ collisions. It is given a detailed account of fermion masses effects which are sizable since several collinear and $t$ channel enancements occur. The…
If supersymmetric particles are produced at the Large Hadron Collider it becomes very important not only to identify them, but also to determine their masses with the highest possible precision, since this may lead to an understanding of…
Possible oblique effects from vector particles that are strongly coupled to the known gauge bosons are calculated for the case of final hadronic states produced at future $e^+e^-$ colliders, using a formalism that was recently proposed and…
New physics could be explored through loop effects by the precision measurements at the Circular Electron Positron Collider due to its clean collision environment and high luminosity. In this work, we focus on two dark matter models that…
The measurements of the parameters of the neutrino mixing matrix in the present and future neutrino oscillation experiments at accelerators are presented. The perspectives for high intensity new neutrino facilities as SuperBeams, BetaBeams…
Flavor symmetry has been widely studied for figuring out the masses and mixing angles of standard-model fermions. In this paper we present a framework for handling flavor symmetry breaking where the symmetry breaking is triggered by…
The smallness and hierarchy in fermion parameters could be the result of selection rules due to an Abelian horizontal symmetry broken by a small parameter. When applied to the lepton sector, then for a large class of models, a number of…