6,803 research outputs found
Light axigluon and single top production at the LHC
The light axigluon model can explain the Tevatron
forward-backward asymmetry and at the same time satisfy the constraints from
the electroweak precision measurement and the and data, which
induces the flavor changing () couplings of axigluon with the and new
quarks. We investigate the effects of these couplings on the s- and
t-channel single top productions at the and the decays , and . Our numerical
results show that the light axigluon can give significantly contributions to
single top production and the rare top decays and .Comment: 22 pages, 8 figures; references added, contributions of new quarks to
rare decay processes adde
Symmetry restoration and quantumness reestablishment
A realistic quantum many-body system, characterized by a generic microscopic
Hamiltonian, is accessible only through approximation methods. The mean field
theories, as the simplest practices of approximation methods, commonly serve as
a powerful tool, but unfortunately often violate the symmetry of the
Hamiltonian. The conventional BCS theory, as an excellent mean field approach,
violates the particle number conservation and completely erases quantumness
characterized by concurrence and quantum discord between different modes. We
restore the symmetry by using the projected BCS theory and the exact numerical
solution and find that the lost quantumness is synchronously reestablished. We
show that while entanglement remains unchanged with the particle numbers,
quantum discord behaves as an extensive quantity with respect to the system
size. Surprisingly, discord is hardly dependent on the interaction strengths.
The new feature of discord offers promising applications in modern quantum
technologies.Comment: 17 pages and 3 figure
Associated production of the heavy charged gauge boson and a top quark at LHC
In the context of topflavor seesaw model, we study the production of the
heavy charged gauge boson associated with a top quark at the LHC.
Focusing on the searching channel , we carry out a full simulation of the signal and the
relevant standard model backgrounds. The kinematical distributions of final
states are presented. It is found that the backgrounds can be significantly
suppressed by sets of kinematic cuts, and the signal of the heavy charged boson
might be detected at the LHC with TeV. With a integrated
luminosity of \LL= 100 , a signal significance can be
achieved for TeV.Comment: 16 pages, 6 figure
Bottom partner B' and Zb production at the LHC
Some new physics models, such as "beautiful mirrors" scenario, predict the
existence of the bottom partner . Considering the constraints from the data
for the branching ratio and the asymmetry
on the relevant free parameters, we calculate the contributions of
to the cross section and the polarization asymmetry
for production at the . We find that the bottom partner
can generate significant corrections to and , which might
be detected in near future.Comment: 15 pages, 5 figures. Version published in Phys. Lett.
- …