7,420 research outputs found
On the renormalization of quasi parton distribution
Recent developments showed that light-cone parton distributions can be
studied by investigating the large momentum limit of the hadronic matrix
elements of spacelike correlators, which are known as quasi parton
distributions. Like a light-cone parton distribution, a quasi parton
distribution also contains ultraviolet divergences and therefore needs
renormalization. The renormalization of non-local operators in general is not
well understood. However, in the case of quasi quark distribution, the bilinear
quark operator with a straight-line gauge link appears to be multiplicatively
renormalizable by the quark wave function renormalization in the axial gauge.
We first show that the renormalization of the self energy correction to the
quasi quark distribution is equivalent to that of the heavy-light quark vector
current in heavy quark effective theory at one-loop order. Assuming this
equivalence at two-loop order, we then show that the multiplicative
renormalizability of the quasi quark distribution is true at two-loop order.Comment: 14 pages, 4 figure
Radiative Corrections to in the MSSM
The electroweak radiative corrections to the decay of
the heavy CP-even MSSM Higgs boson to weak gauge bosons are presented. Due to
the suppression of the tree-level coupling, the electroweak
contributions to the partial decay width are significant. Although the
effective Born decay width can be rather small for certain values
(especially for large ), the corrected partial widths at different
values of are of comparable size.Comment: 13 pages, 7 figures, version to appear in PR
Vacuum Stability and Higgs Diphoton Decay Rate in the Zee-Babu Model
Although recent Higgs data from ATLAS and CMS are compatible with a Standard
Model (SM) signal at level, both experiments see indications for an
excess in the diphoton decay channel, which points to new physics beyond the
SM. Given such a low Higgs mass , another sign
indicating the existence of new physics beyond the SM is the vacuum stability
problem, i.e., the SM Higgs quartic coupling may run to negative values at a
scale below the Planck scale. In this paper, we study the vacuum stability and
enhanced Higgs diphoton decay rate in the Zee-Babu model, which was used to
generate tiny Majorana neutrino masses at two-loop level. We find that it is
rather difficult to find overlapping regions allowed by the vacuum stability
and diphoton enhancement constraints. As a consequence, it is almost inevitable
to introduce new ingredients into the model, in order to resolve these two
issues simultaneously.Comment: 19 pages, 6 figure
Gravity/Fluid Correspondence and Its Application on Bulk Gravity with Gauge Field
As the long wavelength limit of the AdS/CFT correspondence, the gravity/fluid
correspondence has been shown to be a useful tool for extracting properties of
the fluid on the boundary dual to the gravity in the bulk. In this paper, after
briefly reviewing the algorithm of gravity/fluid correspondence, we discuss the
results of its application on bulk gravity with a gauge field. In the
presence of a gauge field, the dual fluid possesses more interesting
properties such as its charge current. Furthermore, an external field
could affect the charge current, and the Chern-Simons term
also reinduces extra structures to the dual current giving anomalous transport
coefficients.Comment: 14 pages, no figure, version publishe
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