1,289 research outputs found
Electroweak Radiative Corrections to Weak Boson Production at Hadron Colliders
We summarize the status of calculations of the electroweak radiative
corrections to W and Z boson production via the Drell-Yan mechanism at hadron
colliders. To fully exploit the precision physics potential of the
high-luminosity environment of the Fermilab Tevatron pbar p (Run II) and the
CERN LHC pp colliders, it is crucial that the theoretical predictions are well
under control. The envisioned precision physics program includes a precise
measurement of the W boson mass and width, and the (leptonic) weak mixing
angle, as well as probing the Standard Model (SM) of electroweak interactions
at the highest accessible center-of-mass energies. Some numerical results are
presented.Comment: Latex, 5 pages, 4 figures, talk given by UB at RADCOR2002/Loops and
Legs, Kloster Banz, Germany, Sep. 2002, to appear in the Proceeding
Combined Electroweak Analysis
Recent developments in the measurement of precision electroweak measurements
are summarised, notably new results on the mass of the top quark and mass and
width of the W boson. Predictions of the Standard Model are compared to the
experimental results which are used to constrain the input parameters of the
Standard Model, in particular the mass of the Higgs boson. The agreement
between measurements and expectations from theory is discussed.
Invited talk presented at the EPS HEP 2007 conference
Manchester, England, July 19th to 25th, 2007Comment: 7 pages and 6 figure
The Eliashberg Function of Amorphous Metals
A connection is proposed between the anomalous thermal transport properties
of amorphous solids and the low-frequency behavior of the Eliashberg function.
By means of a model calculation we show that the size and frequency dependence
of the phonon mean-free-path that has been extracted from measurements of the
thermal conductivity in amorphous solids leads to a sizeable linear region in
the Eliashberg function at small frequencies. Quantitative comparison with
recent experiments gives very good agreement.Comment: 4pp., REVTeX, 1 uuencoded ps fig. Original posting had a corrupted
raw ps fig appended. Published as PRB 51, 689 (1995
Climate risks are real and need to become part of bank capital regulation
Climate risks are building up on banks’ balance sheets. Supervisory reviews show that banks are not well prepared. Yet, supervisors have been slow to include climate risks in minimum capital requirements. This column argues that doing so would speed up the transition to a low-carbon economy. Given the urgency of addressing the environmental risks that are now largely not accounted for, speed is of the essence
Off-equilibrium dynamics of the two-dimensional Coulomb glass
The dynamics of the 2D Coulomb glass model is investigated by kinetic Monte
Carlo simulation. An exponential divergence of the relaxation time signals a
zero-temperature freezing transition. At low temperatures the dynamics of the
system is glassy. The local charge correlations and the response to
perturbations of the local potential show aging. The dynamics of formation of
the Coulomb gap is slow and the density of states at the Fermi level decays in
time as a power law. The relevance of these findings for recent transport
experiments in Anderson-insulating films is pointed out.Comment: 7 pages, 7 figure
Formulating Light Cone QCD on the Lattice
We present the near light cone Hamiltonian in lattice QCD depending on
the parameter , which gives the distance to the light cone. Since the
vacuum has zero momentum we can derive an effective Hamiltonian from
which is only quadratic in the momenta and therefore solvable by standard
methods. An approximate ground state wave functional is determined
variationally in the limit .Comment: 48 pages, 8 figure
On the structure of the energy distribution function in the hopping regime
The impact of the dispersion of the transport coefficients on the structure
of the energy distribution function for charge carriers far from equilibrium
has been investigated in effective-medium approximation for model densities of
states. The investigations show that two regimes can be observed in energy
relaxation processes. Below a characteristic temperature the structure of the
energy distribution function is determined by the dispersion of the transport
coefficients. Thermal energy diffusion is irrelevant in this regime. Above the
characteristic temperature the structure of the energy distribution function is
determined by energy diffusion. The characteristic temperature depends on the
degree of disorder and increases with increasing disorder. Explicit expressions
for the energy distribution function in both regimes are derived for a constant
and an exponential density of states.Comment: 16 page
Gluon Structure Function of a Color Dipole in the Light-Cone Limit of Lattice QCD
We calculate the gluon structure function of a color dipole in
near-light-cone SU(2) lattice QCD as a function of . The quark and
antiquark are external non-dynamical degrees of freedom which act as sources of
the gluon string configuration defining the dipole. We compute the color dipole
matrix element of transversal chromo-electric and chromo-magnetic field
operators separated along a direction close to the light cone, the Fourier
transform of which is the gluon structure function. As vacuum state in the pure
glue sector, we use a variational ground state of the near-light-cone
Hamiltonian. We derive a recursion relation for the gluon structure function on
the lattice similar to the perturbative DGLAP equation. It depends on the
number of transversal links assembling the Schwinger string of the dipole.
Fixing the mean momentum fraction of the gluons to the "experimental value" in
a proton, we compare our gluon structure function for a dipole state with four
links with the NLO \emph{MRST} 2002 and the \emph{CTEQAB-0} parameterizations
at . Within the systematic uncertainty we find rather
good agreement. We also discuss the low behavior of the gluon structure
function in our model calculation.Comment: 44 pages, 10 figures, to be in accordance with the variant submitted
to Phys. Rev.
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