64,417 research outputs found
MCFM for the Tevatron and the LHC
A summary is given of the current status of the next-to-leading order (NLO)
parton-level integrator MCFM. Some details are given about the Higgs + 2-jet
process and the production and decay of , both of which have
recently been added to the code. Using MCFM, comparisons between the Tevatron
running at ~TeV and the LHC running at ~TeV are made
for standard model process including the production of Higgs bosons. The case
for running the Tevatron until 16fb are accumulated by both detectors is
sketched.Comment: Talk presented by R.K Ellis at Loops and Legs in Quantum Field Theory
2010, Woerlitz, Germany, April 25-30, 2010, (6 pages and 4 figures
QCD corrections to the hadronic production of a heavy quark pair and a W-boson including decay correlations
We perform an analytic calculation of the one-loop amplitude for the W-boson
mediated process 0 \to d u-bar Q Q-bar l-bar l, retaining the mass for the
quark Q. The momentum of each of the massive quarks is expressed as the sum of
two massless momenta and the corresponding heavy quark spinor is expressed as a
sum of two massless spinors. Using a special choice for the heavy quark spinors
we obtain analytic expressions for the one-loop amplitudes which are amenable
to fast numerical evaluation. The full next-to-leading order (NLO) calculation
of hadron+hadron \to W(\to e nu) b b-bar with massive b-quarks is included in
the program MCFM. A comparison is performed with previous published work.Comment: 45 pages, 17 figure
Sudden Expansion of a One-Dimensional Bose Gas from Power-Law Traps
We analyze free expansion of a trapped one-dimensional Bose gas after a
sudden release from the confining trap potential. By using the stationary phase
and local density approximations, we show that the long-time asymptotic density
profile and the momentum distribution of the gas are determined by the initial
distribution of Bethe rapidities (quasimomenta) and hence can be obtained from
the solutions to the Lieb-Liniger equations in the thermodynamic limit. For
expansion from a harmonic trap, and in the limits of very weak and very strong
interactions, we recover the self-similar scaling solutions known from the
hydrodynamic approach. For all other power-law traps and arbitrary interaction
strengths, the expansion is not self-similar and shows strong dependence of the
density profile evolution on the trap anharmonicity. We also characterize
dynamical fermionization of the expanding cloud in terms of correlation
functions describing phase and density fluctuations.Comment: Final published version with modified title and a couple of other
minor changes. 5 pages, 2 figures, and Supplemental Materia
Time- and frequency-domain polariton interference
We present experimental observations of interference between an atomic spin
coherence and an optical field in a {\Lambda}-type gradient echo memory. The
interference is mediated by a strong classical field that couples a weak probe
field to the atomic coherence through a resonant Raman transition. Interference
can be observed between a prepared spin coherence and another propagating
optical field, or between multiple {\Lambda} transitions driving a single spin
coherence. In principle, the interference in each scheme can yield a near unity
visibility.Comment: 11 pages, 5 figure
17Beta-estradiol modulates gastroduodenal preneoplastic alterations in rats exposed to the carcinogen N-methyl-N'-nitro-nitrosoguanidine
Lower levels of damaged protein biomarkers in the plasma of overweight type 2 diabetic men following supplementation with a standardised bilberry extract
Peer reviewedPublisher PD
Comment on ``Ground State Phase Diagram of a Half-Filled One-Dimensional Extended Hubbard Model''
In Phys. Rev. Lett. 89, 236401 (2002), Jeckelmann argued that the recently
discovered bond-order-wave (BOW) phase of the 1D extended Hubbard model does
not have a finite extent in the (U,V) plane, but exists only on a segment of a
first-order SDW-CDW phase boundary. We here present quantum Monte Carlo result
of higher precision and for larger system sizes than previously and reconfirm
that the BOW phase does exist a finite distance away from the phase boundary,
which hence is a BOW-CDW transition curve.Comment: 1 page, 1 figure, v2: final published versio
High efficiency coherent optical memory with warm rubidium vapour
By harnessing aspects of quantum mechanics, communication and information
processing could be radically transformed. Promising forms of quantum
information technology include optical quantum cryptographic systems and
computing using photons for quantum logic operations. As with current
information processing systems, some form of memory will be required. Quantum
repeaters, which are required for long distance quantum key distribution,
require optical memory as do deterministic logic gates for optical quantum
computing. In this paper we present results from a coherent optical memory
based on warm rubidium vapour and show 87% efficient recall of light pulses,
the highest efficiency measured to date for any coherent optical memory. We
also show storage recall of up to 20 pulses from our system. These results show
that simple warm atomic vapour systems have clear potential as a platform for
quantum memory
- …