58,089 research outputs found
An evaluation of the suitability of ERTS data for the purposes of petroleum exploration
There are no author-identified significant results in this report
Evaluation of the suitability of Skylab data for the purpose of petroleum exploration
There are no author-identified significant results in this report
QCD Factorization for Semi-Inclusive Deep-Inelastic Scattering at Low Transverse Momentum
We demonstrate a factorization formula for semi-inclusive deep-inelastic
scattering with hadrons in the current fragmentation region detected at low
transverse momentum. To facilitate the factorization, we introduce the
transverse-momentum dependent parton distributions and fragmentation functions
with gauge links slightly off the light-cone, and with soft-gluon radiations
subtracted. We verify the factorization to one-loop order in perturbative
quantum chromodynamics and argue that it is valid to all orders in perturbation
theory.Comment: 28 pages, figures include
Derivation of the Gauge Link in Light Cone Gauge
In light cone gauge, a gauge link at light cone infinity is necessary for
transverse momentum-dependent parton distribution to restore the gauge
invariance in some specific boundary conditions. We derive such transverse
gauge link in a more regular and general method. We find the gauge link at
light cone infinity naturally arises from the contribution of the pinched
poles: one is from the quark propagator and the other is hidden in the gauge
vector field in light cone gauge. Actually, in the amplitude level, we have
obtained a more general gauge link over the hypersurface at light cone infinity
which is beyond the transverse direction. The difference of such gauge link
between semi-inclusive deep inelastic scattering and Drell-Yan processes can
also be obtained directly and clearly in our derivation.Comment: 18 pages, 5 figures, published versio
Non-Markovian Stochastic Resonance
The phenomenological linear response theory of non-Markovian Stochastic
Resonance (SR) is put forward for stationary two-state renewal processes. In
terms of a derivation of a non-Markov regression theorem we evaluate the
characteristic SR-quantifiers; i.e. the spectral power amplification (SPA) and
the signal-to-noise ratio (SNR), respectively. In clear contrast to Markovian
SR, a characteristic benchmark of genuine non-Markovian SR is its distinctive
dependence of the SPA and SNR on small (adiabatic) driving frequencies;
particularly, the adiabatic SNR becomes strongly suppressed over its Markovian
counterpart. This non-Markovian SR theory is elucidated for a fractal gating
dynamics of a potassium ion channel possessing an infinite variance of closed
sojourn times.Comment: 4 pages, 1 figur
The turbulent heat flux in low Mach number flows with large density variations
A transport equation has been derived which is the difference between the volume- and mass-averaged velocities and is simply related to the turbulent heat flux phi sup h. Using this equation and an assumption analogous to the drift flux approximation of two-phase flow modeling, an algebraic closure relation for phi sup h that exibits fluxes due to directed transport proportional to -del anti p and due to gradient transport proportional to -del tau has been obtained
NLO corrections in MC event generator for angular distribution of Drell-Yan lepton pair production
Using a subtraction method, we derive the formulae suitable for use in
Monte-Carlo event generators to give the angular distribution for the
gluon-quark induced NLO corrections in Drell-Yan lepton pair production. We
also give the corresponding helicity density matrix for W and Z boson
production.Comment: 14 pages, 2 figure
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