Search results for "Radiative Transfer"
showing 10 items of 551 documents
Nonlinear Thermal Transport with Inertia in Thin Wires: Thermal Fronts and Steady States
2022
Abstract In a series of papers we have obtained results for nonlinear heat transport when thin wires exchange heat non-linearly with the surroundings, with particular attention to propagating solitons. Here we obtain and discuss new results related to the propagation of nonlinear heat fronts and some conceptual aspects referring to the application of the second principle of thermodynamics to some nonlinear steady states related to non-propagating solitons.
Affine compensation of illumination in hyperspectral remote sensing images
2009
A problem when working with optical satellite or airborne images is the need to compensate for changes in the illumination conditions at the time of acquisition. This is particularly critical when working with time series of data. Atmospheric correction strategies based on radiative transfer codes may provide a rigorous solution but it may not be the best solution for situations where a huge amount of hyperspectral images may need to be processed and computational time is a critical factor. The GMES (”Global Monitoring for Environment and Security”) initiative has promoted the creation of a new generation of satellites (the SENTINEL series) with ”ultra-high resolution” and ”superspectral im…
Measurement of the radiative K-e3 branching ratio
2005
We present a measurement of the relative branching ratio of the decay KL -> pi e nu gamma (Ke3gamma) with respect to KL-> pi e nu (gamma) (Ke3+Ke3gamma) decay. The result is based on observation of 19 000 Ke3gamma and 5.6 x 10^6 Ke3 decays. The value of the branching ratio is Br(Ke3gamma, Egamma^*>30 MeV,theta(e,gamma)^*>20^o)/Br(Ke3)= (0.964+-0.008+0.011-0.009)%. This result agrees with theoretical predictions but is at variance with a recently published result.
High-precision determination of the $K_{e3}$ radiative corrections
2021
We report a high-precision calculation of the Standard Model electroweak radiative corrections in the $K\to \pi e^+\nu(\gamma)$ decay as a part of the combined theory effort to understand the existing anomaly in the determinations of $V_{us}$. Our new analysis features a chiral resummation of the large infrared-singular terms in the radiative corrections and a well-under-control strong interaction uncertainty based on the most recent lattice QCD inputs. While being consistent with the current state-of-the-art results obtained from chiral perturbation theory, we reduce the existing theory uncertainty from $10^{-3}$ to $10^{-4}$. Our result suggests that the Standard Model electroweak effects…
QCD Induced Di-boson Production in Association with Two Jets at NLO QCD
2016
We discuss results for di-boson plus two jets production processes at the LHC at NLO QCD. Issues related to the scale choice are reviewed. We focus on the distributions of the invariant mass and rapidity separation of the two hardest jets and show, for $W^\pm \gamma jj$ and $Z\gamma jj$ production, how the contribution from the radiative decays of the massive gauge bosons can be significantly reduced.
Study of radiative bottomonium transitions using converted photons
2011
We use 111+/-1 million Upsilon(3S) and 89+/-1 million Upsilon(2S) events recorded by the BaBar detector at the PEP-II B-factory at SLAC to perform a study of radiative transitions between bottomonium states using photons that have been converted to e+e- pairs by the detector material. We observe Upsilon(3S) -> gamma chi_b0,2(1P) decay, make precise measurements of the branching fractions for chi_b1,2(1P,2P) -> gamma Upsilon(1S) and chi_b1,2(2P) -> gamma Upsilon(2S) decays, and search for radiative decay to the eta_b(1S) and eta_b(2S) states.
Long range two-particle rapidity correlations in collisions from high energy QCD evolution
2009
Long range rapidity correlations in A+A collisions are sensitive to strong color field dynamics at early times after the collision. These can be computed in a factorization formalism \cite{GelisLV5} which expresses the $n$-gluon inclusive spectrum at arbitrary rapidity separations in terms of the multi-parton correlations in the nuclear wavefunctions. This formalism includes all radiative and rescattering contributions, to leading accuracy in $\alpha_s\Delta Y$, where $\Delta Y$ is the rapidity separation between either one of the measured gluons and a projectile, or between the measured gluons themselves. In this paper, we use a mean field approximation for the evolution of the nuclear wav…
Probing Novel Scalar and Tensor Interactions from (Ultra)Cold Neutrons to the LHC
2012
Scalar and tensor interactions were once competitors to the now well-established V-A structure of the Standard Model weak interactions. We revisit these interactions and survey constraints from low-energy probes (neutron, nuclear, and pion decays) as well as collider searches. Currently, the most stringent limit on scalar and tensor interactions arise from 0+ -> 0+ nuclear decays and the radiative pion decay pi -> e nu gamma, respectively. For the future, we find that upcoming neutron beta decay and LHC measurements will compete in setting the most stringent bounds. For neutron beta decay, we demonstrate the importance of lattice computations of the neutron-to-proton matrix elements t…
Study of the f(2)(1270) , f(2)'(1525) , f(0)(1370) and f(0)(1710) in the J/psi radiative decays
2009
In this paper we present an approach to study the radiative decay modes of the J/psi into a photon and one of the tensor mesons f (2)(1270) , f' (2)(1525) , as well as the scalar ones f (0)(1370) and f (0)(1710) . Especially, we compare predictions that emerge from a scheme where the states appear dynamically in the solution of vector meson-vector meson scattering amplitudes to those from a (admittedly naive) quark model. We provide evidence that it might be possible to distinguish amongst the two scenarios, once improved data are available.
The radiative decay of the Lambda(1405) and its two-pole structure
2007
We evaluate theoretically the radiative decay widths into $\gamma\Lambda$ and $\gamma\Sigma^0$ of the two poles of the $\Lambda(1405)$ found in chiral unitary theories and we find quite different results for each of the two poles. We show that, depending on which reaction is used to measure the $\Lambda(1405)$ radiative decays, one gives more weight to one or the other pole, resulting in quite different shapes in the $\gamma\Lambda(\Sigma^0)$ invariant mass distributions. Our results for the high-energy pole agree with those of the empirical determination of the $\gamma\Lambda$ and $\gamma\Sigma^0$ radiative widths (based on an isobar model fitting of the $K^-p$ atom data), which are someti…