1,621 research outputs found
Forward Compton Scattering with weak neutral current: constraints from sum rules
We generalize forward real Compton amplitude to the case of the interference
of the electromagnetic and weak neutral current, formulate a low-energy
theorem, relate the new amplitudes to the interference structure functions and
obtain a new set of sum rules. We address a possible new sum rule that relates
the product of the axial charge and magnetic moment of the nucleon to the 0th
moment of the structure function . We apply the GDH and the finite
energy sum rule for constraining the dispersive -box correction to
the proton's weak charge.Comment: 6 pages, 2 figure
Perturbation of the Eigenvectors of the Graph Laplacian: Application to Image Denoising
The original contributions of this paper are twofold: a new understanding of
the influence of noise on the eigenvectors of the graph Laplacian of a set of
image patches, and an algorithm to estimate a denoised set of patches from a
noisy image. The algorithm relies on the following two observations: (1) the
low-index eigenvectors of the diffusion, or graph Laplacian, operators are very
robust to random perturbations of the weights and random changes in the
connections of the patch-graph; and (2) patches extracted from smooth regions
of the image are organized along smooth low-dimensional structures in the
patch-set, and therefore can be reconstructed with few eigenvectors.
Experiments demonstrate that our denoising algorithm outperforms the denoising
gold-standards
Can neutrino-induced photon production explain the low energy excess in MiniBooNE?
This report summarizes our study of Neutral Current (NC)-induced photon
production in MiniBooNE, as motivated by the low energy excess in this
experiment [A. A. Aquilar-Arevalo et al. (MiniBooNE Collaboration), Phys. Rev.
Lett. 98, 231801 (2007); 103, 111801 (2009)]. It was proposed that NC photon
production with two anomalous photon- boson-vector meson couplings might
explain the excess. However, our computed event numbers in both neutrino and
antineutrino runs are consistent with the previous MiniBooNE estimate that is
based on their pion production measurement. Various nuclear effects discussed
in our previous works, including nucleon Fermi motion, Pauli blocking, and the
resonance broadening in the nucleus, are taken into account.
Uncertainty due to the two anomalous terms and nuclear effects are studied in a
conservative way.Comment: 7 pages, 4 figures, and 5 tables, typos corrected, references
updated, version for publicatio
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