649 research outputs found
Hadronic Decays of Excited Heavy Mesons
We studied the hadronic decays of excited states of heavy mesons (D, D_s, B
and B_s) to lighter states by emission of pi, eta or K. Wavefunctions and
energy levels of these excited states are determined using a Dirac equation for
the light quark in the potential generated by the heavy quark (including first
order corrections in the heavy quark expansion). Transition amplitudes are
computed in the context of the Heavy Chiral Quark Model.Comment: 4 pages (incl. figures), proceedings of the IV International
Conference on "Hyperons, Charm and Beauty Hadrons", Valencia (Spain
RPA quasi-elastic responses in infinite and finite nuclear systems
Quasi-elastic responses in nuclear matter and in C and Ca
nuclei are calculated in ring approximation to investigate the finite size
effects on the electromagnetic quasi-elastic responses. A method to simulate
these effects in infinite systems calculations is proposed. The sensitivity of
the results to the various terms of the residual interaction is studied. The
results of nuclear matter RPA calculations are compared with those obtained in
ring approximation to evidence the importance of the exchange terms.Comment: 14 pages, 8 figure
Pelletized Forage-Based Rations as Alternative Feeds for Improving Goat Productivity
Goat farming is very popular in the Philippines as it is considered by many to be a viable rural enterprise. Despite this, the goat industry is faced with many challenges, including problems relating to high pre-weaning mortality, poor nutrition and lack of strategic approaches to accelerate genetic improvement. The long term rate of increase of goat numbers is only 0.97% per annum, due to high offtake rates and low productivity. Thus, the Philippine goat population is only expected to reach 4.27million by 2020 (compared with the target of 6.2 million), given the 3.88million population in 2010 (Alo 2012). Interventions are needed to accelerate growth of the goat population. Goats are typically fed on locally available resources which are characterised by low quality and highly variable availability. These characteristics can be overcome through processing techniques such as sun drying and pelleting to ensure year round feed supply. Pelleting offers particular advantages. Feeding animals with pellets provides better feed efficiency, greater starch digestibility, less feed waste, non-selective feeding, better handling and storage, and increased income due to more efficient feeding and higher productivity. While pellets are available for swine, poultry and buffalo in the Philippine market, pellets for goats are not currently available. The aim of this study was to develop pelletized forage-based rations for goats and evaluate them for their technical and financial viability
Neutrino-Oxygen CC0 scattering in the SuSAv2-MEC model
We present the predictions of the SuSAv2-MEC model for the double
differential charged-current muonic neutrino (antineutrino) cross section on
water for the T2K neutrino (antineutrino) beam. We validate our model by
comparing with the available inclusive electron scattering data on oxygen and
compare our predictions with the recent T2K -O data, finding
good agreement at all kinematics. We show that the results are very similar to
those obtained for C scattering, except at low energies, and we
comment on the origin of this difference. A factorized spectral function model
of O is also included for purposes of comparison.Comment: 28 pages, 10 figures, JLAB-THY-17-2586. Version 2 accepted for
publication in Journal of Physics G: Nucl. Part. Phy
Exchange Current Corrections to Neutrino--Nucleus Scattering
Relativistic exchange current corrections to neutrino--nucleus cross sections
are presented assuming non--vanishing strange quark form factors for the
constituent nucleons. For charged current processes the exchange current
corrections can lower the impulse approximation results by 10\% while these
corrections are found to be sensitive to both the nuclear density and the
strange quark axial form factor of the nucleon for neutral current processes.
Implications on the LSND experiment to determine this form factor are
discussed.Comment: 11 pages, 2 figures, revtex 3.0, full postscript version of the file
and figures available at
http://www.nikhefk.nikhef.nl/projects/Theory/preprints/preprints.html To
appear in Phys. Rev. Lett
Deuteron Magnetic and Quadrupole Moments with a Poincar\'e Covariant Current Operator in the Front-Form Dynamics
The deuteron magnetic and quadrupole moments are unambiguosly determined
within the front-form Hamiltonian dynamics, by using a new current operator
which fulfills Poincar\'e, parity and time reversal covariance, together with
hermiticity and the continuity equation. For both quantities the usual
disagreement between theoretical and experimental results is largely removed.Comment: To appear in Phys. Rev. Let
Two-nucleon knockout contributions to the C reaction in the dip and {}(1232) regions
The contributions from C and C to the
semi-exclusive C cross section have been calculated in an
unfactorized model for two-nucleon emission. We assume direct two-nucleon
knockout after virtual photon coupling with the two-body pion-exchange currents
in the target nucleus. Results are presented at several kinematical conditions
in the dip and (1232) regions. The calculated two-nucleon knockout
strength is observed to account for a large fraction of the measured
strength above the two-nucleon emission threshold.Comment: 12 Revtex pages, 4 postscript figures (available upon request),
University of Gent preprint SSF94-02-0
Mean-field calculations of quasi-elastic responses in 4He
We present calculations of the quasi-elastic responses functions in 4He based
upon a mean-field model used to perform analogous calculations in heavier
nuclei. The meson exchange current contribution is small if compared with the
results of calculations where short-range correlations are explicitly
considered. It is argued that the presence of these correlations in the
description of the nuclear wave functions is crucial to make meson exchange
current effects appreciable.Comment: uuencoded file containing 7 LaTex peges plus 3 ps figures. To be
published in Physical Review
Experimental and Theoretical Results for Weak Charge Current Backward Proton Production
In this paper, we do three things in the study of deuteron break-up by high
energy neutrino beams. (1) We present previously unpublished data on neutrino
induced backward protons from deuteron targets; (2) we calculate the
contributions from both the two-nucleon (2N) and six-quark (6q) deuteron
components, which depend upon the overall normalization of the part that is 6q;
and (3) we suggest other signatures for distinguishing the 2N and 6q clusters.
We conclude that the 6q cluster easily explains the shape of the high momentum
backward proton spectrum, and its size is nicely explained if the amount of 6q
is one or a few percent by normalization of the deuteron. There is a crossover,
above which the 6q contribution is important or dominant, at 300--400 MeV/c
backward proton momentum.Comment: 8 pages, 5 figure
Prediction of Mental Health Services Use One Year After Regular Referral to Specialized Care Versus Referral to Stepped Collaborative Care
FSW - Self-regulation models for health behavior and psychopathology - ou
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