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<font color="#000099"><b><font color="#3333ff">Physics Seminar<br>
Friday, Sept. 9, 2011<br>
11:00AM<br>
CEBAF Center AUD.<br>
Cookies & Coffee at 10:45<br>
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<b><big><font color="#ff0000">Gerry Garvey
<br>
Los Alamos National Lab
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<big><br>
</big><font color="#ff0000"><big>"Problems in Neutrino-Nucleus
Scattering"</big>
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<br>
Recently published differential cross sections for neutrino charged
current quasi-elastic scattering (CCQE) on 12C by the MiniBooNE
collaboration are ~40% larger than typical impulse approximations
calculations of CCQE. Some of the difference is do to poor
communication between the theorists and experimentalists as to the
definition of CCQE scattering. More fundamentally the observed cross
section appears to be larger than the CCQE on 6 free neutrons. A
prominent theorist in the field claimed "a new paradigm" will be
required and there have been several recent publications failing to
account for the observed cross sections.
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<br>
In order to proceed with analysis of their data the MiniBooNE
collaboration fit the muon neutrino +12C CCQE yield by employing
MA=1.35 GeV for the nucleon axial vector form factor. The world average
for MA is 1.02� 0.02GeV. There exits an RPA calculation that finds good
agreement with the measured yield using MA=1.03 GeV but does not
reproduce the measured angular distribution.
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<br>
Some earlier work on electron quasi-elastic scattering demonstrated
that short-range correlations plus two-body currents greatly enhance
the nuclear transverse vector response in agreement with experiment.
Extending this approach to neutrino CCQE is most attractive. A direct
consequence of the approach is that the assigned neutrino energy
becomes far more uncertain than previously realized. The current state
of affairs in this active area will be presented noting improvements
needed in theory and experiment for neutrino-nucleus scattering for
0.3<En<3.0 GeV.<br>
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