August 6 Minutes
New Study beginning: Superbeams with more experimental detail!
Table presented for us to consider filling in: Imagine
running narrow band beams at several energies, with realistic
beam fluxes (both signal and background beam fluxes!), and
realistic detector backgrounds and efficiencies:
what is the physics reach as a function of energy/baseline?
This reach should be evaluated as a function of delta m_23^2.
(perhaps 3 values should be chosen, for example).
There are a few baselines and detector options listed in a table
at the end of these minutes. Right now people have signed up for the
FNAL to Soudan and FNAL to SLAC baselines, but if you personally want to
study another baseline not listed then by all means make some flux files
and we can enter them into the machinery to study physics capabilities!
It's assumed that
one would run a narrow band beam at the peak of the "first minimum",
so that one would have the best signal/noise ratio. If the beamline
energy spectrum is narrow enough, one might also consider running at
higher energies, in an already existing beamline. The important thing
about this table is that each beamline be realistic, and then all the
detector, proton power, and running times should be consistent between
each study. Then we can really make comparisons between physics reaches
of different choices.
Although the table below lists several different baselines, it was
noted repeatedly that we should focus on really exploring fully all the
possibilities with the NUMI beamline, since that is what is being
built presently, and it's hard to imagine another beamline being built
any time soon...that being said, people were opposed to ignoring
completely the possibilities of higher energy beamlines going at different
Studies have already been done exploring off-axis beams: Larry Wai
has presented some results at MINOS and Snowmass (which Debbie showed
at the meeting today--just to demonstrate that off-axis beams may provide
more flux at a particular energy than the wide-band beam), and Michal Sleper
and Mayda Velasco will present results from their studies at next week's
Mayda Velasco and Michal Szleper have already started studies to see what
NUMI off-axis beams can produce, they will show the fluxes they have
achieved at the next meeting (August 13). Mayda Velasco and Peter Kasper
will also discuss the interaction between the proton driver upgrade group and
our study group--tune in next week!
Bob Bernstein offered to get his machinery going for these studies: if we can
come up with reasonable fluxes and detector resolutions, he can throw them
into his code and it will come up with physics sensitivities as a function
of delta m_23^2. (We also need to put in backgrounds as a function of
Mario Campanelli also offered to put input fluxes into his
monte carlo fitting aparatus as well. Mario stressed that it's not clear
what the correlation is between these off axis beam energies and beamline
geometry, etc. It would be nice to see a few general studies that give
people a feeling for how the off-axis beams work.
Jorge Morfin will explore the possibility of designer higher energy
but narrow band beamlines going to the MINOS far detector hall.
Debbie Harris offered to look into what high energy off-axis beamlines
might produce in terms of flux.
Although Water Cerenkov hasn't been studied in detail at these energies,
it's hoped that some of the UNO folks can contribute to this study as well
by coming up with background estimates for different fluxes.
|| Neutrino Energy (GeV)
||sin2 theta_13 reach
||sin2 theta_23 precision
||JHF-SK || WC (50)
||JHF-HK || WC (500)
||FNAL-"Soudan" 730km || Fe-based (50)
||FNLA-Homestake 1300km || Fe-based (50)
||FNAL-WIPP 1800km || Fe-based (50)
||FNAL-San Jacinto/SLAC 2900km || Liquid Ar (50)
||FNAL-"Soudan" 730km || Liquid Ar (25)
||FNLA-Homestake 1300km || Liquid Ar (25)
||FNAL-WIPP 1800km || Liquid Ar (25)
||FNAL-San Jacinto/SLAC 2900km || Liquid Ar (25)
||FNAL-"Soudan" 730km || Water Cerenkov (500?)
||FNLA-Homestake 1300km || Water Cerenkov (500?)
||FNAL-WIPP 1800km || Water Cerenkov (500?)
||FNAL-San Jacinto/SLAC 2900km || Water Cerenkov (500?)
Last modified: Mon Aug 6 15:41:56 CDT 2001