Minutes of the Neutrino Factory Physics Study Meeting
Tuesday November 9, 1999
Present LBL, FNAL, Davis, Stonybrook, Brookhaven, CERN
Scribes: Steve Geer, Debbie Harris, Bob Bernstein
1. Group 1 Beams report - Geer
Text for preliminary introductory chapter on beam properties
essentially complete. Need to work on figures. Have begun
looking into issues relevent to an understanding of the systematic
uncertainty on the flux at the far site. As an example, for a
50 GeV muon ring a beam divergence within the straight section of
0.2 mr would decrease the flux at a far site by, typically, 4%.
If L = 2800 km the statistical precision on a disappearance
measurement would be expected to be of order 0.2% .... hence we
would need to know loss due to beam divergence to 5% of itself if
this uncertainty is not to dominate ... looks hard. Anyone want
to start thinking about how to measure the divergence ?
2. Group 3 Oscillations Scenarios - Parke
The group is currently considering scenarios with sterile neutrinos.
Began to discuss this in a meeting last week, and will continue in
a meeting next Tuesday. Video link possibility exists ... send email
to Steve Parke if you wish to participate.
3. Matter Effects - Irina Mocioiu Talk
Matter effects can cause significant changes in the oscillation signals
in long baseline experiments. Matter effects can greatly improve the
sensitivity to certain parameters (e.g.\theta_{13}). They should also allow
the determination of the sign of \delta M^2. Combining different oscillation
channels and/or baselines is necessary to get useful information about all
oscillation parameters.
4. Group 2/4 Detectors/Oscillations - Harris
Two goals have emerged from the oscillation measurement group:
one is to see what detailed simulations of the data would look like,
including as many backgrounds as possible, as well as detector
fiducial effects and of course resolution. The other is to
see how a given set of data can constrain the mixing matrix.
The problem is that all the probabilities are functions of products
of the mixing angles, so one would like ultimately to use as much
information as possible. In the case of muon charge identification
detectors, this means using right sign disappearance as well as wrong-sign
appearance.
Plots were shown of the right sign and wrong sign muon energy
distribution coming from a detailed monte carlo simulation of a MINOS-like
detector. The detector was located 2800km away from the neutrino source,
and had wrong-sign events from both charm production and pi/k decays in
the hadron showers. A plot was also shown describing the sin2(2theta_23)
deltam_23 constraints that would arise from a 0.1kTon year exposure of a
MINOS-like detector located also at 2800km from the source, from muon
neutrino disappearnce alone.
All plots shown in this talk are accessible from the group 4 home
page: see the links in
http://www.fnal.gov/projects/muon_collider/nu/study/group4/group4.html
5. Group 5 - Hawker
Summary of the Non-oscillation group meeting (11/2/99) :
i) Draft outlines were presented for electroweak, structure function,
and spin structure sections of the non-oscillation report.
ii) Kevin McFarland briefly showed what he had presented at the
Neutrino Factory conference in Lyon.
iii) Heidi Schellman presented some more beam characteristics at a near
detector. The possiblity of a short straight section on the surface was
discussed.
Next non-osc meeting will be on Tuesday 11/16/99 at 11:30 CST in
WH12NW.