MINOS and NOvA:
Himmel, Howcroft, Mualem, Newman,
Ochoa, Patterson, Peck, Trevor
 Faculty
MINOS
H. Newman
C. Peck
 MINOS ne Analysis; C. Howcroft,
Neutral Current Bgd. P. Ochoa
Anti-Neutrino & n-n
P. Ochoa, Howcroft,
Oscillation Analysis; A. Himmel
Beam ne Calibration
 MINOS Atmospheric Howcroft
n Analysis
 Veto Shield: Precise Ochoa
Calibration and Ops.
 Proton Intensity
Howcroft, Zheng
 NOnA R&D:
J. Trevor, L. Mualem
Himmel, H. Zheng
Megaton Water-Scint. Trevor, Himmel +
Detector R&D
Undergrads
Neutrino physics at Caltech MINOS
Physics Goals
 Measure nm↔nt flavor oscillations
MINOS
 Precise (<10% Now; to ~5%) measurement of Dm223
 Provide high statistics discrimination against alternatives
such as decoherence, n decay, sterile neutrinos, etc.
 Search for subdominant nm↔ne oscillations
 A shot at measuring q13
(or: improve CHOOZ limit by a good factor of two)
 Directly compare atmospheric n vs anti-n
oscillations:
 MINOS is the first large underground detector
with a magnetic field for m+/m- tagging event-by-event
 First measurement of charge ratio from cosmic neutrinos.
 As data accumulates, probe n & anti-n flavor-content
MINOS
Main Injector Neutrino Oscillation Search
 Investigate n and anti-n flavor
oscillations using intense,
well-understood NuMI beam
 Two similar magnetized ironscintillator calorimeters
 Near Detector
980 tons, 1 km from
target, 90m deep
 Far Detector
5400 tons, 735 km
away, 700 m deep
735 km
MINOS
Veto
Shield
Far Detector
nμ Disappearance
MINOS
Basic idea is to compare oscillated and unoscillated
spectra, using 2 “~identical” Fe-Scint. Tracking Calorimeters
Intense Beam
Monte
Carlo
m
nn
nn
n nn
n
Unoscillated
Oscillated
pure nμ beam
Monte
Carlo
p
proton
Cross Section & Beam uncertainties cancel
to high accuracy between the two Detectors
p
m
proton
nμ Disappearance
MINOS
Comparing the oscillated and unoscillated spectra
P(n m n m )  1  sin 2 2q sin 2 (1.267Dm2 L / E)
2
1
Monte Carlo
Monte Carlo
Unoscillated
Oscillated
1
2
New results from the second year of MINOS running
MINOS: Caltech History and Roles
HISTORY: MINOS at Caltech
MINOS
 Original Detector Concept and Design: Doug Michael
 Led Successful Optical Fiber R&D: ~10 p.e. Per M.I.P;
A Key to Data Quality
 Half of the scintillator modules were built at Caltech, in Lauritsen Lab
ROLES
 Howcroft on MINOS Exec. Committee, paper review committees,
DAQ software, MC production and Software Review Committee
 Central Roles in Atmospheric Neutrino Analysis;
[CH]
ne Analysis: Shower reco., selection, bgd. calculations [PO,CH,AH,HZ]
 CR Veto Shield: Rigorous Geometry, Time-Calibration,
Alignment; Operations
[Pedro Ochoa; now the MINOS expert]
 Proton Intensity R&D [Michael]: Barrier RF Stacking;
[HZ]
Digital Damping System for the 8 GeV Booster
[CH]
New ROLES
 Lead role in ne Analysis (MCNN); ne backgrounds
 Lead role in antineutrino analysis: Dm223,
(CPT Test), beam systematics, other BSM
physics (e.g. n – n oscillations)
[PO, CH]
[PO, CH, AH]
MINOS Status
MINOS
 The last three years have been a very exciting time
for MINOS
 NuMI construction project completed successfully
in January 2005
 Analyzed ~12kTon-years of Atmospheric, signseparated data; including before beam; tested
charge ratio in neutrino interactions
 Have been taking physics beam data since March 2005:
We already collected 3.6 x 1020 protons on target
 MINOS and NUMI have been running well:
now getting a steady 5 x 1018 POT per week
 Expect to reach 1021 p.o.t. within the next ~2.5 years
Atmospheric “cosmic”
neutrino+antineutrino results
MINOS
Caltech (Howcroft) had a central role
in the first MINOS physics publication.
MINOS 23 Oscillation Results
Present & Projected Sensitivity
MINOS
Today

Input
In 2006, MINOS published the most precise determination of Dm223
New results with twice the data (2.5 X 1020 POT) just released.
Physics of Anti-neutrinos
Using MINOS and NUMI
 Caltech [CH, PO] formed a study group in 2006 to
MINOS
investigate the physics of anti-neutrino’s using MINOS.
 Physics subjects investigated:
 Δm223 for anti-neutrinos: CPT violation tests

ν  ν Transitions.
 Obtaining a measurement of the intrinsic beam
an important background for the θ13 analysis.
 A great deal of progress in the last year.
νe
The MINOS Veto Shield [Ochoa]
MINOS
Veto Shield Timing:
 Single hit resolution remains at 4.2ns.
 Calculated 4 more calibration sets in 2006-7.
All data periods are now covered
Veto Shield Maintenance and Operation:
 Calculate efficiencies on plank by plank basis.
Bad cable !
(fixed in June 2006)
 Located 1 bad cable, one light leak, one dead channel in 2006.
ne Appearance: the Search for θ13
 Caltech [CH, PO] have established
MINOS
lead roles in the MINOs search for
ne appearance.
 We have focused on:
 Maximizing the signal selection
using techniques that maximize
information usage
 “MCNN” selects “nearest
neighbor” strip patterns
 Understanding the major
background: esp. Neutral
Currents, which make up
50% of the selected events
“MRCC” technique removes
muon from CC events
MINOS may make the first
 MINOS will reach or surpass the
observation of finite θ13
CHOOZ sensitivity by end of 2007
The NOnA Detector
~80 m
15.7 m
 ~16 kT total mass, off axis
 “Totally Active” granular
liquid scintillator design
 Outstanding ne pattern
recognition & measurement
Working to fit 260M AY$ TPC cap
13
Caltech in NOnA
 Sensitive to Sin2 2q13 down to ~0.01 (~20X better than
MINOS
the current limit); possibly resolve the mass hierarchy
 D. Michael had a founding role; + leading design & development
 Stage 1 approval by Fermilab April 2006; Stage 2 Underway
 Caltech involvement ramped up successfully in 2005-7;
now substantially strengthened by the arrival of Leon Mualem
 LM on the Executive Committee, Technical Board,
and Level 2 Manager for Electronics & DAQ
 Caltech now has the central R&D role, covering the key
measurements that set the design & construction:
light output, fibers, extrusions, mineral oil [J. Trevor, L. Mualem]
 Our experience with MINOS development and fabrication
(Trevor, Mualem) is proving to be invaluable
 Arrival of Tolman Prize Fellow Patterson this August will
substantially strengthen our effort on NOnA, as well as MINOS
NOnA Tasks at Caltech
 Hardware
 DAQ/Electronics Management
 APD Testing
 Cell Tests: PVC, Fiber, Mineral Oil
 Vertical Slice Tests
 Software
 Framework Development
 Subshower Package
 Photon Transport simulation
 Supernova Sensitivity
A wide range of key tasks are the
responsibility of the Caltech group
ADR Grant: Prototyping Next-Generation
Megaton Neutrino Detectors
 $ 48k ADR grant: covers technician
salary and equipment
 Focus is on further development of
water/plastic scintillator readout systems
 Aims: high light output; low cost per
kiloton (projected savings: 80 to 90%)
 Sol’n: 1 cubic meter tank detector 
 Scintillator strands have replaced
granules of earlier design
 Easier to get high quality scintillator,
no circulation system required
 More realistic configuration for larger
detectors, but more difficult to construct
MINOS
WLS Fibers
PMT
Construction is complete!
Promising preliminary results
More complete analysis soon (A 1 m cube)
Scintillator Strands
MINOS Group: Evolution & Impact
MINOS
2 Faculty (HN, Peck), 1 Research Scientist (Leon Mualem),
1 Tolman Fellow (Ryan Patterson), 2 Grad. Students
(Ochoa, Himmel), Technician (Trevor)
 Doug Michael tragically passed away in 2005
 $ 100k cut from MINOS Budget
 Peck and Barish are now Emeritus (Peck part time):
Postdoc Hai Zheng left; Caius Howcroft now part time
 Research Scientist Leon Mualem joined us this year
Tolman Fellow Ryan Patterson will start in August
 Although smaller, the group remains strong:
Caltech now has crucial, central roles in both MINOS
operations and physics, and NOnA R&D and construction
 We need to add a postdoc and a graduate student
Request $ 480k for FY2008 on the DOE Grant [$ 465k in FY06]
 Restore cut in 2007 that could compromise
the MINOS and NOnA Programs.
CALTECH MINOS GROUP
BUDGET Request for FY 2007
MINOS
SALARIES
 Direct Cost
 Staff Benefits 24.5%; Student TR 63.5%
TOTAL SALARIES + SB/TR
$ 183 K
$ 85 K
$ 268 K
TRAVEL and Per Diem
 Direct Cost
$
31 K
SUPPLIES and EXPENSE
 Direct Cost At Caltech and Fermilab
$
15 K
 OVERHEAD (54.7% On Campus)
$ 166 K
Request for FY2008: $ 480 K
[FY06 Budget $ 465 K]
MINOS Group Payoff
MINOS
MINOS and NOnA Leading Contributions
MINOS
CC Analysis for Neutrino 2  3 Oscillations
Antineutrino Oscillation Analysis and Run Plan
ne Optimized Analysis for 1  3 Oscillations
Background studies and tools
n  n Transition Analysis
Proton Intensity Work
NOnA
Key Detector Design and Development Studies
Software: 1st Framework; MC & Reconstruction
Analysis for More Sensitive Tests of q13
MINOS
Extra Slides
Follow
Jason Trevor
 NOnA detector R&D
MINOS
[with Leon Mualem]
 Testing of the various NOnA -type extrusions in order
to establish a relationship between light yield and the
reflectivity of the extrusion cell walls.
 Measurement of of WLS fiber characteristics. In
particular we are looking at the relationship between
dye concentration and attenuation length.
 Perform light yield measurements for a minimum
ionizing muon passing through a baseline NOνA cell
near the U-bend in a full length (~33m) WLS fiber loop.
 Prototyping Next-Generation Megaton Detectors
 Design, construction and testing of a hybrid
water/plastic scintillator detector prototype.
Caius Howcroft
MINOS

MINOS

Central involvement in the group looking for
ne appearance in the nμ beam. In particular
the modeling of Neutral Current
backgrounds
Atmospheric neutrinos - using the MINOS
far detector to test CPT invariance for
neutrinos
Antineutrinos - Looking for appearance in
the beam and research into future antineutrino running
Central role in the running of the
experiment:
MINOS Ex-com, Publications committee and
speakers committee



Atmospheric Neutrino Studies:
Using the Veto Shield (Ochoa)
 Caltech has been looking at ways to improve the
MINOS
current atmospheric neutrino selection
 Upward going events carry a lot of information about
oscillations; as is evident from the recent analysis
 Current upward going selection is based on hit-timing along
the track
 Additional information may come from timing of veto shield
hits, improving the 1/b resol’n, and resolving some Up-Down
ambiguities for PC events
 Ochoa’s precise
veto shield
time-calibration
a key step
Veto shield hit
Gradient =
1/particle velocity
t/s
Hits along track
distance along track
Antineutrino and nn Oscillation Analysis
Studies [PO, AH, CH]
 Combining FHC with RHC can
obtain a measurement of Dm223
that rivals our current
measurements of Dm223:
2
Dm23
Only ~4 months of antineutrino
running (plus ~1 more year of
normal running) are needed !
 This data would considerably
reduce our best current
limits on neutrino CPT
MINOS
6x1020 POT (FHC) +
1x1020 POT (RHC)
90% C.L.
68.3% C.L.
Prelim MC
sin 2 (2q 23 )
90% Tentative exclusion limit
Effort led by Caltech
We are also interested in other BSM
physics such as nn transitions
At Caltech we’ve shown that if these
occur at the 10% level or more, we
should be able to observe them in MINOS
90%
95%
99%
3σ
NOnA Scintillator System
 Each cell an extruded TiO2 loaded PVC tube
with ID 60mm x 39mm x 15.7m long
 Cells filled with mineral oil scintillator;
read out at one end with U-loop WLS fiber,
going to one pixel on a multi-pixel APD
 Kuraray 0.7 mm WLS Fiber
 Light output minimum requirement set by
achievable noise on the APD amplifier;
The current estimate of required Light
Output is ~20-25 photoelectrons
0.7mm WLS
Fiber
R&D at Caltech





Composition of PVC cell walls
Liquid scintillator composition
Fiber diameter and dye concentration
Fiber position
Integration testing
One Cell
25
The Antineutrino-PID Method [Ochoa]
 For each event, calculate the product of probabilities that
MINOS
event comes from the nu or nubar distributions
4
Pn   PDFxn (var x )
x 1
4
Pn   PDFxn (var x )
x 1
all
v
v
NC
Purity
The nubar-PID parameter is given by: PIDn /n    log Pn   log Pn
 Observe very clear separation: Very high purity with good efficiency
Fit significance cut:
Pr ob(  2 , ndf )  0.1
Increase
NuBarPID cut
without fit signif. cut
with fit signif. cut
Efficiency
Note: Efficiency measured w.r.t. all true CC antineutrinos
Antineutrino systematics [Himmel]
MINOS
 Systematic errors are a crucial question in combining FHC and RHC
data.
 ~30% of antineutrinos produced outside of the target region
 While neutrinos are also produced outside the target, they are
negligible compared to those focused from the target.
 A large fraction of the difference between the near and far detectors
comes from decay pipe antineutrinos.
Antineutrino systematics [Himmel]
MINOS
 Uncertainties in the decay pipe modeling could affect the far/near
ratio creating a false signal.
 Toy systematic model:
 50% Scaling of the decay pipe component
 The other components of the flux unchanged
 Preliminary results suggest that the effect is small compared to the
expected statistical error.
Beam systematics [Himmel]
Old Monte Carlo
New Monte Carlo
Geant 3
Geometry
Geant 4
Geometry
MINOS
Flugg
Flugg
Fluka
Geometry
Geant-Fluka
Physics
Geant 4 Physics
Fluka Physics
 Working to update the beam Monte Carlo from Geant3 to
Geant4.
 Use Flugg to run the new geometry in Fluka, a more trusted
physics simulation
Proton Intensity and
Barrier RF Stacking R&D [Zheng]
 Doug Michael originated and leads the conceptual
MINOS
development of the FNAL proton intensity program
 Part of Caltech's involvement, in collaboration with
Fermilab Beam Division, is Barrier RF Stacking
(an alternative to slip stacking)
 Utilizes HV pulses as barriers to stack & squeeze the beam
 Two schemes are being studied: on-momentum injection
and off-momentum injection
 Barrier RF Stacking on-momentum injection study has
made a lot of progress over the year
 Successfully stacked two Booster batches and
reached 8.3e12 at 120 GeV (60% Increase)
 Barrier RF Stacking off-momentum injection study
demonstrates stacking is possible even with one barrier
 Hardware system for 2nd barrier has been assembled
and will be installed
 One of several Proton Intensity projects involving Caltech
NOnA Software R&D at Caltech
[CH, HZ]
 Our group also has built the first software
MINOS
framework, and is participating in the development
of NOnA detector simulation & event reconstruction
software
 Photon production and propagation simulation software
based on detector R&D measurements done locally
 Patterson will work with Howcroft to continue
these efforts
Initial Simulations at Caltech
(Howcroft, Zheng), building on MINOS
ne reconstruction work, showed
remarkable pattern recognition capability
Shower Reconstruction
and ne Analysis [HZ, CH]
MINOS
 The Caltech 3D Shower and Subshower packages
for ne event ID and reconstruction have become
the standard for MINOS, as anticipated in 2005.
 Based on PH distributions in 2D, SubShowers are
formed and ID’ed, then combined into 3D showers
 ne discriminants developed at Caltech, with
Cambridge, provide improved performance
 New technique to optimize the
ne ID capability using
full event-by-event shower pattern matching against
ne event templates, have been developed and are
now being successfully applied
[CH, PO]
MINOS – NUMI Running
Now 3.6 X 1020 POT
Accelerator shutdown
Many thanks to Accelerator Division Colleagues!!
Dataset used in the first
and current analysis
(1.27E20 POTs) Run I
Additional Data Set used
in current analysis
(1.23E20 POTs) Run IIa
Running in higher energy beam configurations
MINOS
MINOS Sensitivity to Sterile Neutrinos
(very preliminary)
MINOS