NO A goals & physics NO A goals & physics NO A sites & detectors NO A sites & detectors NO A now &...

NOANuMI Off-Axis νe Appearance Experiment

FZU – Atlas seminar Praha 2012/6/15

Jaroslav Zálešák (FZU)

NOA goals & physics NOA sites & detectors NOA now & future

FZU - Atlas seminar, 15. 6. 2012 2Jaroslav Zalesak

Neutrino Mixing Matrix and Masses

atmospheric n solar nMixed Term

e

1 0 0

0 cos23 sin23

0 sin23 cos23

cos13 0 sin13e i

0 1 0

sin13e i 0 cos13

cos12 sin12 0

sin12 cos12 0

0 0 1

1

2

3

Pontecorvo–Maki–Nakagawa–Sakata matrix


Atmospheric:

m312 (2.45 0.009) 10 3eV 2

sin223 0.510.06

Solar:

m212 (7.59 0.18

0.20) 10 5eV 2

sin212 0.312 0.0150.017


e

1 0 0

0 cos23 sin23

0 sin23 cos23

cos13 0 sin13e i

0 1 0

sin13e i 0 cos13

cos12 sin12 0

sin12 cos12 0

0 0 1

1

2

3

solar natmospheric n Mixed Term

arXiv:1108.1376



e

1 0 0

0 cos23 sin23

0 sin23 cos23

cos13 0 sin13e i

0 1 0

sin13e i 0 cos13

cos12 sin12 0

sin12 cos12 0

0 0 1

1

2

3

atmospheric n solar nMixed Term

M. Messier (Indiana)

sin22θ13

Daya Bay 0.092 ± 0.017 arXiv:1203.1669v2 [hep-ex]

RENO 0.113 ± 0.023 (revised)

arXiv:1204.0626v2 [hep-ex] Reactor Average

0.099 ± 0.014 Combined Average

0.092 ± 0.012


Mass Hierarchy

Currently the mass hierarchy is unknown


NO A Collaboration𝜈150+ scientists and engineers from 25 institutions, 5 countriesANL / Athens / Caltech / Institute of Physics ASCR / Charles University / FNAL / Harvard

India Universities Consortium / Indiana / Iowa State / Lebedev / Michigan StateMinnesota, Crookston / Minnesota, Duluth / Minnesota, Twin Cities / INR Moscow / South Carolina

SMU / Stanford / Tennessee / Texas, Austin / Tufts / Virginia / WSU / William & Mary


The NO A Experiment𝜈 Long baseline neutrino oscillation

experiment: Near (ND) and far (FD) detector Off-axis in order to have a narrow

neutrino flux with the energy peak is at 2GeV

810 km long baseline from Fermilab to Ash River, Minnesota.

Physics goals: Search for νμ→νe oscillations. precision measurements of |Δm2

31|, θ23 octant determine mass hierarchy. constrain CP violating phase. and more: cross sections, sterile ,

supernova , other exotics

810 km

baseline

NOvA Far Detector (Ash River, MN)

MINOS Far Detector (Soudan, MN)


Extracting Nature’s Parameters

≈

+

×

The NOνA baseline (L = 810 km) and neutrino beam energy (E = 2 GeV) place our detector at the first νμ νe oscillation peak.

Extract the following terms by measuring the νe appearance rate: sin22θ13: the leading term in this equation has already been measured and it is large! sin2θ23: we can gleam information about the θ23 octant from the leading term. δCP: using the measured value of θ13, we can determine the CP-violating phase angle.

Mass hierarchy: depending on the sign of Δm231 ~ Δm2

32, the oscillation probability is either enhanced or

suppressed. This difference can be determined by comparing neutrino running with anti-neutrino running (30% matter effect on oscillation).

_

_

+


Neutrino Landscape

Forero, Tortola, Valle 2012 arXiv:1205.4018

Latest ν Oscillations Global fit:

Our knowledge of neutrino mixing has changed dramatically over the last year

We have gone from having no information on θ13 to knowing that: θ13 is large ≈9° θ13 is the most precise neutrino

measurements we have.

The experimental picture for neutrino physics now shifts from trying to measure if θ13 ≠ 0 to three general experimental thrusts:1. Is δ≠0?

Is there CP violation in the ν sector?2. Is Δm13 > 0?

Is the neutrino mass hierarchy normal or inverted?

3. Make precision measurements of θ23, θ13, θ12

Over constrain the standard mixing model to look for new physics.

This has dramatically changed the experimental landscape & opened up new possibilities in the ν sector


Off-axis beam

E 1 m

2

m2

E

12 2

target

Decay Pipe

p+

n

q

ND

FD

Placing detectors 14 mrad off the beam axis results in 2GeV narrow band beam with Eν width ≈20%. Close to the oscillation maximum.

The detector technology, geometry and baseline are then tuned to give: L/E for 1st Oscillation Maximum Energy resolution for νμ CC events ≈ 4% High efficiency EM shower reconstruction in sub 2GeV region


Magnet Near Detector

Far Detectorp 14.6 mrad

νμ

νμ/νe

π+

NuMI Beamline

NuMI Beam

Target

NuMI: Neutrinos at the Main Injector Beam delivered to several neutrino experiments since 2005

MINOS, MINERνA, and ArgoNeut Beam shutdown: May 2012 – May 2013

upgrade beam:• increase beam power from 300 kW to 700 kW (6 month rump-up)• reduce cycle time from 2.2 s to 1.3 s• upgrade graphite target and magnetic focusing horns 4.9e13 POT/pulse or 6e20 POT/year.

near detector cavern excavation


NO A experiment sites𝜈

Far Detector (15 kT)

2012-2014

Near Det

Proto Det

2010

12

★

★

It includes: Doubling of the Fermilab NuMI

beam power to 700 kW An 15kTon totally active surface

detector, 14 mrad off axis at 810km Far detector (FD)(first oscillation max for 2GeV )

A 300 Ton totally active near detector Near detector (FD)

Prototype NDOS

Optimized as a segmented low Z highly-active tracking calorimeter : Reconstruct EM showers Measure muon tracks Detect nuclear recoils and

interaction vertices

FZU - Atlas seminar, 15. 6. 2012 13

To APD

4 cm ⨯ 6 cm

1560 cm

Jaroslav Zalesak

NO A Detectors𝜈

Near Detector0.3 kton

206 layers

Far Detector14 kton

928 layers15.6

m

4.1 m

Fiber pairs from 32 cells

32-pixel APD

Far detector: 14-kton, fine-grained,

tracking calorimeter → 360,000 channels → 77% active by mass Near detector: 0.3-kton version of the same → 18,000 channels

cell

Extruded PVC cells filled with 11M liters of scintillator instrumented with -shifting fiber and APDs𝜆


Far Detector (FD) 15kT “Totally Active”, Low Z, Range

Stack/Calorimeter Surface Detector Liquid Scintillator filled PVC 960 alternating X-Y planes Optimized for EM shower reconstruction

& muon tracking, X0 ≈40cm, Rm≈11cm Dims: 53x53x180ft “Largest Plastic Structure built by man” Began construction May 2012 First operation est. Sep. 2012 (cosmics)

Near Detector (ND) Identical to far detector 1:4 scale size Underground Detector Optimized for NuMI

cavern rates -- 4x sampling rate electronics

…are BIG !NOvA Detectors …


Near Detector(s) at Fermilab

105 m underground: beam is aimed downward using MINOS near detector shaft construction will start after cavern excavation 4 m × 4 m × 14 m 266 tons = 639 modules = 20,448 channels

On the surface: prototype detector to test detector technology Completed in May 2011 3 m × 4 m × 14 m 222 tons = 496 modules = 15,904 channels successful running until beam shutdown in April


NOνA Near Detector Prototype (NDOS) The NOνA Prototype detector (NDOS)

located on the surface at Fermilab. Uses the same materials and technologies

as the Near and Far detectors. The NDOS is ~6.1 ̊ off the NuMI beam axis

(120GeV) and on the Booster beam (8GeV)

Goals: Testing assembly techniques for the Near and Far Detectors. Installing, operating, testing the NOνA electronics and DAQ. Developing reconstruction and calibration methods, and physics analyses & MC. Can measure different neutrino fluxes, beam time structures, low energy detector

response, quasi-elastic cross sections


The Detector Technology

Jaroslav Zalesak

Light is generated by charged particles and collected by wavelength-shifting fiber. Each avalanche photodiode (APD) reads out 32 cells. Each APD is connected to a Front End Board (FEB). The FEB digitizes signal, sends it to a Data Concentrator Module (DCM). Each DCM can read 64 FEBs. The NDOS uses 11 DCMs.

15.5m

6.6cm3.9cm

Particle Trajectory

Scintillation Light

Wavelength shiftingFiber Loop

To APD Readout


Avalanche photo-diode (APD)

Jaroslav Zalesak

Relatively inexpensive (about $10 per channel)

85% QE for 520 – 550 nm light. Gain of 100 @ 375 volts. Array of 32 pixels Actively cooled to -15oC. 11,150 APDs at the Far detector

NOνA Detection Cell The base detector unit 3.9x6.6cm cell 15.5m long, filled

with a mineral oil based liquid scintillator. Passage of MIP through the cell (longitudinal to beam)

results in dE/dx ≈12.9 MeV across the cell. Roughly 10% of energy loss is in the PVC wall Yields 10-12MeV of deposition in the scint.

The measured light output is 30-38 p.e. from the far end of the cell into the APD readout

Light yield gives a minimum Sig/Noise 10:1 (far end) Signal is amplified and shaped Channel is continuously sampled at 2MHz

to obtain wave form Zero suppression is performed at

(0.5-0.66) MIP (15-20 p.e.) via a dual correlated sampling (dcs) algorithm

Results in a single cell, lower energy detection threshold of ≈6-8MeV (far end)

Fits to the shape of the waveform recover the timing and pulse height information


Front-end-board (FEB)

Jaroslav Zalesak

Low noise ASIC amplifier is developed to maximize the sensitivity to small signals from the fiber.

Analog-to-Digital converter samples each pixel with a frequency of 2 MHz (8 MHz at the Near Detector)

Field Programmable Gate Array preselects “hits” and sends the readout information to DAQ.

Thermo Electric Cooler Controller controls the amount of drive current to supply for a Thermo Electric Cooler installed on the APD module.

ASIC signal output as a function of time


Construction Schedule NOvA will turn on April 2013 with 5 kton of Far detector in place and beam

operating at about 400 kW. We will add detector mass at a rate of ~ 1 kton/month. Beam intensity will ramp up to 700 kW in approximately 6 months.

Far Detector at 5 ktonwhen beam returns

Six months to 700 kW NuMI

14 kton in May 2014

Evolution of detector mass and beam power…


Prototype Near Detector (2010-2012)

Jaroslav Zalesak

Designed for: Running 2010-Present Component

installation, testing and integration,

DAQ & readout development

Calibration, reconstruction and background studies

Flux and cross section measurements


Far Detector Building – Complete

Jaroslav Zalesak


Inside the Hall (looking south)

Jaroslav Zalesak


With the block pivoter

Jaroslav Zalesak


Simulated Event Signatures

Jaroslav Zalesak

νμ charged-current long, well-defined muon

track short proton track with

large energy deposition at end

νe charged-current single EM shower characteristic EM shower

development

neutral-current with π0 final state multiple displaced EM

showers possible gaps near event

vertex


NDOS: Cosmic Ray Muon Data

Jaroslav Zalesak

Reconstructed cosmic ray muons are used for calibration and commissioning. Efficiency of cosmic tracker: >98%.


NDOS: Neutrino Candidate

Jaroslav Zalesak


Events in NDOS

Jaroslav Zalesak

Neutrino & cosmic ray @ NDOSDevelop commissioning, calibration,

reconstruction, and analysis tools

coincident

cosmic ray

NuMI neutrinointeraction

Neutrino eventsin beam direction


Neutrino event distributions

Jaroslav Zalesak

NuMI neutrino events at NDOS Two example distributions: angle of primary track w.r.t. the

neutrino beam, and total visible energy [in photoelectrons] Monte Carlo simulation agrees well with observations


Estimated νe Appearance Signal

Jaroslav Zalesak

The large θ13 is extremely good for NOvA since it leads to large event rates in the far detector and enhancing early sensitivities.

The following sensitivities use our earlier analysis approaches but include the latest knowledge of θ13:

Sin22θ13=0.095 Optimized for 4% oscillation probability∼ 10% uncertainty on backgrounds 41% (ν) and 48% (anti-ν) signal efficiency

Estimated numbers based on:15 kton, 18 x 1020 POT (3 years each neutrino-mode running)No solar-atmospheric terms and no matter effects


Early Reach

Jaroslav Zalesak

Will start with 𝜈 runningCan switch to �͞� 𝜇 any time,

optimizing the run planbased on our or others’results

5𝜎 observation of 𝜈𝜇→𝜈e

in first year if NH(even with partial detector and beam commissioning!)

… and beyondNominal run plan: 3 yr (𝜈) + 3 yr

(�͞� ) (with 6×1020 p.o.t./year)

NC𝜈𝜇 CC𝜈e CCtot. BG𝜈𝜇→𝜈e

1958

3268

10<15

1532

�͞� 𝜈 beam =


NO A measurement principle𝜈

Jaroslav Zalesak

NO𝜈A will measure:

P(𝜈 𝜇→𝜈 e) at 2 GeV

P(�͞� 𝜇→�͞� e) at 2 GeV&

These depend in differentways on the CP phase 𝛿and on sign(m2) .

Appearance probabilities are plotted as:

P(�͞� e) vs. P(𝜈 e)

for all 𝛿 and both hierarchies[ assuming: sin2(2 13)=0.095, sin2(2 23)=1 ]𝜃 𝜃


NO A measurement principle𝜈

Jaroslav Zalesak

Example NO A result…𝜈P(𝜈 𝜇→𝜈 e) at 2 GeV

P(�͞� 𝜇→�͞� e) at 2 GeV&

Data will yield allowed regions in P(�͞� e) vs. P(𝜈 e) space (3 yr + 3 yr possibility shown)

Here, all inverted hierarchyscenarios are

excluded at >2𝜎


sin2(2𝜃23) ≠ 1 ? (non maximal)

Jaroslav Zalesak

sin2(2𝜃)

|m

2 | (

10-3

eV2 )

Example NO𝜈A contoursfor three test points

sin2(2𝜃23) = 1

sin2(2𝜃23) = 0.94

4% energy resolutionfor the QE sample.

Inclusive 𝜈𝜇 CC sampleshould be background-free


𝜃23 octant sensitivity

P(𝜈 e) ∝ sin2(𝜃23)sin2(2𝜃13) Expected NO𝜈A contoursfor one example scenarioat 3 yr + 3 yr

𝜈e 𝜈𝜇𝜈𝜏𝜈e 𝜈𝜇𝜈𝜏

𝜈3?

𝜃23 > 45°

𝜃23 < 45°

Simultaneous hierarchy, CP phase & 𝜃23 octant information from NO A𝜈

Θ23=45°


Mass Hierarchy resolution

Jaroslav Zalesak

Including T2K information In T2K, P(𝜈 𝜇→𝜈 e) has 𝛿 dependence

but comparatively little hierarchydependence (shorter baseline).

When CPv and matter effectscancel in NO𝜈A, the NO𝜈A + T2Kcombination helps.

𝛿 range included for givensignificance of hierarchy

determination (m2 > 0 case)


Summary

Jaroslav Zalesak

NO𝜈A FD assembly underway at Ash River!NuMI upgrades underway → 700 kW First neutrino events in the partial FD

next SpringNDOS run:

→ commissioning, cosmic ray, and neutrino data → invaluable for assembly practice and analysis development

Actively developing analyses for 1st FD data → aiming to surpass the sensitivities shown

The observed 𝜃13 is great for NO𝜈A program → mass hierarchy, 𝛿CP, 𝜃23 → broad range of 𝜈-sector measurements

Far Detector Hall


END


NOνA Measurements

Jaroslav Zalesak

The transition probability is dependent on θ13,θ23,δCP and Δm31

The reactor measurements do not have the these dependencies

NOvA measures P(𝜈 𝜇→𝜈 e) & P(�͞� 𝜇→�͞� e)over an 810 km baseline at a central energy of 2GeV.

NO A goals & physics NO A goals & physics NO A sites & detectors NO A sites & detectors NO A now &...

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