# Presentation: 520238

## The Future of Neutrino Physics in a Post-MiniBooNE Era

**H. Ray**
*Los Alamos National Laboratory*

## Outline

- Introduction to neutrino oscillations
- LSND : The motivation for MiniBooNE
- MiniBooNE Overview & Current Status
- The Spallation Neutron Source

- H. Ray

## Standard Model of Physics

**  ****0**
** ********1**

**+2/3**
** ****-1/3**

** ****0**
**-1**

- H. Ray

## Wave-Particle Duality

-     Flavor states are comprised of mass states

**ELECTRON**

- 

- e

**m****1**

**m****2**

- 

- e

- H. Ray

## Superposition of Masses

-   e

- H. Ray

## Neutrino Oscillations

********

******e**

**=**

**Weak state**

**Mass state**

******1**

******2**

**cos ******

**cos ******

**-sin ******

**sin ******

**|************(0)> = -sin ******** |********1****> + cos**** ******** |********2****> **

- H. Ray

## Neutrino Oscillations

********

******e**

**=**

**Weak state**

**Mass state**

******1**

******2**

**cos ******

**cos ******

**-sin ******

**sin ******

**|************(t)> = -sin ******** |********1****> + cos**** ******** |********2****> **

**e-****iE1t**

**e****-iE2t**

- H. Ray

## Neutrino Oscillations

**P****osc**** = |<********e ****| ************(t)>|****2**

- H. Ray

## Neutrino Oscillations

**P****osc**** =****sin****2****2******** sin****2**** 1.27 ********m****2**** ****L**
**	****	****	****	****	****	****E**

**Distance from point of creation of neutrino beam to detection point **

****** ****Is the mixing angle**

******m****2  ****is the difference of the squared masses of the two neutrino states**

**E is the energy of the neutrino beam**

- H. Ray

## Neutrino Oscillations

- H. Ray

## Current Oscillation Status

******m****2 ****= m****a****2**** - m****b****2**

- If there are only 3 :
******m****ac****2**** = **
**	********m****ab****2**** + **
**	********m****bc****2**

**P****osc**** =****sin****2****2******** sin****2**** 1.27 ********m****2**** ****L**

**        ****E**

- H. Ray

## Exploring LSND

- Want the same L/E
- Want higher statistics
- Want different systematics
- Want different signal signature and backgrounds

**Fit to oscillation hypothesis**

**Backgrounds**

- H. Ray

**Notes:**
Systematics and stats are in the ERROR BARS!  So error from bgd subtraction, too!

## MiniBooNE

- H. Ray

## MiniBooNE Neutrino Beam

- Start with an 8 GeV beam of protons from the booster

- Fermilab

- H. Ray

## MiniBooNE Neutrino Beam

- The proton beam enters the magnetic horn where it interacts with a Beryllium target
- Focusing horn allows us to run in neutrino, anti-neutrino mode
- Collected ~6x1020 POT, ~600,000  events
- Running in anti- mode now, collected ~1x1020 POT

- Fermilab

- World record for pulses pre-MB = 10M
- MB = 100M+

- H. Ray

## MiniBooNE Neutrino Beam

- p + Be = stream of mesons (, K)
- Mesons decay into the neutrino beam seen by the detector
- K+ / +  + + 
- +  e+ +  +  e

- Fermilab

- H. Ray

**Notes:**
99.4% of nu beam is from pip, 0.4% from k decays
K+ -> pio e+ nue, k0L -> pi- e+ nue, k0L -> pi+ e- nuebar 

## MiniBooNE Neutrino Beam

- An absorber is in place to stop muons and un-decayed mesons
-  Neutrino beam travels through 450 m of dirt absorber before arriving at the MiniBooNE detector

- Fermilab

- H. Ray

## MiniBooNE Detector

- 12.2 meter diameter sphere
**Pure**** **mineral oil
- 2 regions
**Inner light-tight region, 1280 PMTs (10% coverage)**
**Optically isolated outer veto-region, 240 PMTs**

- H. Ray

**Notes:**
1st expt to use non-doped oil!
MB = 800 tons

## Detecting Neutrinos

- Neutrinos interact with material in the detector.  It’s the outcome of these interactions that we look for

- H. Ray

## Neutrino Interactions

- Elastic Scattering
- Quasi-Elastic Scattering
- Single Pion Production
- Deep Inelastic Scattering

**MeV**
**GeV**

- H. Ray

## Neutrino Interactions

- Target left intact
- Neutrino imparts recoil energy to target

- Neutrino in, charged lepton out
- Target changes type
- Need minimum neutrino E
- Need enough CM energy to make the two outgoing particles

**n**

**p**

**W****+**

******e**

**e-**

- Elastic Scattering

- Quasi-Elastic Scattering

- H. Ray

## Observing  Interactions

- Don’t look directly for neutrinos
- Look for products of neutrino interactions
- Passage of charged particles through matter leaves a distinct mark
**Cerenkov effect / light**
**Scintillation light**

- H. Ray

## Cerenkov and Scintillation Light

- Charged particles deposit energy in the medium
- Isotropic, delayed

- Charged particles with a velocity greater than the speed of light * in the medium* produce an E-M shock wave
-  v > c/n
- Similar to a sonic boom
-  Prompt light signature

- H. Ray

## Event Signature

- H. Ray

## MiniBooNE

- Lots of e in MiniBooNE beam vs ~no e in LSND beam
- Complicated and degenerate light sources
- Require excellent data to MC agreement in MiniBooNE

- MB      : ********** ******** ********e**
- LSND  : ********** ******** ********e**** **

- Lots of e in MiniBooNE beam vs ~no e in LSND beam
- Complicated and degenerate light sources
- Require excellent data to MC agreement in MiniBooNE

- H. Ray

## The Monte Carlo

- Cerenkov light
- Scintillation light
- Fluorescence from Cerenkov light that is absorbed/re-emitted

- Reflection
- Tank walls, PMT faces, etc.
- Scattering off of mineral oil
- Raman, Rayleigh
- PMT Properties

**Sources of Light**

**Tank Effects**

- H. Ray

## Perfecting the Monte Carlo

- External Measurements and Laser Calibration

- Calibrate with variety of internal
- Physics samples

- Validate final Model through
- Data to Monte Carlo comparisons

- H. Ray

## Quasi-Elastic  Events

**Constrain the intrinsic ********e**** flux estimate - crucial to get right!**

- H. Ray

**Notes:**
Use to constrain mis-id numu events and nue from mu+

## MiniBooNE Current Status

- MiniBooNE is performing a blind analysis (closed box)
- Some of the info in all of the data
- All of the info in some of the data
- All of the info in all of the data

**Public results : April 11th**

- MiniBooNE is performing a blind analysis (closed box)
- Some of the info in all of the data
- All of the info in some of the data

- MiniBooNE is performing a blind analysis (closed box)
- Some of the info in all of the data

- H. Ray

## Final Outcomes

**Confirm LSND**

**Inconclusive**

**Reject LSND**

- H. Ray

## Final Outcomes

**Confirm LSND**

**Inconclusive**

**Reject LSND**

**Need to determine **
**what causes **
**oscillations**

**Sterile neutrinos?**

- H. Ray

## Final Outcomes

**Confirm LSND**

**Inconclusive**

**Reject LSND**

**Need to collect **
**more data / perform **
**a new experiment**

- H. Ray

## Final Outcomes

**Confirm LSND**

**Inconclusive**

**Reject LSND**

**Need to determine **
**what causes **
**oscillations**

**Need to collect **
**more data / perform **
**a new experiment**

**SNS**

- H. Ray

## Final Outcomes

**Confirm LSND**

**Inconclusive**

**Reject LSND**

- H. Ray

## Final Outcomes

**Confirm LSND**

**Inconclusive**

**Reject LSND**

**SNS**

- H. Ray

## All Roads Lead to the SNS

**Confirm LSND**

**Inconclusive**

**Reject LSND**

**Need to determine **
**what causes **
**oscillations**

**Need to collect **
**more data / perform **
**a new experiment**

**SNS**

- H. Ray

## What is the SNS?

- Accelerator based neutron source in Oak Ridge, TN

- Spallation Neutron Source

- H. Ray

## The Spallation Neutron Source

- 1 GeV protons
- Liquid Mercury target
- First use of pure mercury as			 a proton beam target
- 60 bunches/second
- Pulses 695 ns wide
- LAMPF = 600 s wide,
- FNAL = 1600 ns wide
- Neutrons freed by the spallation process are collected and guided through beam lines to various experiments

**Hg**

- Neutrinos come for free!

- H. Ray

**Notes:**
Mercury : not damaged by radiation as are solids, source of numerous neutrons b/c of high atomic number, 
Liquid at room temp, able to dissipate large, rapid rise in Temp & withstand shock effects from pulses

## The Spallation Neutron Source

- Target Area

- - absorbed by target

- + DAR

- Mono-Energetic!
- = 29.8 MeV

- E range up to 52.8 MeV

*(Liquid Mercury (Hg+) target)*

- H. Ray

## The Spallation Neutron Source

-  +  + + 
-   = 26 ns
-  +  e+ +  + e
-   = 2.2 s

- Pulse timing, beam width, lifetime of particles = excellent separation of neutrino types

**Simple cut on beam timing = 72% pure **********

- H. Ray

## The Spallation Neutron Source

-  +  + + 
-   = 26 ns
-  +  e+ +  + e
-   = 2.2 s

- Mono-energetic 
-  E = 29.8 MeV
-  , e = known distributions
-  end-point E = 52.8 MeV

**MiniBooNE**

**SNS**

**GeV**

- H. Ray

## The Spallation Neutron Source

**Neutrino spectrum in range relevant to astrophysics / supernova predictions!**

- H. Ray

## Proposed Experiments

- Osc-SNS
- Sterile Neutrinos

- -SNS
- Supernova Cross Sections

- H. Ray

## Neutrino Interactions

- Elastic Scattering
- Quasi-Elastic Scattering
- Single Pion Production
- Deep Inelastic Scattering

**MeV**
**GeV**

- SNS Allowed Interactions

- H. Ray

## Neutrino Interactions @ SNS

- All neutrino types may engage in elastic scattering interactions

- Sterile Neutrino Search

- H. Ray

## Neutrino Interactions @ SNS

- All neutrino types may engage in elastic scattering interactions
- Muon mass = 105.7 MeV, Electron mass = 0.511 MeV
- Muon neutrinos do not have a high enough energy at the SNS to engage in quasi-elastic interactions!

- Oscillation Search

- Sterile Neutrino Search

- H. Ray

## Neutrino Interactions @ SNS

- Appearance :   e
- e + 12C   e- + 12N
- 12N   12C + e+ (~8 MeV) + e

- Intrinsic e vs        mono-energetic e  from 

- E of e- (MeV)

- E of e- (MeV)

- H. Ray

## Why the SNS?

|  | Beam Width | S:B | Osc. Candidates |
| --- | --- | --- | --- |
| LSND
  e  | 600 s | 1:1 | 35
(observed R > 10) |
| FNAL
  e  | 1600 ns | 1:3 | ~400 |
| SNS
  e  | 695 ns | 5:1 | ~448/year
 |

- Expected for LSND best fit point of : sin22 =0.004 dm2 = 1

**May be < 500 ns!**

- H. Ray

## Sterile Neutrinos

- Sterile neutrinos = RH neutrinos, don’t interact with other matter (LH = Weak)
- Use super-allowed elastic scattering interactions to search for oscillations between flavor states and sterile neutrinos
- Disappearance :   e
- + C   + C *
- C *  C + 15.11 MeV photon
- One detector : look for deficit in x events
- Two detectors : compare overall x event rates

- H. Ray

**Notes:**
R-process = heavy element production in supernova through rapid-neutron-capture.
Observed abundance of heavy elements >> SM prediction b/c available neutron density too small
Can be explained if oscillations to sterile neutrinos

## Sterile Neutrinos

- Near Detector only

- Near + Far Detector

- H. Ray

## Sterile Neutrinos

**“****There are several indirect astrophysical hints in favor of sterile neutrinos at the keV scale.  Such neutrinos can explain the observed velocities of pulsars, they can be dark matter, and they can play a role in star formation and reionization of the universe.”**

- Kusenko, hep-ph/0609158

- H. Ray

## Sterile Neutrinos

- R-process nucleosynthesis
- Balantekin and Fuller, Astropart. Phys. **18**, 433 (2003)
- Pulsar kicks
- Kusenko, Int. J. Mod. Phys. D **13**, 2065 (2004)
- Dark matter
- Asaka, Blanchet, Shaposhnikov, Phys. Lett. B **631**, 151 (2005)
- Formation of supermassive black holes
- Munyaneza, Biermann, Astron and Astrophys., 436, 805 (2005)
- Play impt. role in Big Bang nucleosynthesis
- Smith, Fuller, Kishimoto, Abazajian, astro-ph/0608377

- H. Ray

## ... but that’s not all!

- CPT violation (or CP + sterile neutrinos) allows different mixing for , anti-
- Possible explanation for positive LSND, null MiniBooNE
- Compare , anti- measured oscillation probabilities
-  CP :   e      e
-  CPT :   X    X

- H. Ray

## Mass Varying Neutrinos

- All positive oscillation signals occur in matter (K2K, KamLAND, LSND); no direct information on oscillation parameters in air/vacuum
- Require a path to detector which can be vacated/filled with dirt to test
- Barger, Marfalia, Whisnant.  Phys. Rev. D 73, 013005 (2006)
- Schwetz, Winter.  Phys. Lett. B633, 557-562 (2006)

- H. Ray

## Why the SNS?

**Confirm LSND**

**Inconclusive**

**Reject LSND**

**Looking for**
**new physics**

**Need much higher **
**statistics**

**Need to perform **
**analysis with **
**anti-neutrinos **
**to completely **
**rule out LSND**

- Precise, well-defined neutrino/anti-neutrino beam
- with very high statistics and low backgrounds

- H. Ray

## Why the SNS?

- SNS : well known E spectrum to allow precise measurements
- SNS : simultaneous measurements in neutrino, anti-neutrino modes
- SNS : different systematics to LSND, MB
- Second cross check of LSND
- SNS : can perform beyond the standard model searches not open to MB
- Sterile neutrino search, CP/CPT, MaVaNus

- H. Ray

## The Global Picture

- The Neutrino Matrix
- APS Multi-Divisional Neutrino Study, Nov 2004
- www.aps.org/policy/reports/multidivisional/neutrino/upload/main.pdf

- Pg ii

- H. Ray

## The Global Picture

- The Neutrino Matrix
- APS Multi-Divisional Neutrino Study, Nov 2004
- www.aps.org/policy/reports/multidivisional/neutrino/upload/main.pdf

- Pg iii

- H. Ray

## The Global Picture

- The Neutrino Matrix
- APS Multi-Divisional Neutrino Study, Nov 2004
- www.aps.org/policy/reports/multidivisional/neutrino/upload/main.pdf

- Pg 27

- H. Ray

## The Global Picture

- The Neutrino Matrix
- APS Multi-Divisional Neutrino Study, Nov 2004
- www.aps.org/policy/reports/multidivisional/neutrino/upload/main.pdf

- Pg 27

- H. Ray

## Summary

- SNS is about to become the best neutrino based facility in the US
- DOE proposal for 2 near detectors awaiting funding
- Internal LANL proposal produced for far detector
- Regardless of the outcome of MiniBooNE, the future of *precision* neutrino measurements in the US lies at the SNS!

- H. Ray

## Backup Slides

## A Brief History of Neutrinos

- 1930 : Postulated by Pauli
- 1950-60 : First detection by Reines-Cowan, inverse beta decay
- ~1935 : First nu mass experiments
- 1972 Bergkvist, mass upper limit
- 1980 - 85 : Soviet ITEP, mass up&low limit
- Infamous 17 keV neutrino

- H. Ray

## Ex : Beta Decay

**n**

**p**

**W****-**

******e**

**e****-**

**du****d = -1/3**

**du****u = +2/3**

**W****- ****= -1**

**time**

- H. Ray

## Standard Model of Physics

- Also have 12 anti-particles (same mass & lifetime, opposite charge)
- Gauge particles mediate or transmit forces between particles
- Forces that create particles also dictate which interactions particles can participate in
- E-M : particles with electric charge
- Quarks, leptons
- Strong : binds quarks together
- Quarks

- H. Ray

## Standard Model of Physics

**Weak : ****force of transmutation!**
**changes flavor of quarks, leptons **_***within a family***_
**Only force that acts on neutrinos**
**Neutral current = no exchange of electric charge (Z)**
**Charged current = exchange electric charge (W****+****, W****-****)**

- H. Ray

## Standard Model of Physics

**W-**

**W**+

- H. Ray

**Notes:**
Can’t switch between families

## Quark Mixing

- Problem! If Weak force only acts inside of a family - how do you explain lambda decay?

******-**

**u**

**u**

**u**

**d**

**d**

**s**

****

**p**

**W****-**

**u**

**d**

- H. Ray

**Notes:**
We know it’s the weak force and not strong b/c of lifetime of lambda.  If strong see super quick decay

## Quark Mixing

- Solution : quark generations are rotated for the purposes of weak interactions
- Instead of the Weak force coupling
- It couples

**u**

**d**

**u**

**d’**

- H. Ray

## Quark Mixing

- Where d’ is a linear combination of the d, s, b quarks

**s’**

**b’**

**d’**

**s**

**b**

**d**

**V****ud**

**V****us**

**V****ub**

**V****cd**

**V****td**

**=**

**Weak state**

**Mass state**

- H. Ray

**Notes:**
Rubik cube : strong sees one side, week sees other (mixed side)

## Quark Mixing

- States which participate in Strong interactions are mass states
- States which participate in Weak interactions are mixtures of mass states

**W-**

**W**+

**’**

**’**

**’**

- H. Ray

## Standard Model of Physics

- Neutrino
- Oscillations
- Observed

- Assume Neutrinos
- Have Mass

- Introduce  mass
- into SM via RH field
- (Sterile Neutrinos)
- which mix w/ LH fields
- (SM )

- Use Oscillations to
- find
- Sterile Neutrinos

- Neutrino
- Oscillations
- Observed

- Assume Neutrinos
- Have Mass

- Introduce  mass
- into SM via RH field
- (Sterile Neutrinos)
- which mix w/ LH fields
- (SM )

- Use Oscillations to
- find
- Sterile Neutrinos

- H. Ray

**Notes:**
There’s a problem.  In the SM the three flavor eigenstates of neutrinos have no mass.  No mass = they have the 
Same energy.  Same energy = you can’t have oscillations.  We have oscillations, therefore we must have an energy 
Splitting between the flavor eigen states.  Energy splitting = mass difference.  Thus, neutrinos must have mass.

## LSND

- 800 MeV proton beam + H20 target, Copper beam stop
- 167 ton tank, liquid scintillator, 25% PMT coverage
- E =20-52.8 MeV
- L =25-35 meters
-  e + p  e+ + n
- n + p  d  +  (2.2 MeV)

- H. Ray

## The LSND Result

- Different from other oscillation signals
- Higher m2
-  Smaller mixing angle
- Much smaller probability (very small signal) ~0.3%

- H. Ray

## The LSND Problem

**P****osc**** =****sin****2****2******** sin****2****  1.27 ********m****2**** ****L**

**        ****E**

- m2ab= ma2 - mb2

- Something must be wrong!
- Flux calculation
- Measurement in the detector
- Both
- Neither

**Reminiscent of the great Ray Davis**
**Homestake missing solar neutrino problem!**

- H. Ray

**Notes:**
Me < 2.2 ev, mmu < 170 keV, mtau < 1.5 MeV

## Confirming LSND

**P****osc**** =****sin****2****2******** sin****2****  1.27 ********m****2**** ****L**

**        ****E**

- m2ab= ma2 - mb2

- Want the same L/E
- Want higher statistics
- Want different sources of systematic errors
- Want different signal signature and backgrounds

- H. Ray

## Step 1 : External Measurements

- Start with external desktop measurements

- IU Cyclotron 200 MeV proton beam

- Extinction rate = 1 / Extinction Length

- H. Ray

**Notes:**
Measurements of the transmission using samples of Marcol 7 oil drawn from the MiniBooNE detector are analyzed to provide a measurement of the extinction rate (inverse of extinction length) over a range of wavelengths. At Johns Hopkins University (JHU), transmission compared with water (corrected for reflections) using a spectrophotometer with 1 cm cell are shown in blue. Measurements at JHU comparing Marcol 7 to cyclohexane are shown in red. The agreement below 270 nm is impaired by absorption in the cyclohexane. Measurements with the spectrophotometer at Fermilab compared air (empty cell) and Marcol 7. Corrections were applied for reflection and focusing effects in the instrument. Results for Quartz cells of 1 cm (<310 nm) , 2 cm (<360 nm), 5 cm (<360 nm) , and 10 cm are show with black lines of various styles. The agreement of the data causes these line to obscure the blue JHU line. The maroon dot shows the result from the MiniBooNE 460 nm variable path length instrument (Alabama Tester). The dashed maroon line uses data from the MiniBooNE 1.6 m variable wavelength instrument (Cincinnati Tester) normalized to the maroon dot (Fit from MiniBooNE TN95). The magenta dot shows the results of scattering measurements at Princeton U (MiniBooNE TN 144) for the isotropic component of Rayleigh scattering which agree with predictions based on the measured compressibility of Marcol 7. The dashed magenta line shows the predicted rate for the isotropic component normalized to the measured point. The anisotropic component is measured to provide a scattering rate of 27% of the isotropic rate. The magenta dots show the wavelength dependence of that component assuming that the ratio is wavelength independent. A matrix of emission and excitation fluorescence spectra measured in a spectrofluoremeter with a 1 cm x 1 cm cell was analyzed using Singular Valued Decomposition (SVD) to extract the dominant spectral components. Corrections for the the instrument response and normalization to the quantum yield of para-terphenyl provides the probability of fluorescent emission per excitation photon per meter of path in Marcol 7. Rates for four hypothetical fluorescent species are shown with solid green, turquoise, maroon and indigo lines. The extinction contribution of these components is obtained by dividing these curves by their respective quantum yields. We identify Fluor 3 with Vitamin E which was introduced at the refinery. We have studied it separately and estimate a quantum yield of about 5% from the Strickler and Berg Equation whereas this determination yields 9%. 

## Step 2 : Internal Samples

- Identify internal samples which isolate various components of the OM
- UVF, Scint are both isotropic, same wave-shifting/time constants
- Low-E Neutral Current Elastic events below Cerenkov threshold

- H. Ray

**Notes:**
Use NCE events to break degeneracy b/c UVF comes from Cerenkov light

## Step 3 : Verify MC Evolution 

- Calibration Sample

- Provide e Constraint

- Background to CCQE Sample

- Mean = 1.80, RMS = 1.47
- Mean = 1.19, RMS = 0.76

- Mean = 20.83, RMS = 25.59
- Mean = 3.48, RMS = 3.17

- Mean = 16.02, RMS = 25.90
- Mean = 3.24, RMS = 2.94

- Examine cumulative 2/NDF distributions across many physics samples, many variables

- H. Ray

**Notes:**
Point is we don’t want to degrade any performance
** mention that these comparisons also feed in to choosing the PID inputs!

## Signal Region e Events

- PRELIMINARY

- H. Ray

**Notes:**
Intrinsic nue = 10% k0, 38.5% k+-, 49.5% mu, 2% pi+-
Misid = 53% ncpi0, 29% other, 18% nc delta

## SNS Stats

- ~17% of incident protons produce pions
- 2.3 x 10-5 - decay before capture
- + stopped <0.3 ns
- 1.3 GeV protons produce :
- 0.098 +, 0.061 -
- For 9.6 x 1015 protons/sec on target get 0.94 x 1015 of each flavor : , Anti-, e
- Anti-e  / Anti- < 3 x 10-4
- Flux @ 50 m from target = 3 x 106 s-1 cm-2

- H. Ray

## -SNS Near Detectors

- Homogeneous, Segmented
- Primary function = cross sections for astrophysics
- Most relevant for supernova neutrino detection = 2H, C, O, Fe, Pb

**Full proposal submitted to DOE in August, 2005**

- H. Ray

**Notes:**
Gas == less expensive than scintillator, easily change targets
Fe highest priority for seg.
Seg spec at 0.6 GB/day, but want to study improving performance & eff in R&D program

Homo = min 10 fid tons of liquid target material, 41% pmt coverage
Homo will run first in C mode for calibrations!

## Osc-SNS Far Detector

- MiniBooNE/LSND-type detector
- Higher PMT coverage (25% vs 10%)
- Mineral oil + scintillator (vs pure oil)
- Faster electronics (200 MHz vs 10 MHz)
- ~60m upstream of the beam dump/target
- Removes DIF bgd

- H. Ray

**Notes:**
Primary function = sterile neutrino search, oscillations
Excellent test bed for sterile neutrinos regardless of the outcome of miniboone

This is the expt I think should go forward regardless of miniboone

## Appearance Osc. Searches

- 2 oscillation searches at SNS can be performed with CC interactions to look for flavor change
- Appearance :   e   (ala LSND)
- e + p  e+ + n
- n + p  d + 2.2 MeV photon
- Appearance :   e
- e + 12C   e- + 12Ngs
- 12Ngs   12C + e+ (~8 MeV) + e
- MiniBooNE uses e + n   e- + p

- lower E e vs        higher E  e

- H. Ray

## Sterile Neutrinos

- Near detector : ~2056 events/year (25 ton)
- Far detector : ~3702 events/year (500 ton)

- + C   + C *
- C *  C + 15.11 MeV photon

- Event rates only for 

- H. Ray

## Event Rates per Year

- 250 ton detector @ 60 m, 100% eff

| e 12C  e- 12Ngs | 9378 |
| --- | --- |
| e 12C  e- 12N* | 4294 |
| Total e 12C  e- X | 13,672 |

|  12C   12C*15.11 | 3702 |
| --- | --- |
|  12C   12C*15.11  | 7504 |
| e 12C  e 12C*15.11  | 6186 |
| Total  12C   12C*15.11  | 17,392 |

- H. Ray

## Lorentz Violation

- LSND, Atm, Solar oscillations explained by small Lorentz violation
- Size of violation consistent with size of effects emerging from underlying unified theory at Planck scale
- Kostelecky, Mewes.  hep-ph/0406255  (2004)
- Oscillations depend on direction of  propagation
- Don’t need to introduce neutrino mass!
- Look for sidereal variations in oscillation probability

- H. Ray

## Neutron Background

- 109 neutrons/day pass through near detectors
- CC measurements = bgd free
- neutron bgds greatly suppressed for t > ~1 s  after start of beam spill
-  production is governed by  lifetime (~2.2 s )

- H. Ray

## Near Detector Rates

- Segmented (10 ton fiducial mass)
- Iron = 3200 CC/year
- Lead = 14,000
- Al = 3,100
- Homogeneous
- Carbon = 1,000
- Oxygen = 450

- H. Ray

## Minos

- 120 GeV proton beam
- Graphite target
- 2 movable horns
- 1.27x1020 POT
- Next up :   e osc search

- H. Ray

**Notes:**
MINOS Far Detector nu_{mu} CC disappearance analysis and shows the final results from the first year of NuMI beam running with 1.27x10^{20} POT. The data are shown to be consistent with nu_{mu} to nu_{tau} oscillations with parameters: |Dm^{2}_{32}| = 2.74^{+0.44}_{-0.26}x10^{-3} eV^{2}/c^{4} and sin^{2}(2\theta_{23})>0.87 (68% C.L.).

Graphite target, 2 movable horns = nu or antinu running (same as MB)

Near + far detectors = iron/scintillator tracking calorimeter, spectrometer in back
Minos did a numu disappearance result
They’re going to try to do a numu -> nue search, but it will be difficult - they’re not really built for nue/ele 
Event identification.  If they can do the measurement, can do first ever 
Measurement of theta_13, reach depends on POT.  Need about 16e20 pOT
But only have 1.27e20 POT - so need a factor of 4 or so more!

## MINERA

- Placed in NuMi beamline, directly upstream of Minos
- Segmented solid scintillator detector, use Minos as  det
- C, Fe, Pb targets
- Quasi-Elastic Q2, CC Coherent  prod. at very high E (6, 20 GeV)
- Construction complete by 2009
- 4 yr run plan

- H. Ray

**Notes:**
Placed in numi beamline directly upstreaem of minos near detector
Active core = segmented solid scintillator
Core surrounded by em and had calorimeters
Use minos near detector as muon detector
Nuclear targets = carbon, iron, lead
Qe qsq, cc coherent pion production = all at very very high E
(qsq = up to 6 GeV, enu cc pion = up to 20 GeV)
Construction complete by fy 2009
Minos = graphite target! Double horn focusing system
4 year run plan
Run 1 year with minos, 3 years with nova

## NOA

- Off-Axis detector
- Near & Far Detectors

- H. Ray

**Notes:**
 Off-axis == more flux, less bgd
Liquid scint in tubes/cells, with WLS fiber collecting light & sending it to a pixel readout
Plan on having prototype of near detector running at fnal by end of 2007, at 75 mrad angle to minos 
Numi beam
Plan includes 1 yr downtime in 2010 to convert the MI into a 1MW proton source
Begin running when 5kT is commissioned, run for 6 years from end of construction
Measure CCQE numu events
Plan on building far detector enclosure starting oct 07, occupy enclosure around june 09
Complete 5 kT in nov 2010, complete far detector in nov 2011

T2k vs nova : t2k = 2.5 deg off axis, nova = 14 km off axis ??
14 km = ~17 mrad off
reactor only measures nue <-> numu + nutau (theta13).  Accerator measures nue<-> numu 
(theta23 & theta13)
 larger off axis at nova == more sensitive (30%) to inverted vs normal heirarchy
at oscillation maximum

Noval measures sin22theta_23  (using ccqe numu events)??? 
Sin2theta23 = superK @ 1.  Dm32^2 = Minos of 2.7+- 0.3 10^-3
K2K = 2.8x10^-3, SuperK = 2.4x10^-3

Measuring numu -> nue at the atm osc length.  These haven’t been observed, characterized 
By theta13.  The study of these oscillations = goal of nova.  If these osc. Exist 
Ie if theta13 != 0, then will be able to determine ordering of neutrino masses

If observe these oscillations, then run in antinu mode to get the ordering of masses
Nova far detector sits on earths surface, compared to minos

Neutrinos in the beam propagate through earth.  Matter induced contributions to 
The propagation amplitude are nonn-negligible.  Matter effects have opposite signs 
For nu and antinu and for the nonrmal and inverted heirarchy - so use the matter 
Effects to distinguish the hierarchies.

The 30% enahncement or suppresion is at 2 GeV

High precision measurment determines atm dm2 to the 10^-4 ev level, 
And sin22theta_23 to the 1-2% level

Beam = 120 GeV protons

Off-axis == chosing detector location/angle from  beam tunes the central E of the beam = 
Spectrum in the peak is narrow, so reduces bgds.  Main peak = almost all nu from pi decays
So insensitive to K/pi production ratio knowledge

Ash river = 810 km from FNAL

Chooz = reactor expt constructed to test the atm. Result is due to numu <-> nue oscillations
At sin22theta set limit on dm2 of 9x10^-4 ev