# Presentation: 895568

## Zelimir Djurcic Physics Department

***Zelimir Djurcic****** Physics Department***
***Columbia University***

***MiniBooNE Neutrino Experiment***

- Zelimir Djurcic - Columbia University @ IofP Zemun

- 31-May-05

## Slide 2

- Zelimir Djurcic - Columbia University @ IofP Zemun

- 31-May-05

## Non-zero neutrino mass tests “new” physics in a 

**“****Minimal Standard Model” constructed with m********=0**
**  ****extensions with finite***** *****m********* *****naturally give***** *****m******** = m****l****2****/M****Planck*****  ***
**  ****where m****l***** *****is lepton mass and***** *****M***** *****is scale for new physics**

- Non-zero neutrino mass tests “new” physics in a
- very cost effective way.

- Universe contains 330 /cm3 (410 /cm3), from  Big
- Bang.
**m****** important ingredient for Dark Matter problem.
- /B< 0.3 (WMAP) /B < 3.0  (Tritium decay)
- B = 0.047±0.006, M = 0.29±0.07 and Tot = 1.02±0.02

- Interesting astrophysical probes allowing us to
- “look” inside our Sun and Supernovae.

- Zelimir Djurcic - Columbia University @ IofP Zemun

- 31-May-05

## Why Neutrino Mass Matters?

***See-Saw Mechanism***

- Set of very lightneutrinos

- Heavy RHneutrino

- Typical Dirac Mass

- Set of heavysterile neutrinos

- Massive neutrinos with osc. important for heavy element production in supernova
- Light neutrinos effect galactic structure formation

**Why Neutrino Mass Matters?**

- Zelimir Djurcic - Columbia University @ IofP Zemun

- 31-May-05

## How many neutrinos are there?

**interactions are different from neutrinos involved in **
**interactions with electrons.**

**How many neutrinos are there?**

- A third kind of particle, the
- tau, is heavier version of muon
- which is itself a heavier version
- of the electron.
- (It has its own neutrino as well.)

- We have (at least) 3 kind of neutrinos:
- the electron neutrino (******e**), the muon neutrino (********),
- and the tau neutrino (********).
- Sterile ******?**

- Zelimir Djurcic - Columbia University @ IofP Zemun

- 31-May-05

## Neutrinos in the Standard Model

- Neutrinos are the only fundamental fermions with no electric charge
- Neutrinos only interact through the “weak force”
- Neutrino interaction thru W and Z bosons exchange is (V-A)
- Neutrinos are left-handed(Antineutrinos are right-handed)
- Neutrinos are massless
- Neutrinos have three types
- Electron e  e
- Muon        
- Tau           

- Zelimir Djurcic - Columbia University @ IofP Zemun

- 31-May-05

## Weak interactions are weak because of the massive W and Z boson exchange           weak  GF2   (1/MW or Z)4

For 100 MeV Neutrinos:
 (e)  ~ 10-42 and (n) ~ 10-39 cm2   compared to (pp) ~ 10-24 cm2 
A neutrino has a good chance of traveling through 3 million earths before interacting at all!
-Mean free path length in Steel  ~ 1013 meters! (Need big detectors and lots of ’s )

- Weak interactions are weak because of the massive W and Z boson exchange         ****** ******** ****weak**** ******** *****G******F******2*****  ******** (*****1/M******W or Z*****)****4**
- For 100 MeV Neutrinos:
-  (e)  ~ 10-42 and (n) ~ 10-39 cm2   compared to (pp) ~ 10-24 cm2
- A neutrino has a good chance of traveling through 3 million earths before interacting at all!
***-Mean free path length in Steel  ~ 10******13****** meters! (Need big detectors and lots of ************’s )***

- MW ~ 80 GeVMZ  ~ 91 GeV

**Neutrino Cross Section: Very Small!**

- Zelimir Djurcic - Columbia University @ IofP Zemun

- 31-May-05

## Neutrino masses are interesting. How to measure them?

- Zelimir Djurcic - Columbia University @ IofP Zemun

- 31-May-05

## 
Electron neutrino:  
3H3He + e + e  
Muon neutrino: 
  decays 
Tau neutrino: 
 n decays

- Electron neutrino:
- 3H3He + e + e
- Muon neutrino:
-   decays
- Tau neutrino:
-  n decays

***< 2 eV***

***< 170 keV***

***< 18 MeV***

*Direct decay studies have made steady progress but limited*

*********  ******Need to use “***_***Neutrino Oscillations***_***” to probe for smaller neutrino masses***

**Experimental Limits on Neutrino Mass**

- Zelimir Djurcic - Columbia University @ IofP Zemun

- 31-May-05

## What are Neutrino Oscillations?

**What are Neutrino Oscillations?**

- Zelimir Djurcic - Columbia University @ IofP Zemun

- 31-May-05

## Standard parametrization: 3 rotations through angles 

- 12 (sol), 23 (atm), 13 (unknown).
- cij = cos ij  sij = sin ij

- : Dirac phase giving rise to CP-violating effects in oscillations.
- α1, α2: Majorana phases, not observable in oscillations.

**Parameters of Mixing Matrix**

- Zelimir Djurcic - Columbia University @ IofP Zemun

- 31-May-05

## Flight path

**Neutrino Propagation**

- Zelimir Djurcic - Columbia University @ IofP Zemun

- 31-May-05

## A transition probability P can be defined. It is an

- oscillatory function of the flight path L.

**Oscillation Probability**

- Zelimir Djurcic - Columbia University @ IofP Zemun

- 31-May-05

## Two Generation Model

**Assume Only Two Neutrinos Mix**

- Zelimir Djurcic - Columbia University @ IofP Zemun

- 31-May-05

## νe

**wave 1**

**wave 2**

**wave 1 **
**+ wave 2**

**ν****e**

**ν****e**

- sometimes
- the waves are
- in-phase

- sometimes they
- are out of phase

**Wave Analogy**

- Zelimir Djurcic - Columbia University @ IofP Zemun

- 31-May-05

## If you see an oscillation signal with 
   Posc = P    P then carve out an allowed region in (m2,sin22) plane.
If you see no signal and limit oscillation with 
    Posc<P @90%CLthen carve out an excluded region in the (m2,sin22) plane.

**   ****P****osc**** = P  ********  ********P **then carve out an **allowed region** in (m2,sin22) plane.
- If you see no signal and limit oscillation with
**    ****P****osc****<P @90%CL**then carve out an **excluded region** in the (m2,sin22) plane.

**Oscillation Plots**

- Zelimir Djurcic - Columbia University @ IofP Zemun

- 31-May-05

## But we have 3-generations: eand                    (and maybe even more   .....  the sterile neutrino s’s )

- Naively might expect the neutrino and quark matrix to look similar

- Zelimir Djurcic - Columbia University @ IofP Zemun

- 31-May-05

## Sources of neutrinos: artificial and natural

**Sources of neutrinos: artificial and natural**

- Zelimir Djurcic - Columbia University @ IofP Zemun

- 31-May-05

## Signal Regions (Mid 1990s)

**Small****Mixing****Solution**

**Large****Mixing****Solution**

**Signal Regions (Mid 1990s)**

- Zelimir Djurcic - Columbia University @ IofP Zemun

- 31-May-05

## Natural scale for m2 ~ 10 – 100 eV2 	  since needed to explain dark matter

Oscillation mixing angles must be small 	  like the quark mixing angles

Solar neutrino oscillations must be 		   small mixing angle MSW solutionbecause it is “cool”

Atmospheric neutrino anomaly must be 	 other physics or experimental problembecause it needs such a large mixing angle

LSND result doesn’t fit in so must not 		 be an oscillation signal

- Oscillation mixing angles must be small 	  like the quark mixing angles
- Solar neutrino oscillations must be 		   small mixing angle MSW solutionbecause it is “cool”
- Atmospheric neutrino anomaly must be 	 other physics or experimental problembecause it needs such a large mixing angle
- LSND result doesn’t fit in so must not 		 be an oscillation signal

**Theoretical Prejudices Before 1995**

- Zelimir Djurcic - Columbia University @ IofP Zemun

- 31-May-05

## Natural scale for m2 ~ 10 – 100 eV2 	  since needed to explain dark matter           Wrong

- Oscillation mixing angles must be small 	  like the quark mixing angles                         Wrong
- Solar neutrino oscillations must be 		   small mixing angle MSW solutionbecause it is “cool”                                      Wrong
- Atmospheric neutrino anomaly must be 	 other physics or experimental problembecause it needs such a large mixing angle  Wrong
- LSND result doesn’t fit in so must not 		 be an oscillation signal                                 Wrong

**Theoretical Prejudices Before 1995**

_**What we know now**_

- Zelimir Djurcic - Columbia University @ IofP Zemun

- 31-May-05

## Atmospheric neutrino oscillations definitively confirmed
“Smoking Gun”  Super-K flux change with zenith angle
Accelerator neutrino confirmation with KEK to Super-K exp. (K2K)
Value of m2:  1.5 to 3.5 × 10-3 eV2

- Super-K (SK)Atmospheric NeutrinoExperiment

- Atmospheric neutrino oscillations definitively confirmed
- “Smoking Gun”  Super-K flux change with zenith angle
- Accelerator neutrino confirmation with KEK to Super-K exp. (K2K)
- Value of m2:  1.5 to 3.5 × 10-3 eV2

- K2K Accelerator Neutrino Exp.

**Neutrino Revolution 1995-2005**

- Zelimir Djurcic - Columbia University @ IofP Zemun

- 31-May-05

## Solar Neutrino Oscillations Confirmed and Constrained
Many different exp’s see deficit
SNO experiments sees that total neutrino flux correct from sun but just changing flavor
Kamland experiment using reactor neutrinos confirms solar oscillations
Combination of experiments  Large Mixing Angle MSW Solution

- Many different exp’s see deficit
- SNO experiments sees that total neutrino flux correct from sun but just changing flavor
- Kamland experiment using reactor neutrinos confirms solar oscillations
- Combination of experiments  Large Mixing Angle MSW Solution

- KamLAND Reactor Exp.

- SNO Solar  Exp.

- Combination All Solar + KamLAND

**Neutrino Revolution 1995-2005**

- Zelimir Djurcic - Columbia University @ IofP Zemun

- 31-May-05

## The LSND Experiment

- LSND took data from 1993-98  - 49,000 Coulombs of protons  - L = 30m and 20 < E< 53 MeV

**Saw an excess of********e**** :****87.9 ****± 22.4 ± 6.0 events.**
**With an oscillation probability of ****(0.264 ± 0.067 ± 0.045)%.**
**3.8 ******** evidence for oscillation.**

***Oscillations?***

**The LSND Experiment**

- Signal:    p  e+ n
- 			 n p  d (2.2MeV)

- Zelimir Djurcic - Columbia University @ IofP Zemun

- 31-May-05

## After LSND Experiment

**After LSND Experiment**

- Zelimir Djurcic - Columbia University @ IofP Zemun

- 31-May-05

## One of the experimental measurements is wrong
One of the experimental measurements is not neutrino oscillations
Neutrino decay
Neutrino production from flavor violating decays
Additional “sterile” neutrinos involved in oscillations
CPT violation (or CP viol. and sterile ’s ) allows different mixing for ’s and ’s

- One of the experimental measurements is not neutrino oscillations
- Neutrino decay
- Neutrino production from flavor violating decays
- Additional “sterile” neutrinos involved in oscillations
- CPT violation (or CP viol. and sterile ’s ) allows different mixing for ’s and ’s

**How can one get 3 distinct ********m****2 ****?**

- Zelimir Djurcic - Columbia University @ IofP Zemun

- 31-May-05

## Similar beam and detector to LSND
Closer distance and less target mass    x10 less sensitive than LSND
Joint analysis with LSND gives restricted region (Church et al. hep-ex/0203023)

- Closer distance and less target mass    x10 less sensitive than LSND
- Joint analysis with LSND gives restricted region (Church et al. hep-ex/0203023)

- KARMEN also limits e+e  ratio: BR branching < 0.9 x 10-3 (90% CL)
- LSND signal would require:
- 1.9x10-3 < BR < 4.0 x 10-3 (90% CL)
-    ****** ****************e****+********e ******** ****unlikely to explain LSND signal**
**(also will be investigated by TWIST exp. at TRIUMF)**

**KARMEN vs LSND**

- Zelimir Djurcic - Columbia University @ IofP Zemun

- 31-May-05

## Constraints from atmos. and solar data Sterile mainly associated with the LSND m2

3+1
3+2
3+3 Models

- 3+1
- 3+2
- 3+3 Models

- Then these are the mainmixing matrix elements

**Are There Sterile Neutrinos?**

- Reconcile three separate m2 by adding additional sterile ’s

- Zelimir Djurcic - Columbia University @ IofP Zemun

- 31-May-05

## MiniBooNE will be one of the first experiments to check these sterile neutrino models

Investigate LSND Anomaly
Is it oscillations?
Measure the oscillation parameters

Investigate oscillations to sterile neutrino using  disappearance

- Investigate LSND Anomaly
- Is it oscillations?
- Measure the oscillation parameters
- Investigate oscillations to sterile neutrino using  disappearance

**Next Step is MiniBooNE**

- Zelimir Djurcic - Columbia University @ IofP Zemun

- 31-May-05

## MiniBooNE Experiment

- 12m sphere filled withmineral oil and 1500 PMTslocated 500m from source

- Use protons from the 8 GeV booster  Neutrino Beam      <E>~ 1 GeV

**Need definitive study of ****************e**** at high ********m****2**** ...  MiniBooNE **

**MiniBooNE Experiment**

- Zelimir Djurcic - Columbia University @ IofP Zemun

- 31-May-05

## MiniBooNE 

**MiniBooNE consists of about 70 scientists from 13 institutions. **

-    Y. Liu, I. Stancu   *Alabama*
-    S. Koutsoliotas   *Bucknell*
-    E. Hawker, R.A. Johnson, J.L. Raaf   *Cincinnati*
-    T. Hart, R.H. Nelson, E.D. Zimmerman   *Colorado*
-    A. Aguilar-Arevalo, L.Bugel, L. Coney,
-   **J.M. Conrad**, Z. Djurcic, J. Link, J. Monroe,
-    K. McConnel, D. Schmitz, M.H. Shaevitz,
-    M. Sorel, G.P. Zeller   *Columbia*
-    D. Smith   *Embry Riddle*

-    L.Bartoszek, C. Bhat, S J. Brice, B.C. Brown,
-    D.A. Finley, R. Ford, F.G.Garcia,
-    P. Kasper, T. Kobilarcik, I. Kourbanis,
-    A. Malensek, W. Marsh, P. Martin, F. Mills,
-    C. Moore, P. Nienaber, E. Prebys,
-    A.D. Russell, P. Spentzouris, R. Stefanski,
-    T. Williams   *Fermilab*
-     D. C. Cox, A. Green, H.-O. Meyer, C. Polly,
-     R. Tayloe   *Indiana*
-    G.T. Garvey, C. Green, **W.C. Louis**, G.McGregor,
-    S.McKenney, G.B. Mills, H. Ray, V. Sandberg,
-    B. Sapp, R. Schirato, R. Van de Water,
-    D.H. White  *Los Alamos*
-    R. Imlay, W. Metcalf, M. Sung, M.O. Wascko
*   **Louisiana State *
-    J. Cao, Y. Liu, B.P. Roe, H. Yang   *Michigan*
-    A.O. Bazarko, P.D. Meyers, R.B. Patterson,
-    F.C. Shoemaker, H.A.Tanaka   *Princeton*
-    A. Currioni, B.T. Fleming *Yale*

**MiniBooNE **
**Collaboration**

- Zelimir Djurcic - Columbia University @ IofP Zemun

- 31-May-05

## MiniBooNE 

**magnetic horn: ****meson focusing**

**decay region: **
********************** ****K→**********

**movable absorber: ****stops muons, undecayed mesons**

**“****little muon **
**       ****counters:” **
**                 ****measure K flux in-situ**

**450 m earth berm: ****************→********e****?**

- 50 m decay pipe

- magnetic focusing horn

- FNAL 8 GeV Booster

**MiniBooNE detector**

- designed a beamline & detector optimized for this direct search ...

**MiniBooNE **
**Beamline**

- Zelimir Djurcic - Columbia University @ IofP Zemun

- 31-May-05

## Beam to MiniBooNE

-  proton output of FNAL Booster has improved dramatically
-  ~ 577k  events providing a valuable sample to
**   **study low energy (~ 1 GeV) neutrino physics

**~ 5.5 x 10****20**** **
**POT**

** ****~ 577,000 **
** ****************events**
- (~10k ’s/week)

**Beam to MiniBooNE**

- Zelimir Djurcic - Columbia University @ IofP Zemun

- 31-May-05

## MiniBooNE Horn

-  technically, one of the most
-   impressive components of MBooNE
-  pulsed at ~5 Hz, 170kA
-  capable of running with polarity
-   reversed  running
-  increases  flux by factor ~6

- -1st horn failed past Fall
-   (could not be brought up to safe operation)
-  set world record with >92M pulses
-    (previous record set at BNL with 13M pulses, 0.5 Hz)
-  horn replaced
-  2nd horn performing well

**MiniBooNE Horn**

- Zelimir Djurcic - Columbia University @ IofP Zemun

- 31-May-05

## Primary Beam
8 GeV protons from Booster
Into MiniBooNE beamline
Secondary Beam
Mesons from protons striking Be target
Focused by magnetic horn
Tertiary Beam
Neutrinos from meson decay in 50m pipe
Pass through 500m dirt (and oscillate?) to reach detector

***8 GeV protons from Booster***
***Into MiniBooNE beamline***
***Secondary Beam***
***Mesons from protons striking Be target***
***Focused by magnetic horn***
***Tertiary Beam***
- Neutrinos from meson decay in 50m pipe
- Pass through 500m dirt (and oscillate?) to reach detector

**Booster**

**Beamline**

**Target and Horn**

**LMC**

**Decay Region**

**500m dirt**

**Detector**

- Primary Beam
- (protons)

- Secondary Beam
- (mesons)

- Tertiary Beam
- (neutrinos)

**All together...**

- Zelimir Djurcic - Columbia University @ IofP Zemun

- 31-May-05

## 

************
** ****mainly from**** ************ ******** ******************
-  **<E********> ~ 700 MeV**

- predicted energy spectrum

-  p production at target
-   determined from global fit
-   (world’s p data + new BNL E910)

-  high purity beam

******Flux at MiniBooNE Detector**

- Zelimir Djurcic - Columbia University @ IofP Zemun

- 31-May-05

## HARP: Precision /K Production Measurement

-  flux knowledge important for osc and ’s
- working w/ the HARP exp at CERN to mea- sure hadron prod off MiniBooNEtarget
- 1st goal: measure + prod  on Be at
-   pp=8.9 GeV/c (MiniBooNE replica target)
-  additional measurements include:
-       *  prod  (important for  running)
-       * K prod  (important for intrinsic e)
-  ~30 Tb data ... still analyzing

- Be target is ~71cm long, 1cm in diameter

- target tomography

- HARP: Precision /K Production Measurement

- Zelimir Djurcic - Columbia University @ IofP Zemun

- 31-May-05

## 12m diameter tank
800 tons ultra-pure mineral oil
      n interactions in oil produce:
	- prompt ring of Cerenkov light
      - delayed isotropic scintillation light

1280 8” phototubes in 
       interior signal region

- 800 tons ultra-pure mineral oil
-       n interactions in oil produce:
- 	- prompt ring of Cerenkov light
-       - delayed isotropic scintillation light
- 1280 8” phototubes in
-        interior signal region

-  240 8” phototubes
-   in outer veto region

- (> 99% veto efficiency)

**MiniBooNE Detector**

- Zelimir Djurcic - Columbia University @ IofP Zemun

- 31-May-05

## Separation of  from e events
Exiting  events fire the veto
Stopping  events have a Michel electron after a few sec
Also, scintillation light with longer time constant  enhanced for slow pions and protons
Čerenkov rings from outgoing particles
Shows up as a ring of hits in the phototubes mounted inside the MiniBooNE sphere
Pattern of phototube hits tells the particle type

- Stopping muon event

- Separation of  from e events
- Exiting  events fire the veto
- Stopping  events have a Michel electron after a few sec
- Also, scintillation light with longer time constant  enhanced for slow pions and protons
- Čerenkov rings from outgoing particles
- Shows up as a ring of hits in the phototubes mounted inside the MiniBooNE sphere
- Pattern of phototube hits tells the particle type

**Particle Identification**

- Zelimir Djurcic - Columbia University @ IofP Zemun

- 31-May-05

## Particle Identification II

******0**** ****→**** ******

**Michel e****-**
**candidate**

**beam ******
**candidate**

**beam ********0**
**candidate**

- Čerenkov rings provide primary means of identifying
-       products of n interactions in the detector

********** ****n ******** ********-**** p**

******e**** ****n ******** e****-**** ****p**

********** ****p ******** ************ p**** ********0**

**n          n**

- ring profile → can distinguish particles
- which shower from those which don’t

**Particle Identification II**

- Zelimir Djurcic - Columbia University @ IofP Zemun

- 31-May-05

## Examples of Real Data Events

**Charged Current****************n ****************p****with outgoing muon (1 ring)**

**Neutral Current****************n ************************p****with outgoing**** ****************(2 rings)**

**Examples of Real Data Events**

- Zelimir Djurcic - Columbia University @ IofP Zemun

- 31-May-05

## Time (Color)

**Time (Color)**

- Charge (Size)

**Muon Identification****  Signature:****      ********e****************e**** ****      ****after**** ~2********sec**

- Zelimir Djurcic - Columbia University @ IofP Zemun

- 31-May-05

## Events vs PMT Hits

**Events vs PMT Hits**

- Zelimir Djurcic - Columbia University @ IofP Zemun

- 31-May-05

## Neutrino Events

- beam comes in spills @ up to 5 Hz
- each spill lasts 1.6 sec
- trigger on signal from Booster
- read out for 19.2 sec; beam at [4.6, 6.2] sec
- no high level analysis needed to see
- neutrino events
- backgrounds: cosmic muons
-                       decay electrons
- simple cuts reduce non-beam
-    backgrounds to ~10-3

- Current Collected data:
- 577k neutrino candidates
-      for 5.5 x 1020 protons on target

**Neutrino Events**

- Zelimir Djurcic - Columbia University @ IofP Zemun

- 31-May-05

## Calibration Sources

** ****Michel electrons prod from ******** decay**:
- provide E calibration at low energy **(50 MeV),**
- good monitor of light transmission, electron PID

******0**** mass peak**: energy scale & resolution
- at medium energy **(135 MeV),** reconstruction

**      ****cosmic ray ******** + tracker + cubes**:
-     energy scale & resolution at high energy
**(100-800 MeV),** cross-checks track reconstruction

- provides  tracks of
-  known length → E

- We have calibration sources spanning wide range of energies

- 15%
- E res
-  at
- 53 MeV

**Calibration Sources**

- Zelimir Djurcic - Columbia University @ IofP Zemun

- 31-May-05

## For quasi-elastic events ( np and enep) 	  Can use kinematics to             find E from Ee) and e)  

**Neutrino Energy Reconstruction**

- Zelimir Djurcic - Columbia University @ IofP Zemun

- 31-May-05

## Blind (or “Closed Box”) e appearance analysis
you can see all of the info on some events
     or
some of the info on all events
     but
you cannot see all of the info on all of the events
Other analysis topics give early interesting physics results and serve as a cross check and calibration before “opening the e box”
  disappearance oscillation search
Cross section measurements for low-energy  processes
Studies of  NC 0 production          coherent (nucleus) vs nucleon
Studies of  NC elastic scattering 
            Measurements of s (strange quark spin contribution)

- you can see all of the info on some events
-      or
- some of the info on all events
-      but
**you cannot see all of the info on all of the events**
- Other analysis topics give early interesting physics results and serve as a cross check and calibration before “opening the e box”
-   disappearance oscillation search
- Cross section measurements for low-energy  processes
- Studies of  NC 0 production          coherent (nucleus) vs nucleon
- Studies of  NC elastic scattering
-             Measurements of s (strange quark spin contribution)

**Oscillation Analysis: Status and Plans**

- Zelimir Djurcic - Columbia University @ IofP Zemun

- 31-May-05

##  Analyses

- NC 0 production
- NC elastic

- Use to understand
-  e CCQE cross-section

- background to e
- appearance

- Use to understand
-  lower vertex

*************** ******Analyses***

- Zelimir Djurcic - Columbia University @ IofP Zemun

- 31-May-05

## Charged 

- Cosmic ray cuts
- Single -like ring
- Topology
- MC & Data relatively normalized.
- Red Band: MC 1 uncertainty from...
- flux shape
- cross-section
- Yellow Region: idea of variation from...
- optical properties (atten. length, scintillation, scattering, ...)

**Charged **
**Current QE**

- Zelimir Djurcic - Columbia University @ IofP Zemun

- 31-May-05

## CCQE Reconstruction

***CCQE Reconstruction***

- Zelimir Djurcic - Columbia University @ IofP Zemun

- 31-May-05

## NC 0 

- Ntank > 200, Nveto < 6, Fid.Vol.
- No Michel electron
- Clear 2-ring fit on all events
- Each ring: E1, E2 > 40 MeV.

- Signal yield extracted from fit with background MC.

- Zelimir Djurcic - Columbia University @ IofP Zemun

- 31-May-05

##  0 Variables

- High Momentum tail
- from  flux
- distorted by 2 ring cut

- No preferred CM   direction, but distorted by Lab E and 2 ring cuts.

** ********0**** Variables**

- Zelimir Djurcic - Columbia University @ IofP Zemun

- 31-May-05

## NC Elastic 

- Select NTANK < 150
-           NVETO< 6

- clear beam
- excess
- use random
- triggers to
- subtract
- non-beam
- background

- beam after
- strobe
- subtraction

- Monte Carlo

**NC Elastic **
**Scattering**

- Zelimir Djurcic - Columbia University @ IofP Zemun

- 31-May-05

## Look for appearance of e events above background expectation
Use data measurements both internal and external to constrain background rates

- Look for appearance of e events above background expectation
- Use data measurements both internal and external to constrain background rates

**Appearance Sensitivity**

- Zelimir Djurcic - Columbia University @ IofP Zemun

- 31-May-05

## Intrinsic e in the beam

**Intrinsic ********e**** in the beam**

-  e from decay
- Directly tied to the observed half-million  interactions

- Kaon rates measured in low energy proton production experiments
- HARP experiment (CERN)
- E910 (Brookhaven)

- Small intrinsic e rate  Event Ratio e/6x10-3

- “Little Muon Counter” measures
- rate of kaons in-situ

- Zelimir Djurcic - Columbia University @ IofP Zemun

- 31-May-05

## Background mainly from NC production
p p   
followed by
           where one g is lost because it is too low energy
Over 99.5% of these events are identified and the kinematics are measured
 Can constrain this background directly from the observed data 

**************p ****************p **********
- followed by
-          ************** **** **where one g is lost because it is too low energy
- Over 99.5% of these events are identified and the ********kinematics are measured
-  Can constrain this background directly from the observed data

**Mis-identification background**

- Zelimir Djurcic - Columbia University @ IofP Zemun

- 31-May-05

## MiniBooNE Oscillation Sensitivity

- Oscillation sensitivity and measurement capability
- Data sample corresponding to 1x1021 pot
- Systematic errors on the backgrounds average ~5%

- Zelimir Djurcic - Columbia University @ IofP Zemun

- 31-May-05

## At the current time have collected 5.5x1020 p.o.t.
Data collection rate is steadily improving as the Booster accelerator losses are reduced
Many improvement being implemented into the Booster and Linac  (these not only help MiniBooNE but also the Tevatron and NuMI in the future)
Plan is to “open the box” when analysis is ready      Current estimate is end of 2005
Which then leads to the question of the next step
If MiniBooNE sees no indications of oscillations with Need to run with since LSND signal wase 
If MiniBooNE sees an oscillation signal   Then ............

- Data collection rate is steadily improving as the Booster accelerator losses are reduced
- Many improvement being implemented into the Booster and Linac  (these not only help MiniBooNE but also the Tevatron and NuMI in the future)
- Plan is to “open the box” when analysis is ready     ****** Current estimate is end of 2005**
- Which then leads to the question of the next step
- If MiniBooNE sees no indications of oscillations with ******Need to run with************ since LSND signal was****************e**** **
- If MiniBooNE sees an oscillation signal  ****** Then ............**

**Run Plan **

- Zelimir Djurcic - Columbia University @ IofP Zemun

- 31-May-05

## But It’s Not All About MiniBooNE

- there are many
-  neutrino experiments
-       several of which have
-                     unearthed some
-                    surprises along
-                            the way

**it’s an exciting time to be a neutrino physicist!**

- CHARM II

- Zelimir Djurcic - Columbia University @ IofP Zemun

- 31-May-05