# Presentation: 683955

## The Very Long Baseline

**The Very Long Baseline**
**Neutrino Oscillations Experiment**
**Presented to**
**FCP05 Neutrino Session**
**by**
**Tom Kirk**
**Brookhaven National Laboratory**
**Nashville, TN**
**May 23, 2005**

## Chiaki  Yanagisawa – SBU

- likelihood cut (100%signal retained)

- Background from 

- CP+45

- o

- Signal 700 ev

- Bkgs  2005
-          (1878 from +others)
-          (  127 from e)

- Signal

- e background

- o

- CP+45

- likelihood cut (~50%signal retained)

-  Effect of cut on  likelihood

- Erec

- Erec

- Preliminary

- Preliminary

**Signal/Background**

- Signal 321 ev

- Bkgs  169
-          (112 from +others)
-          (  57 from e)

- e CC for signal ; all e NC , e beam
-          for background

**Traditional Analysis**

**Chiaki  Yanagisawa – SBU**
**February 28, 2005**

**Maximum  Likelihood Method**

## Maximum  Likelihood Method

-  Effect of cut on likelihood

- CP +45o

- Background

- All

- o

- CP-45

- Erec

- Erec

- Preliminary

- Preliminary

**S/B**

- Erec

- Erec

- Erec

- Erec

- e CC for signal ; all e NC , e beam
-  for backgrounds

- 100%

- 50%

- 40%

- 50%

- 100%

- 40%

**Chiaki  Yanagisawa – SBU**
**February 28, 2005**

**Maximum  Likelihood Method**

## Maximum  Likelihood Method

-  Effect of cut on likelihood

- CP +135o

- Background

- All

- o

- CP-135

- Erec

- Erec

- Preliminary

- Preliminary

**S/B**

- Erec

- Erec

- Erec

- Erec

- 100%

- 100%

- 50%

- 50%

- 40%

- 40%

- e CC for signal ; all e NC , e beam
-  for backgrounds

**Chiaki  Yanagisawa – SBU**
**February 28, 2005**

**Maximum  Likelihood Method**

## Scientific Reach of Future Neutrino Oscillations Exps. 

- T. Kirk
- May 3, 2005

**Scientific Reach of Future Neutrino Oscillations Exps. **

_**      **__**Parameter**__**	**__**  T2K      T2K2        Reactor       No**__****__**a     No**__****__**a2        VLBNO.**_
******m****32****2****	********4 ********4********-********2********2********1******
**sin****2****(2********23****) ****	********1.5********0.4********-           ********0.4********%********0.2********0.5******
**sin****2****(2********13****) ****a****	****>0.02     >0.01          >0.01        >0.01      >0.01         >0.01**
******m****21****2**** sin(2********12****) ****b****	****    -            -                  -                -              -               12 %**
**sign of (********m****32****2****) ****c****	****      ****-            -                  -          possible     yes             yes**
**measure ********CP ****d****	****      ****-         ~20********               -                -           ~20********13******
**N-decay gain****	****   x1        x20               -                -              -                 x8**
**Detector (Ktons)****	****   50       1000              20             30        30+50           400      **
**Beam Power (MW)****	****  0.74       4.0            14000         0.4           2.0              1.5**
**Baseline (km)****	****  295 ****e****     295 ****e****             1             810 ****e****        810 ****e****       >2500**
**Detector Cost ($M)****	****exists  ~1000             20            165        +200            400**
**Beam Cost ($M)****	****exists      500          exists          50         1000            400**
**Ops. Cost ($M/10 yrs)  500         700             50            500          600        150/500 ****f**
**a**** detection of ************ ******** ********e ****, upper limit on or determination of sin****2****(2********13****)**
**b**** ****detection of ************ ******** ********e ****appearance, even if sin****2****(2********13****) = 0; determine ********23**** angle ambiguity**
**c**** ****detection of the matter enhancement effect over the entire ********CP**** angle range**
**d ****measure the CP-violation phase ********CP**** in the lepton sector; No********a2 depends on T2K2 **
**e**** ****beam is ‘off-axis’ from 0-degree target direction;    ****f**** ****with/without RHIC operations**

_*Both*_ results needed to
- resolve ambiguities!

## Comments on Neutrino Oscillations Experiments 

- T. Kirk
- May 3, 2005

**Comments on Neutrino Oscillations Experiments **

- • _***All***__** **__***parameters***_** of neutrino oscillations can be measured in **_***one***_** experiment**
**	****- the Very Long Baseline Neutrino Oscillation (*****VLBNO*****) at >2000 km**
**	****- Use of a **_***broadband***_** *****Super Neutrino Beam***** at very long distances is the  key**
**	****- worries about ********0**** channel background have been successfully addressed**
**	****- the VLBNO cost is comparable to or lower than less comprehensive methods**
- • **The massive LBNO detector empowers **_***additional forefront physics***_** topics**
**	****- a powerful next-generation**** *****Nucleon Decay***** ****search**
**	****- supernova and relic neutrino searches are also possible**
**	****- a deep underground detector is required for these searches – NSF’s *****DUSEL!***
- • **The CP-violation parameter ********CP**** is the most difficult parameter to determine**
- 	**- matter effects interact with CP-violation effects**
**	****- the CP-violation phase ********CP**** has distinct effects over the **_***full 360o range***_
- • **Off-axis beam method requires multiple distances and detectors**
**	****- all experiments will require of order 10 Snomass years of running**
**	****- each proposed detector will achieve good statistics for most parameters**
- • **All measured oscillation parameters will be limited to ~1% precision by **
**   ****systematic errors except ****sin****2****(2********23****)**