# Presentation: 300480

## Reminder of method and projected result

**obtain an  estimate of the beam ********e****’s from antineutrinos**

**David Jaffe, Pedro Ochoa**

- Impact on     disappearance analysis
- Impact on     appearance analysis
- Optimizing the target position for the
- measurement

- See doc-2706 for technical note with many additional details

- 27 Feb 2007

## Reminder of method

- pME

- LE

*(pME-LE)**”TRUE”** at 1e18 POT*

- And fit with two parameters:

- To make feasibility study, get “true” distributions by fitting raw MC:

**Reminder of method**
**(doc-2504,2706)**

- 27 Feb 2007

## Expected results

- Conservatively assigning a 30% unc. in difference of pME and LE-10 spectra from hadrons and a 10% (8% in pME) unc. due to cross-section shape:

**Stat + Syst**
**Stat only**

- Expect <30% overall unc. In
- LE-10            rate
- measurement

- 27 Feb 2007

## Impact on     disappearance analysis

- Compare expected results for 3e20 LE-10 POT with 2.75e20 LE-10 + 0.25e20 pME POT
- Many thanks to Masaki Ishitsuka for this comparison (uses similar approach to doc-2349)

- 27 Feb 2007

## Expected sensitivity (68% & 90%CL) for

**Expected sensitivity (68% & 90%CL) for**
**2.75e20 LE-10 POT**
**2.75e20 LE-10 + 0.25e20 pME POT**
**3.00e20 LE-10 POT**

- Input oscillation parameters:

- Impact on standard
-      disappearance
- analysis

- Minimal impact on sin22 measurement
- Negligible impact on m2 measurement

- 27 Feb 2007

## Impact on alternate hypotheses for disappearance analysis

|  | 3.00e20LE-10 | 2.75e20LE-10 + 0.25e20pME |
| --- | --- | --- |
| Decay | 11.0 | 11.8 |
| Decoh. | 30.4 | 30.7 |

- 2.75e20 LE-10

- 0.25e20 pME

- Best fit  for
**Neutrino decay hypothesis**
**Neutrino decoherence hypothesis**

- Marginally better ability to exclude
- decay or decoherence hypotheses
- with pME running

- Hatched histograms show ratio of NC bkgd to unoscillated spectra

- 27 Feb 2007

## Impact on    appearance analysis

- Under similar assumptions for LE-10 and pME exposure and
- assuming that the pME provides ***no*** sensitivity to
- appearance, then the loss in the figure-of-merit is 4.3% :

- 27 Feb 2007

## Optimizing target position?

- Can we achieve a <30% precision on              with fewer POT than the pME position?
- Study effect of target position on spectra using gnumi v.19 with FLUKA05 hadronic spectra
- Study of pHE with full MC & recon. is in progress

- 27 Feb 2007

## Expected       CC 

- Expected       CC
- ND events per 1e20 per kiloton
- for muon and hadronic parents
- for different target positions
- using gnumi v.19.
- LE-10 assumes 185kA horn current
- other positions assume 200kA

- 27 Feb 2007

## Difference in rates wrt LE-10

- GNUMI V.19

- Carrot MC-Birch Recon

- Difference in spectra from hadrons from gnumi differs from fully processed MC

**pME-LE**

**Note size**
**Of hadronic**
**contribution**

- 27 Feb 2007

## Conclusions

- Unique method proposed to use        to constrain the beam     flux to <30% using 0.25e20 POT of pME
- Complementary to other techniques that predict nue flux based on      measurements and a 26 parameter fit
- Amount of pME running has minimal effect on sensitivity of      disappearance and   appearance analyses and slightly improves the sensitivity to alternate explanations of  disappearance

**Many thanks to Masaki Ishituka for his contribution**

- 27 Feb 2007

## BACKUP

- 27 Feb 2007

## Difference in antineutrino spectra from hadrons dominated by pions

- 27 Feb 2007