1. 1 A preliminary estimate of the beam e ’s from antineutrinos David Jaffe, Pedro Ochoa December 7 th 2006

2. 2  Data used:  Horn-off: LE-10, Birch, 2.77x10 18 POT (couple of days Feb-2006)  Horn-on: LE-10, Birch, 8.15x10 19 POT (Oct 2005 -Jan 2006)  MC used:  Horn-off: LE010000, Carrot, 1.32x10 19 POT  Horn-on: LE010185, Carrot, 4.17x10 19 POT Data and MC used

3. 3 Preliminary results of from  +: from  + decay E < E cut data-(Fit or Scaled) MC, E cut < E < 30 GeV raw MC1553.7 ± 55.1 (stat)283.0 ± 23.0 (stat) reweighed MC1538.2 ± 54.8 (stat)386.5 ± 32.4 (stat) Scale method 14685.4 ± 367.4 (stat)-5914.9 Scale method 24628.8 ± 367.8 (stat)-5991.6 Stan’s method3163.6 ± 1122.0 (stat)-243.5 ± 1169.1 (stat) Scale method 33820.2 ± 374.5 (stat)584.3 ± 339.5 (stat) Scale method 46392.8 ± 355.1 (stat)412.4± 341.4 (stat) Fit method1735.5 ± 380.3 (stat)-357.1 ± 351.8 (stat)  Note: talked with Zarko about using new neutrino-antineutrino combined fit in modified energy range for nubars. In progress. Should be real nubars from  + if data/MC from horn-off is trust- worthy in this region Should be ~0 by construction Should be real nubars from  + Expected to be highly negative by construction  Details can be found in backup slides and in minos-docs 2421 and 2218).

4. 4 Systematics  In addition, uncertainties when going from to e :  from  + selection efficiency: no systematic yet.   (  )/  ( e ):  Error in fit: no current estimate for SKZP “a la Boston” with antineutrinos. Will have one with new fit.  How accurate is the Horn-off disagreement between data and MC to scale the Horn-on MC? No systematic yet  Purity of antineutrino sample: see minos-doc-2205 For the atmospheric paper, Hugh G. estimated 13.5 % uncertainty in  (  )/  (  ) (see minos-doc-1424). Should be almost identical for  (  )/  ( e )  Main systematics for from  + are:  Deconvolution to extract e spectrum: no systematic yet  ND-FD extrapolation: no systematic yet  Cross-section shape uncertainty: see talk tomorrow  Reconstruction efficiencies for and e ’s: small effect (?)

5. 5 Doing the numbers e from  + e from  +, 0 < E < 30 GeV Stan’s method2920.1 ± 1677.2(all) Fit method1378.3 ± 532.8(stat) Combination of scaling methods 1,2 and 4 gives: 5235.7 ± 629.6(stat) ± 818.5 (syst)   from  +:  Necessary parameters from MC (all below 30 GeV):  With Stan’s method, at 1x10 19 POT we get: e ’s from  +, fid vol e ’s from  + Stan’s method3,391.1±2017,417,091±10,178.8 Raw MC2,121.1±52.55(stat)10,691.4±118.0(stat) - Selection efficiency for from  + is 31.38 % ± 1.9% (stat) - Ratio of e ’s from  + to ’s from  + is 2.97±0.14(stat) ±0.40(syst) - Ratio of e ’s from  + in detector to those in fiducial volume is 5.04±0.14(stat) (this is reconstructed e ’s from  +, not all e ’s that go through the detector) Assume we are dominated by statistics

6. 6 Backup

7. 7 Reweighting nubars from  + from m+, raw MC from m+, reweighted MC

8. 8 Scaling method 1

9. 9 Scaling method 2

10. 10 Scaling method 3

11. 11 Scaling method 3-alt (no fit to ratio)

12. 12 Scaling method 4

13. 13 Fit method

14. 14 (Fit method 2 – discredited)

15. 15 (Fit method 3 – discredited)