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P AUL N IENABER S AINT M ARY ’ S U NIVERSITY OF M INNESOTA FOR THE M INI B OO NE C OLLABORATION J ULY 28 2009 -- DPF2009.

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Presentation on theme: "P AUL N IENABER S AINT M ARY ’ S U NIVERSITY OF M INNESOTA FOR THE M INI B OO NE C OLLABORATION J ULY 28 2009 -- DPF2009."— Presentation transcript:

1 P AUL N IENABER S AINT M ARY ’ S U NIVERSITY OF M INNESOTA FOR THE M INI B OO NE C OLLABORATION J ULY DPF2009

2  motivated by LSND observation of electron antineutrino events in a muon antineutrino beam 28 July 2009MiniBooNE Update -- DPF20092 PRD 64, (2001)

3  motivated by LSND observation of electron antineutrino events in a muon antineutrino beam  MB start: muon neutrino beam  different L, E; same L/E 28 July 2009MiniBooNE Update -- DPF20093

4  motivated by LSND observation of electron antineutrino events in a muon antineutrino beam  MB start: muon neutrino beam  different L, E; same L/E  6.9 E+20 POT neutrino mode  5.1 E+20 POT antineutrino mode 28 July 2009MiniBooNE Update -- DPF20094 about 2 mg of protons delivered to date!

5  motivated by LSND observation of electron antineutrino events in a muon antineutrino beam  MB start: muon neutrino beam  different L, E; same L/E  6.9 E+20 POT neutrino mode  5.1 E+20 POT antineutrino mode 28 July 2009MiniBooNE Update -- DPF20095 pion production (& hence  flux) well constrained by HARP data/analysis Eur. Phys. J. C52, 29 (2007)

6 28 July 2009MiniBooNE Update -- DPF20096 Collaborators from Alabama, Bucknell, Cincinnati, Colorado, Columbia, Embry- Riddle, Fermilab, Florida, Illinois, Indiana, Los Alamos, LSU, MIT, Michigan, Princeton, Saint Mary’s, Virginia Tech, Yale

7  cross section measurements  oscillation analyses 28 July 2009MiniBooNE Update -- DPF20097

8 28 July 2009MiniBooNE Update -- DPF neutrino CC cross sections when dinosaurs roamed the Earth (i.e., pre- MiniBooNE)

9 these numbers are of fundamental interest, but also relevant to future experiments 28 July 2009MiniBooNE Update -- DPF2009 9

10 these numbers are of fundamental interest, but also relevant to future experiments 28 July 2009MiniBooNE Update -- DPF NOvA T2K CNGS DUSEL

11 these numbers are of fundamental interest, but also relevant to future experiments focus here on two processes: CC QE (signal for oscillation) 28 July 2009MiniBooNE Update -- DPF

12 these numbers are of fundamental interest, but also relevant to future experiments focus here on two processes: CC QE (signal for oscillation) NC π 0 (background) 28 July 2009MiniBooNE Update -- DPF

13 LARGE SAMPLE! 146,070  QE events (76% purity, 27%  ) [analyzed, after cuts] provide most complete information on  QE scattering to date (full  kinematics: E  and   ) 28 July 2009MiniBooNE Update -- DPF W+W+ n 

14 (T. Katori) 28 July 2009MiniBooNE Update -- DPF W+W+ n  T  (GeV) cos   (draft in preparation)

15 (T. Katori) 28 July 2009MiniBooNE Update -- DPF W+W+ n  T  (GeV) cos   first double differential cross section for QE!! (draft in preparation)

16 28 July 2009MiniBooNE Update -- DPF W+W+ n  - Q 2 shape fit results: M A =1.35  0.17 GeV - Higher value of M A also consistent with  total vs. E - Consistent w/ K2K, MINOS, but not w/ M A D 2 =1.03 GeV

17 28 July 2009MiniBooNE Update -- DPF W+W+ n  - Q 2 shape fit results: M A =1.35  0.17 GeV - Higher value of M A also consistent with  total vs. E - Consistent w/ K2K, MINOS, but not w/ M A D 2 =1.03 GeV preliminary RFG = relativistic Fermi gas (v. Smith & Moniz, NP B43, 605 [1972]) model predictions, NOT fits

18 28 July 2009MiniBooNE Update -- DPF W+W+ n  preliminary MiniBooNE and recent SciBooNE  in good agreement Both higher than recent NOMAD  QE ?! (all three on 12 C)  look to MINOS and MINER A for more data MINOS, MINER A

19 28 July 2009MiniBooNE Update -- DPF n,p 00  0   LARGE SAMPLE! neutrino: 21,542 NC  0 events (73% purity, 36%  ) antineutrino: 2,305 NC  0 events (58% purity, 36%  )

20 28 July 2009MiniBooNE Update -- DPF n,p 00 p  (GeV) cos   cos   (C. Anderson) [flux averaged] (draft in preparation)

21 28 July 2009MiniBooNE Update -- DPF n,p 00 p  (GeV) cos   cos   (C. Anderson) first measurement of absolute NC  0 differential cross section [flux averaged] (draft in preparation)

22 28 July 2009MiniBooNE Update -- DPF M O R E ! ! ! --  CC  + /CCQE: arXiv: [hep-ex] [S Linden, J Nowak] --  CC  + : d  /dT , d  /d    d 2  /dT  d    d  /dT , d  /d  , d 2  /dT  d  ,d  /dQ 2,  (E ) [M Wilking] --  NC elastic: d  /dQ 2 [D Perevalov]

23 28 July 2009MiniBooNE Update -- DPF result: In analysis region 475 < E < 3000 MeV, no evidence for oscillation (interpretation of LSND as simple two-neutrino oscillation excluded at 98% CL) Unexpected excess of events at low energy < 475 MeV PRL 98, (2007) 5.6  POT

24 28 July 2009MiniBooNE Update -- DPF update: improved statistics, better modelling of some background processes, and enhanced cuts on external interactions analysis threshold extended down to 200 MeV over 475 MeV: no change

25 28 July 2009MiniBooNE Update -- DPF update: improved statistics, better modelling of some background processes, and enhanced cuts on external interactions analysis threshold extended down to 200 MeV under 475 MeV: excess persists PRL 102, (2009)

26 28 July 2009MiniBooNE Update -- DPF statistics are low (does not include spring 2009 runs) -- no definitive statement on LSND yet -- no low energy excess?! __ - arXiv:0904:1958 [hep-ex] - (G. Karagiorgi) arXiv: [hep-ex] submitted to PRL

27 28 July 2009MiniBooNE Update -- DPF at 90%CL, no neutrino or antineutrino disappearance observed neutrino results agree with earlier experiments (CDHS + CCFR) antineutrino results map out new excluded region in parameter space arXiv: [hep-ex] (PRL in proof) mode (K. Mahn)

28  cross section results:  unprecedentedly large samples allow measurements to be unpacked as differential rather than total  flux understanding (HARP, &c.) allows absolute rather than ratio measurements  some interesting unanswered questions (M A, &c.)  oscillations:  provenance of low energy excess remains an open question  antineutrino results await more statistics 28 July 2009MiniBooNE Update -- DPF200928

29  combined antineutrino/neutrino appearance analysis  combined MiniBooNE/SciBooNE disappearance analysis  three more years antineutrino running 28 July 2009MiniBooNE Update -- DPF200929

30  combined antineutrino/neutrino appearance analysis  combined MiniBooNE/SciBooNE disappearance analysis  three more years antineutrino running  MicroBooNE: liquid argon TPC in BNB line, upstream of MiniBooNE  upgrade to BooNE: second detector 28 July 2009MiniBooNE Update -- DPF see B Fleming Friday morning plenary!


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