Mini Overview Peter Kasper NBI 2002

The MiniBooNE Collaboration University of Alabama, Tuscaloosa Bucknell University, Lewisburg University of California, Riverside University of Cincinnati, Cincinnati University of Colorado, Boulder Columbia University, Nevis Labs, Irvington Embry Riddle Aeronautical University Fermi National Accelerator Laboratory Indiana University, Bloomington Los Alamos National Laboratory Louisiana State University, Baton Rouge University of Michigan, Ann Arbor Princeton University, Princeton

MiniBooNE Goals MiniBooNE’s primary goal is to unequivocally confirm or refute the LSND oscillation signal for   eMiniBooNE’s primary goal is to unequivocally confirm or refute the LSND oscillation signal for   e Similar L/E ~ 1 to LSND but ~10x higher energySimilar L/E ~ 1 to LSND but ~10x higher energy –E ~ GeV –L = 500 m Experimental signatures and backgrounds are completely different from LSNDExperimental signatures and backgrounds are completely different from LSND –provides a truly independent test of their result. If the signal is confirmed, a second detector will be built...If the signal is confirmed, a second detector will be built... –i.e. full BooNE

LSND and KARMEN Results KARMEN limitsKARMEN limits – Solid curve calculated with the Feldman & Cousins approach – Dashed curve is experiment’s sensitivity LSND signal region LSND signal region –  90% Lmax - L < 2.3 –  99% Lmax - L < 4.6

The LSND Signal Signal discrimination is encapsulated into a variable R Signal discrimination is encapsulated into a variable R  –Ratio of likelihood that e + and  are correlated to likelihood that  is accidental ± 22.4 ± 6.0 event excess consistent with  e p  e + n followed by n p  d  ± 22.4 ± 6.0 event excess consistent with  e p  e + n followed by n p  d . –4 times the expected rate from beam  e `s signal

LSND Implications What we know from other experimentsWhat we know from other experiments –Atmospheric  ’s oscillate at  m 2 ~ with maximal mixing ( e.g. SuperK )    favored    favored –Solar e ’s oscillate at  m 2 < ( e.g. SNO )    e favored    e favored LSND results has  m 2 ~ for    eLSND results has  m 2 ~ for    e –hence require  4 neutrino mass states Only 3 active flavors ( LEP )Only 3 active flavors ( LEP ) –hence sterile ’s are required OR –neutrino masses  antineutrino masses

An Experimentally Allowed Model Bimaximal mixing in modelsBimaximal mixing in models –W. Krolikowski HEP-PH/ – R.N.Mohapatra Phys.Rev. D64 (2001) ,      m 2 LSND  m 2 Solar  m 2 Atm. e   s

An Alternative Model Maximal CPT violation in Dirac mass termsMaximal CPT violation in Dirac mass terms –Barenboim, Borissov, Lykken & Smirnov HEP-PH/ –Generates independent masses for ’s and  ’s –Motivated by branes with extra dimensions     m 2 LSND  m 2 Solar  m 2 Atm. e        

Proton Beam MiniBooNE’s neutrino beam will be produced with a high intensity ( 5 Hz ) 8 GeV proton beam from the Fermilab Booster.MiniBooNE’s neutrino beam will be produced with a high intensity ( 5 Hz ) 8 GeV proton beam from the Fermilab Booster. The Booster cycles at 15 Hz and produces 1.6  sec beam pulses.The Booster cycles at 15 Hz and produces 1.6  sec beam pulses. New construction Proton beam line Target Hall Decay pipe Detector building

Beam Layout Beam Layout Civil construction for the 8 GeV Beamline, Target Hall, and Decay Pipe began in June  50m long decay pipe

Beam Line Construction Civil Construction is complete and component installation is well advanced. Ready for beam tests this April.Civil Construction is complete and component installation is well advanced. Ready for beam tests this April. 24-Jan-02

Target Hall Construction Civil and target pile construction is complete. Horn installation is scheduled to start in early May.Civil and target pile construction is complete. Horn installation is scheduled to start in early May. 24-Jan-02

Decay Pipe Construction Two absorbers at 25m (removable) and 50m (fixed) provide a cross check of the intrinsic e component in the beam. 13-Nov-00 50m absorber with muon counters 25m absorber 24-Jan-02 Air heat exchanger for cooling berm

The Target A 65cm, air cooled Be target will be inserted inside a single focussing horn Hadroproduction studies will be done for our energy and target. (BNL910 and HARP) 7-Feb-02

The Horn A single horn system will be used ( proposal had two )A single horn system will be used ( proposal had two ) Less flux but also less background from high energy (>1 GeV) neutrinos than the original 2 horn designLess flux but also less background from high energy (>1 GeV) neutrinos than the original 2 horn design Horn has been built and tested for > 10 7 pulsesHorn has been built and tested for > 10 7 pulses 20-Jun-01

The Neutrino Beam Intrinsic e contamination can be.. – –Inferred from  events – –Simulated using hadroproduction measurements – –Measured using muon counters in and around the decay pipe – –Checked by comparing 50m and 25m absorber results

The Detector The detector is a 40ft (12.2m) diameter sphere filled with 800 tons of pure mineral oil and instrumented with ~1500 8” PMTs.The detector is a 40ft (12.2m) diameter sphere filled with 800 tons of pure mineral oil and instrumented with ~1500 8” PMTs. It is housed underground in order to provide some cosmic ray shielding.It is housed underground in order to provide some cosmic ray shielding.

The Detector (cont.) It will consist two optically separated regions...It will consist two optically separated regions... –An inner sphere with 1280 PMTs viewing a 445 ton fiducial volume ( 10% photocathode coverage) –An outer veto shell 35cm thick monitored by 240 PMTs.

Detector Status The detector enclosure was completed in December 2000.The detector enclosure was completed in December The PMT installation was completed in October 2001.The PMT installation was completed in October Oil fill started early January and the detector is now 60% full.Oil fill started early January and the detector is now 60% full. Detector Enclosure Jan 2001 PMT installation Sept. 2001

A Possible Stopping Cosmic Ray Muon

Event Reconstruction MiniBooNE will reconstruct quasi-elastic e interactions by identifying the characteristic Cerenkov rings produced by the electrons...MiniBooNE will reconstruct quasi-elastic e interactions by identifying the characteristic Cerenkov rings produced by the electrons...

Approximate # of Events after 1-2 Years

MiniBooNE Sensitivity: 2 yr’s of  The major backgroundsThe major backgrounds –misid  ’s from CC  – misid  0 ’s from NC  Uncertainties in these rates to be < 5% in each case.Uncertainties in these rates to be < 5% in each case. e ‘s Intrinsic to the beam have a different energy distribution than oscillation e ‘s e ‘s Intrinsic to the beam have a different energy distribution than oscillation e ‘s –Event energy can be measured using scintillation light

Summary All civil construction projects for MiniBooNE are essentially complete.All civil construction projects for MiniBooNE are essentially complete. The detector instrumentation is complete and the oil fill is well under way.The detector instrumentation is complete and the oil fill is well under way. MiniBooNE is on schedule for taking first data later this summer.MiniBooNE is on schedule for taking first data later this summer. The biggest issue facing the experiment at this point is the Booster’s ability to deliver the required number of protons.The biggest issue facing the experiment at this point is the Booster’s ability to deliver the required number of protons. –The limits will be due to radiation levels both in the tunnel and above ground.