MINOS+ Results and Future Plans A.P. Schreckenberger The University - - PowerPoint PPT Presentation
MINOS+ Results and Future Plans A.P. Schreckenberger The University of Texas at Austin (On behalf of the MINOS and MINOS+ Collaborations) Why we are excited MINOS/MINOS+ makes use of the NuMI beam Most powerful neutrino beam in
A.P. Schreckenberger – The University of Texas at Austin (On behalf of the MINOS and MINOS+ Collaborations)
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Most powerful neutrino beam in operation with upgrades in the works
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Same magnetized MINOS detectors used in MINOS+
Medium-energy NuMI beam
Higher energy spectra and decreased cycle time when compared to MINOS
New target design implemented to handle increased beam power
Expect roughly 4000 νµ CC events per 6×1020 protons-on-target (POT) year
Only wide-band beam long baseline experiment operating in this decade
New physics to be investigated in this new energy window!
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6/12/2014 A.P. Schreckenberger - UT Austin 7 Combine various analyses from MINOS/MINOS+
Full MINOS νμ-CC and ν̄μ-CC disappearance sample
Full νe-CC, ν̄e-CC appearance sample, described in PRL 110 171801 (2013)
Full MINOS and new MINOS+ atmospheric samples
Sensitivity to θ13, θ23 octant, mass
Enhanced by atmospheric data
Matter effects give rise to larger differences in multi-GeV, upward-going events
6/12/2014 A.P. Schreckenberger - UT Austin 8 Combine various analyses from MINOS/MINOS+
Full MINOS νμ-CC and ν̄μ-CC disappearance sample
Full νe-CC, ν̄e-CC appearance sample, described in PRL 110 171801 (2013)
Full MINOS and new MINOS+ atmospheric samples
Sensitivity to θ13, θ23 octant, mass
Enhanced by atmospheric data
Matter effects give rise to larger differences in multi-GeV, upward-going events
Effects are dependent on mass hierarchy and charge conjugation
MINOS first to probe effect
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Contained νµ events as a function of angle for three energy ranges Fits to three-flavor oscillation framework include non-fiducial events
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Solar parameters fixed to ∆𝑛21
2 = 7.54 × 10−5eV2 and sin2 𝜄12 = 0.307
θ13 fit as nuisance parameter, constrained by reactor results: sin2 𝜄13 = 0.0242 ± 0.0025
θ23, ∆𝑛32
2 , and δCP unconstrained
19 systematics included as nuisance parameters in fit
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εµτ study from PRD 88, 072011 (2013)
εeτ study is the first MINOS only analysis regarding this parameter
Presented at Neutrino 2014 in Boston
Follows formulation from: Friedland, Lunardini, Maltoni PRD 70, 111301(2004) Coelho, Kafka, Mann, Schneps, Altinok PRD 86, 113015 (2012) |εeτ|
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6/12/2014 A.P. Schreckenberger - UT Austin 20 Sterile neutrino: theorized additional states that do not
Would add additional parameters to the oscillation model
Anomalies in reactor, short-baseline, radiochemical experiments
Oscillations into light sterile neutrino possible explanation
Evidence of sterile mixing is inconclusive due to tension between various experiment
MiniBooNE, PRL 110, 161801(2013)
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Small ∆𝑛43 2 :
Spectra distortions above oscillation maximum at Far Detector
No Near Detector effects
Medium ∆𝑛43 2 :
Rapid oscillations average out at Far Detector
No Near Detector effects
Counting experiment
Large ∆𝑛43 2 :
Rapid oscillations average out at Far Detector
Near Detector distortions affect Far Detector prediction
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Sterile neutrinos could appear in
1221 NC-like events in 10.56⨉1020
Construct rate metric that
R < 1.0 hints sterile neutrino
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Assume a four-flavor 3+1
Apply oscillations to both Near and
Make use of distance to meson
Fit for ∆𝑛43 2 , ∆𝑛32 2 , θ23, θ24, and θ34
Near Detector oscillation handling
Constrain ND event rate Fit data directly to oscillated F/N
Systematics enter fit as covariance
Re-evaluated beam flux
Feldman-Cousins correction
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Hadron production, beam optics,
Sensitivity to sterile mixing
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6/12/2014 A.P. Schreckenberger - UT Austin 27 Combine MINOS disappearance 90% C.L. in θ24 and Bugey reactor experiment 90%
For a 3+1 model: Bugey limit computed from GLoBES 2012 fit using new reactor fluxes, provided by
MINOS results increases tension between null and signal results for ∆𝑛43 2 < 1 eV2
6/12/2014 A.P. Schreckenberger - UT Austin 28 Compare MINOS neutrino data to world antineutrino data Assuming 3+1 model and CPT conservation (makes SBL neutrino and antineutrino
MINOS results increases tension between null and signal results for ∆𝑛43 2 < 1 eV2 Work on 3.4×1020 POT antineutrino data sterile neutrino search underway
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No evidence of sterile neutrino oscillations found Limits span four orders of magnitude of ∆𝑛43
2
Precision test of oscillation parameters in different energy range Results of oscillation analysis from beam data in Fall Keep watch for any surprises
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First limits on this parameter
Addition of disappearance and
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