Transcript Frontiers of Diffuse Analysis - University of California

3rd Oscillations Working Group Report:
It just got interesting
Kurt Woschnagg*
UC Berkeley
*WG co-lead with Ty DeYoung
IceCube collaboration meeting, Banff, March 8, 2014
Atmospheric Neutrino Oscillations
Search for muon neutrino disappearance in DeepCore data
Atmospheric Neutrino Oscillations
Theoretical oscillogram
Observables
Likelihood scan in
parameter space
Search for muon neutrino disappearance in DeepCore data
Current νμ disappearance results
Other analyses, including ντ appearance, in event selection stage
→ Low-Energy Summary by Jason K.
IC79 νμ disappearance: final level expectations
Event rates (normalized to burn sample)
Laura Gladstone (UW)
~80% neutrino purity
~7000 events in full sample
needs to be understood
35% energy error
down to ~15 GeV
using Monopod
Confidence contours with Multillh
Confidence contours with Multillh
IC79 νμ disappearance: data challenge
Laura Gladstone (UW)
IC86 νμ disappearance: multiyear extension
Results from IC86-I analysis:
Juan Pablo Yáñez (DESY)
IC86 νμ disappearance: multiyear extension
Extension to three years:
Juan Pablo Yáñez (DESY)
(LE summary has details)
IC86 νμ disappearance: new energy estimator
Use combinedReco by Andrii Terliuk
IC86 νμ disappearance: new energy estimator
IC86 νμ disappearance: new energy estimator
IC86 νμ disappearance: background template
Need background template for likelihood fit
Relaxed veto cuts to estimate background from CORSIKA
New approach: estimate background from data
IC86 νμ disappearance: background template
IC86 νμ disappearance: background template
IC86 νμ disappearance: gains in statistics
Take three years instead of one:
Remove faulty selection logic:
+200%
+40%
Remove RTVeto cut:
+20%
Total increase:
1500 events to 7500 events
And it all adds up to…
Sensitivity for three years of IC86 data
Now we’re
talking!
Upgoing νμ survival probability
Standard 3-flavor oscillations
With a sterile neutrino
Including Matter
4 Flavors
3 Flavors
Vacuum only
4 Flavors
Including Matter
3 Flavors
Vacuum only
IC59 sterile neutrino search
(from Friday plenary)
Marius Wallraff, Christopher Wiebusch (Aachen)
IC59 diffuse HE
sample
(A. Schukraft)
Ratio: Experiment and Best Fit relative to Null
Warning, the fit is 2-d
Shown are projections
Pulls: Experiment and Best Fit relative to Null
IC59 sterile neutrino search
(from Friday plenary)
Marius Wallraff, Christopher Wiebusch (Aachen)
Significances calculated from log L = log L(Best fit) – log L(null) (assuming 2 dof)
 m422 = 0.156 eV2
q24 = 17°
IC79+IC86 sterile neutrino search
Carlos Argüelles Delgado, Jordi Salvadó Serra (Madison)
IC79+IC86 diffuse HE samples (C. Weaver)
Higher energy range than IC59 sample
Different theoretical approach to calculating oscillation probabilities
As in IC59 analysis, action is in zenith angle:
Caution: We have had a zenith dip at -0.4 due to a bug (“the NiuGen bug”) before
IC86 sensitivity (one year)
Disfavored by cosmological data
Burn sample fits
IC79
IC59
IC86
IC79+IC86 sterile neutrino search: outlook
+ Explain things like this:
IC86
IC59
Conclusions
1. IceCube is competitive
with dedicated
oscillation experiments
2. Marius may not graduate for a while…
3. We will have frequent oscillation calls