Impact of NSI on NMO and Octant Sensitivity with ORCA N. R. Khan Chowdhury, Tarak Thakore 1 Oct. 10, 2019 | N. R. Khan Chowdhury | ANTARES & KM3NeT Collaboration Meeting | Warsaw |
1) Impact of NSI on NMO 2
NSI mimics the wrong ordering! 𝛇 𝜈𝜐 = -0.05 𝛇 𝜈𝜐 = 0 𝛇 𝜈𝜐 = 0.05 P NH 𝜈𝜈 P IH 𝜈𝜈 3
Methodology: Treating NSI as systematics 1) Simulate toy data set with some value of NSI. 2) Release the NSI parameter in the fit. 3) Calculate NMO sensitivity. 4
NMO sensitivity in presence of NSI in data NMO sensitivity considerably abated by 𝛇 e 𝜈 and 𝛇 e 𝜐 5
NMO sensitivity in presence of NSI in data NMO sensitivity marginally “not” affected by 𝛇 𝜈𝜐 and 𝛇 𝜐𝜐 6
NMO sensitivity with NSI in fit Data generated with standard 3 flavor oscillations. Fit over oscillation parameters, systematics and NSI parameter. Repeat for different true values of 𝜾 23 . ~1 𝜏 dilution with NSI 𝛝 e 𝝊 . Asimov NMO sensitivity 7
2) Octant Sensitivity with ORCA115 8
Octant degeneracy The ambiguity in the determination of 𝜾 23 can be from 1) Inherent octant degeneracy: oscillation and survival probabilities are function of sin 2 2 𝜾 23 . 2) Degeneracy of the octant with other oscillation parameters: oscillation and survival probabilities are function of sin 2 𝜾 23 . 9
Octant ambiguity ensued in P 𝝂 e and P ee The relevant probabilities in the OMSD approximation with matter effects reads m reaches value of 1 irrespective of the value of During matter resonance, sin2 𝜾 13 𝜾 13 and the product is no longer invariant. The electron survival probability is independent of 𝜾 23 and does not contribute to octant sensitivity. 10
Octant ambiguity ensued in P 𝝂𝝂 The muon survival probability in matter has leading terms proportional to sin 2 2 𝜾 23 (intrinsic octant degeneracy). But the strong octant sensitive behaviour of sin 4 𝜾 23 sin 2 2 𝜾 13 m near resonance can override the degeneracy. 11
Asymmetry in P 𝝂𝝂 and P 𝝂 e channel 12
Octant Sensitivity: Effect on 𝜺 CP NMO is assumed to be known since the time scale involved would ensure NMO is determined before any significant octant sensitivity is achieved. (Wrong octant - wrong ordering excluded.) 1) Nearly independent of 𝜺 CP . Dependence is suppressed by matter resonance. 2) Assuming IH gives worse results since, matter resonance and octant sensitivity comes from the anti-nu channel for which flux and cross-section are lower. 3) HO (true) gives lower sensitivity because of normalisation factor. 13
Octant Sensitivity Hierarchy not fitted again. IH gives worse sensitivity for low lower anti-neutrino flux and interaction cross-section. 14
Summary: 1) Impact of NSI on NMO sensitivity has been explored. 2) Preliminary estimation of octant sensitivity has been studied. 3) Study of NSI impact on octant sensitivity is foreseen in coming days. 15
THANKS 16
ANTARES Sensitivity: 17
ANTARES Upper Limits: 1) Same Data sample used as in ANTARES Oscil. paper. 2) Same set of systematic parameters and priors. 18
ANTARES (3+NSI) Fit results: 1) Fit for NO. No priors on atmo. osc. parameters. 2) All other NSIs are fixed at zero. (conservative limit!) 3) Systematics and priors as in the official analysis. 19
Effect of systematics: Old plot! 20
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