Download presentation

Presentation is loading. Please wait.

Published byMyles Sweeting Modified over 2 years ago

1
1 3+2 Neutrino Phenomenology and Studies at MiniBooNE PHENO 2007 Symposium May 7-9, 2007 U. Wisconsin, Madison Georgia Karagiorgi, Columbia University

2
Georgia Karagiorgi, Columbia U.2 Outline Motivation for 3+2 models 3+2 phenomenology and oscillation formalism The MiniBooNE result and experimental constraints for 3+2 models CP violation studies in 3+2 models and prospects for CPV measurement at MiniBooNE Current status of 3+2 analysis and future plans Conclusions G. Karagiorgi et al., “Leptonic CP violation studies at MiniBooNE in a (3+2) sterile neutrino oscillation hypothesis,” Phys. Rev. D. 75, 013011 (2007) [hep-ph/0609177].

3
Georgia Karagiorgi, Columbia U.3 The LSND Signal Δm 2 LSND >> Δm 2 atm >> Δm 2 sol Δm 2 LSND ~ 0.1- 10 eV 2 + small mixing one option: 3 active + n “sterile” neutrinos other options: neutrino decay, extra-D, etc.

4
Georgia Karagiorgi, Columbia U.4 3+2 Model Phenomenology 3 active + 2 sterile neutrinos light sterile neutrinos they can interact thru non-standard weak couplings they have very small active flavor content (U e4,…, U e5,…) can participate in neutrino oscillations νeνμντνsνeνμντνs increasing m 2 (not to scale) Why n=2? 3+1 models: SBL and LSND marginally consistent with each other 3+2: next natural step… [M. Sorel, et al. hep-ph/0305255]

5
Georgia Karagiorgi, Columbia U.5 3+2 Model Phenomenology GUT’s Mohapatra, Nasri, & Yu [hep-ph/0505021] De Gouvea, Jenkins, & Vasudevan [hep-ph/0608147] Extra-D Pas, Pakvasa, & Weiler [hep-ph/0504096] Ma, Rajasekaran, & Sarkar [hep-ph/0006340] SUSY Kang, & Li [hep-ph/0501101] Dvali, & Nirb [hep-ph/9810257]

6
Georgia Karagiorgi, Columbia U.6 3+2 Neutrino Oscillation Formalism General neutrino oscillation formula: P(ν α ν β ) = δ αβ – 4 Σ Re ( U* αi U βi U αj U* βj ) sin 2 x ij + 2 Σ Im (U* αi U βi U αj U* βj ) sin2x ij P(ν μ ν e ) = 4|U μ4 | 2 |U e4 | 2 sin 2 x 41 + 4|U μ5 | 2 |U e5 | 2 sin 2 x 51 + + 8 |U μ5 ||U e5 ||U μ4 ||U e4 |sinx 41 sinx 51 cos(x 54 +φ 45 ) Assumptions for 3+2 model analysis: approximate m 1 = m 2 = m 3 = 0 * two independent mass splittings: Δm 2 41, Δm 2 51 four moduli: |U e4 |, |U μ4 |, |U e5 |, |U μ5 | one CPV phase: φ 54 = arg(U* μ5 U e5 U μ4 U* e4 ) * This allows for 6 1 CPV phase in a (3+2) hypothesis (3 0 CPV phases in a (3+1) hypothesis) (1 0 CPV phases in a (3+0) hypothesis) 3+2 model = most minimal model for CPV studies! x ij = 1.27Δm 2 ij L/E

7
Georgia Karagiorgi, Columbia U.7 First Results from MiniBooNE “A Search for Electron Neutrino Appearance at the Δm 2 ~ 1eV 2 Scale,” The MiniBooNE Collaboration [hep-ex/0704.1500]. MiniBooNE result excludes the LSND 90%CL allowed region at > 90% CL…

8
Georgia Karagiorgi, Columbia U.8 First Results from MiniBooNE …MiniBooNE result assumes: CP-conserving, 2-neutrino oscillation scenario E > 475 MeV Excess of ν e events at low energies: Currently investigating if this is a detector effect, or SM background… Could be a manifestation of beyond the SM physics… For more information on this, see talk by Chris Polly

9
Georgia Karagiorgi, Columbia U.9 Experimental Constraints We are interested in: studying the compatibility of null SBL results with LSND and MiniBooNE results in a 3 active + 2 sterile neutrino hypothesis constraining the 3+2 model parameters ChannelExperiment Lowest Δm 2 Reach (90%CL) High Δm 2 Optimal Δm 2 ν μ ν e LSND KARMEN NOMAD MiniBooNE 3x10 -2 6x10 -2 4x10 -1 2.5x10 -2 > 2.5x10 -3 < 1.7x10 -3 < 1.4x10 -3 > 1.2x10 -3 < 1.0x10 -3 < 1.0x10 -3 ν e ν e Bugey Chooz 1x10 -2 7x10 -4 < 1.4x10 -1 < 1.0x10 -1 < 1.3x10 -2 < 5x10 -2 ν μ ν μ CCFR84 CDHS 6x10 0 3x10 -1none < 2x10 -1 < 5.3x10 -1 sin 2 θ constraint (90%CL)

10
Georgia Karagiorgi, Columbia U.10 Combined NSBL+LSND+MiniBooNE 3+2 analysis (including MB ν e background disappearance) and compatibility tests are currently in progress… Recent studies: Leptonic CP violation studies at MiniBooNE in a 3+2 sterile neutrino oscillation hypothesis Expected oscillation probability at MiniBooNE Potential of CP-violation measurement at MiniBooNE [hep-ph/0609177] Dataset: NSBL + LSND only (no atmospheric or solar experiment data) + Super-K atm. constraint

11
Georgia Karagiorgi, Columbia U.11 Oscillation Analysis for CPV Studies at MiniBooNE Generate masses and mixing parameters (models): –0.1eV 2 ≤ Δm 2 41, Δm 2 51 ≤ 100eV 2 Δm 2 51 ≥ Δm 2 41 –|U e4 |, |U μ4 |, |U e5 |, |U μ5 | U ei 2 + U μi 2 ≤ 0.5, U α4 2 + U α5 2 ≤ 0.5 –atmospheric constraint: d μ = ½ - √(1-4A) /2 where A = (1 - |U μ4 | 2 - |U μ5 | 2 )(|U μ4 | 2 + |U μ5 | 2 ) + |U μ4 | 2 |U μ5 | 2 CP violation option: Fix φ 54 = 0, π, or allow to vary within (0,2π) Calculate expected oscillation probabilities in neutrino and anti-neutrino running mode at MiniBooNE (using expected full ν μ ν e transmutation rates) Determine allowed regions by Gaussian approximation Importance sampling via Markov chain: P(x i x i+1 ) = min{1,exp[-(χ 2 i+1 -χ 2 ι )/Τ]} x i+1 = x i + e P(ν μ ν e ) = 4|U μ4 | 2 |U e4 | 2 sin 2 x 41 + 4|U μ5 | 2 |U e5 | 2 sin 2 x 51 + + 8 |U μ5 ||U e5 ||U μ4 ||U e4 |sinx 41 sinx 51 cos(x 54 +φ 45 )

12
Georgia Karagiorgi, Columbia U.12 Oscillation probability expected at MiniBooNE CP-violating 3+2 modelsCP-conserving 3+2 models 90%CL 99%CL Best fit models: CPC: χ 2 /dof = 141.4/145 CPV: χ 2 /dof = 140.8/144

13
Georgia Karagiorgi, Columbia U.13 Potential observation of CP-violation at MiniBooNE All CP-violating phase values allowed at 99%CL by the NSBL+LSND data are measurable at MiniBooNE Small degrees of CPV preferred Large asymmetries allowed, but not required 90%CL 99%CL

14
Georgia Karagiorgi, Columbia U.14 First global fit results Analysis by Maltoni & Schwetz Fig. 7 [hep-ph/0705.0107] Best fit parameters for global fit with full MiniBooNE E range: Δm 2 41 = 0.87eV 2 x 2 min /dof = 104.4/(109-7) Δm 2 51 = 1.91eV 2 gof = 41% cpv-phase = 1.44 π χ 2 PG = 17.5, PG = 1.5 x 10 −3 (no MB) χ 2 PG = 25.1, PG = 4.8 x 10 −5 (MB300)

15
Georgia Karagiorgi, Columbia U.15 Potential observation of CP-violation at MiniBooNE MiniBooNE expected oscillation probability asymmetry based on calculated best fit model parameters from hep-ph/0705.0107 global 3+2 analysis (MB300 and MB475) MB300 A p/p = -0.448 φ 45 = 1.44π MB475 A p/p = -0.207 φ 45 = 1.64π

16
Georgia Karagiorgi, Columbia U.16 First global fit results Maltoni & Schwetz Fig. 3 [hep-ph/0705.0107] MB signal prediction from best fit points from SBL appearance data (LSND, KARMEN, NOMAD, MB) in a 3+2 oscillation analysis 3+2 neutrino models: provide a good fit to LSND and the recent MB data can account for the low energy event excess in MB However: there is significant tension between appearance and disappearance data (according to the PG test at the level of 3σ for MB475 and 4σ for MB300). Note: analysis done without full MiniBooNE error matrix

17
Georgia Karagiorgi, Columbia U.17 Our next 3+2 steps… More detailed combined NSBL + LSND + MiniBooNE 3+2 oscillation analysis and compatibility tests, that take into consideration: Full MiniBooNE error matrix Disappearance of MiniBooNE ν e background

18
Georgia Karagiorgi, Columbia U.18 Conclusions Original motivation: accommodate null SBL and LSND results within the framework of neutrino oscillations MiniBooNE data: key in addressing the viability of 3+2 models with sterile neutrinos Leptonic CP-violation possibility opened up in the 3+2 sterile neutrino hypothesis could have large measurable effects at MiniBooNE

Similar presentations

OK

Resonant Leptogenesis In S4 Model Nguyen Thanh Phong Cantho University In cooperation with Prof. CSKim, SKKang and Dr. YHAhn (work in progress)

Resonant Leptogenesis In S4 Model Nguyen Thanh Phong Cantho University In cooperation with Prof. CSKim, SKKang and Dr. YHAhn (work in progress)

© 2017 SlidePlayer.com Inc.

All rights reserved.

Ads by Google

Ppt on upcoming technologies in computer science Ppt on content addressable memory Make a ppt on natural disasters Leadership ppt on accountability Ppt on glasgow coma scale Ppt on porter's five forces model pdf Ppt on nmr spectroscopy Slideshare ppt on cloud computing Ppt on db2 architecture Ppt on data handling for grade 3