Test of Non-Standard Interactions at Super-K

Transcription

1 Test of Non-Standard Interactions at Super-K G. Mitsuka Nagoya University Now1, Sep. 6th, 1 Otranto

2 Outline Introduction & Physics motivation Expected NSI phenomena at SK Data sets Analysis results Conclusions

3 What is NSI? Note: there are many non-standard interaction NSI in markets. In this analysis, NSI is defined as either FCNC and Non-universality(NU). σ(ν α + f ν β + f) = σ(ν α + f) = σ(ν β + f) ε αβ ε αα, ε ββ H NSI = G F N f (r) NSI driven transition probability εµµ ε µτ ε µτ ε ττ ε ε µτ P νµ ν µ = sin ( ε ε µµ G F <N f >L ε ττ /4+ ) Probability changes as depending only on the number density Nf and the flight length L.

4 Transition Probabilities Standard Oscillation NSI P νµ ν µ =1 sin θ sin 1.7 m L E ν P νµ ν µ = 1 f(ε, ε ) sin ( G F <N f >Lεf(ε, ε )) ε=fcnc ε =NU f(ε, ε ) 4ε 4ε + ε Pνµ νµ Eν=1GeV Eν=1GeV Eν=1GeV sin θ = 1. Δm =.x1-3 ev log(l(km)) Pνµ νµ ε=1, ε =.1 Large ε,ε drives transition in short L ε=1., ε =1. ε >ε suppress P(να νβ) ε=1., ε = log(l(km)) Sizable transition can occur in NSI even in high energy.

5 ν NSI hunting? Precise measurement of ν-int. cross section CHARM, NuTeV, etc... Atmospheric neutrino Super-Kamiokande, MACRO Solar neutrino(matter vacuum transition) Borexino Accelerator neutrino ν factory? NOTE:MACRO data is phenomenologically analyzed

6 Advantage of Super-K GFNf Fermion number density sensitive to FCNC & NU Super-K MINOSx1 Entries Mean RMS Zenith angle Prediction by PREM model Surveying wide range energy Events/year/bin MeV - 1TeV Sub-GeV Multi-GeV PC Up-thr Up-stop log(eν(gev)) Large number of

7 Pure NSI Hybrid NSI SK-I & SK-II Null OSC. <Eν>~1GeV NSI(ε=ε =1.) Standard Oscillation (sin θ=1., Δm =.5x1-3 ev ) <Eν>~1GeV No significant inconsistency is in fully or partially contained event, while clear difference in Upward going µ. Pure NSI scenario is ruled out. H αβ = 1 E U αj m 1 (U ) kβ +V MSW + G F N f (r) m 31 Standard Oscillation Hybrid NSI Model ε ee ε eµ ε eτ ε eµ ε µµ ε µτ ε eτ ε µτ ε ττ This talk presents the analyses based on the Hybrid model. NSI

8 Analysis procedures Data&MC sets - FC, PC, and UPμ SK-I & II atm-ν data. -,8 livedays = 6.5years - MC statistics is 5years. Reconstruction tools and MC have been updated since the past oscillation analysis with SK-I and II. Agreement between data and MC is derived by checking zenith angle and momentum bins. Systematic errors related to neutrino flux, interaction, detector responses are taken into account(totally 9 terms).

9 -Flavor Hybrid(μτ sector) -Flavor Hybrid model = -flavor OSC.( 3) + -flavor NSI(μτ) Flavor transition from source to detector H NSI αβ NSI Hamiltonian = ε ee ε eµ ε eτ G F N f (r) ε eµ ε µµ ε µτ ε eτ ε µτ ε ττ Focusing only on μτ sector Events/bin SK-1+ PC through Zenith angle distributions with typical parameters cos Events/bin SK-1+ UPMU thru showering cos (ε,ε )= ε=fcnc ε =NU Green:(1.x1-3, -.4x1 - ) Blue: (1.x1-3, -.38) Red: (3.x1-3, -.4x1 - ) Note : All lines after χ fitting with systematics.

10 3 (ev ) m 1 ε (NU) 3 -Flavor Hybrid(μτ sector) D contour(osc pars.) Δm (ev ) vs. Δχ sin θ vs. Δχ SK I + SK II 99% C.L. 9% C.L. 68% C.L. Best fit parameters Δm =.x1-3 ev sin θ = 1. ε = 1.x1-3 ε = -.7x %C.L. - 9%C.L. - 99%C.L. Hybrid NSI Standard OSC sin D contour(nsi pars.) - 68%C.L. - 9%C.L. - 99%C.L. 3 Δχ ε(fcnc) Best fit parameters ε = 1.x1-3 ε = -.7x1 - Limit from SK-1 & SK-II (9%C.L.) ε <1.1x1 - ε <4.9x1-1 Δm (ev ) ε=fcnc ε =NU ε (NU) - Δχ D contour by sub-samples SK I + SK II PC+UPμ stop UPμ thr FC Multi-GeV 1 sin θ ε(fcnc)

11 3-Flavor Hybrid(eτ sector) 3-Flavor Hybrid model = -flavor OSC.( 3) + -flavor NSI(eτ) Flavor transition from source to detector H NSI αβ NSI Hamiltonian = ε ee ε eµ ε eτ G F N f (r) ε eµ ε µµ ε µτ ε eτ ε µτ ε ττ Events/bin Focusing only on eτ sector Zenith angle distributions with typical parameters Events/bin Red : Standard oscillation Green : NSI εee =. εeτ =. εττ =. Note : All lines after χ fitting with systematics.

12 3-Flavor Hybrid(eτ sector) Note : No constraint to εee can be given by atm-ν. External constraint by CHARM is added(-.6<εee<.5). εττ D contour(nsi parameters) SK I + SK II 99% C.L. 9% C.L. 68% C.L. - 68%C.L. - 9%C.L. - 99%C.L. εeτ e εeτ Best fit parameters Δm =.1x1-3 ev sin θ = 1. εee = -.5 εeτ =.16 εττ =.4 εττ D contour by sub-samples SK I + SK II UPμ thr. Each curves show 68%C.L. PC+UPμ stop FC Multi-GeV Limit from SK-1 & SK-II (9%C.L.) εeτ < <εττ< e εeτ

13 Constraints by SK Note : Atm-ν cannot distinguish L and R. ε αβ = ε dl αβ + ε dr αβ εeτ(r) Constraint on εeτ εμτ(r) Constraint on εμτ Existing limits CHARM(9%C.L.) ε dl eτ <.5 ε dr eτ <.5 Constraint on εμμ εeτ(l) Constraint on εττ εμτ(l) ε dl µµ <.3.8 < ε dr µµ <.15 ε dl NuTeV(9%C.L.) µτ <.5 ε dr µτ <.5 εμμ(r) εττ(r) εμμ(l) εττ(l)

14 Conclusion ν oscillation is stable even with additional NSI term. NSI is consistent with. Limit on FCNC is tighter by an order of magnitude. Limit on NU(ττ) is significantly improved.

15 Backup

16 What is NSI? NSI : Interaction between a given particle and another one beyond standard model NSI is studied in neutrino as well as toppair and decay etc...

17 Theorists opinions Hybrid mode with oscillation and NSI can be expected, where NSI is contained as sub-dominant channel[1,] Large value is theoretically allowed in eτ channel[3] Loose limit on eτ channel can spoils the sensitivity ofθ13[3,4] [1] N. Fornengo et al., Phys. Rev. D65 () 131 [hep-ph/1843] [] M. C. Gonzalez-Garcia and M. Maltoni,

18 Hybrid model with oscillation and NSI We follow the formalism by M. C. Gonzalez-Garcia and Michele Maltoni in PRD 7, 331 (4) where R θ = oscillation cos θ sin θ sin θ cos θ R φ = cos φ sin φ sin φ cos φ NSI φ = 1 arctan ε ε / where P νµ ν µ sin Θ = Survival probability =1 sin Θ sin m L 4E R relative phase: 1 η=arg(ε) sin R θ + R sin φ +Rsin θ sin φ cos η Scanning parameters sinθ,δm(for osc.) ε,ε,cosη(for NSI) R = 1+R +R(cos θ cos φ + sin θ sin φ cos η)

19 3 (ev ) m 1 3 -Flavor Hybrid(μτ sector) D contour(osc pars.) Δm (ev ) vs. Δχ sin θ vs. Δχ SK I + SK II 99% C.L. 9% C.L. 68% C.L. Best fit parameters Δm =.x1-3 ev sin θ = 1. ε = 1.x1-3 ε = -.7x %C.L. - 9%C.L. - 99%C.L. Hybrid NSI Standard OSC sin 3 Δχ Δm (ev ) - Δχ sin θ D contour(nsi pars.) ε(fcnc) vs. Δχ ε (NU) vs. Δχ ε(fcnc) - 68%C.L. - 9%C.L. - 99%C.L. Δχ min Δχ min Limit from SK-1 & SK-II ε <1.1x1 - ε <4.9x1 - ε (NU) ε(fcnc) ε (NU)