Searching for non-standard interactions at the future long baseline experiments

Transcription

1 Searching for non-standard interactions at the future long baseline experiments Osamu Yasuda Tokyo Metropolitan University Dec /34

2 1. Introduction. New Physics in propagation 3. Sensitivity of THK & DUNE to NSI in propagation 4. Conclusions /34

3 1. Introduction Framework of 3 flavor ν oscillation Mixing matrix Functions of mixing angles θ 1, θ 3, θ 13, and CP phase δ e = μ τ μ1 τ1 ν solar +KamLAND (reactor) ν ν ν U U U e1 U U U e μ τ U U U e3 μ3 τ3 All 3 mixing angles have been measured (01): θ ν ν ν 1 3 π 6 5 1, m ev ν atm +KK,MINOS(accelerators) π 3 DCHOOZ+Daya Bay+Reno (reactors), TK+MINOS, others θ 3, m ev θ 13 4 π Both hierarchy patterns are allowed Normal Hierarchy Inverted Hierarchy / 0 3/34

4 U U e1 = U μ1 U τ1 U e U μ U τ U e3 U μ3 U τ3 c1 s / 1 s / 1 s1 c / 1 c / ε / / Next task is to measure sign(δm 31), π/4-θ 3 and δ These quantities are expected to be determined in future experiments with huge detectors. n Both mass hierarchies are allowed 3 1 normal hierarchy 1 3 inverted hierarchy m > 0 m < /34

5 n Proposed experiments (----) ν μ ν (----) (----) (----) μ + ν μ ν e THK (JP, JPARC HK) L=95km, E~0.6GeV DUNE (US, FNAL Homestake, SD), E ~ GeV, L ~ 1300km 5/34

6 Future plan: THK Extension of TK (large #(events)) 1.66MW ν beam Hyperkamiokande (300 times KK) (0 times SK) Main purpose: Measurement of CP phase δ Hyper-kamiokande 6/34

7 Hyperkamiokande (H O:1Mt=SKx0, 05(?)-) Precision measurement of ν oscillation Further search for nucleon decays Precision measurement of supernova ν (if any) 7/34

8 Nu Frontier W/S, Dec /34

9 Future plan: DUNE.3MW ν 40-kt Liquid Argon Sanford Underground RF E ~ GeV, L ~ 1300km 9/34

10 CIPANP /34

11 In the mean time, TK found ν e appearance TK Collaboration, Phys.Rev. D91 (015) 7, (Received 6 February 015) 11/34

12 TK+reactors results Nakaya-Plunkett, arxiv: [hep-ex] (Received 9 Jul 015) normal hierarchy We even already have a hint on the value of δ: δ = -π/ seems to be favored Things are moving faster than we expected! inverted hierarchy 1/34

13 Motivation for research on New Physics High precision measurements of ν oscillation in future experiments can be used to probe physics beyond SM by looking at deviation from SM+m ν (like at B factories). Research on New Physics is important. 13/34

14 Phenomenological scenarios of New Physics Scenarios Light sterile neutrinos Non Standard Interactions in propagation NSI at production / detection Violation of unitarity due to heavy particles Possible magnitude relative to standard value O(10%) e-τ: O(100%) μ: O(1%) O(1%) O(0.1%) While no concrete model is known, scenarios with Non Standard Interactions in propagation could exhibit the largest effect. 14/34

15 . New Physics in propagation Phenomenological New Physics considered in this talk: 4-fermi Non Standard Interactions: ν α f neutral current non-standard interaction ν β f Modification of matter effect NP 15/34

16 Constraints on ε αβ for expts on Earth Davidson et al., JHEP 0303:011,003; Berezhiani, Rossi, PLB535 ( 0) 07; Barranco et al., PRD73 ( 06) ; Barranco et al., arxiv: Biggio et al., JHEP 0908, 090 (009) w/o 1-loop arguments Constraints are weak 16/34

17 Constraints on NSI from high energy behavior of ν atm data Oki-OY PRD8 ( 10) Standard case with N ν = Standard case with N ν =3 = Deviation of 1-P(ν μ ν μ ) due to NSI contradicts with data c c High energy ν atm data is well described by standard scheme constraints on NSI: c 0 1, c /34

18 with NSI c c c 0 1 ε eμ <<1, ε μμ <<1, ε μτ <<1 ε μτ <<1: Fornengo et al. PRD65, , 0; Gonzalez- Garcia&Maltoni, PRD70, , 04; Mitsuka@nufact08 ε μμ <<1: Davidson et al. JHEP 0303:011, 03 ε eμ <<1: (analytical discussions only) Oki-OY PRD8 ( 10) ε eε c 1 1 τ εττ << 1 1+ ee Friedland-Lunardini, PRD7:053009, 05 18/34

19 Summary of the constraints on ε αβ To a good approximation, we are left with 3 independent variables ε ee, ε eτ, arg(ε eτ ): Furthermore, ν atm data implies tanβ= ε eτ /(1+ε ee ) Friedland-Lunardini, PRD7:053009, 05 Allowed region in (ε ee, ε eτ ) 19/34

20 Constraint by SK on ε ee, ε eτ Fukasawa-OY arxiv Best fit std 0/34

21 Fukasawa-OY arxiv Best fit std 1/34

22 3. Sensitivity of THK & DUNE to NSI in propagation The behaviors of the oscillation probabilities at THK & DUNE are considered for several reference points with tanβ = 0.5. /34

23 THK Appearance channel Modest effect Disappearance channel Little effect 3/34

24 DUNE Appearance channel Large effect Disappearance channel Modest effect 4/34

25 5 5/34 /34 Parameters Fixed: θ 1, θ 13, Δm 1 Marginalized: θ 3, Δm 31, δ, arg(ε eτ ) Hypothetical #(events) with standard 3-flavor scheme: θ 3 =π/4, Δm 31 =.5x10-3 ev, δ=-π/ A G F n e Outline of our Analysis + = τ μ τ μ ν ν ν ν ν ν e e A U E m E m E m diag U dt d i ,, ee e e e ee ε ε ε ε ε τ τ τ Our ansatz [ ] = Δ i i i e ee i e ee N N 0 parameters ) ( ), ( min ), ( σ ε ε ε ε χ τ τ std For simplicity only statistical errors are taken into account.

26 Sensitivity of THK to ε ee, ε eτ OY (Preliminary) std=best fit Sensitivity is no better than that of present ν atm at SK true: std-nh fit: NH is correctly assumed 6/34

27 Sensitivity of DUNE to ε ee, ε eτ OY (Preliminary) Sensitivity is better than that of present ν atm at SK std=best fit true: std-nh fit: NH is correctly assumed 7/34

28 Sensitivity of TK-DUNE combined to ε ee, ε eτ OY (Preliminary) Sensitivity is completely dominated by DUNE std=best fit true: std-nh fit: NH is correctly assumed 8/34

29 Sensitivity of TK-DUNE combined to ε ee, ε eτ OY (Preliminary) true: std-nh fit: IH is wrongly assumed std=best fit 9/34

30 Sensitivity of TK-DUNE combined to ε ee, ε eτ OY (Preliminary) true: std-ih fit: IH is correctly assumed std=best fit 30/34

31 Sensitivity of TK-DUNE combined to ε ee, ε eτ OY (Preliminary) true: std-ih fit: NH is wrongly assumed std=best fit 31/34

32 Ratio of ν and ν TK ν:ν = 1:3 R:(1-R) DUNE ν:ν = 1:1 R:(1-R) Δχ of TK-DUNE combined at ε ee =1, ε eτ =1/ OY (Preliminary) The planned ratio The planned ratio for TK & DUNE seems to be relatively closed to the optimized value. 3/34

33 Sensitivity of HK ν atm with spectrum analysis Fukasawa-OY arxiv tanβ 33/34

34 4. Conclusions Under the assumptions ε eμ = ε μμ = ε μτ = 0 & ε ττ = ε eτ /(1+ε ee ), we studied sensitivity to NSI in propagation of THK & DUNE. Sensitivity of DUNE to NSI in propagation is much better than that of THK, and it is expected to improve (tanβ<0.4@.5σcl). the present constraint on NSI in propagation by ν atm at SK (tanβ<0.8@.5σcl). The planned ratio of ν & ν for THK & DUNE seems to be close to the optimized also to ε ee =1, ε eτ. Future observations of ν atm at HK are expected to improve the constraint further (tanβ<0.1@.5σcl). 34/34