Low energy neutrino experiments sensitivity to physics beyond the - PowerPoint PPT Presentation

Low energy neutrino experiments sensitivity to physics beyond the Standard Model Timur Rashba MPI, Munich Low energy neutrino experiments sensitivity to physics beyond the Standard Model – p.1

Outline Motivations Non-standard ν -e and ν -q interactions Non-standard contributions to ν - N coherent scattering Sensitivity to specific NSI scenarios: Z ′ , leptoquark and R-parity breaking SUSY Weak mixing angle and neutrino charge radius Summary References: J. Barranco, O. Miranda and TR, hep-ph/0508299, hep-ph/0702175, arXiv:0707.4319 Low energy neutrino experiments sensitivity to physics beyond the Standard Model – p.2

Non Standard Interactions (NSI) Most extensions of the SM, in particular neutrino mass theories, predict neutral current non-standard interactions (NSI) of neutrinos which can be either flavor preserving (NU – non-universal) or flavor-changing (FC). NSI effective Lagragian form: √ � ν α γ ρ Lν β )( ¯ ε fP L NSI fγ ρ Pf ) eff = − αβ 2 2 G F (¯ αβfP � � a b e, u, d e, u, d Here α, β = e, µ, τ ; f = e, u, d ; P = L, R ; L = (1 − γ 5 ) / 2 ; R = (1 + γ 5 ) / 2 Low energy neutrino experiments sensitivity to physics beyond the Standard Model – p.3

Non Standard Interactions (NSI) Non-standard neutral current neutrino interactions may arise: from a non trivial non-unitary lepton mixing matrix Schechter & Valle’80 in models where neutrino masses are "calculable" from radiative corrections Zee’80, Babu’88 in SUSY models with broken R-parity see review by Hirsch & Valle [hep-ph/0405015] and refs therein in unified SUSY models as a renormalization effect Hall, Kostelecky & Raby’86 . . . some other models, like left-right models, etc . . . Predictions: In most models NSI contributions are expected to be small, e.g. being supressed by the smallness of neutrino masses, however in some models NSI is not strongly restricted Low energy neutrino experiments sensitivity to physics beyond the Standard Model – p.4

Current bounds on NSI couplings Bounds on NSI couplings come from ν -scattering experiments: LSND, CHARM, NuTeV, MUNU, MINOS Barger et al’91, Davidson et al’03, Barranco et al’05 Friedland et al’06 e − e + → ν ¯ νγ measured at LEP Berezhiani & Rossi’02 analysis of atmospheric neutrino data Fornengo et al’02, Friedland et al’04’05 lepton flavor violating interactions, appeared at loop level from NSI, like µ capture by nuclei Davidson et al’03 Invisible Z-boson decay width including loop corrections due to NSI Davidson et al’03 Low energy neutrino experiments sensitivity to physics beyond the Standard Model – p.5

Solar + KamLAND without and with NSI -4 2 ] 10 SOL [eV ★ ★ ★ 2 ∆ m -5 10 0 0.2 0.4 0.6 0.8 1 0 0.2 0.4 0.6 0.8 1 2 θ SOL 2 θ SOL sin sin -3 10 2 ] -4 10 SOL [eV ★ LMA-D LMA-I ★ 2 -5 ∆ m 10 LMA-0 -6 10 0 0.2 0.4 0.6 0.8 1 0 0.2 0.4 0.6 0.8 1 2 θ SOL 2 θ SOL sin sin Miranda, Tortola, Valle, hep-ph/0406280 Low energy neutrino experiments sensitivity to physics beyond the Standard Model – p.6

Applications (not complete list!) ν oscillations in matter . . . , Guzzo et al’91, Fornengo et al’02, Friedland et al’04’05, Miranda et al’04, Kopp et al’07 ν scattering experiments . . . , Barger et al’91, Davidson et al’03, Barranco et al’05, Kopp et al’07 supernovae explosion Freedman et al’77, Fuller et al’87’88, Amanik et al’04’06, Esteban-Pretel et al’07 LEP (ILC) Berezhiani & Rossi’02, Davidson et al’03 Early Universe Mangano et al’06 . . . Low energy neutrino experiments sensitivity to physics beyond the Standard Model – p.7

Coherent neutrino scattering off nuclei (Henry Wong talk yesterday!) Good statistics due to quadratic coherent enhancement Sensitivity to ν -quark couplings Coherent scattering if the momentum transfer, Q , is small, QR < 1 ( R is radius of nucleus): = ⇒ ν -s doesn’t "see" structure of nucleus! For most of nuclei: 1 /R ∼ 25 − 150 MeV Well satisfied for most neutrino sources like supernovae, solar, reactor and artificial neutrino sources Planned experiments to measure coherent ν - N scattering: NOSTOS, TEXONO . . . and other proposals Experimentally difficult: very low energy threshold Low energy neutrino experiments sensitivity to physics beyond the Standard Model – p.8

Proposed experiments to measure coherent ν - N scattering TEXONO: 1kg of germanium, reactor neutrinos hep-ex/0511001, H.Wong talk yesterday NOSTOS: spherical TPC detector, 10 ton of Xenon astro-ph/0511470 Stopped- π ν beam and kg-to-ton mass detector hep-ex/0511042 beta-beams Bueno et al, PRD’06 more ideas in the past, superconducting detector (Drukier & Stodolsky’84) acoustic (Krauss’91) cryogenic (Oberauer’02) Low energy neutrino experiments sensitivity to physics beyond the Standard Model – p.9

ν - N coherent scattering ( ) G 2 « 2 ´ MT F M dσ „ 1 − T ( G V + G A ) 2 + ( G V − G A ) 2 G 2 V − G 2 ` = − A E 2 dT 2 π E ν ν h“ ” “ ” i g p V + 2 ε uV ee + ε dV g n V + ε uV ee + 2 ε dV F V nucl ( Q 2 ) G V = Z + N ee ee h“ ” “ ” i g p nucl ( Q 2 ) A + 2 ε uA ee + ε dA g n A + ε uA ee + 2 ε dA F A G A = ( Z + − Z − ) + ( N + − N − ) ee ee G 2 F M dσ „ 1 − MT « dT ( E ν , T ) = × 2 E 2 π ν h i 2 Z ( g p V + 2 ε uV ee + ε dV ee ) + N ( g n V + ε uV ee + 2 ε dV × ee ) + 9 i 2 = h X Z (2 ε uV αe + ε dV αe ) + N ( ε uV αe + 2 ε dV + αe ) α = µ,τ ; Axial couplings contribution is zero or can be neglected Coherent enhancement of cross section Degeneracy in determination of NSI parameters Low energy neutrino experiments sensitivity to physics beyond the Standard Model – p.10

Resolving degeneracy i 2 h ˜ 2 Z ( g p Zg p V + 2 ε uV ee + ε dV ee ) + N ( g n V + ε uV ee + 2 ε dV V + Ng n ˆ ee ) = V ε uV ee ( A + Z ) + ε dV ee ( A + N ) = const . Solution: take two targets with maximally different k = ( A + N ) / ( A + Z ) ■ 208 Pb ■ 208 Pb 120 120 k=1.15 1 k=1.15 1 = = k k 100 100 136 Xe ■ 136 Xe ■ 80 80 ■ 132 Xe ■ 132 Xe N [neutrons] N [neutrons] 60 60 86 Kr ■ 86 Kr ■ 76 Ge ■ 76 Ge ■ 40 40 4 events 4 events 10 5 x 10 3 4 5 x 10 3 x 10 ■ 40 Ar ■ 40 Ar 20 20 3 4 3 x 10 2 x 10 ■ 28 Si ■ 28 Si T th =400eV T th =100eV 3 4 ■ 22 Ne ■ 22 Ne 10 10 0 0 0 20 40 60 80 100 120 0 20 40 60 80 100 120 Z [protons] Z [protons] Low energy neutrino experiments sensitivity to physics beyond the Standard Model – p.11

Estimated bounds on NSI from TEXONO-like experiment (Ge+Si) 0.06 0.6 T th = 400eV T th = 400eV 0.04 0.4 76 Ge + 28 Si T th =400 eV 0.2 0.02 | ǫ dV ee | < 0 . 036 uV 0 ε τ e uV 0 ε ee | ǫ uV ee | < 0 . 038 76 Ge [90% C.L.] -0.2 76 Ge [90% C.L.] -0.02 | ǫ dV τe | < 0 . 48 76 Ge [99%] 76 Ge [99%] 76 Ge+ 28 Si [90%] -0.4 76 Ge+ 28 Si [90%] -0.04 | ǫ uV τe | < 0 . 50 76 Ge+ 28 Si [99%] 76 Ge+ 28 Si [99%] -0.6 -0.06 -0.06 -0.04 -0.02 0 0.02 0.04 0.06 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 dV dV ε τ e ε ee 0.06 0.6 T th = 100eV T th = 100eV 76 Ge + 28 Si T th =100 eV 0.04 0.4 | ǫ dV ee | < 0 . 018 0.2 0.02 | ǫ uV ee | < 0 . 019 uV 0 ε τ e uV 0 ε ee | ǫ dV τe | < 0 . 34 76 Ge [90% C.L.] -0.2 76 Ge [90% C.L.] -0.02 | ǫ uV τe | < 0 . 37 76 Ge [99%] 76 Ge [99%] 76 Ge+ 28 Si [90%] -0.4 76 Ge+ 28 Si [90%] -0.04 76 Ge+ 28 Si [99%] 76 Ge+ 28 Si [99%] -0.6 -0.06 -0.06 -0.04 -0.02 0 0.02 0.04 0.06 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 dV dV ε τ e ε ee Low energy neutrino experiments sensitivity to physics beyond the Standard Model – p.12

Present bounds and future sensitivity to NSI One parameter analysis to compare coherent scattering sensitivity with present bounds and ν Factory sensitivity (from Davidson et al’03), see also Kropp et al, hep-ph/0702269 76 Ge T th =400 eV 76 Ge + 28 Si T th =400 eV Present Limits ν Factory ( 76 Ge T th =100 eV ) ( 76 Ge + 28 Si T th =100 eV ) ǫ dV − 0 . 5 < ǫ dV | ǫ dV | ǫ dV | ǫ dV ee < 1 . 2 ee | < 0 . 002 ee | < 0 . 003 ee | < 0 . 002 ee ( | ǫ dV ( | ǫ dV ee | < 0 . 001 ) ee | < 0 . 001 ) ǫ dV | ǫ dV | ǫ dV | ǫ dV | ǫ dV τe | < 0 . 78 τe | < 0 . 06 τe | < 0 . 032 τe | < 0 . 024 τe ( | ǫ dV ( | ǫ dV τe | < 0 . 020 ) τe | < 0 . 017 ) ǫ uV − 1 . 0 < ǫ uV | ǫ uV | ǫ uV | ǫ uV ee < 0 . 61 ee | < 0 . 002 ee | < 0 . 003 ee | < 0 . 002 ee ( | ǫ uV ( | ǫ uV ee | < 0 . 001 ) ee | < 0 . 001 ) ǫ uV | ǫ uV | ǫ uV | ǫ uV | ǫ uV τe | < 0 . 78 τe | < 0 . 06 τe | < 0 . 036 τe | < 0 . 023 τe ( | ǫ uV ( | ǫ uV τe | < 0 . 023 ) τe | < 0 . 018 ) Low energy neutrino experiments sensitivity to physics beyond the Standard Model – p.13

Specific NSI scenarios Low energy neutrino experiments sensitivity to physics beyond the Standard Model – p.14

Extra heavy neutral gauge boson Z ′ ! ! r r c β − s β 5 3 c β + s β 5 ee = − 4 γ sin 2 θ W ρ NC ε uL ε dL ee = − ε uR = √ √ ee νN 3 8 6 8 24 2 24 ! 2 r 3 c β + s β 5 − 8 γ sin 2 θ W ρ NC γ = ( M Z /M Z ′ ) 2 ε dR = √ , ee νN 6 8 2 24 1600 beta beam 15 keV TEXONO 100 eV 1400 beta beam 5 keV TEXONO 400 eV Stopped pion source 1200 Double Chooz M Z’ (GeV) current limit 1000 800 600 400 200 0 -1 -0.5 0 0.5 1 cos β Low energy neutrino experiments sensitivity to physics beyond the Standard Model – p.15