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Takehiro Nabeshima University of Toyama

Phenomenology at a linear collider in a radiative seesaw model from TeV scale B-L breaking. Takehiro Nabeshima University of Toyama. S. Kanemura, T.N., H. Sugiyama, Phys. Lett . B703:66-70 S. Kanemura, T.N., H. Sugiyama, Phys. Rev. D85, 033004. ILC physics general meeting 9 jun. 2012.

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Takehiro Nabeshima University of Toyama

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  1. Phenomenology at a linear collider in a radiative seesaw model from TeV scale B-L breaking Takehiro Nabeshima University of Toyama S. Kanemura, T.N., H. Sugiyama, Phys. Lett. B703:66-70 S. Kanemura, T.N., H. Sugiyama, Phys. Rev. D85, 033004 ILC physics general meeting 9 jun. 2012

  2. 1.Introduction The standard model (SM) is a very successful model to describe physics below O(100)GeV. However, we know the phenomena of the beyond-SM. 1. Neutrino oscillation 2. Dark matter 3. Baryon asymmetry of the Universe Especially, neutrino oscillation and dark matter would be explained by radiative seesaw models at TeV scale.

  3. 1.Introduction Neutrino masses Aoki, Kanemura, Seto(2008) Φ Φ νL νL νR νR νR M ～ O(1)TeV → c ～ O(10-6) M ～ O(1)TeV → c ～ O(1) M ～ O(1)TeV → c ～ O(10-4)

  4. 1.Introduction Neutrino masses Aoki, Kanemura, Seto (2008) Φ Φ νL νL νR νR νR M ～ O(1)TeV → c ～ O(10-6) M ～ O(1)TeV → c ～ O(1) M ～ O(1)TeV → c ～ O(10-4) Φ Φ Kanemura, T.N., Sugiyama (2011) Kanemura, T.N., Sugiyama (2012) Φ νR νL νL νR νL M ～ O(1)TeV → c ～ O(10-2-10-1) νRare not stable.

  5. 1.Introduction Neutrino masses Aoki, Kanemura, Seto (2008) Φ Φ νL νL νR νR νR M ～ O(1)TeV → c ～ O(10-6) M ～ O(1)TeV → c ～ O(1) M ～ O(1)TeV → c ～ O(10-4) Φ Φ Kanemura, T.N., Sugiyama (2011) Kanemura, T.N., Sugiyama (2012) Φ νR νL νL νR νL M ～ O(1)TeV → c ～ O(10-2-10-1) νRare not stable. We consider this case.

  6. 1.Introduction WIMP dark matter ・WIMP dark matter mass: MDM～ O(100-1000)GeV U(1)B-L <s> What is the origin of MDM? If U(1)B-L gauge symmetry is broken by the vev of additional scalar boson sat O(1-10)TeV , MDMis given by this vev through yDM Y Y s coupling. 1TeV yDM Y Y s Y (DM) 100 GeV

  7. 1.Introduction WIMP dark matter ・WIMP dark matter mass: MDM～ O(100-1000)GeV U(1)B-L <s> What is the origin of MDM? If U(1)B-L gauge symmetry is broken by the vev of additional scalar boson sat O(1-10)TeV , MDMis given by this vev throughyDM Y Y s coupling. 1TeV yDM Y Y s Y (DM) 100 GeV Dark matter and neutrino masses could be naturally explain byTeV scale physics with U(1)B-L gauge symmetry.

  8. 2.Model ・SU(3)C×SU(2)I×U(1)Y×U(1)B-L ・New matter particle: -B-L Higgs scalarσ -Right handed neutrinosνR1,2 -SU(2)I singlet scalar s -SU(2)I doublet scalarη - Chiral fermionΨR1,,2L Half unit of U(1)B-L charge → U(1)DM U(1)B-L protect: Tree-level LfSMnR Majorana mass of nR Dirac mass of Ψ

  9. 2.Model U(1)B-Lsymmetry breaking ・nR, YR andYL ←　 tree level → Electroweak symmetry breaking ・f, s, s and h Physical state: h,H,S1,S2,η± → Global U(1)DM remains after U(1)B-Lgaugesymmetry breaking. We assume that the Ψ1is the lightest U(1)DM particle. U(1)B-L: Neutrino masses The dark matter mass Stability of the dark matter

  10. 2.Model Neutrino masses <Φ> <Φ> Φ h h s s νR νL νL h s YR YL YL YR <σ> <σ> <σ> <Φ> νR νL YR YL h s <σ> U(1)B-L EW <σ> <σ> YL YR νL νL νR YR YL <σ> h s <Φ> The O(0.1) eV neutrino masses can be naturally deduced from TeV scale physics with O(0.01-0.1) coupling constant

  11. 2.Model Abundance of Ψ1 Ψ1 f f Ψ1 f e σ φ Ψ1 Z’ yY yf gB-L gB-L η+ s channel e Ψ1 f Ψ1 f f Ψ1 Z’ is heavy constraint by m→eg Mh=120GeV MH=140GeV cosα=1/√2 Higgs resonance is important Okada and Seto (2010) Kanemura, Seto and Shimomura (2011) Maximal mixing between s and f is required!

  12. 2.Model LFV constraint f f Experimental bound(MEG): BR(μ→e,γ) < 2.4×10-12 J. Adam et al.(2011) Direct detection of Ψ1 Ψ1 γ Ψ1 η± Z’ N e N μ Ψ < 8×10-45cm2 Experimental bound(XENON100): E. Aprile et al. (2011) Consistent with current experimental bound.

  13. 2.Model Parameter set Z’ ・neutrino oscillation ・LFV ・LEP ・DM abundance ・DM direct detection 1TeV Ψ2 Normal Hierarchy, Tri-bi maximal (Our results are not sensitive to value of q13 ) 0.0757 0.0445 fij= 0.01 -0.0123 -0.141 -0.0723 MR = 250 GeV , MΨ1 = 57.0 GeV , MΨ2 = 800 GeV MS1 = 200 GeV, MS2 = 300 GeV , Mh = 120 GeV, MH = 140 GeV, Mη±=280 GeV, cosθ= 0.05, cosα=1/√2, gB-L=0.2, MZ’=2000GeV, vφ=246 GeV, vσ= 5 TeV S2 η± S1 -0.131 0.1 0.1 0.1 hij= h H νR1,2 100 GeV Ψ1 (DM) All coupling constant are O(0.01-0.1) and all masses are O(100-1000) GeV.

  14. 3. Physics at the LHC Physics of Z’ Z’ mass: O(1-10)TeV G(Z’→XX) ∝ (B-L charge)2 Z’ decay into invisible about 30% Z’ production cross section is 70 ｆbat the LHC for √s = 14 TeV , MZ’= 2000 GeV and gB-L= 0.2 Our model could be tested by measuring decay of the Z’ at the LHC. L. Basso, A. Belyaev, S.Moretti and C. H. Shepherd-Themistocleous (2009); L.Basso(2011) However, if Z’ mass is heavy, our model would be difficult to be tested at the LHC.

  15. 4. Physics at the ILC Physics ofY1 E E Y1 g, Z e e h- f m f Y1 In our model, dark matter and electron are coupled via the Lyh coupling The energy momentum conservation is used to detect the dark matter. 3. Background are e, E → e, m, p processes.

  16. 4. Physics at the ILC Electron efficiency Identical efficiency of electron 100 efficiency (%) 80 60 ●：250GeV ■：150GeV ▲：75GeV 40 20 I.Bozovic-Jelisavcic [on behalf of the FCAL Collaboration], (2011) 0 10 20 30 40 Detect area (mrad) In the signal processes, Electron tend to be emitted forward region. We assume detectable area of electron 30 mrad and 20 mrad for 350 GeV and 500 GeV collider respectively

  17. 4. Physics at the ILC The cross section of the signal is very low in this case. The kinematical cuts to reduce B.G. √ｓ= 350 GeV √ｓ= 500 GeV 10 1 Back ground Back ground 0.1 signal 3s Cross section (fb) Cross section (fb) 0.01 1 signal 0.001 3s 0.0001 0.1 50 55 60 65 70 75 80 50 55 60 65 70 75 80 Dark matter mass (GeV) Dark matter mass (GeV) Dark matter can be testedwith 1ab-1 data: at the √s = 350GeV collider for MDM≲ 64 GeV at 3s C.L. at the √s = 500GeV collider at 5s C.L.

  18. 4. Physics at the ILC e, E → e, t, p processes E E Y1 g, Z e e h- f t f Y1 In our model, ftjcoupling can take larger value than fmjcoupling. Signal cross section increase about 100 times more than e, E → e, m, p processes in our parameter set. 3. Background are same value to e, E → e, m, p processes.

  19. 4. Physics at the ILC 10-1 10-2 10-3 XENON100 Parameter set 10-4 S.Kanemura, S.Matsumoto, TN, H.Taniguchi (2011). 10-5 10 100 1000 Y1 would be tested by invisible decay of h at √s=350 GeV with 500fb-1 at 3s C.L..

  20. 4. Physics at the ILC Physics of nR S1, S2 f W+ e hij Y2 nR h- l- E Y1 f In our parameter set, nR→W±,l∓is main decay mode. We consider W→jet, jet process. Background are e, E → e (or m), W, p processes.

  21. 4. Physics at the ILC The cross section of the signal is very low in this case. The kinematical cuts to reduce B.G. √ｓ= 1 TeV 10 Back ground 1 signal 3s with 1ab-1 Cross section (fb) 0.1 3s with 3ab-1 Parameter set 0.01 0.001 0 0.15 0.05 0.1 0.2 0.3 0.25 Lyh coupling constant f Right handed neutrino can be tested at 3s C.L. at the √s = 1 TeV collider with 3ab-1 data.

  22. Most optimistic case Z’B-L is detected at the LHC ・350 GeV – 500 GeV (also 1 TeV) e, m with missing momentum → Dark matter which is directly coupled to charged lepton. LHC ILC ・1 TeV e, W with Missing momentum → O(100) GeV right handed neutrino Radiative seesaw model with B-L gauge symmetry which include non stable right handed neutrino exist at TeV scale

  23. 5.Conclusion ① We consider possibility of testing the TeV-scale seesaw model in which U(1)B−L gauge symmetry is the common origin of neutrino masses, the dark matter mass, and stability of the dark matter. ② Z’ boson could be tested at the LHC. ③ Dark matter Y1can be tested with 1 ab-1data: at √s = 350 GeV linear collider with MDM≲ 64 GeV at 3s C.L.. at √s = 500 GeV linear collider at 5s C.L. . ⑤ Right handed neutrino could be tested at 3s C.L. at √s = 1 TeV linear collider with 3 ab-1data. ⑥ ILC have potential which distinguish between around U(1)B-L models.

  24. Back up

  25. charge assign Z’ U(1)DM tree 1TeV tree Ψ2 S2 η± S1 νR1,2 h H Ψ1 (DM) 100 GeV EWSB Maximalmixing Type I like 2-loop seesaw 1-loop neutrino Dirac Yukawa U(1)B-L Wh2=0.1 ≈ 0.1eV νL

  26. 2.Model U(1)B-Lanomaly Our model focus to explain TeV scale physics. U(1)B-Lanomaly would be resolved by some heavy singlet fermions with appropriate B-L charge. For example; Right hand: 1×9, -1/2×14, 1/3×9 left hand: 3/2×14, -5/3×9 U(1)B-Lanomaly is not serious

  27. ラグランジアン U(1)B-Lbreaking - U(1)B-L Remnant global U(1)DM remains on half unit of U(1)B-L charged particles after SSB of U(1)B-L. U(1)DM guarantee stability of dark matter. We consider that the Ψ1 is lightest U(1)DM particle case.

  28. 3.Neutrino mass and dark matter Relic abundance of Ψ1 Ψ1 f f e σ φ Ψ1 LΨη coupling is small due to LFV constraint η+ Ψ1 f e Ψ1 f ΨΨσ coupling ～O(0.01) but resonance can be used. yf yY Mixing between B-L Higgs σand SM Higgs Φ is essentially important.

  29. 3.Neutrino mass and dark matter Relic abundance of Ψ1 Okada and Seto (2010) Kanemura, Seto and Shimomura (2011) Ψ1 f σ φ Ψ1 f Mh=120GeV MH=140GeV cosα～1/√2 yf yY Ψ1 is consistent with WMAP data at the MΨ1 = 57.0 GeV .

  30. 3.Neutrino mass and dark matter LFV constraint f f Experimental upper bound: BR(μ→e,γ) < 2.4×10-12 J. Adam et al.(2011) γ η± For our parameter set, it is evaluated as e μ Ψ BR(μ→e,γ) = 5.1×10-13 Our parameter set safety current experimental upper bound but could be within future experimental reach.

  31. 3.Neutrino mass and dark matter Direct detection of Ψ1 yY Ψ1 Ψ1 Ψ1 Ψ1 σ Z’ φ N N N N yf Experimental bound (XENON100): =8×10-45cm2 E. Aprile et al. (2011) For our parameter set, it is evaluated as =2.7×10-45cm2 Our parameter set safety current experimental bound but could be within future experimental reach.

  32. 4.Phenomenology Physics of νR ・νRare light (O(100) GeV) and are not stable. ・νRareproduced about 1200 pair from decay of 7000 Z’ at the LHC for √s = 14 TeV with 100 fb-1 data. j W+ ・The mass of νR can be reconstructed by jjl± j νR νL l

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