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

1.Introductio n 1. Neutrino oscillation 2. Dark matter 3. Baryon asymmetry of the Universe 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. Especially, neutrino oscillation and dark matter would be explained by radiative seesaw models at TeV scale.

Neutrino masses νLνL νLνL ΦΦ νRνR 1.Introductio n Aoki, Kanemura, Seto (2008) νRνR νRνR M ～ O(1) TeV → c ～ O(10 -6 ) M ～ O(1) TeV → c ～ O(10 -4 ) M ～ O(1) TeV → c ～ O(1)

Neutrino masses 1.Introductio n Aoki, Kanemura, Seto (2008) Φ νLνL νRνR Φ Φ νLνL νRνR νLνL νLνL νLνL ΦΦ νRνR νRνR νRνR M ～ O(1) TeV → c ～ O(10 -6 ) M ～ O(1) TeV → c ～ O(10 -4 ) M ～ O(1) TeV → c ～ O(1) Kanemura, T.N., Sugiyama (2011) Kanemura, T.N., Sugiyama (2012) M ～ O(1) TeV → c ～ O( ) ν R are not stable.

Neutrino masses 1.Introductio n Aoki, Kanemura, Seto (2008) Φ νLνL νRνR Φ Φ νLνL νRνR νLνL νLνL νLνL ΦΦ νRνR νRνR νRνR M ～ O(1) TeV → c ～ O(10 -6 ) M ～ O(1) TeV → c ～ O(10 -4 ) M ～ O(1) TeV → c ～ O(1) Kanemura, T.N., Sugiyama (2011) Kanemura, T.N., Sugiyama (2012) We consider this case. M ～ O(1) TeV → c ～ O( ) ν R are not stable.

1.Introductio n 100 GeV 1TeV U(1) B-L  y DM   (DM) What is the origin of M DM ? If U(1) B-L gauge symmetry is broken by the vev of additional scalar boson  at O(1- 10)TeV, M DM is given by this vev through y DM  coupling. ・ WIMP dark matter mass: M DM ～ O( )GeV WIMP dark matter

1.Introductio n 100 GeV 1TeV U(1) B-L  y DM   (DM) ・ WIMP dark matter mass: M DM ～ O( )GeV WIMP dark matter Dark matter and neutrino masses could be naturally explain by TeV scale physics with U(1) B-L gauge symmetry. What is the origin of M DM ? If U(1) B-L gauge symmetry is broken by the vev of additional scalar boson  at O(1- 10)TeV, M DM is given by this vev through y DM  coupling.

・ SU(3) C ×SU(2) I ×U(1) Y ×U(1) B-L ・ New matter particle: -B-L Higgs scalar σ -Right handed neutrinos ν R 1,2 -SU(2) I singlet scalar s -SU(2) I doublet scalar η - Chiral fermion Ψ R 1,,2 L Half unit of U(1) B-L charge → U(1) DM U(1) B-L protect: Tree-level L  SM R Majorana mass of R Dirac mass of Ψ 2.Model

Electroweak symmetry breaking 2.Model  s and  → Physical state: h,H,S1,S2,η ± U(1) B-L symmetry breaking  R,  R and  L U(1) B-L : Neutrino masses The dark matter mass Stability of the dark matter → ← tree level Global U(1) DM remains after U(1) B-L gauge symmetry breaking. We assume that the Ψ 1 is the lightest U(1) DM particle.

Neutrino masses The O(0.1) eV neutrino masses can be naturally deduced from TeV scale physics with O( ) coupling constant Φ νLνL νRνR νLνL νLνL νLνL νLνL νRνR νRνR LL RR LL RR LL RR LL RR LL RR  s  s  s  s  s U(1) B-L EW 2.Model

f f Ψ1Ψ1 Ψ1Ψ1 σ φ yy yfyf M h =120GeV M H =140GeV cosα=1/√2 Okada and Seto (2010) Kanemura, Seto and Shimomura (2011) s channel Higgs resonance is important f f Ψ1Ψ1 Ψ1Ψ1 Z’ g B- L Maximal mixing between  and  is required! η+η+ f f Ψ1Ψ1 Ψ1Ψ1 e e Z’ is heavy constraint by  →e  Abundance of Ψ 1 2.Model

BR(μ→e,γ) < 2.4× Experimental bound(MEG): LFV constraint e η±η± μ Ψ γ J. Adam et al.(2011) f f Direct detection of Ψ 1 N Ψ1Ψ1 Ψ1Ψ1 Z’ N Experimental bound(XENON100): < 8× cm 2 E. Aprile et al. (2011) Consistent with current experimental bound. 2.Model

Parameter set Normal Hierarchy, Tri-bi maximal (Our results are not sensitive to value of  13 ) f ij = M R = 250 GeV, M Ψ1 = 57.0 GeV, M Ψ2 = 800 GeV M S1 = 200 GeV, M S2 = 300 GeV, M h = 120 GeV, M H = 140 GeV, M η ± = 280 GeV, cosθ= 0.05, cosα=1/√2, g B-L =0.2, M Z’ =2000GeV, v φ =246 GeV, v σ = 5 TeV ・ neutrino oscillation ・ LFV ・ LEP ・ DM abundance ・ DM direct detection h ij = GeV 1TeV S2η±S1S2η±S1 Ψ2Ψ2 h H ν R 1,2 Z’ Ψ 1 (DM) 2.Model All coupling constant are O( ) and all masses are O( ) GeV.

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

Physics of  1 4. Physics at the ILC f f 1.In our model, dark matter and electron are coupled via the L  coupling 2.The energy momentum conservation is used to detect the dark matter. 3. Background are e, E → e,  p processes. E e E e , Z -- 11  11

Electron efficiency 4. Physics at the ILC 1.In the signal processes, Electron tend to be emitted forward region. 2.We assume detectable area of electron 30 mrad and 20 mrad for 350 GeV and 500 GeV collider respectively ● ： 250GeV ■ ： 150GeV ▲ ： 75GeV Identical efficiency of electron Detect area (mrad) I.Bozovic-Jelisavcic [on behalf of the FCAL Collaboration], (2011)

Physics at the ILC The cross section of the signal is very low in this case. The kinematical cuts to reduce B.G. Dark matter can be tested with 1ab -1 data: at the √s = 350GeV collider for M DM ≲ 64 GeV at 3  C.L. at the √s = 500GeV collider at 5  C.L Dark matter mass (GeV) √ ｓ = 500 GeV √ ｓ = 350 GeV Back ground signal 33 33

e, E → e,  p processes 4. Physics at the ILC f f 1.In our model, f  j coupling can take larger value than f  j coupling. 2.Signal cross section increase about 100 times more than e, E → e,  p processes in our parameter set. 3. Background are same value to e, E → e,  p processes. E e E e , Z -- 11  11

 1 would be tested by invisible decay of h at √s=350 GeV with 500fb -1 at 3  C.L XENON Physics at the ILC Parameter set S.Kanemura, S.Matsumoto, TN, H.Taniguchi (2011).

22 Physics of R 4. Physics at the ILC 1.In our parameter set, R →W ±, l ∓  is main decay mode. 2.We consider W→jet, jet process. 3.Background are e, E → e (or  ), W  p processes. f f h ij E e -- R 11 S1, S2 l-l- W+W+

L  coupling constant f 0 4. Physics at the ILC The cross section of the signal is very low in this case. The kinematical cuts to reduce B.G. Right handed neutrino can be tested at 3  C.L. at the √s = 1 TeV collider with 3ab -1 data Back ground signal 3  with 1ab  with 3ab Parameter set √ ｓ = 1 TeV

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

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  1 can be tested with 1 ab -1 data: at √s = 350 GeV linear collider with M DM ≲ 64 GeV at 3  C.L.. at √s = 500 GeV linear collider at 5  C.L.. ⑤ Right handed neutrino could be tested at 3  C.L. at √s = 1 TeV linear collider with 3 ab - 1 data. ⑥ ILC have potential which distinguish between around U(1) B-L models. 5.Conclusion

Back up

0.1eV 1TeV S2η±S1S2η±S1 Ψ 1 (DM) Ψ2Ψ2 νLνL Z’ U(1) B-L U(1) DM hHhH EWS B ν R 1,2 Type I like 2-loop seesaw 100 GeV ≈ Maxim al mixing 1-loop neutrino Dirac Yukawa tree charge assign  h 2 =0.1

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

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 Ψ 1 is lightest U(1) DM particle case. U(1) B-L U(1) B-L breaking - ラグランジアン

e e Ψ1Ψ1 Ψ1Ψ1 η+η+ Relic abundance of Ψ 1 LΨη coupling is small due to LFV constraint f f Ψ1Ψ1 Ψ1Ψ1 σ φ ΨΨσ coupling ～ O(0.01) but resonance can be used. Mixing between B-L Higgs σ and SM Higgs Φ is essentially important. 3.Neutrino mass and dark matter f f yy yfyf

f f Ψ1Ψ1 Ψ1Ψ1 σ φ Relic abundance of Ψ 1 M h =120GeV M H =140GeV cosα ～ 1/√2 Ψ 1 is consistent with WMAP data at the M Ψ1 = 57.0 GeV. 3.Neutrino mass and dark matter Okada and Seto (2010) Kanemura, Seto and Shimomura (2011) yy yfyf

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

Our parameter set safety current experimental bound but could be within future experimental reach. N N Ψ1Ψ1 Ψ1Ψ1 σ φ Direct detection of Ψ 1 N Ψ1Ψ1 Ψ1Ψ1 Z’ Experimental bound (XENON100): For our parameter set, it is evaluated as =8× cm 2 =2.7× cm 2 N E. Aprile et al. (2011) 3.Neutrino mass and dark matter yy yfyf

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