Dark Z & Doubly Charged Leptons. Qing Wang. 6th FCPPL workshop, NanJing, China. Mar 28, 2013, Ying Zhang. Giacomo Cacciapaglia & Aldo Deandrea IPNL

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1 Dark Z & Doubly Charged Leptons Qing Wang In collaboration with Bin Zhang & Nan Chen THU Ying Zhang XJU Giacomo Cacciapaglia & Aldo Deandrea IPNL Mar 28, 2013, 6th FCPPL workshop, NanJing, China Qing Wang P. 1

2 Discovery of Higgs-like particle if it is proved really to be higgs completes SM No hint of New Physics up to now from particle physics experiments More than 40 years development of new physics modelssince founding of SM Unfortunately Non of them show sign in the experiments! This forces us to consider some exotic things familiar matter is already well investigated Two exotic thing will be discussed in this talk: Dark Z Doubly Charged Leptons Qing Wang P. 2

3 Dark Z Although No hint of New Physics from particle physics experiments Cosmology tells us DM must exist its particle characteristics? Search DM in particle physics! Most discussed DM are spin 1/2 fermions and spin 0 scalars Spin 1 vectors are usually treated as messengers connecting SM particles with dark world We investigate possibility that Spin 1 vector is as DM candidate simplest case is Z Qing Wang P. 3

4 Stability of dark Z Does not allow it directly couple to SM fermions Also prohibits Z mixing with Z and γ mass, kinetic, Stueckelberg type mixings Further forbids Z V V and Z V V V operators V = Z, W ±, γ Search for dark Z model independently Start from a electroweak chiral Lagrangian for Z, Z, W ± and γ Investigate the possibility satisfying above constraints Fortunately there exist such kind of a nontrivial chiral Lagrangian Qing Wang P. 4

5 EWCL for W ±, Z, Z, γ T = Ûτ3 Û ˆVµ = (D µ Û)Û D µ Û = µ Û + i(gw µ g X µ )Û iû(τ 3 L boson EWCL = f 2 4 tr( ˆV µ ˆV µ ) + f 2 4 β 1[tr(T ˆV µ )] 2 + f 2 4 β 2tr( ˆV µ )tr(t ˆV µ ) + f 2 4 β 3[tr( ˆV µ )] B µνb µν 1 2 tr[w µνw µν ] 1 4 X µνx µν α 1 gg Bµνtr[T W µν ] + i 2 α 2 g Bµνtr[T [ ˆV µ, ˆV ν ]] + iα 3 gtr[w µν [ ˆV µ, ˆV ν ]] +α 4 tr[ ˆVµ ˆVν]tr[ ˆV µ ˆV ν ] + α5 tr[ ˆVµ ˆV µ ]tr[ ˆV ν ˆVν] + α 6 tr[ ˆVµ ˆVν]tr[T ˆV µ ]tr[t ˆV ν ] + α 7 tr[ ˆVµ ˆV µ ]tr[t ˆVν]tr[T ˆV ν ] 2 g + g )B µ α 8 g2 tr[t Wµν]tr[T W µν ] + i 2 α 9 gtr[t W µν ]tr[t [ ˆVµ, ˆVν]] α 10 tr[t ˆV µ ]tr[t ˆV ν ]tr[t ˆVµ]tr[T ˆVν] + α 11 gϵ µνρλ tr[t ˆVµ]tr[ ˆVνW ρλ ] +α 12 gtr[t ˆV µ ]tr[ ˆV ν Wµν] + α 13 gg ϵ µνρλ Bµνtr[T W ρλ ] + α 14 g 2 ϵ µνρλ tr[t Wµν]tr[T W ρλ ] + α 15 tr[ ˆVµ]tr[T ˆV µ ]tr[t ˆVν]tr[T ˆV ν ] +α 16 tr[ ˆVµ]tr[T ˆV µ ]tr[ ˆVν ˆV ν ] + α 17 tr[ ˆVµ]tr[T ˆVν]tr[ ˆV µ ˆV ν ] + α18 tr[ ˆVµ]tr[ ˆVν]tr[T ˆV µ ]tr[t ˆV ν ] + α 19 tr[ ˆVµ]tr[ ˆVν]tr[ ˆV µ ˆV ν ] +α 20 tr[ ˆVµ]tr[ ˆV µ ]tr[t ˆVν]tr[T ˆV ν ] + α 21 tr[ ˆVµ]tr[ ˆV µ ]tr[ ˆVν ˆV ν ] + α 22 tr[ ˆVµ]tr[ ˆV µ ]tr[ ˆVν]tr[T ˆV ν ] + α 23 tr[ ˆVµ]tr[ ˆVν]tr[ ˆV µ ]tr[ ˆV ν ] +gg α 24 Xµνtr[T W µν ] + g g α 25 BµνX µν + α 26 ϵ µνρλ tr[ ˆVµ]tr[T ˆVν]tr[T [ ˆVρ, ˆV λ ]] + ig α 27 ϵ µνρλ tr[ ˆVµ]tr[T ˆVν]B ρλ +igα 28 ϵ µνρλ tr[ ˆVµ]tr[T ˆVν]tr[T W ρλ ] + gα 29 ϵ µνρλ tr[ ˆVµ]tr[ ˆVνW ρλ ] + ig α 30 ϵ µνρλ Xµνtr[T [ ˆVρ, ˆV λ ]] + ig α 31 Xµνtr[T [ ˆV µ, ˆV ν ]] +g α 32 ϵ µνρλ tr[ ˆVµ]tr[T ˆVν]X ρλ + α 33 tr[ ˆVµ]tr[T ˆVν]tr[T [ ˆV µ, ˆV ν ]] + g g α 34 ϵ µνρλ BµνX ρλ + gg α 35 ϵ µνρλ Xµνtr[T W ρλ ] +ig α 36 tr[ ˆVµ]tr[T ˆVν]B µν + igα 37 tr[ ˆVµ]tr[T ˆVν]tr[T W µν ] + gα 38 tr[ ˆV µ ]tr[ ˆV ν Wµν] + g µν α 39 tr[ ˆVµ]tr[T ˆVν]X +igα 40 tr[ ˆV µ ]tr[t ˆV ν Wµν]+O(p 6 ) Y.Zhang, S.Z.Wang and Q.Wang JHEP03(2008)047 No mixings β 1 = β 2 = β 3 = α 1 = α 8 = α 24 = α 25 = g = 0 No Z V V, Z V V V vertices α 15 = α 16 = α 17 = α 22 = α 31 = 0 Qing Wang P. 5

6 Relic Density D + Z Z W + µ W µ Z ν Z ν + D+Z Z W + µ Z µ W ν Z ν D V1 V 2 V 3 V 4 V 1µ V µ 2 V 3νV ν 4 σ W v = σ Z v = D + Z Z = g 1 = 4g 2 g 2 (α 5 + α 21 ) D Z Z ZZ = g 3 = g 2 Z g 2 (α 5 + 2α 7 + 4α α 21 ) D +Z Z = g 2 = 4g 2 g 2 (α 4 + α 19 ) D Z ZZ Z = g 4 = 4g 2 Z g 2 (α 4 + α 6 + 2α 18 + α 19 ) 1 1 r 2 W 9 64πm Z 1 1 r Z πm Z [ (224rW r2 W + 136)g2 1 (160r4 W + 80r2 W + 176)g 1g 2 + (152rW 4 ] + 128r2 W + 96)g2 2 [ (224rZ r2 Z + 136)g2 1 (160r4 Z + 80r2 Z + 176)g 1g 2 + (152rZ 4 ] + 128r2 Z + 96)g2 2 r W = m Z /m W r Z = m Z /m Z Qing Wang P. 6

7 Relic Density Constraint 0.01 g 1 =g 2 =g 3 =g 4 =g 0 g 1 =g 0,g 2 =g 3 =g 4 =0 g 2 =g 0,g 1 =g 3 =g 4 =0 g 3 =g 0,g 1 =g 2 =g 4 =0 g 4 =g 0,g 1 =g 2 =g 3 =0 g 0 Allowed Region 1E M D (GeV) Qing Wang P. 7

8 Direct Detection c u = c d = ig 4 cos θ W (1 8 3 sin2 θ W ) ig 4 cos θ W ( sin2 θ W ) c u = ig 4 cos θ W c d = ig 4 cos θ W L eff = q K V,q 2 (Z ν i µ Z ν ) qγ µ q + q K A,q 2 (Z ν i µ Z ν ) qγ µ γ 5 q } {{ } No contribution to spin independent DD σ V,Z N = m 2 N m2 Z π(m Z + m N ) 2(K V,N 2 ) 2 K V,p = 2K V,u + K V,d, K V,n = K V,u + 2K V,d K V,q q ) = (g 1 + g 2 )(c 2 q + c π 2 m 2 W + (g 3 + g 4 )(c 2 q + c 2 q ) 32π 2 m 2 Z Qing Wang P. 8

9 Direct Detection Constraint 1E-41 (cm 2 ) 1E-42 1E-43 1E-44 XENON 100 g 0 =1 g 0 =0.1 g 0 =0.01 g 1 = g 2 = g 3 = g 4 = g 0 1E-45 Allowed Region 1E M D (GeV) Qing Wang P. 9

10 Combination Constraints 0.1 XENON100 relic density g g 1 = g 2 = g 3 = g 4 = g 0 Allowed Region 1E M D (GeV) Qing Wang P. 10

11 Doubly Charged Leptons Two possibilities to embed the doubly charged lepton in a representation of SU(2): Doublet: ψ D = (2, 2/3) = (x d, τ d ) Triplet: ψ T = (3, 1) = (ν t, τ t, x t ) L mass = L Yukawa = (e 1 L, e2 L, e3 L, τ dl) The masses of the two new states and are very close. New state can not decay to the other, only to light leptons. Single production of the heavy leptons is negligible. off-diagonal couplings small, can work in same mass approx y i L i ϕ H e i R λ jψ DL ϕ c He j }{{ R} Mψ DL ψ DR + h.c. doublet couple to e R y i L i ϕ H e i R λ jl j ϕ H ψ }{{ T R } Mψ T L ψ T R + h.c. triplet couple to e L m e m µ m τ 0 x 1 x 2 x 3 M e 1 R e 2 R e 3 R τ dr Mx dx d + h.c. mixing in e L and τ dl sector are suppressed by m e,µ,τ /M; mixing in e R and τ dr sector x i /M m e,µ,τ are proportional to SM Yukawa couplings m e,µ,τ mixing in e R and τ tr sector are suppressed by m e,µ,τ /M; mixing in e L and τ tl sector x i /M m e 0 0 x 1 e 1 R (e 1 L, e2 L, e3 L, τ tl) 0 m µ 0 x m τ x 3 e 2 R e 3 R Mx tx t + h.c M doublet τ tr Qing Wang P. 11 triplet

12 LHC phenomenology Qing Wang P. 12

13 Pair production process at LHC and decay modes pp X X ++ l W l + W + One of the W s in the final state is required to decay leptonically for the charge identification and the other W to decay hadronically for the mass reconstruction. The production cross section at the 14TeV LHC is 13fb, for M=200GeV and the background is 5.5fb with kinematical acceptance on the transverse momentum, rapidity, missing transverse energy, and the particle separation as: p T (l) > 15GeV, η l < 2.5, /E T > 25GeV; p T (j) > 15GeV, η j < 2.5; R(jj) > 0.4, R(jl) > 0.4, R(ll) > 0.3. pp X ++ X l + W + l Z l + l + νl jj The Drell-Yan production process can contribute the same signal as pair prodution And the final cross section for mass 200GeV is 13fb. pp X ++ X l + W + (jj)l Z(l + l ) The final cross section for mass 200GeV is 3.9 fb and the background is 1.2fb. pp X ++ X l + W + (jj)l Z(bb) The b-jet decay modes, the final cross section for mass 200GeV is 6 fb after consider the B-tagging efficiency as 70%. And the background is 0.2fb. pp X ++ X l + W + (jj)l H(bb) The Drell-Yan production process X- also can decay to Higgs boson,, the final cross section for mass 200GeV is 15 fb when consider the Higgs mass is 126GeV, and the background is 0.3fb. Qing Wang P. 13

14 Qing Wang P. 14

15 Distinguish Doublet or Triplet Qing Wang P. 15

16 Summary Z is possible to be as a dark matter candidate Relic density and DD give constraints on the couplings Further constraints from ID and collider exp are under investigation Doubly charged leptons only alow electroweak doublet and triplet Their very small mixing with light leptons lead rich phenomenology Qing Wang P. 16

17 Thanks! Qing Wang P. 17