Doubly charged Higgs bosons at Hadron Colliders and neutrino mass hierarchy

Mayumi Aoki (KEK)

A.G.Akeroyd and M.A. PRD72,035011 (2005) (hep-ph/0506176)

Motivation

（ Q=I3+Y/

2 ） 0

2

( ). . . .

2i j i jT

ij iL jL ij i j i j

l lL h Ci h c h l l h c

2/

2/0

The observed neutrino oscillation data predict nonzero neutrino masses and mixings.

•　 Higgs Triplet Model : SM + Δ SU(2)L Higgs triplet boson (Y=2)

GeVmH

001•LEP

The most striking signature of Δ would be the observation of H±±.

H±± →ℓi±ℓj

± strong search potential

• Hadron colliders

scatteringBhabha

eeHee

HHZee

** , jiH decay with

Motivation

CDF Collab. PRL93(2004)

GeV

GeVe

GeVmeeHH

136

115

133

HHZpp **,

　　 Assuming B(H±±→li±lj±)=100%

240pb-1 of data collected at √s=1.96TeV

CDFIITevatron

)( WHH

•Single production of H±± HHWpp *

•Nonleptonic decay (for ｍ H±±> ｍ H± )

•H±±→li±lj± in light of neutrino data

We study the search potential for H±± at Tevatron in HTM.

only

1

B.Dion et al, PRD59 (1999)

E.J.Chun et al, PLB566(2003)S.Chakrabarti et al, PLB434 (1998)

J.F.Gunion et al, hep-ph/9610237

Higgs Triplet Model

Δ ０ develops a

VEV :

)eV 75.0 WMAP( , 2 iijij mhm

•Neutrino mass matrix

eV 10 10 roughly very : LFV 3 ijh

We are interested in

.~ M

03.0 10|1| 3

20

2

2

M

(*),5

,5

,00

00

WHHmmmHmmm

AHHH

HHAH

0 0

000 ,,,),( hAHHH Physical Higgs bosons

2 † † 2 2 † † 2 †1 2 3

† † † †4 5 2

( ) ( ) Tr( ) [Tr( )] + Det( )

( )Tr( ) ( ) ( . .)Ti

V m M

i h c

doublet SM Higgs :

HHWppHHZpp *** ,,Production of H±± at Tevatron

)(2)( HHppHHppH Total H±±cross section

Single H±± production can be as large as the pair production.Mass limit on mH±± increases significantly.

Decay of H±±

)8/(||)( 2 ijHji hSmH )()2(1 jijiforS

i

iji

ij mh 2

,

2 The total leptonic decay width depends on which solution to the neutrino mass hierarchy is realized.

Leptonic decay

real :)(2

13,2,1 i

Tij mVmmmdiagVh MNSMNS

3 2 1

2 1 3

21 2 3

~ ~ ATM

m m m

m m m

m m m m

Normal hierarchy (NH)Inverted hierarchy (IH)Degenerate (DG)

2/2

2/1

13

00

00

001

2/13/16/1

2/13/16/1

sin3/13/2

i

i

i

MNS

e

e

e

V

phases Majorana :phase Dirac

21

132

,:

16.02sin

GeV 20 HH mm eV2.0 im

Decay of H±±

)16/(36)( 342* GmMGWHH HWF G: phase space

factor

Nonleptonic decay H±± → H±W(* )

Current search strategy is

ineffective.

Current search strategy is effective. If H±± → ℓ± ℓ± are measured then the ratios of hij can be evaluated.

An order of magnitudeestimate of hij could be obtaiened.

HHmm

123 mmm : NH

Limit on mH±±

'''' )(2)2()( llllllll BHHppBBHHpp Bilepton cross section

case. violatingCP no and assume We 013

)(' jill llHBB

2009)(~GeV fb 1905 Hm

mH±± > 130 GeV (μμ)

: IH1 321 mmm

Majorana phase dependenceAssuming CP conservation, the following different patterns can be allowed.

or 0, 21

: IH2 321 mmm

mH±± > 138 GeV (ee) mH±± > 120 GeV (eμ)

: DG1 321 mmm

mH±± > 132 GeV (μμ)

: DG2 321 mmm

mH±± > 122 GeV (ee)

: DG3 321 mmm

mH±± > 105 GeV (eμ)

: DG4 321 mmm

mH±± > 115 GeV (μμ)

Summary

We have studied the search potential for H±± at Tevatron.

•　 Higgs Triplet Model : SM + Δ SU(2)L Higgs triplet boson (Y=2)

HHppHHpp ,

(*), WHllH ji

production

decay

We encourage a detailed experimental simulation of this decay mode at Tevatron.

significantly improves the search

potential for H±±

might be helpful to determine the absolute value of hij .

Neutrino mass spectrum might be distinguished by the leptonic decay mode.

LHC)()()( HHppHHppHHpp

H

Total H±±cross section

sensitivity up to 1 TeV