Contents1. Introduction2. Conclusions3. Analysis4. Results on operators5. Conclusions

Presice measurement of the Higgs-boson electroweak coupling

s at Linear Collider and its physics impacts

H

V

V

Yu Matsumoto (KEK) 2009,1,21 ILC Physics Meeting @ KEK

In collaboration with K.Hagiwara (KEK) and S.Dutta (Univ. of Delhi)

1-1. Motivation

SM

・ Light Higgs scenarios

・ Heavy Higgs or Higgsless scenarios

・ W, Z-boson discovery・ top-quark discovery・ W,Z boson precision measurements

LHC LC

Tevatron LEP

・ LHC can probe light Higgs scenario・ precision measurements of the Higgs-boson properties

NP3

NP2

NP6

NP4

NP8

NP9

NP5

NP7

NP1 NP1

0NP1

1 NP12

NP13

New physics theories

1-2. Effective Lagrangian with a Higgs doublet

,8dim7dim6dim5dim LLLLLL SMeff

contribute to majonara neutrino mass

contribute to four fermion coupling (Proton decay, etc) purely gauge term (Triple gauge coupling, etc) Higgs electroweak couplings

New physics can be represented by higher mass dimension operators

We can write the effective Lagrangian including Higgs doublet as

)6(2 i

i

iSMeff

fLL

New physics effects. Here we consider only dimension 6

and the operators are …

We focused on this physics

are calculable in each particular modelsif

1-3. dimension 6 operators including Higgs

Dimension 6 operators

2 point function, TGC, vertices include Higgs boson

Precision measurement (SLC, LEP, Tevatron)

Triple gauge couplings (LEP2,Tevatron)

LH

C

LC

High energy experiments ( ) are important for the measurements of couplings

beam polarization plays an important role to obtain high accuracy

2. ConclusionsThe most accurately measured combinations of dim-6 operators are sensitive to the quantum corrections

ILC experiment can constrain completely different combinations of dim-6 operators from EWPM We can select new physics by multi-dimensional operator space

e

HZ

These accuracy of the combinations are not affected from systematic errors ex) luminosity uncertainty

GeVs 500

(EWPM)

(ILC our result)

2min

,

12min

,

2min

2

2min

2

12

)( )(

)()(

)()(

),,(

jijijik

k kSM

kjki

jiji

k kSM

ikkii

kkEXP

ikTH

kEXP

n

cVcLcc

L

cL

N

cNNcc

3-1. Optimal observable methodThe differential cross section can be expressed by using non-SM couplings

can be expressed in terms of non-SM couplings

)( i

iiSM c

d

d

number of event in the k-th bin for experiment and theory

2

,kSMkEXP LN

if is given, we can calculate

1V iciii Vc

The large discrepancy between and

makes larger errors become small 1VSM )(i

kii

ikSMkTH cLLN )(

3,2,1,,,,, 232 icccccc iWWZZiZZi

is 3-body phase space

3-2. Operators and Vertices, Form Factors

： EW precision, S and T parameter

： Triple Gauge Couplings

.)].))()(((2

[

]))()(([

)1(2

)1(

32

,32

1WW1ZZ)6(

2

chWWHWHc

WHWcm

g

VZHZHcVHZcm

g

WHWgmcZHZmg

cf

LL

WWWW

Z

Z

ZVZVZV

Z

Z

WZZ

ii

iSMeff

We exchange the operators into HVV interaction vertices as the experimental observables

※ 　　　　　　　　　 　　　 are the linear function of

if iWWZZiZZi cccccc ,,,, 232

double-tag eeHZH production

3-3. Cross section

WW-fusion

iWWc

～　 ILC phase I phase II

WW

W

f

f

fff 421 ,,

iZZc

BWBBWW

BW

fff

ff

fff

,

,

,,

,

421

double-tag eeHsingle-tag eeHZH production

iZcBWBBWW

BW

fff

ff

,

,

,

no-tag (ee)H 2c BWBBWW fff ,,

High

experiment

polarization

no-tag

(ee)H

s

if

VVf

BW ff ,

3-4. Luminosity uncertaintyHere we set

L is true luminosity

can be redefined as2

Luminosity uncertainty is absorbed into errors

WWZZ cc 11 ,

The correlation between and

is generated through luminosity uncertainty

ZZc1 WWc1

111 fcc ZZWW The measurement of

doesn’t depend on 1f

f

4-1. constraint on dim-6 operators (1)

① EWPM results

② ILC-I+ILC-II 　with

11200,01.0,0.0||,8.0|| fbLfPP totalee

③ ILC-I with 1700,01.0,0.0||,8.0|| fbLfPP totalee

④ ILC-I (250,350GeV) with

1700,01.0,0.0||,8.0|| fbLfPP totalee

1 dimensional

5 dimensional

1000,500,350,250:s500,500,100,100:L

500,350,250:s500,100,100:L

350,250:s350,350:L

4-2. Constraints on dim6-Operators (2)

combining with LEP and future experimentsEWPM will be also improved at ILC experiments

if

+

@ ILC

@ GigaZ

The results combining our HVV measurements at ILC and EWPM at ILC are

@ LEP2,Tevatron (present EWPM)

+

5. Conclusions

We obtain the sensitivity to the ILC experiment on 8 dim-6 operator space by using Optimal observable method

The expected accuracy of the measurements will be sensitive to quantum corrections as same accuracy as EWPM.And its constraints are in the multi dimensional space.

The t-channel processes of and at high energy experiment are important to measure and couplings

Hee Heeee

HHZHWW ,

Polarization is important to obtain high accurate measurement on coupling 　　

HZ

Luminosity uncertainty affects measurements, but only one combination of the operators, is affected

WWZZ cc 11 ,

24 23 ff