Overview of Options

Eri AsakawaYITP, Kyoto Univ.1. Intoduction

2. γγ3. e-γ, e+γ4. e-e-5. e+ polarization6. fixed target7. Summary

2005/7/11

1. Introduction

a. Nothingb. A light Higgs onlyc. A heavy Higgs onlyd. Many new particles and/or non-SM phenomena

LHC will start operation in 2007. After several years operation, it should reveal what LHC seemed to find.

What kinds of tasks is LC expected to perform in each case ? Search something? Precise measurement? What roles can options play among the tasks ?

a. Nothing New charged particle search in γγ, eγ exotics search in e-e- EWPT in e+ pol., e-e-, γγ, eγ

b. A light Higgs only Γ(h→γγ) measurement in γγ heavy Higgs search in γγ

c. A heavy Higgs only EWPT in e+ pol., e-e-, γγ, eγ heavy Higgs factory in γγ

d. Many new particles and/or non-SM phenomena　　　　　 PT for new particles in γγ, eγ, e-e- heavy Higgs search in γγ (in the case that new particles = sparticles, but h only) PT for scalar electron in e-e- (in the case that new particles = sparticles)

2. γγ collisionIn order to realize γγ option,e-e- mode is necessary and eγ option can be realized at the same time.

Therefore,the question “Do we really need options?” may be rephrased

“Do we really need γγoption?”.

Advantage : beam polarization (circular and linear) large cross sections for charged particle production

Disadvantage : less luminosity not-well-defined energy of initial state

・・・

Asner, Gronberg, Gunion (01)Asner et. al. (02)

heavy H, A search b, c (,d)

ⅠⅡ

type

Han, Logan, McElrath, L.T. Wang (03)

: with 2% precision

: 5%

: 8%

h BR h bb

h BR h WW

h BR h

t, b, W, ‥‥

measurementh b, c, d

Littlest Higgs modelMSSM and 2HDM

Ginzburg, Krawczyk, Osland(99)

It is possible to determine

for 115 GeVhm

4 : GSB scaleS f

1 2M

Amplitude in helicity basis

Amplitude in linear pol. basis

2 1 2 1 2 1 2 1

1 2

, ,1

2i i i iM e M e M e M e M

signal background

Probing property of CP

1 2, : azimuthal angles of pol. vectors

In general, mixing between H and A can be considered:1

2

cos sin

sin cos

H

A

1

2

1

1 2 2 1 2 1cos cos sin sinH AM M M H H

A A

M M

M M

where we use

0 indirect CPV

12 22 2

1 2 2 1, cos sin 1 cos 2H AM M

1

1

0

/ 2

0, / 2

H

A

CPV

b, c, dE.A., Kamoshita, Sugamoto, Watanabe (99)E.A., S.Y. Choi, Hagiwara, J.S. Lee (00)Godbole, Rindani, Singh (02)E.A., Hagiwara (03)S.Y. Choi, Kalinowski, Liao, Zerwas (04)J. Ellis, J.S. Lee, Pilaftsis (04)

For simplicity, 0fm

2 2 2 2

2 2 2 2

2 2 2 2

*2 1

cos 2 2 Re sin 2

C C

C C C C

T T T T

f f M M M M

P P M M M M

P P M M P P M M

P P M M P P

*2 1

* *2 1 2 1

2Im

cos 2 2Re sin 2 2 ImT T T T

M M

P P M M P P M M

* *1

* *1

* *1

* *1

*2

cos 2 2 Re Re

cos 2 2 Re Re

sin 2 2 Im Im

sin 2 2 Im Im

cos 2 2 Re Re

T

C T

T

C T

T

P M M M M

P P M M M M

P M M M M

P P M M M M

P M M M

*

* *2

* *2

* *2

cos 2 2 Re Re

sin 2 2 Im Im

sin 2 2 Im Im

C T

T

C T

M

P P M M M M

P M M M M

P P M M M M

H H

A A

M M

M M

Various observables which aresensitive to CP property of Φcan be obtained by using rich variation of polarizations.

: CPV observables

Linear pol. can use effectively only for light Higgs bosons

For heavy Higgs bosons, we use process and observing

interference between signal and background processes in

enables us to probe CP property of by circular pol.

t t

M

To probe CP mixing in the Higgs mass eigenstate (indirect CPV) γγ option is powerful because both H and A have finite couplings to γγ.

Remarks

3. γ collision　e

Advantages: less background beam polarization

a, c, d

・・・

4. collision e e a, b, c, d

Advantages: less background beam polarization peculiar initial state quantum numbers

Disadvantages: less luminosity

0e

・・・

1

1

10 100 MeV for 1 fb

cf. 100 fb is required

e e e

e e

m L

L

1 : mass of neutralinoM

precise determination of

1 verify that is suparpartner of

1 probe kinematically inaccessible superpartners

g eeB

g eeB

g eeBe e

g eeB

g eeB

g eeB

H.C.Cheng, J.Feng, Polonsky (97)

Hikasa,Nakamura(95), Nojiri,Fujii,Tsukamoto(96)H.C.Cheng, J.Feng, Polonsky (97)Katz,Randall,S.Su(98), Nojiri,Pierce,Yamada(97)Kiyoura,Nojiri,Pierce,Yamada(98)

J.Feng, Peskin(01)

selectron production d

5. polarization in collisione e e

Moortgat-Pick et al. (2005)

2precision measurement of sin W

2 5sin 1 10 with , 80%,60%effW e e

P P

a, c

RPV production

6. fixed target

e τ

N

qq

h, H, A

X

Kanemura, Kuno, Kuze, Ota (2004)

LFV in Higgs coupling

For E > 60 GeV, For E > 60 GeV, the cross section is enhanced the cross section is enhanced due to the sub-process of Higgs mediation due to the sub-process of Higgs mediation with sea b-quarkswith sea b-quarks

Non-observation of the signal Non-observation of the signal (high-energy muons) (high-energy muons) would improve the current limit by 10^4.would improve the current limit by 10^4.

CTEQ6L

7. SummaryIt is certain that

the options extend physics possible to probe.

a. Nothing New charged particle search in γγ, eγ exotics search in e-e- EWPT in e+ pol., e-e-, γγ, eγ

b. A light Higgs only Γ(h→γγ) measurement in γγ heavy Higgs search in γγ

c. A heavy Higgs only EWPT in e+ pol., e-e-, γγ, eγ heavy Higgs factory in γγ

d. Many new particles and/or non-SM phenomena　　　　　 PT for new particles in γγ, eγ, e-e- heavy Higgs search in γγ (in the case that new particles = sparticles, but h only) PT for scalar electron in e-e- (in the case that new particles = sparticles)