Collider Phenomenology of SUSY

Cosmic Connections

杨 金 民中科院理论物理所

2006.9.16 于清华

&

目 录1 、 Introduction to SUSY

2 、 Fine-tuning & SUSY

3 、 GUT & SUSY

4 、 Cosmic Dark Matter & SUSY

5 、 SUSY at Colliders

6 、 Conclusion

1 、 Introduction

|F |B SUSY

1.1 What is and why SUSY ?

起源 :

起源于 60 年代末 ; 起源于纯数学逻辑

物理模型创建于 70 年代初

一直是研究热点，有 30000 篇文章发表 !

Why ?

Fine Tuning

GUT

ElectroweakBaryogenesis

Affleck-DineBaryogenesis

Inflation

Dark Matter

SUSY

SUSY

超对称是物理吗？超粒子有多重？LHC 上发现？

???

R- 宇称 R- 宇称

1.2 SUSY Models

MSSM NMSSM

Singlet S

MSSM mSUGRA

mSUGRA

不同的破缺机制

Split-SUSY

• Fine-tuning • GUT • 暗物质

TeV-Scale SUSYall sparticles < TeV

5 Higgs bosons1 < 130 GeV

4 < TeV

sparticles

Higgs Bosons1 < 150 GeV

4 ： superheav

y

Gauginos/Higgsinos < TeV

Others ： superheavy

Weak Scale 100 GeV

1 TeV SM break

1015 GeV

2. Fine-tuning & SUSY

1019 GeV

GUT

究竟是多大？

2100 GeV

Bare

In SUSY:

2 cancel

remain

How heavy ? Depends on

More about

Higgs mass:

EW baryogenesis:

3. GUT & SUSY

not sensitive to sfermions

light gauginos/higgsino (??)

SU

SY

SM

sfermions

gauginos/higgsino GUT

Maybe unaccessible at LHC

Light !Not necessarily so light for LHC

4. Dark Matter & SUSY

Mass: weak-scale

Interaction: weak-scale

Dark Matter

WIMP

Which one is LSP dark matter ?

LSP ?

LSP (Dark Matter)

mSUGRA

Split-SUSY

sfermions

gauginos/higgsino

DarkMatter

Maybe heavyMaybe unaccessible at LHC

Light !Most likely so light for LHC

5 、 SUSY Search at Colliders

LEP (I, II)Tevatron I

Tevatron II

LHC

closed

on-going

up-coming

ILC imagining

LEP (I, II)

Tevatron (I,II)

SUSY

tan > 2

m h , m A ,

m H >

95 GeV

Selectron > 100 GeV

Smuon > 97 GeV

Stau> 93 GeV

100 GeV < stop

100

GeV

< s

bott

om

100 GeV < squark

103.5 GeV < chargino47 GeV < neutralino

LEP

stop -> c chi

stop -> b l snu stop -> c chi

Tevatron

LHC ILC

沙漠淘金！

1 粒金子 /100 亿粒沙子

LHC ILC

在 LHC 上发现

在 ILC 上精确测量粒子谱

LHC: SUSY Typical Signature

ET

b

b

b-jet

b-jet ET

LHC

Sparticlessfermions

gauginosHiggsinos

squarks

sleptons

gluinocharginosneutralinos

Higgs Bosonsh, H (CP-even)

H

A (CP-odd)

What SUSY partilces can be found at LHC?

Depends on good

detection capabilities

for b’s and tau’s

只能发现 h

, muonsH A

Gold-plated signal

LEP II excluded

LHC

TeV-scale SUSY

mSUGRA

LHC

LHC Dark Matter Constraint

sparticle

sfermion

gauginohiggsino

MSSM

SplitSUSY

man

y

seve

ral

maybe no

?

Higgs h, H

A, H

all

at least h

onl

y h

Split-SUSY

+

1-

1pp

e+e- +

1-

1

h H, A, H 　　 sfermions gaugino/Higgsino

Higgs bosons sparticles

SM

weak-scale SUSY

Split-SUSY

??

??

LHC

LHCweak-scale

SUSY 发现初步测量参数

预言

暗物

质密

度

ILC

精确

测量

精确预言暗物质密度

astrophysics

6 、 Conclusion

E. Witten2002, Beijing