An

Ove

rvie

wof

Hig

hE

nerg

yP

hysi

cs

Cos

mas

Zac

hos,

HE

P

CZ

acho

s,O

verv

iew

ofH

EP

–p.

1/?

?

Th

om

as

Cu

rtri

gh

t,P

HY

666,S

pri

ng

2011,In

tro

du

cto

ryL

ectu

re

Ad

ap

ted

fro

mm

ate

rialb

yC

osm

as

Zach

os,A

NL

HE

P

Week

of

18

Jan

2011

Sim

ple

sour

ces

and

refe

renc

esT

heP

artic

leA

dven

ture

,ht

tp://

part

icle

adve

ntur

e.or

g

The

Nob

elFo

unda

tion,

http

://no

belp

rize.

org/

nobe

l_pr

izes

/phy

sics

/

DP

erki

ns,I

ntro

.to

Hig

hE

nerg

yP

hysi

cs(A

ddis

on-W

esle

y)D

Grif

fiths

,Int

ro.

toE

lem

enta

ryP

artic

les

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y-V

CH

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PFe

ynm

an,Q

ED

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guin

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CW

Dav

ies,

The

Forc

esof

Nat

ure

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brid

geU

Pre

ss)

FC

lose

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ticle

Phy

sics

:A

Ver

yS

hort

Intr

oduc

tion

(Oxf

ord)

GF

Giu

dice

,AZ

epto

spac

eO

dyss

ey(O

xfor

d)

CZ

acho

s,O

verv

iew

ofH

EP

–p.

2/?

?

For

tech

nica

ldet

ails

,see

Ste

ven

Wei

nber

g,T

heQ

uant

umT

heor

yof

Fie

lds,

Vol

s.I,

II,III

(Cam

brid

ge)

Part

icle

Phys

ics

Boo

klet

•ht

tp://

pdg.

lbl.g

ovLa

test

listin

gsan

dpr

oper

ties

ofal

lkn

own

part

icle

s,se

arch

es(li

mits

)fo

rhy

poth

etic

alon

es,a

ndni

cere

view

s.•

One

copy

isav

aila

ble

byre

ques

t,fo

rfr

ee,e

ither

:•

On

the

web

atht

tp://

pdg.

lbl.g

ov/p

dgm

ail

•B

yem

ailf

rom

pdgr

eque

st@

lbl.g

ov•

By

post

alm

ail(

!):

Par

ticle

Dat

aG

roup

,MS

50R

6008

Law

renc

eB

erke

ley

Nat

iona

lLab

One

Cyc

lotr

onR

oad

Ber

kele

y,C

A94

720-

8166

US

A

CZ

acho

s,O

verv

iew

ofH

EP

–p.

3/?

?

Wha

tis

Hig

hE

nerg

yPh

ysic

s?•

Hig

hE

nerg

yph

ysic

sex

plor

esob

ject

sth

atar

eve

ryen

erge

tican

dve

rysm

all:

the

fund

amen

tals

truc

ture

sof

mat

ter

and

ener

gyan

dth

ein

terp

lay

betw

een

them

.•

The

sear

eth

eE

lem

enta

ryP

artic

les

and

thei

rin

tera

ctio

ns—

henc

eth

eal

tern

ativ

ena

me,

“Par

ticle

Phy

sics

”.•

Led

todi

scov

ery

ofne

wla

ws

ofN

atur

ew

ithex

quis

item

athe

mat

ical

beau

ty.

(Muc

hof

the

rele

vant

mat

hem

atic

s,so

me

ofit

quite

olde

r,ha

dbe

enco

nsid

ered

esot

eric

—un

tilna

ture

was

reco

gniz

edto

rely

onit,

afte

ral

l!)

CZ

acho

s,O

verv

iew

ofH

EP

–p.

4/?

?

Smal

land

Ene

rget

icT

hese

tell

usw

hatt

heor

ies

we

shou

ldus

efo

rou

rph

ysic

s.•

“Sm

all”

mea

nsth

atQ

UA

NT

UM

ME

CH

AN

ICS

isim

port

ant,

whe

repa

rtic

les

tend

tobe

have

abi

tlik

ew

aves

,acc

ordi

ngto

deB

rogl

ie’s

rela

tion:

wav

elen

gth

=h

mom

entu

mor

λ=

� p

h≡

2π�

isP

lanc

k’s

cons

tant

and

smal

l,6.

63×

10−

34Js

.•

“Ene

rget

ic”

mea

nsth

atS

PE

CIA

LR

ELA

TIV

ITY

isim

port

ant,

and

we

shou

ldus

eE

inst

ein’

s

E=

√(m

c2)2

+(p

c)2

cis

the

vacu

umsp

eed

oflig

htan

dla

rge,

3.0×

108

m/s

.

CZ

acho

s,O

verv

iew

ofH

EP

–p.

5/?

?

mor

epr

ecis

ely,

c=

2997

9245

8m

/s(d

efin

esth

em

eter

!)

Wha

tdo

we

mea

n?•

Inth

eP

artic

leP

hysi

csB

ookl

eton

efin

ds,f

orex

ampl

e:

“..

.yie

lds

anav

erag

eW

-bos

onm

ass

of80

.4G

eV..

.”

Why

isa

mas

sbe

ing

repo

rted

inun

itsof

ener

gy?

[1G

eV=

109

eV=

1.6·10

−10

J]

•S

imila

ry,w

hyis

the

“rad

ius”

ofth

epr

oton

ofte

nap

prox

imat

edby

4G

eV−

1?

Why

isa

leng

thre

pres

ente

dby

anin

vers

een

ergy

?

CZ

acho

s,O

verv

iew

ofH

EP

–p.

6/?

?

Nat

ural

Uni

tsT

hetr

aditi

onal

seto

funi

tsth

atw

ear

em

ostf

amili

arw

ithis

{M

,L,T

}.

Inte

rms

ofth

ese,

the

dim

ensi

ons

ofou

rth

ree

impo

rtan

tqua

ntiti

esin

Hig

hE

nerg

yP

hysi

csar

e:

[c]=

[vel

oci

ty]=

LT

−1

[�]=

[len

gth×

mom

entu

m]=

ML

2T

−1

[E]=

[mas

s×

velo

city

2]=

ML

2T

−2

How

ever

,now

we

real

ize

that

we

can

inve

rtth

ese

rela

tions

hips

soth

atth

ese

t{M

,L,T

}−→

{[c

],[�

],E}:

L=

[�][c]

[E]−

1

M=

[E][c]

−2

T=

[�][E

]−1

CZ

acho

s,O

verv

iew

ofH

EP

–p.

7/?

?

Tra

nsla

tion

For

sim

plic

ity,w

ebl

ind

ours

elve

sto

�an

dc,

sow

esk

ipth

em(s

et�

=c

=1)

,with

the

unde

rsta

ndin

gth

at,s

ince

they

have

dist

inct

dim

ensi

ons,

we

can

alw

ays

rein

stat

eth

emin

form

ulae

uniq

uely

,usi

ngdi

men

sion

alan

alys

is.

The

new

dim

ensi

ons

are:

lengt

h∼

L=

[�][c]

[E]−

1→

[E]−

1

mas

s∼

M=

[E][c]

−2→

[E]

life

tim

e∼

T=

[�][E

]−1→

[E]−

1

•S

oa

mas

sof

80.4

GeV

real

lym

eans

80.4

GeV

/c2

and,

•a

prot

onra

dius

of4

GeV

−1

isre

ally

r=

4(�

c)G

eV−

1=

4·(

6.63

·10−

34·3

·10

8)/(

2π·1

.6·1

0−10)m

=8·1

0−16m

.

•a

lifet

ime

of1/

63keV

real

lym

eans

∼10

−20se

c.

CZ

acho

s,O

verv

iew

ofH

EP

–p.

8/?

?

Hig

hE

nerg

yA

ccel

erat

ors

How

doyo

ust

udy

the

inna

rds

ofa

gadg

et—

ora

car—

ifyo

udo

n’th

ave

the

tool

sto

pick

itap

art?

You

mig

htsm

ash

itag

ains

taw

all,

oran

othe

rca

r,an

dlo

okat

the

ejec

ta:

we

lear

nab

outa

tom

san

dnu

clei

this

way

,by

acce

lera

ting

them

,col

lidin

gth

em,a

ndst

udyi

ngth

efr

agm

ents

.B

ut,a

tver

yhi

ghen

ergi

es,s

omet

hing

diffe

rent

happ

ens:

(c=

1)w

hen

you

acce

lera

tepa

rtic

les

tola

rge

mom

enta

p larg

ean

den

ergi

esE

=√

m2 sm

all

+p2 la

rge>

>m

small,y

ou

have

enou

ghen

ergy

topr

oduc

ene

wty

pes

ofm

atte

rto

stud

y:un

stab

lene

wpa

rtic

les.

Itis

asif

you

colli

deca

rsto

get

bicy

cles

,w

ater

mel

ons,

shoe

s,iP

ods.

..

CZ

acho

s,O

verv

iew

ofH

EP

–p.

9/?

?

orpe

rhap

sbe

tter,

colli

detw

osk

ateb

oard

san

den

dup

with

aV

eyro

nsp

orts

car

(uns

tabl

e!)

•T

his

isa

cruc

ialf

eatu

reof

Hig

hE

nerg

yP

hysi

cs:

the

crea

tion

ofne

w(u

nsta

ble)

form

sof

mat

ter

byco

nsum

ing

high

ener

gies

.S

omet

imes

the

univ

erse

does

this

for

us:

cosm

icra

ys.

•O

urne

ighb

ors

atFe

rmila

bac

cele

rate

prot

ons

and

anti-

prot

ons

inth

eir

Teva

tron

colli

der:

mpro

ton

≈1

GeV

Eto

tal≈

2TeV

=20

00G

eV∼

3erg

s!

•P

hysi

cist

sth

ere

prod

uced

(and

disc

over

ed)

the

heav

iest

elem

enta

rypa

rtic

leye

tfou

nd—

the

top

quar

kof

mas

s17

5G

eV.

•To

day,

the

high

este

nerg

yco

llide

rin

the

wor

ldis

the

Larg

eH

adro

nC

ollid

er(L

HC

)in

Gen

eva,

Sw

itzer

land

;ul

timat

ely,

itw

illre

ach

Eto

tal=

14Te

V:p

roto

nsgo

ing

just

10pt

spe

rbi

llion

(7m

/hr)

slow

erth

anlig

ht(c

).

CZ

acho

s,O

verv

iew

ofH

EP

–p.

10/?

?

(in19

95.

also

the

botto

mqu

ark

in19

77.

note

m_b

=4.

5G

ev)

Ene

rgy

vsSi

zes

Mos

toft

hepa

rtic

les

that

we

prod

uce

ina

high

ener

gyco

llisi

onar

eun

stab

le—

they

dono

tliv

efo

rve

rylo

ng.

•T

hehi

gher

the

mas

sth

ata

part

icle

has,

the

shor

ter

itliv

es,s

oth

esh

orte

rth

edi

stan

ceit

trav

els.

•Fo

rin

stan

ce,t

heto

pqu

ark

isno

tsee

ndi

rect

ly,b

utis

obse

rved

via

itsm

ulti-

stag

ede

cay:

top

quar

k(t

)−→

Wbos

on(W

+)

+bot

tom

quar

k(b

)

↪→pos

itro

n(e

+)+

neu

trin

o(ν

e)

•P

arto

fthe

chal

leng

eof

expe

rimen

talh

igh

ener

gyph

ysic

sis

figur

ing

oute

xact

lyw

here

allt

hepa

rtic

les

dete

cted

cam

efr

om!

CZ

acho

s,O

verv

iew

ofH

EP

–p.

11/?

?

Mul

ti-st

age

deca

ysi

gnat

ures

:th

eΩ−

The

part

icle

know

nas

the

Ω−

was

anea

rlysu

cces

sful

pred

ictio

nof

the

theo

ry,a

ndw

asdi

scov

ered

inth

e60

s:Ω

−

↙↘

Ξ0

π−

↙↘

↙↘

Λπ

0ν μ

μ−

↙↘

↙↘

↙↓↘

π−

pγ

γν μ

ν ee−

↙↘

ν μμ−

↙↓↘

ν μν e

e−

CZ

acho

s,O

verv

iew

ofH

EP

–p.

12/?

?

The

Ele

ctro

mag

netic

Spec

trum

E=

hc λ

=⇒

high

ener

gy∼

shor

twav

elen

gth

Reg

ion

Wav

elen

gth

(m)

Ene

rgy

(eV

)R

adio

/TV

>0.

1<

10−

5

Rad

ar/M

icro

wav

e0.

1–

10−

410

−5

–0.

01

Infr

ared

10−

4–

7·1

0−7

0.01

–2

Vis

ible

7·1

0−7

–4·1

0−7

2–

3

Ultr

avio

let

4·10

−7

–10

−9

3–

103

X-R

ays

10−

9–

10−

11

103

–10

5

Gam

ma

Ray

s<

10−

11

>10

5

Teva

tron

10−

19

2·10

12

LHC

2·10

−20

1013

CZ

acho

s,O

verv

iew

ofH

EP

–p.

13/?

?

The

Unc

erta

inty

Prin

cipl

ein

Part

icle

Prob

esTo

reso

lve

anob

ject

,we

can

“look

init"

with

part

icle

sw

hich

have

aw

avel

engt

hle

ssth

anth

eob

ject

’ssi

ze.

•S

ize

ofan

atom

∼0.

2nm

=2·10

−10m

.↪→

X-R

aydi

ffrac

tion

•S

ize

ofth

enu

cleu

sof

Ura

nium

-238

∼10

−14m

.↪→

Nuc

lear

phys

ics

•S

ize

ofth

epr

oton

∼10

−15m

(=a

ferm

i).↪→

Hig

h-en

ergy

phys

ics

↓nu

clea

rsu

b-st

ruct

ure

↓qu

arks

•S

ize

ofa

quar

k∼

??

CZ

acho

s,O

verv

iew

ofH

EP

–p.

14/?

?

Part

icle

Prop

ertie

sJu

stas

with

atom

s,it

ispo

ssib

leto

clas

sify

the

elem

enta

rypa

rtic

les

that

we

know

abou

tint

ofa

mili

esw

ithsi

mila

rpr

oper

ties.

•W

hich

part

icle

sam

ong

thes

ear

e‘tr

uly’

elem

enta

ry?

Sta

ble:

p,n

,e±

,γ,ν

Uns

tabl

e:W

±,t

,Ω−

,Ξ0,Λ

,π•

Wha

tcha

ract

eris

tics

doth

eysh

are?

•M

ass?

•E

lect

ricch

arge

?•

Som

ethi

ngel

sew

edo

n’tk

now

abou

t?

CZ

acho

s,O

verv

iew

ofH

EP

–p.

15/?

?

The

“Per

iodi

cTa

ble"

ofH

EP

Mat

ter

(ferm

ions

)R

adia

tion

lept

ons

quar

ksbo

sons

char

ge−

10

+2/

3−

1/3

00

±1

0

e−ν e

ud

inte

ract

ions

μ−

ν μc

sg

γW

±Z

0

↓τ−

ν τt

b

stro

ngX

X�

elec

trom

agne

ticX

XX

�

—w

eak

XX

XX

��

grav

itatio

nal

XX

XX

XX

XX

...pl

usth

efe

rmio

ns’a

nti-p

artic

les,

with

oppo

site

char

ge.

CZ

acho

s,O

verv

iew

ofH

EP

–p.

16/?

?

Had

rons

and

confi

nem

ent

•W

edo

n’ts

eequ

arks

and

gluo

nsdi

rect

ly,b

ecau

seth

est

rong

‘col

or’i

nter

actio

nco

nfine

sth

emin

toha

dron

s.

mes

ons

-(q

q)

e.g.

pion

,π+

,ud

(cha

rge

=+

2/3

+1/

3=

+1)

kaon

,K0,d

s(c

harg

e=−

1/3

+1/

3=

0)

bary

ons

-(q

qq)

or(q

qq)

e.g.

prot

on,u

ud

(cha

rge

=2/

3+

2/3−

1/3

=+

1)ne

utro

n,udd

(cha

rge

=2/

3−

1/3−

1/3

=0)

CZ

acho

s,O

verv

iew

ofH

EP

–p.

17/?

?

Con

serv

atio

nL

aws

•B

yw

ritin

gou

tthe

quar

kco

nten

tofb

aryo

nsan

dm

eson

sit

isea

syto

deci

dew

hatt

ypes

ofre

actio

nsar

eal

low

ed.

•W

ear

eus

edto

the

cons

erva

tion

ofel

ectr

icch

arge

and

mus

taug

men

tthi

sw

itha

few

mor

ela

ws

–su

chas

cons

erva

tion

of“s

tran

gene

ss”

unde

rth

est

rong

forc

e.

e.g.

K−

(us)

+p

(uud)−→

Λ0

(uds)

+π

0(u

u)

K−

π0

pΛ

0 CZ

acho

s,O

verv

iew

ofH

EP

–p.

18/?

?

Forc

esof

Nat

ure

Let’s

com

pare

the

forc

esat

ener

gies

(and

dist

ance

s)ty

pica

lfor

HE

P,sa

yE

∼1

GeV

(r∼

0.1

fm).

stro

nge.

-m.

wea

kgr

avity

stre

ngth

1α

=1

137∼

10−

210

−7

10−

38

lifet

ime(

s)10

−23

10−

16

10−

8–

boso

ngl

uons

phot

onW

±,Z

grav

itons

theo

ryQ

CD

QE

DQ

uant

um

sym

met

rySU

(3) c

olo

rU

(1)×

SU

(2)

Gra

vity

QE

D=

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sequ

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use:

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diag

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gram

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ple,

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ures

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repr

esen

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the

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22/?

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verv

iew

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EP

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23/?

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The

Hig

gsB

oson

The

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ard

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eN

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hani

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the

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ryw

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veis

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dm

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else

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goal

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eLH

C:t

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ysic

sof

zept

ospa

ce.

CZ

acho

s,O

verv

iew

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EP

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24/?

?

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vity

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er-T

heor

ies,

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ive

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ions

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stas

we

real

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coul

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scrib

eth

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elec

tro-

mag

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theo

ries

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inon

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brac

ing

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trow

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theo

ry,a

ttem

pts

have

also

been

mad

eto

unify

this

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ryw

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atof

the

stro

ngin

tera

ctio

ns,

into

Gra

ndU

nifie

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ies.

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ther

theo

rists

try

tolin

kfe

rmio

nsan

dbo

sons

thro

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supe

rsym

met

ry,i

ntro

duci

ngye

tmor

eun

disc

over

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rtic

les

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uark

s,pa

rtne

rsof

the

regu

lar

quar

ks).

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seth

eorie

sna

tura

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corp

orat

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avity

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ding

toev

enm

ore

unifi

catio

n—

supe

rgra

vity

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mat

ely,

thes

eth

eorie

sm

aybe

embe

dded

ina

spec

ulat

ive

fram

ewor

k,su

pers

trin

gs,b

rane

-wor

ldth

eorie

s,et

c,in

mor

eth

an4

dim

ensi

ons.

..in

side

eleg

antm

athe

mat

ical

wor

lds,

pret

tier

than

ours

!

CZ

acho

s,O

verv

iew

ofH

EP

–p.

25/?

?

AT

LA

Sde

tect

orat

the

CE

RN

LH

C

CZ

acho

s,O

verv

iew

ofH

EP

–p.

26/?

?