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T he N ex t Li near Col l i d er and t he Or i gi n of El ect r oweak Physi cs

J i m Br au OSU Physi cs Depar t ment Col l oqui um M ay 6 , 2 0 0 2

Colloquium, Corvallis, OR, J. Brau, May 6, 2002

1


T he N ex t Li near Col l i der and t he Or i gi n of El ect r oweak Physi cs · W hat i s t he N ex t Li near Col l i der ? · El ect r oweak Physi cs
­ Devel opment · uni f i cat i on of E&M wi t h b et a d ecay ( weak i nt er act i on) ­ Pr ed i ct i ons ... · eg. M W , M Z , ... . ­ M i ssi ng component s · or i gi n of symmet r y b r eak i ng ( H i ggs M echani sm)

· T he H unt f or t he H i ggs Boson
­ Li mi t s f r om LEP2 and f ut ur e accel er at or s

· Ot her i nvest i gat i ons
­ super symmet r y, ex t r a d i mensi ons
Colloquium, Corvallis, OR, J. Brau, May 6, 2002
2


T he N ex t Li near Col l i d er
· A ccel er at i on of el ect r ons i n a ci r cul ar accel er at or i s pl agued b y N at ur e's r esi st ance t o accel er at i on
­ Synchr ot r on r adi at i on ­ E = 4 / 3 ( e2 3 4 / R) per t ur n ( r ecal l = E/ m, so E ~ E4 / m4) E = 4 GeV Power ~ 2 0 M W ­ eg. LEP2

· For t hi s r eason, at ver y hi gh ener gy i t i s pr ef er ab l e t o accel er at e el ect r ons i n a l i near accel er at or , r at her t han a ci r cul ar accel er at or
el ect r ons posi t r ons

Colloquium, Corvallis, OR, J. Brau, May 6, 2002

3


Li near Col l i d er s
· Synchr ot r on r ad i at i on
­ E ~ ( E4 / m4 R)

· T her ef or e
­ Cost ( ci r cul ar ) ~ a R + b E ~ a R + b ( E4 / m4 R) · Opt i mi z at i on R ~ E2
Cost ~ c E2

­ Cost ( l i near ) ~ ac L, wher e L ~ E
Ci r cul ar Col l i d er Li near Col l i d er

Ener gy

· A t hi gh ener gy, l i near col l i d er i s mor e cost ef f ect i ve
4

cost

Colloquium, Corvallis, OR, J. Brau, May 6, 2002


T he Li near Col l i d er
· A pl an f or a hi gh- ener gy, hi ghl umi nosi t y, el ect r on- posi t r on col l i d er ( i nt er nat i onal pr oj ect )
­ Ecm = 5 0 0 - 10 0 0 GeV ­ Lengt h ~2 5 k m ~15 mi l es
~100 m ~20 m 560 m Pre-Linac 6 GeV (S) Compressor 136 MeV (L) Damping Ring e­ (UHF) 0.6 GeV (X) Compressor Electron Injector ~10 m

170 m

2 GeV (S) e­ 9.9 km

Electron Main Linac 240-490 GeV (X)

Final Focus Dump

· Physi cs M ot i vat i on f or t he N LC
­ El uci d at e El ect r oweak I nt er act i on · par t i cul ar symmet r y b r eak i ng · T hi s i ncl ud es
­ H i ggs b osons ­ super symmet r i c par t i cl es ­ ex t r a d i mensi ons

RF Systems (X) 11.424 GHz (S) 2.856 GHz (L ) 1.428 GHz (UHF) 0.714 GHz

~300 m ~5 km Low E Detector Hi E Detector

Dump Final Focus

e­ 510 m 200 m 6 GeV (S) 2 GeV (L) Pre-Damping Ring (UHF) e+ 136 MeV (L) Compressor Pre-Linac 6 GeV (S)

9.9 km e+ Target Positron Main Linac 240-490 GeV (X)

Positron Injector

10 m

Damping e+ Ring (UHF)

560 m

Compressor ~20 m ~100 m 0.6 GeV (X)

· Const r uct i on coul d b egi n ar ound 2 0 0 5 - 6 and oper at i on ar ound 2 0 11- 12
Colloquium, Corvallis, OR, J. Brau, May 6, 2002

10-2000

8047A611

not t o scal e
5


T he Fi r st Li near Col l i d er
· T hi s concept was d emonst r at ed at SLA C i n a l i near col l i d er pr ot ot ype oper at i ng at ~9 1 GeV ( t he SLC)
­ Or egon col l ab or at ed

· SLC was b ui l t i n t he 8 0 's wi t hi n t he ex i st i ng SLA C l i near accel er at or · Oper at ed 19 8 9 - 9 8
­ pr eci si on Z 0 measur ement s ­ est ab l i shed LC concept s
Colloquium, Corvallis, OR, J. Brau, May 6, 2002
6


T he N ex t Li near Col l i d er

· DOE/ N SF H i gh Ener gy Physi cs A dvi sor y Panel
­ Sub panel on Long Range Pl anni ng f or U.S. H i gh Ener gy Physi cs ­ A year l ong st ud y was concl uded ear l y t hi s year wi t h t he r el ease of t he r epor t of r ecommend at i ons ­ A hi gh- ener gy, hi gh- l umi nosi t y el ect r on- posi t r on l i near col l i d er shoul d b e t he hi ghest pr i or i t y of t he US H EP communi t y, pr ef er ab l y one si t ed i n t he US
Colloquium, Corvallis, OR, J. Brau, May 6, 2002
7


T he " nex t " Li near Col l i d er
T he next L inear Collider pr opos als include plans to deliver a f ew hundr ed fb-1 of integrated lum. per year
T ESLA
( D E S Y -G e r m a n y )

J LC- C
(J a p a n )

N LC/ J LC- X *
( S L A C /K E K - J a p a n )

d esi gn

( 10 3 4 ) ( GeV)

3 .4

o o o

5 .8 800 35

0 .4 3 500 34 5 .7

2 .2

o

3 .4 10 0 0

ECM
RF f r eq.

500 2 3 .4

500

o

Ef f . Gr ad i ent ( M V/ m) ( GH z ) ( ns)

70 11.4 1.4 19 0 4 .6
o

1.3 337 2820 3 .2
o o o

t

b unch

17 6 4886 4 .4

2 .8 72

# b unch/ t r ai n Beamst r ahl ung ( %)

8 .8

T her e wi l l onl y b e one i n t he wor l d , b ut t he t echnol ogy choi ce r emai ns t o b e mad e
Colloquium, Corvallis, OR, J. Brau, May 6, 2002

* US and J apanese X - b and R&D cooper at i on, b ut machi ne par amet er s may d i f f er 8


N LC Engi neer i ng
· Power per b eam
­ 6 .6 M W cw ( 2 5 0 GW d ur i ng pul se t r ai n of 2 6 6 nsec) ( 5 0 0 ,0 0 0 GW wi t hi n a b unch of t he t r ai n)

· Beam si z e at i nt er act i on
­ 2 4 5 nanomet er s x 3 nanomet er s
St abiliz e

· Beam f l ux at i nt er act i on
­ 10
12

M W / cm2 cw ( 3 x 10

13

GW / cm2 d ur i ng pul se t r ai n)

· Cur r ent d ensi t y
­ 6 .8 x 10
12

A / m2

( 1.4 x 10

15

A / m2 wi t hi n a b unch)

· I nduced magnet i c f i el d ( b eam- b eam)
­ > 10 T esl a beam- beam induced br emsst r ahlung - "beamst r ahlung" >
Colloquium, Corvallis, OR, J. Brau, May 6, 2002
9


T he " nex t " Li near Col l i d er
S tandar d P ackage: e+ e Collis ions I nitially at 500 GeV E lectron P olariz ation 80%


Options : E ner gy upgr ades to 1.0 -1.5 T eV P os itron P olariz ation (~ 40 - 60% ?) JJ Col l i s i ons e e and e J Collis ions Giga-Z (precis ion meas urements )


Colloquium, Corvallis, OR, J. Brau, May 6, 2002

10


Speci al A d vant ages of Ex per i ment s at t he Li near Col l i der
E lementar y inter actions at known E eg. e+e- Z H
* cm

Democr atic Cr os s s ections eg. (e+e - ZH) 1/2 (e+e - d d) I nclus ive T r igger total cross-section H ighly P olar iz ed E lectr on B eam ~ 80% E xquis ite ver tex detection eg. Rbeampipe 1 cm and 3 µm

hit

Calor imetr y with Jet E ner gy F low E/E 30-40%/E
* beams trahlung mus t be dealt with, but it's manageable

Colloquium, Corvallis, OR, J. Brau, May 6, 2002

11


Li near Col l i d er Det ect or s
T he Li near Col l i d er pr ovi d es ver y speci al ex per i ment al cond i t i ons ( eg. super b ver t ex i ng and j et cal or i met r y)

CCD Ver t ex Det ect or s

Si l i con/ T ungst en Cal or i met r y SLD Lum ( 19 9 0 ) A l eph Lum ( 19 9 3 ) Opal Lum ( 19 9 3 )

N LC a T ES LA

Snowmass - 9 6 Pr oceed i ngs
N LC Det ect or - f i ne gr an. Si / W
T ESLA N LC

N ow T ESLA & N LD have pr oposed Si / W as cent r al el ement s i n j et f l ow measur ement
12

S LD's VX D3

Colloquium, Corvallis, OR, J. Brau, May 6, 2002


El ect r oweak Symmet r y Br eak i ng
· A pr i mar y goal of t he N ex t Li near Col l i d er i s t o el uci d at e t he or i gi n of El ect r oweak Symmet r y Br eak i ng
­ T he weak nucl ear f or ce and t he el ect r omagnet i c f or ce have b een uni f i ed i nt o a si ngl e d escr i pt i on SU( 2 ) x U( 1) Y ­ W hy i s t hi s symmet r y hi d d en? ­ T he answer t o t hi s appear s t o pr omi se d eep und er st and i ng of f und ament al physi cs · t he or i gi n of mass · super symmet r y and possi b l y t he or i gi n of d ar k mat t er · ad d i t i onal uni f i cat i on ( st r ong f or ce, gr avi t y) and possi b l y hi d d en space- t i me d i mensi ons
Colloquium, Corvallis, OR, J. Brau, May 6, 2002
13


El ect r omagnet i sm and Rad i oact i vi t y
· M ax wel l uni f i ed El ect r i ci t y and M agnet i sm wi t h hi s f amous equat i ons ( 18 7 3 ) · M at t er spont aneousl y emi t s penet r at i ng r ad i at i on ­ Becquer el ur ani um emi ssi ons i n 18 9 6 ­ T he Cur i es f i nd r ad i um emi ssi ons b y 18 9 8

Coul d t hi s new i nt er act i on ( t he weak f or ce) b e r el at ed t o E&M ?
Colloquium, Corvallis, OR, J. Brau, May 6, 2002
14


A d vanci ng und er st and i ng of Bet a Decay · Paul i r eal i z es t her e must b e a neut r al i nvi si b l e par t i cl e accompanyi ng t he b et a par t i cl e: b et a
­ t he neut r i no
ener gy

· Fer mi d evel ops a t heor y of b et a d ecay ( 19 3 4 )
np ee

neut r i no

· 19 5 6 - N eut r i no d i scover ed b y Rei nes and Cowan - Savannah Ri ver React or , SC
Colloquium, Corvallis, OR, J. Brau, May 6, 2002
15


St at us of EM and W eak T heor y i n 19 6 0
W eak I nt er act i on T heor y · Fer mi 's 19 3 4 poi nt l i k e, f our - f er mi on i nt er act i on t heor y

V- A

· T heor y f ai l s at hi gher ener gy, si nce r at e i ncr eases wi t h ener gy, and t her ef or e wi l l vi ol at e t he " uni t ar i t y l i mi t "
­ Specul at i on on heavy med i at i ng b osons b ut no t heor et i cal gui d ance on what t o ex pect
Colloquium, Corvallis, OR, J. Brau, May 6, 2002
16


St at us of EM and W eak T heor y i n 19 6 0
Q uant um El ect r od ynami cs ( Q ED)
· Di r ac i nt r od uced t heor y of el ect r on - 19 2 6 · T hr ough t he pi oneer i ng t heor et i cal wor k of Feynman, Schwi nger , T omonga, and ot her s, a t heor y of el ect r ons and phot ons was wor k ed out wi t h pr eci se pr ed i ct i ve power · ex ampl e: magnet i c d i pol e of t he el ect r on [ ( g- 2 ) / 2 ] µ = g ( eh/ 2 mc) S
· cur r ent val ues of el ect r on ( g- 2 ) / 2
= ( 115 9 6 5 2 3 0 ± 10 ) x 10
- 11 - 11

t heor y: 0 .5 ( / ) - 0 .3 2 8 4 8 ( / ) 2 + 1.19 ( / ) 3 +.. ex per i ment = ( 115 9 6 5 2 18 .7 ± 0 .4 ) x 10

Colloquium, Corvallis, OR, J. Brau, May 6, 2002

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T he N ew Symmet r y Emer ges

Colloquium, Corvallis, OR, J. Brau, May 6, 2002

18


Ent er El ect r oweak Uni f i cat i on
· W ei nb er g r eal i z ed t hat t he vect or f i el d r esponsi b l e f or t he EM f or ce
­ ( t he phot on)

and t he vect or f i el d s r esponsi b l e f or t he W eak f or ce
­ ( yet und i scover ed W + and W - )

coul d b e uni f i ed i f anot her vect or f i el d , med i at ed b y a heavy neut r al b oson ( Z ) , wer e t o ex i st · T hi s same not i on occur r ed t o Sal am
t an W = g'/ g
si n2 W =g'2 / ( g'2 +g2 )

eJ

( em) µ

A

µ

Colloquium, Corvallis, OR, J. Brau, May 6, 2002

e = g si n W = g' cos

W

19


El ect r oweak Uni f i cat i on
· T her e r emai ned a phenomenol ogi cal pr ob l em:
­ wher e wer e t he ef f ect s of t he Z
0

· T hese d o not appear so cl ear l y i n N at ur e
­ t hey ar e smal l ef f ect s i n t he at omi c el ect r on ener gy l evel

· One has t o l ook f or t hem i n hi gh ener gy ex per i ment s

Colloquium, Corvallis, OR, J. Brau, May 6, 2002

20


N eut r al Cur r ent s Di scover ed !
· 19 7 3 - gi ant b ub b l e chamb er Gar gamel l e at CERN
­ 12 cub i c met er s of heavy l i qui d

· M uon neut r i no b eam · El ect r on r ecoi l · N ot hi ng el se · N eut r al Cur r ent Di scover ed t hat i s, t he ef f ect of t he Z

0

Colloquium, Corvallis, OR, J. Brau, May 6, 2002

21


Conf i r mat i on of N eut r al Cur r ent s
· W ei nb er g- Sal am M od el pr ed i ct s t her e shoul d b e some par i t y vi ol at i on i n pol ar i z ed el ect r on scat t er i ng
­ T he d omi nant ex change i s t he phot on ( L/ R symmet r i c) ­ A smal l ad d i t i on of t he weak neut r al cur r ent ex change l ead s t o an ex pect ed asymmet r y of ~ 10 - 4 b et ween t he scat t er i ng of l ef t and r i ght - hand ed el ect r ons Z ex change vi ol at es par i t y
pol ar i z ed

e d

pol ar i z ed



+

e d Z

gR z gL A n asymmet r y of 10

-4

­ T hi s was ob ser ved b y Pr escot t et al . at SLA C i n 19 7 8 , conf i r mi ng t he t heor y, and pr ovi d i ng t he f i r st accur at e measur ement of t he weak mi x i ng angl e si n2 W = 0 .2 2 ± 0 .0 2
Colloquium, Corvallis, OR, J. Brau, May 6, 2002
22


T he W and Z M asses
· Knowi ng si n2 W al l ows one t o pr ed i ct t he W and Z b oson masses i n t he W ei nb er g- Sal am M odel

~ 8 0 GeV/ c

2

~ 9 0 GeV/ c

2

Colloquium, Corvallis, OR, J. Brau, May 6, 2002

23


Di scover y of t he W and Z
· M ot i vat ed b y t hese pr ed i ct i ons, ex per i ment s at CERN wer e mount ed t o f i nd t he W and Z

- d ecay

+ d ecay

q ant i - q anni hi l at i on t o W

±

Colloquium, Corvallis, OR, J. Brau, May 6, 2002

24


Di scover y of t he W and Z
· 19 8 1 - ant i pr ot ons wer e st or ed i n t he CERN SPS r i ng and b r ought i nt o col l i si on wi t h pr ot ons

Colloquium, Corvallis, OR, J. Brau, May 6, 2002

25


Di scover y of t he W and Z
· 19 8 1 UA 1

Colloquium, Corvallis, OR, J. Brau, May 6, 2002

26


Di scover y of t he W and Z
W e- e e- u
p=uud

W e

PT

d
p=uud

mi ss PT

Colloquium, Corvallis, OR, J. Brau, May 6, 2002

27


Di scover y of t he W and Z
· T hat was 2 0 year s ago · Si nce t hen:
­ pr · ­ pr · eci si on st ud i es at Z 0 Fact or i es LEP and SLC eci si on W measur ement s at col l i d er s LEP2 and T eVat r on M
W

M Z = 9 118 7 .5 ± 2 .1 M eV

= 8 0 4 5 1 ± 3 3 M eV/ c

2

· T hese pr eci se measur ement s ( al ong wi t h ot her pr eci si on measur ement s) t est t he St and ar d M od el wi t h k een sensi t i vi t y
­ eg. ar e al l ob ser vab l es consi st ent wi t h t he same val ue of si n2 W
Colloquium, Corvallis, OR, J. Brau, May 6, 2002
28


El ect r oweak Symmet r y Br eak i ng
· Conf i r mat i on of t he compl et eness of t he St andar d M odel ( LEP2 ) e e- W W e++e- W ++W--

Colloquium, Corvallis, OR, J. Brau, May 6, 2002

29


T he H i ggs Boson
· W hy i s t he under l yi ng SU( 2 ) x U( 1) symmet r y

b r ok en

· T heor et i cal conj ect ur e i s t he H i ggs M echani sm: a non- z er o vacuum ex pect at i on val ue of a scal ar f i el d, gi ves mass t o W and Z and l eaves phot on massl ess
Colloquium, Corvallis, OR, J. Brau, May 6, 2002
30


St and ar d M od el Fi t
· MH = 88
+5 3 - 35

GeV/ c

2

Colloquium, Corvallis, OR, J. Brau, May 6, 2002

31


T he H i ggs Boson
· T hi s f i el d, l i k e any f i el d , has quant a, t he H i ggs Boson or Bosons
­ M i ni mal mod el - one compl ex d oub l et 4 f i el d s
­ 3 " eat en" b y W +, W - , Z t o gi ve mass ­ 1 l ef t as physi cal H i ggs

· T hi s spont aneousl y b r ok en l ocal gauge t heor y i s r enor mal i z ab l e - t 'H oof t ( 19 7 1) · T he H i ggs b oson pr oper t i es
­ M ass < ~ 8 0 0 GeV/ c2 ( uni t ar i t y ar gument s) ­ St r engt h of H i ggs coupl i ng i ncr eases wi t h mass v = 2 4 6 GeV · f er mi ons: gf f h = mf / v · gauge b oson: gwwh = 2 mZ 2 / v
Colloquium, Corvallis, OR, J. Brau, May 6, 2002
32


Par t i cl e Physi cs H i st or y of A nt i ci pat ed Par t i cl es Posi t r on N eut r i no Pi meson Char med quar k Bot t om quar k W b oson Z b oson T op quar k H i ggs b oson
Di r ac t heor y of t he el ect r on mi ssi ng ener gy i n b et a d ecay Yuk awa's t heor y of st r ong i nt er act i on ab sence of f l avor changi ng neut r al cur r ent s Kob ayashi - M ask awa t heor y of CP vi ol at i on W ei nb er g- Sal am el ect r oweak t heor y

"

"

M ass pr ed i ct ed b y pr eci si on Z 0 measur ement s

El ect r oweak t heor y and ex per i ment s

Colloquium, Corvallis, OR, J. Brau, May 6, 2002

33


T he Sear ch f or t he H i ggs Boson
· LEP I I ( 19 9 6 - 2 0 0 0 )
­ M H > 114 GeV/ c2 ( 9 5 % conf .)

Colloquium, Corvallis, OR, J. Brau, May 6, 2002

34


T he Sear ch f or t he H i ggs Boson
· T evat r on at Fer mi l ab
­ Pr ot on/ ant i - pr ot on col l i si ons at Ecm=2 0 0 0 GeV ­ N ow

· LH C at CERN
­ Pr ot on/ pr ot on col l i si ons at Ecm=14 ,0 0 0 GeV ­ Begi ns oper at i on ~2 0 0 7
Colloquium, Corvallis, OR, J. Brau, May 6, 2002
35


I ndi cat i ons f or a Li ght St andar d M odel - l i k e H i ggs

(SM) Mhiggs < 195 GeV at 95% CL. LEP2 limit Mhiggs > 114.1 GeV. Tevatron can discover up to 180 GeV

W mass ( r 33 MeV) and top mass ( r 5 GeV) agree with precision measures and indicate low SM Higgs mass
V

LEP H iggs sear ch ­ M ax imum Likelihood f or H iggs signal at mH = 1 1 5 . 6 GeV wit h over all signif icance ( 4 ex per iment s) ~ 2
Colloquium, Corvallis, OR, J. Brau, May 6, 2002

36


Est ab l i shi ng St and ar d M od el H i ggs
precis ion s tudies of the H iggs bos on will be r equired to unders tand E lectr oweak S ymmetry B reaking; jus t finding the H iggs is of limited value
We expect the H iggs to be dis covered at L H C (or T evatron) and the meas ur ement of its properties will begin at the L H C We need to meas ure the full nature of the H iggs to unders tand E WS B T he 500 GeV (and beyond) L inear Collider is the tool needed to complete thes e precis ion s tudies
R efer ences : T E S L A T echnical Des ign R epor t L inear Collider P hys ics R es our ce B ook for S nowmas s 2001 (contain r eferences to many s tudies ) Colloquium, Corvallis, OR, J. Brau, May 6, 2002

37


Cand i d at e M odel s f or El ect r oweak Symmet r y Br eak i ng
St and ar d M odel H i ggs
ex cel l ent agr eement wi t h EW pr eci si on measur ement s i mpl i es M H < 2 0 0 GeV ( b ut t heor et i cal l y ugl y - h'ar chy pr ob .)

M SSM H i ggs
ex pect M h< ~13 5 GeV l i ght H i ggs b oson ( h) may b e ver y " SM H i ggs- l i k e" ( d e- coupl i ng l i mi t )

N on- ex ot i c ex t ended H i ggs sect or
eg. 2 H DM

St r ong Coupl i ng M od el s
N ew st r ong i nt er act i on T he N LC will pr ovide cr it ical dat a f or all of t hese possibilit ies
Colloquium, Corvallis, OR, J. Brau, May 6, 2002
38


T he H i ggs Physi cs Pr ogr am of t he N ex t Li near Col l i d er
E lectroweak precis ion meas urements s ugges t there s hould be a r elatively light H iggs bos on:
W hen we f ind it , we will want t o st udy it s nat ur e. T he LC i s capab l e of cont r i b ut i ng si gni f i cant l y t o t hi s st ud y.

Mas s Meas urement T otal width P article couplings vector bos ons fermions (including top) S pin-parity-char ge conjugation S elf-coupling

H

?

H
H

?

H

T he Linear Collider could measur e all t his wit h gr eat pr ecision
Colloquium, Corvallis, OR, J. Brau, May 6, 2002
39


Ex ampl e of Pr eci si on of H i ggs M easur ement s at t he N ex t Li near Col l i d er
F or MH = 140 GeV, 500 fb-1 @ 500 GeV Mas s Meas ur ement T otal width P ar ticle couplings tt bb cc WW* ZZ gg
WW


M H 6 0 M eV 5 x 10 - 4 M / 3 %

H

JJ

S pin-par ity-char ge conjugation S elf-coupling

(need s hi gher s f or 14 0 GeV, ex cept t hr ough H gg) gbb / gbb 2 % gcc / gcc 2 2 .5 % g / g 5 % gww/ gH ww 2 % g/ gH Z Z 6 % ggg / ggg 12 .5 % g / g 10 %
WW WW JJ JJ

est ab l i sh J

PC

=0

++

HH H / H HH 3 2 % ( st at i st i cs l i mi t ed )
40

I f H iggs is lighter, pr ecis ion is often better Colloquium, Corvallis, OR, J. Brau, May 6, 2002


H i ggs Pr od uct i on Cr oss- sect i on at t he N ex t Li near Col l i d er N LC ~ 5 0 0 event s / f b
H iggs- st r ahlung

W W f usion

R ecall, pt = 87 nb / (Ecm) 2 ~ 350 f b @ 5 0 0 GeV
Colloquium, Corvallis, OR, J. Brau, May 6, 2002
41


H i ggs St udi es - t he Power of Si mpl e React i ons

T he LC can pr od uce t he H i ggs r ecoi l i ng f r om a Z , wi t h k nown CM ener gy, whi ch pr ovi d es a power f ul channel f or unb i assed t aggi ng of H i ggs event s, al l owi ng measur ement of even i nvi si b l e d ecays ( - some b eamst r ahl ung) · T ag Z l+ l- · Sel ect M r ec
oi l

=M

H i ggs

I nvi si b l e d ecays ar e i ncl ud ed

5 0 0 f b- 1 @ 5 0 0 GeV,ColloLA iTmR, Firv2l1.s, OR, T ES qu u D , Co g a .li 4

42

J. Brau, May 6, 2002


H i ggs Coupl i ngs - t he Br anchi ng Rat i os

bb cc
WW


ZZ gg
JJ

WW*



g g g g g g g

WW

JJ

/ cc / / ww/ / gg / /
bb

gbb 2 % gcc 2 2 .5 % g 5 % gH ww 2 % gH Z Z 6 % ggg 12 .5 % g 10 %
WW JJ

M easur ement of BR's i s power f ul i nd i cat or of new physi cs e.g. i n M S S M , t hese d i f f er f r om t he S M i n a char act er i st i c way. H i ggs BR must agr ee wi t h M S SM par amet er s f r om many ot her measur ement s. Colloquium, Corvallis, OR, J. Brau, May 6, 2002
43


H i ggs Spi n Par i t y and Char ge Conj ugat i on ( J PC)
H or H r ul es out J =1 and i nd i cat es C=+1 T hr eshol d cr oss sect i on ( e+ e- Z H ) f or J =0 , whi l e f or J > 0 , gener al l y hi gher power of ( assumi ng n = ( - 1) J P) Pr od uct i on angl e ( ) and Z d ecay angl e i n H i ggs- st r ahl ung r eveal s J P ( e+ e- Z H f f H )
J P= 0 d / d cos d / d cos si n2 si n2
+

J P= 0

-

( 1 - si n2 ) ( 1 +/ - cos )
2

LC Physi cs Resour ce Book , Fi g 3 .2 3 (a)
i s angl e of t he f er mi on,

r el at i ve t o t he Z d i r ect i on of f l i ght , i n Z r est f r ame

A l so e+e- e+e-Z H an, J i ang Colloquium, Corvallis, OR, T ESLA T DR, raiu, 2 .2a8 6, 2002 J. B F g M . y
44


I s T hi s t he St and ar d M od el H i ggs?
1.) Does t he hZ Z coupl i ng sat ur at e t he Z coupl i ng sum r ul e? gh
ZZ

=M

Z

2

gew2 / 4 cos2

W

eg. ghZ Z = gZ M Z si n( - ) gH Z Z = gZ M Z cos( - )

gZ = gew/ 2 cos

W

2 .) A r e t he measur ed BRs consi st ent wi t h t he S M ? eg. gh gh gh
M SSM

bb

= ghbb( - si n / cos ) - ghbb( si n( - ) - cos( - ) t an ) = gh( - si n / cos ) - gh ( si n( - ) - cos( - ) t an ) = ght t ( - cos / si n ) ght t ( si n(- ) + cos( - ) / t an )

M SSM



M SSM

tt

(i n M S SM onl y f or smal l er val ues of M A wi l l t her e b e sensi t i vi t y, si nce si n( - ) 1 as M A gr ows - d ecoupl i ng) 3 .) I s t he wi d t h consi st ent wi t h S M ? 4 .) H ave ot her H i ggs b osons or super - par t ner s b een d i scover ed ? 5 .) et c. Colloquium, Corvallis, OR, J. Brau, May 6, 2002
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I s T hi s t he St and ar d M od el H i ggs?

Z vs. W

b vs. c

A r r ows MA = 2 MA = 4 MA = 6 MA = 8

at : 00000000-

400 600 800 10 0 0
b vs. t au b vs. W

H FI T T ER out put concl usi on: f or M A < 6 0 0 , l i k el y d i st i ngui sh

Colloquium, Corvallis, OR, J. T ESu,A TayR, ,Fi g022 .6 Bra L M D 6 20 2 .

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Ot her scenar i os
· Super symmet r y
­ al l par t i cl es mat ched b y super - par t ner s · super - par t ner s of f er mi ons ar e b osons · super - par t ner s of b osons ar e f er mi ons ­ i nspi r ed b y st r i ng t heor y ­ hi gh ener gy cancel l at i on of di ver gences ­ coul d pl ay r ol e i n d ar k mat t er pr ob l em ­ many new par t i cl es ( d et ai l ed pr oper t i es onl y at N LC)

· Ex t r a Di mensi ons
­ st r i ng t heor y pr ed i ct s ­ sol ves hi er ar chy ( M pl anck > M EW ) pr ob l em i f ex t r a d i mensi ons ar e l ar ge ( or why gr avi t y i s so weak ) ­ l ar ge ex t r a d i mensi ons woul d b e ob ser vab l e at N LC ( see Physi cs T od ay, Feb r uar y 2 0 0 2 )
Colloquium, Corvallis, OR, J. Brau, May 6, 2002
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Lar ge Ex t r a Di mensi ons
· I n add i t i on t o t he t hr ee i nf i ni t e spat i al d i mensi ons we k now ab out , i t i s assumed t her e ar e n new spat i al d i mensi ons of f i ni t e ex t ent R · Some of t he ex t r a d i mensi ons coul d b e qui t e l ar ge · T he ex per i ment al l i mi t s on t he si z e of ex t r a d i mensi ons ar e not ver y r est r i ct i ve
­ t o what d i st ance has t he 1/ r 2 f or ce l aw b een measur ed ? ­ ex t r a d i mensi ons coul d b e as l ar ge as 0 .1 mm, f or ex ampl e ­ ex per i ment al wor k i s und er way now t o l ook f or such l ar ge ex t r a d i mensi ons

Colloquium, Corvallis, OR, J. Brau, May 6, 2002

48


Lar ge Ex t r a Di mensi ons
· Par t i cl es and t he El ect r oweak and St r ong i nt er act i ons ar e conf i ned t o 3 space d i mensi ons Gr avi t y i s d i f f er ent :
­ Gr avi t ons pr opagat e i n t he f ul l ( 3 + n) d i mensi onal space

·

·

· ·

I f t her e wer e onl y one l ar ge ex t r a d i mensi on, i t s si z e R woul d have t o b e of or d er 10 10 k m t o account f or t he weak ness of gr avi t y. But t wo ex t r a d i mensi ons woul d b e on t he or d er of a mi l l i met er i n si z e. (see A s t he numb er of t he new d i mensi ons Sav i ncr eases, t hei r r equi r ed si z e get s smal l er .
­ For si x equal ex t r a d i mensi ons, t he si z e i s onl y ab out 10 - 12 cm

Large Extra Dimensions: A New Arena for Particle Physics, Nima Arkani-Hamed, as Dimopoulos, and Georgi Dvali, Physics Today, February, 2002)

Ex pl ai ni ng t he weak ness of gr avi t y
49

Colloquium, Corvallis, OR, J. Brau, May 6, 2002


Cosmi c connect i ons
· · · · · Bi g Bang T heor y GUT mot i vat ed i nf l at i on d ar k mat t er accel er at i ng uni ver se d ar k ener gy

Colloquium, Corvallis, OR, J. Brau, May 6, 2002

50


T he Lar ge H ad r on Col l i d er ( LH C)
· T he LH C at CERN , col l i di ng pr ot on b eams, wi l l b egi n oper at i on ar ound 2 0 0 7 · T hi s " had r on- col l i der " i s a d i scover y machi ne, as t he hi st or y of d i scover i es show
d i scover y char m t au b ot t om Z0 f aci l i t y of d i scover y BN L + S PEA R SPEA R Fer mi l ab SPPS f aci l i t y of st ud y SPEA R at SLA C SPEA R at SLA C Cor nel l LEP and SLC

· T he " el ect r on- col l i d er " ( t he N LC) wi l l l i k el y b e need ed t o sor t out t he LH C d i scover i es
Colloquium, Corvallis, OR, J. Brau, May 6, 2002
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A d di ng Val ue t o LH C measur ement s T he Li near Col l i d er wi l l ad d val ue t o t he LH C measur ement s ( " enab l i ng t echnol ogy" ) H ow t hi s happens d epend s on t he Physi cs:
· A d d pr eci si on t o t he d i scover i es of LH C · Susy par amet er s may f al l i n t he t an / M A wed ge. · Di r ect l y ob ser ved st r ong W W / Z Z r esonances at LH C ar e und er st ood f r om asymmet r i es at Li near Col l i d er · A nal yz e ex t r a neut r al gauge b osons · Gi ga- Z const r ai nt s
· eg. l i ght hi ggs measur ement s

Colloquium, Corvallis, OR, J. Brau, May 6, 2002

52


Compl ement ar i t y wi t h LH C
T he SM - l i k e H i ggs Boson T hese pr eci si on measur ement s wi l l b e cr uci al i n und er st and i ng t he H i ggs Boson

T ESLA T DR, T ab l e 2 .5 .1

Colloquium, Corvallis, OR, J. Brau, May 6, 2002

53


Concl usi on
T he Li near Col l i d er wi l l b e a power f ul t ool f or st ud yi ng t he H i ggs M echani sm and El ect r oweak Symmet r y Br eak i ng. T hi s physi cs f ol l ows a cent ur y of unr avel i ng t he t heor y of t he el ect r oweak i nt er act i on W e can ex pect t hese st ud i es t o f ur t her our k nowl ed ge of f und ament al physi cs i n unant i ci pat ed ways Cur r ent st at us of El ect r oweak Pr eci si on measur ement s st r ongl y suggest s t hat t he physi cs at t he LC wi l l b e r i ch

Colloquium, Corvallis, OR, J. Brau, May 6, 2002

54


Colloquium, Corvallis, OR, J. Brau, May 6, 2002

55


H i ggs St udi es - t he M ass M easur ement

5 0 0 f b - 1, LC Physi cs Resour ce Book , Fi g. 3 .17

( m=12 0 GeV @ 5 0 0 GeV ) M / M ~ 1.2 x 10 - 3 f r om r ecoi l al one ( d ecay mod e i nd ep.) , b ut r econst r uct i on of H i ggs d ecay pr od uct s and f i t d oes even b et t er ... ... Colloquium, Corvallis, OR, J. Brau, May 6, 2002
56


I s T hi s t he St and ar d M od el H i ggs?
F or MH = 140 GeV, 500 fb-1 @ 500 GeV Mas s Meas ur ement T otal width P ar ticle couplings tt bb cc
WW


M H 6 0 M eV 5 x 10 - 4 M / 3 %

H

WW ZZ gg
JJ

S pin-par ity-char ge conjugation S elf-coupling

(need s hi gher s f or 14 0 GeV, ex cept t hr ough H gg) gbb / gbb 2 % gcc / gcc 2 2 .5 % g / g 5 % gww/ gH ww 2 % g/ gH Z Z 6 % ggg / ggg 12 .5 % g / g 10 %
WW WW JJ JJ

est ab l i sh J

PC

=0

++

HH H / H HH 3 2 % ( st at i st i cs l i mi t ed )

Colloquium, Corvallis, OR, J. Brau, May 6, 2002

57


I s T hi s t he St and ar d M od el H i ggs?

Ar e consi ( onl MA

t he measur ed BRs st ent wi t h t he SM ? y f or smal l er val ues of wi l l t her e b e sensi t i vi t y - d ecoupl i ng)


M. Carena, H.E. Haber, H.E. Logan, and S. Mrenna, FERMILAB-Pub-00/334-T

I f M A i s l ar ge, d ecoupl i ng set s i n

Colloquium, Corvallis, OR, J. Brau, May 6, 2002

58