a Higgs Story

(1)

a Higgstory

— Special Colloquium on the 2013 Nobel Prize in Physics

October 22, 2013, Joint Colloquium @ NTU

(2)

Nobel 2013 – a Higgstory George W.S. Hou (NTU) NTU Colloquium, 10/22, ’13 2

a Higgs Story

Origin

of

Mass

recent discovery of predicted fundamental particle

(3)

(4)

ATLAS, CMS, and 3 First SPs Receive EPS Prize

(5)

a Higgs Story

(6)

a Higgs Story

Hitoshi Murayama

(7)

Experimental Summary, Dimitri Denisov (FNAL)

Theoretical Summary

, Michelangelo Mangano (CERN)

New results indicate that new particle is a Higgs boson

http://home.web.cern.ch/about/updates/2013/03/new-results-indicate-new-particle-higgs-boson

posted March 14, 2013

Smells to me of a time threshold for Nobel …

a Higgs Story

March

(8)

a Higgstory

— Special Colloquium on the 2013 Nobel Prize in Physics

– a Higgs Story

– a History of Higgs, ^{or BEH} , Mechanism

Prehistory 1 Prehistory 2

Making History: Nambu; Anderson; BE H (GHK) History Made ― Standard Model

– the Hunt towards gg-fusion Search/Discovery

P/F CMP ^bridge

Epilogue ― the Squalid-Higgs, etc.

50 yrs !

BCS

(9)

a History of Higgs ^, ^{or BEH} ^, Mechanism

(10)

Prehistory 1: 1896 – 1911

J.J. Thomson

Henri Becqurel

Ernest Rutherford

a, b, g

electron

radioactivity

Weak Interaction

Our Common Heritage

H. Kamerlingh Onnes

superconductivity

(11)

Prehistory 2: 1950 – 1957

Triumph of Squalid ^*

State Physics !

* quip due to Gell-Mann

N.B. BCS theory can be put in simpler form as Ginzburg-Landau theory w/ “order parameter”

φ ~ Cooper pair

P/F & CMP

have

parted ways

(12)

Making History

"for the discovery of the mechanism of spontaneous broken symmetry in

subatomic physics"

"for the discovery of the origin of the broken symmetry which predicts the existence of at least three families of quarks in nature"

Photo: Universtity of Chicago Photo: KEK Photo: Kyoto University

Yoichiro Nambu Makoto Kobayashi Toshihide Maskawa 1/2 of the prize 1/4 of the prize 1/4 of the prize

USA Japan Japan

Enrico Fermi Institute, University of Chicago Chicago, IL, USA

High Energy Accelerator Research Organization (KEK)

Tsukuba, Japan

Kyoto Sangyo University;

Yukawa Institute for Theoretical Physics (YITP), Kyoto University

Kyoto, Japan

b. 1921

(in Tokyo, Japan) b. 1944 b. 1940

CP Violation in SM

7 October 2008

B Factories

(BaBar & Belle)

The Nobel Prize in Physics 2008

SSB

CMP

^bridge

P/F

Nambu

(13)

Sc.D., 1952

(age:31)

from Nambu’s Nobel Lecture slides

(14)

...

BCS, Spontaneous Symmetry Breaking, and Gauge Inv.

Schrieffer joined Chicago faculty

for a year

it took him two years

“zero modes”

(15)

Nambu-Goldstone Boson and Higgs Mechanism

Nambu (1960);

NJL (1961)

Goldstone (1961);

Goldstone, Salam &

Weinberg (1962) Anderson (1958; 1963)

Englert & Brout (1964) Higgs (1964; 1966)

[Guralnik, Hagen, Kibble (1964)

NR

Ginzburg & Landau (1950)

Wolf Prize 2004

Nambu uses the term Ginzburg-Landau-Higgs

“ effective” field

Meissner

Effect

(16)

Nambu’s comment on Higgs Mechanism

But Brout and Englert

(curiously not Higgs)

, give clear reference that their

interest started with Nambu 1960 !

hand-drawn by Higgs to illustrate Nambu’s model

For BCS, f ~ y

_e

y

_e

<f> ≠ 0, or condensate, is SSB

N.B. Nambu pierced thru the clouds and saw how proton mass arose.

(17)

What is Meissner Effect ?

Magnetic Field damped

Photon acquires “Mass”

Higgs Mechanism !

~

Absence of B in SC Attentuation, or penetration depth

(18)

Robert Brout: In Memoriam

1928 - 2011

Born American, on Cornell faculty since 1953 with field in statistical physics and phase transitions. Englert was his postdoc at Cornell, 1959-1961, but when Englert returned to Brussels in 1961, Brout resigned from Cornell and moved to Brussels, becoming Belgian citizen eventually. [the 9/2008 LHC accident/delay really costed him]

Higgs and Brout knew each other. According to Higgs, Brout recalls that in 1960 at a Cornell seminar Victor Weisskopf remarked that “Particle physicists are so desperate these days that they have to borrow from the new things coming up in many-body theory like BCS. Perhaps something will come of it.”

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Terror of the Goldstone Theorem (1962)

In reading Nambu’s 1960 papers, Jeffrey Goldstone published a paper on field theories with superconductor solutions. He introduced elementary scalar fields and the Mexican hat (Higgs prefers calling it “

wine bottle”; me too !)

potential

:

V( φ ) ~ - m

²

| φ |

²

+ l | φ |

⁴

One can easily visualize spontaneous symmetry breaking, because the lowest-energy state (note minus sign) of the system is down in the trough of the wine bottle, not at the symmetry point. The minimum is at

:

| φ |

²

= υ

²

~ m

²

/l

Shifting fields, one can do the math, which we refrain from.

Goldstone Theorem: In Lorentz invariant theory, SSB necessitates massless particles w.r.t. the broken symmetries.

Goldstone, Salam and Weinberg (1962) Problem: No such massless states observed !

comment by Higgs

(20)

Anderson (1963), and an influential work of Schwinger

Conjecture

from NR

(21)

Digression on Yang-Mills: Non-Abelian Gauge Theory

Abelian g.i., i.e. U(1) Non-Abelian g.i., e.g. SU(2)

covariant derivative Problem: No massless “isotopic photon” observed !

Pauli & Yang

Anderson Conjecture: “Cancel” YM against Goldstone ?

(22)

Spat of Ben Lee and Walter Gilbert [Chemistry Nobel 1980]

Assoc.

Prof. of Biophys.

Prof. of Biochem.

1968

(23)

gauge invariant self-energy:

0

Making History Brout & Englert

Schwinger

scalar electrodynamics,

g.i. vector mass

Goldstone

(24)

Making History ^Higgs

1.1 page, refute Gilbert: “gauge fixing”

(e.g. Coulomb gauge)

gives “special frame”

[no cite of Nambu, nor Anderson/Schwinger]

…

sent 7/24 Fri

(PL office @ CERN)

sent 7/31 Fri

< 1.5 page

(25)

So, What did Higgs Present ?

Scalar electrodynamics (gauging Goldstone’s complex scalar field), same as Englert & Brout, except , so is the Goldstone.

Making small oscillations , around the minimum and absorbing by a gauge transform, one gets

with

which is equation for massive vector field. For remaining scalar, he finds

with mass squared . Only Higgs

gave this, hence the name “Higgs boson”.

brought to Higgs’s attention by referee: Nambu;

but paper still did not cite Nambu.

Both Englert & Brout (with Thiry), and Higgs published further work in 1966 …

(26)

“Footnotes” to History

originally written early 1964 neither yet turned 19!

(27)

SU(2)xU(1) U ^SSB _Q (1)

Weinberg (1967) Salam (1968)

Breakthru ^: SB NAGT renormalizable

’t Hooft (1971); ’t Hooft & Veltman (1972) Glashow (1961)

D ^eeply I ^nelastic S cattering expt

Friedman, Kendall, Taylor (1969) Bjorken scaling, Feynman Parton

Asymptotic Freedom ...

Gross & Wilczek (1973), Politzer (1973)

[Fritzsch & Gell-Mann (1972)]

SU _C (3)

SU _C (3) x SU(2) x U(1) History Made Standard Model

1979: Electroweak Theory

1984: W, Z boson

1990: D.I.S. (quark-parton)

1999: Electroweak Renorm.

2004: Asymptotic Freedom

2008: SSB & Broken CP

2013: Higgs Mech./Particle dynamics

^*

Englert & Higgs

* Leave out matter fields

(28)

b Decay, Weak Interaction, W & Z Weak Bosons

Rutherford

Fermi

p

e e

Deeply Inelastic Scattering

M

_W

≃ 80.4 GeV/c

²

M _Z ≃ 91.2 GeV/c

²

M

_g

≃ 0

SU(2)xU(1) U ^SSB

_Q (1)

BEH

(29)

the Hunt towards gg-fusion Search/Discovery

(30)

Ellis, Gaillard and Nanopoulos (1976):

“We should perhaps finish with an apology and a caution. We apologize to experimentalists for not having any idea what is the mass of the Higgs boson, unlike the case with charm, and for not being sure of its couplings to other particles, except that they are probably all very small. For these reasons, we do not want to encourage big experimental searches for the Higgs boson, but we do feel that people performing experiments vulnerable to the Higgs boson should know how it may turn up.”

the Hunt Starts (Standard Model “complete”)

1983: W, Z bosons discovered at CERN ➽ 1984 Nobel to Rubbia & van der Meer

SSC approved

Dawson, Gunion, Haber and Kane(1990), the Higgs-Hunters Guide:

“The success of the Standard Model has been astonishing.

The central problem in particle physics today is to understand the Higgs sector.”

The God Particle: If the Universe Is the Answer, What Is the Question?

Lederman (1993)

SSC canceled later 1993 … LHC approved 1994

(31)

The “God” Particle: the Origin of Mass

(32)

The “God” Particle: the Origin of Mass

unbroken

~ 80 – 90 GeV !

massless

m _F ~ l _F υ

m _V ~ g υ

l _F : Yukawa Coupling

gauge coupling

g

Enigma

(33)

sightings just before landfall

“Blueband” plot

(electroweak precision data )

Tevatron swan song

(Higgs direct search )

(34)

TIME

&

Science

Triumphal at CERN, July 4th, 2012

[5 former CERN DGs]

Holy Grail !!

(35)

C M S

oroidal

A T L A S

HC

pparatu S

Big ^Science

M ûon S ôlenoid C ômpact

NTU & NCU

(36)

Candidate Events Leading Processes

H → gg

H → ZZ* → eemm

Production & Decay: Complex Processes

(37)

Against Horrendous Background

(38)

Making Particular History

rejected Higgs 

(39)

Bumps in the Night

(40)

Epilogue

(41)

a Field that permeates the Universe

… since the Beginning of Time … ?

(42)

damn

• Elusive … till July 4th, 2012 — 48 yrs stretch

God, or Goddamn, Particle ?

• First “elementary” scalar, ever !

NOT provided in QED, nor QCD.

• Fermion Mass Generation seem fortuitous:

• Opens a “Can of Worms”:

– Hierarchy Problem

– Vacuum Stability … etc.

m _f ~ l _f υ

(43)

the Squalid State Higgs, 1980

(44)

a Higgs Story

a Higgstory

— Special Colloquium on the 2013 Nobel Prize in Physics

October 22, 2013, Joint Colloquium @ NTU

a Higgs Story

ATLAS, CMS, and 3 First SPs Receive EPS Prize

a Higgs Story

a Higgs Story

Theoretical Summary

New results indicate that new particle is a Higgs boson

posted March 14, 2013

Smells to me of a time threshold for Nobel …

a Higgs Story

March

a Higgstory

— Special Colloquium on the 2013 Nobel Prize in Physics

– a Higgs Story

– a History of Higgs, or BEH , Mechanism

Prehistory 1 Prehistory 2

Making History: Nambu; Anderson; BE H (GHK) History Made ― Standard Model

– the Hunt towards gg-fusion Search/Discovery

P/F CMP bridge

Epilogue ― the Squalid-Higgs, etc.

50 yrs !

BCS

a History of Higgs , or BEH , Mechanism

Prehistory 1: 1896 – 1911

J.J. Thomson

Henri Becqurel

Ernest Rutherford

a, b, g

Weak Interaction

Our Common Heritage

Prehistory 2: 1950 – 1957

Triumph of Squalid *

State Physics !

N.B. BCS theory can be put in simpler form as Ginzburg-Landau theory w/ “order parameter”

φ ~ Cooper pair

P/F & CMP

have

parted ways

Making History

CP Violation in SM

B Factories

(BaBar & Belle)

The Nobel Prize in Physics 2008

SSB

CMP

P/F

Nambu

Sc.D., 1952

(age:31)

from Nambu’s Nobel Lecture slides

...

BCS, Spontaneous Symmetry Breaking, and Gauge Inv.

Schrieffer joined Chicago faculty

for a year

Nambu-Goldstone Boson and Higgs Mechanism

Nambu (1960);

Goldstone (1961);

Goldstone, Salam &

Weinberg (1962) Anderson (1958; 1963)

Englert & Brout (1964) Higgs (1964; 1966)

[Guralnik, Hagen, Kibble (1964)

NR

Ginzburg & Landau (1950)

Wolf Prize 2004

Nambu uses the term Ginzburg-Landau-Higgs

“ effective” field

Meissner

Effect

Nambu’s comment on Higgs Mechanism

But Brout and Englert

, give clear reference that their

interest started with Nambu 1960 !

hand-drawn by Higgs to illustrate Nambu’s model

For BCS, f ~ y

y

<f> ≠ 0, or condensate, is SSB

What is Meissner Effect ?

– a History of Higgs, ^{or BEH} , Mechanism

P/F CMP ^bridge

a History of Higgs ^, ^{or BEH} ^, Mechanism

Triumph of Squalid ^*

Making History ^Higgs

SU(2)xU(1) U ^SSB _Q (1)

Breakthru ^: SB NAGT renormalizable

D ^eeply I ^nelastic S cattering expt

SU _C (3)

SU _C (3) x SU(2) x U(1) History Made Standard Model