The Known Knowns and the
Known Unknowns
20 Years of Tevatron Collider
Physics
The Tevatron c. 2006
p
p
CDF
D0
 1968 – Fermilab opens
 1972 – Main Ring starts @
400 GeV
 1977 – CDF Department
established
Booster
1982 – Tevatron begins
operation @ 800 GeV
1985 – First Collisions at
CDF
p source
p p Tevatron
Main Injector
Two Hulking Detectors
D0
CDF
The World in 1985
• 3 Generations of quarks and leptons
u
d
c
s
t
ne
e-
nm
m
nt
t
b
Discovered at FNAL in 1977
• Electroweak
Electromagnetic,
& Strong
WeakForces
& Strong Forces
 ,W , Z , g

0
W, Z get their masses via the Higgs mechanism
3 Generations Are Needed
3x3 unitary matrix can be
expressed with 4 parameters – 3
mixing angles + 1 complex phase
Complex phase  CP Violation
Particles &
Antiparticles with
different decay rates
= CP violation
 d c   Vud
  d s ds
 sc    Vcd
 b  V
 c   td
Vus
Vcs
Vts
In the SM all CP effects are related
Vubby this
d single phase.
  for30 years, CP was only
VcbBut
s


observed in K  K
Vtb   b 
0
0
(1964 – Fitch & Cronin 1980
Nobel)
1983
• W±, Z0 discovered at CERN collider
– MW~81±5 GeV/c2
– MZ=95.2±2.5 GeV/c2 (UA1)
–
=91.9±1.9 GeV/c2 (UA2)
Everything is Connected
“When one tugs at a single thing in nature, he finds it
attached to the rest of the world” – John Muir
PBSM??
Z boson
MW
Top Quark
MH
BBS Mixing
Mixing
CKM
CP
S  mm
CDF December 1984
September 1985
The CDF detector (not) ready to take data:
First Collisions: October 13, 1985
Data Taking
p
p
Protons & antiprotons
collide at ~2.5 MHz
0.25Hz of W/Z
production
~100 Hz of
high ET jets
~100 Hz of
b-quark
production
.0002 Hz of top
quark
production
?? Hz of
new physics
20%
“Acceptance”
Prescale/20
10%
“Acceptance”
1%
“Acceptance”
10%
“Acceptance”
??
“Acceptance”
~20% Analysis
Mode
85% to
analysis
~1% Analysis
Mode
~40% Analysis
Mode
?? Analysis
Mode
~10-2 Hz for
analysis
~0.4 Hz for
analysis
~10-2 Hz for
analysis
~10-5 Hz for
analysis
First Precise Measurements of the Z (1989)
Z0
e
Z0
m
m
e
Phys. Rev. Lett. 63 (1989)
Z0
q
q
CDF
Mark II at SLC
M Z  90.9  0.36 GeV/c2
MZ
M Z  91.11  0.23GeV/c2
Now: M Z  91.1876  0.0021 GeV c2
MW
W
e
ne
m
nm
W
W Mass
1990: CDF used 1130 W→en &
592 W→mn to measure:
MW  79.91  0.39 GeV c2
1995: 5718 W→en ; 3268 W→mn
MW  80.410  0.180 GeV c2
MZ
MW
W Mass
MW=80.433±0.079 GeV/c2
MW=80.482±0.091 GeV/c2
14740 events
11089 events
2006: MW=XX.XXX±0.049 GeV/c2 (.06%!!!)
MZ
MW
Based on >116,000 W decays!
MZ
MW
sin2 W  1  MW2 M Z2
Z
0
e

e

*
e

e
These two processes interfere to produce a “forwardbackward” asymmetry that depends on sin2W
1989: B0 Mixing
V*tb=1
B0
b
•
W–
•
•
Vtd
d
B0
u,c,t
u,c,t
d
Vtd
W+
•
b
V*tb=1
First observation in at UA1 meant
the top quark was heavy
m X
B
B hadron
b
MTOP
B
Mixing
b
B0
0
m X
m X
Indirect Measurements of Mtop
t
Z0
Z0
t
MZ
MTOP
The Top Quark
• In 1990 CDF published a limit
– Mtop> 77 GeV/c2
This put UA1/UA2 out of business in the search
for top
• By 1992 the top non-discovery meant
– Mtop>91 GeV/c2
– I.e. Mtop>MW+Mb
What We Found: 1994
• 10 events in the
lepton+jets channel
(5 e, 5 m)
• 2 events in the dilepton channel (both
em)
• About 6 events
expected from
backgrounds
Not your typical event
The First Direct Measurement of Mtop
Discovery
Top Mass GeV/c2
MZ
Mtop  174 16 GeV c
2
MTOP
By 1995
Back-to-back papers in Phys. Rev. Lett. 74 (1995)
• CDF:
– 37 events in
lepton+jets
– 6 events in dileptons
• D0
– 14 events in lepton+jets
– 3 events in dileptons
MZ
MTOP
Mtop  176 13 GeV c2
2006
MZ
MW
MTOP
Mtop= 171.4 ± 2.1 GeV/c2
MH
Mtop, MW & MHiggs
t
W
W
2
M top
b
W
H
Soon
W
ln M H
MW
MTOP
MH
Higgs
W Polarization in Top Decay
b
t
SM says V-A
FLongitudinal 
W+
2
M top
2M  M
2
W
2
top
FLeft  1  FLongitudinal
Single Top
q
t
W*
q
b
Vtb here
A very tough measurement
Top
Quark
CKM
B Physics
b
CKM 1989
 Vud

 Vcd
V
 td
Vus Vub 

Vcs Vcb  
Vts Vtb 
0.001  0.007 
 0.9747  0.9759 0.218  0.224


0.218

0.224
0.9734

0.9752
0.030

0.058


 0.003  0.019

0.029

0.058
0.9983

0.9996


Assuming 3 generation unitarity
CP Violation in B mesons
Unitarity of CKM matrix  (among
VubVud*
other things)

VudVub*

B
0

B 0
d
t
W
b
W
d
VtdVtb*
VcdVcb*
c J /
W
t
A triangle in the
complex plane
(provided the CKM
phase is non-zero)

W
b
 VcbVcd*  VtbVtd*  0
c
s K
s
d
c J /
c
s Ks
N  B 0  J  K S   N  B0  J  K S 
All
d
sin 2
CKM
B Mixing
CP
First Hint ≠0 (1999)
sin 2  0.790.41
0.44
Now, from b factories:
sin 2  0.687  0.032
Unfortunately, the SM is quite happy with this.
CKM
B Mixing
CP
BS Oscillations
V*tb=1
Bs
b
•
W–
•
•
Vts
W+
•
b
V*tb=1
Mixing Frequency is  |Vts|2
CKM
BS Mixing
s
u,c,t
u,c,t
s
Vts
Bs
Matter-Antimatter Oscillations
2.8THz
CKM
BS Mixing
ms = 17.33 +0.42 (stat) ± 0.07 (syst) ps-1
CKM 2006
 Vud

 Vcd
V
 td
Vus Vub 

Vcs Vcb  
Vts Vtb 
 0.97377  0.00027

 0.230  0.011
  7.4  0.8 103

0.2257  0.0021
0.957  0.095
 40.6  2.7  103
 4.31  0.30  10 3 
3 
41.6

0.6

10



0.9982  0.0002 
Still assumes 3 generation
unitarity.
BS Mixing measurement
CKM
BS Mixing
Rare Decays
V*tb=1
Bs
b
t
s
Vts
•
•
W+
W-
•
•
m
n
m
BR  Bs  m  m   ~ 109
PBSM?
CKM
S  mm
Corrections from BSM physics can
enhance this significantly and g-2 of
the muon as well.
CDF+D0 limit BR<1.5x10-7
Supersymmetry
Add this complication.
Get this simplification.
PBSM??
PBSM??
Interesting Events Happen
1995:
Missing Energy (GeV)
PBSM??
That’s interesting…
The EggMet Event
Two high-energy electrons
Two high-energy photons
e
Large missing energy
e
e
e

 10
e
G

G
G
 10
Nothing more through 2006…
PBSM??

Everything is Connected
“When one tugs at a single thing in nature, he finds it
attached to the rest of the world” – John Muir
PBSM??
Z boson
MW
Top Quark
MH
BBS Mixing
Mixing
CKM
CP
S  mm
You’re going to be told lots of things.
You get told things every day that don’t happen.
It doesn’t seem to bother people, they don’t –
It’s printed in the press.
The world thinks all these things happen.
They never happened.
Everyone’s so eager to get the story
Before in fact the story’s there
That the world is constantly being fed
Things that haven’t happened.
All I can tell you is,
It hasn’t happened.
It’s going to happen.