Particle Physics and the Higgs for High School Kids. (Quark ... - HEP
Particle Physics and the Higgs for High School Kids. (Quark ... - HEP
Particle Physics and the Higgs for High School Kids. (Quark ... - HEP
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What do <strong>Particle</strong><br />
Physicists do ?
Everything<br />
Molecules<br />
Atoms<br />
No Body<br />
Knows<br />
<strong>Quark</strong>s<br />
Protons<br />
? u
What’s in <strong>the</strong> Lunch Box ?
What’s in <strong>the</strong> Lunch Box ?<br />
Look inside.<br />
No Fun!
What’s in <strong>the</strong> Lunch Box ?<br />
SMASH THEM!!!<br />
Bang!
What’s in <strong>the</strong> Lunch Box ?<br />
Bang!
What’s in <strong>the</strong> Proton ?<br />
Protons are Too<br />
small to look inside.
What’s in <strong>the</strong> Proton ?<br />
Protons are Too<br />
small to look inside.<br />
SMASH THEM!!!<br />
Bang!
The Worlds Biggest Cannon<br />
CERN<br />
Switzerl<strong>and</strong>/France<br />
Philadelphia
The Worlds Biggest Cannon
The Worlds Biggest Cannon<br />
Philadelphia
The Worlds Biggest Cannon
Really Big Camera!!!
Really Big Camera!!!
Really Big Camera!!!
Really Big Camera!!!
Building Atlas Video
What do <strong>Particle</strong><br />
Physicists really do ?
Everything* that we know:<br />
<strong>Particle</strong>s + Interactions
The <strong>Particle</strong>s<br />
e - electron<br />
ν - neutrino<br />
u - up-quark<br />
d - down-quark<br />
γ / graviton / W / Z / gluon
The <strong>Particle</strong>s<br />
e - electron<br />
ν - neutrino<br />
u - up-quark<br />
d - down-quark<br />
Essentially all of everything that<br />
matters to you.<br />
- periodic table (chemistry/biology)<br />
- light<br />
- gravity.<br />
- electricity<br />
- mechanics<br />
γ / graviton / W / Z / gluon
The Interactions
A(w + w − → w + w − )=−<br />
[<br />
2 M H<br />
2 +<br />
v 2<br />
( M<br />
2<br />
H<br />
The <strong>Higgs</strong><br />
v<br />
) 2<br />
1<br />
s − M 2 H<br />
+<br />
( M<br />
2<br />
H<br />
v<br />
)<br />
after some manipulations, can be cast into <strong>the</strong> result of eq.(1<br />
W<br />
W +<br />
W<br />
W −<br />
•<br />
W<br />
W −<br />
W<br />
H<br />
• •<br />
W<br />
+ W<br />
W<br />
W<br />
ure 1.15: Some Feynman diagrams <strong>for</strong> <strong>the</strong> scattering of W bo<br />
se amplitudes will lead to cross sections σ(W + W − → W + W −<br />
could violate <strong>the</strong>ir unitarity bounds. To see this explicitly,
not allowed<br />
allowed<br />
not allowed
The <strong>Particle</strong>s<br />
e - electron<br />
ν - neutrino<br />
u - up-quark<br />
d - down-quark<br />
γ / graviton / W / Z / gluon / <strong>Higgs</strong>
The <strong>Particle</strong>s<br />
e - electron<br />
ν - neutrino<br />
u - up-quark<br />
d - down-quark<br />
µ - muon<br />
ν - neutrino<br />
c - charm-quark<br />
s - strange-quark<br />
τ - tauon<br />
ν - neutrino<br />
t - top-quark<br />
b - bottom-quark<br />
γ / graviton / W / Z / gluon / <strong>Higgs</strong>
10 5<br />
Z<br />
10 4 CESR<br />
Cross-section (pb)<br />
10 3<br />
10 2<br />
DORIS<br />
PEP<br />
W + W –<br />
10<br />
KEKB<br />
PEP-II<br />
PETRA<br />
TRISTAN<br />
SLC<br />
LEP1<br />
LEP2<br />
0 20 40 60 80 100 120 140 160 180 200 220<br />
Centre-of-mass energy (GeV)
Measurement Fit |O meas O fit |/ meas<br />
0 1 2 3<br />
(5) had<br />
(m Z<br />
) 0.02750 ! 0.00033 0.02759<br />
m Z "GeV# 91.1875 ! 0.0021 91.1874<br />
Z "GeV# 2.4952 ! 0.0023 2.4959<br />
0 had<br />
"nb# 41.540 ! 0.037 41.478<br />
R l<br />
20.767 ! 0.025 20.742<br />
A 0,l fb<br />
0.01714 ! 0.00095 0.01645<br />
A l (P ) 0.1465 ! 0.0032 0.1481<br />
R b<br />
0.21629 ! 0.00066 0.21579<br />
R c<br />
0.1721 ! 0.0030 0.1723<br />
A 0,b fb<br />
0.0992 ! 0.0016 0.1038<br />
A 0,c fb<br />
0.0707 ! 0.0035 0.0742<br />
A b<br />
0.923 ! 0.020 0.935<br />
A c<br />
0.670 ! 0.027 0.668<br />
A l (SLD) 0.1513 ! 0.0021 0.1481<br />
sin 2 lept eff<br />
(Q fb<br />
) 0.2324 ! 0.0012 0.2314<br />
m W "GeV# 80.385 ! 0.015 80.377<br />
W "GeV# 2.085 ! 0.042 2.092<br />
m t "GeV# 173.20 ! 0.90 173.26<br />
March 2012<br />
0 1 2 3
John Couch Adams<br />
Urbain Jean-Joseph<br />
Le Verrier<br />
Neptune<br />
Predicted 1845<br />
Observed 1846
Top-<strong>Quark</strong> Mass !GeV"<br />
CDF 172.5 # 1.0<br />
D 174.9 # 1.4<br />
Average 173.2 # 0.9<br />
2 /DoF: 6.1 / 10<br />
LEP1/SLD 172.6 $ 13.5 172.6 10.4<br />
LEP1/SLD/m W<br />
/ W<br />
179.7 $ 11.7 179.7 8.7<br />
160 170 180 190<br />
m t<br />
!GeV"<br />
March 2012
March 2012<br />
Z<br />
0<br />
had<br />
R 0<br />
l<br />
A 0,l<br />
fb<br />
A l (P )<br />
R 0<br />
b<br />
R 0<br />
c<br />
A 0,b<br />
fb<br />
A 0,c<br />
fb<br />
A b<br />
A c<br />
A l (SLD)<br />
sin 2 lept eff<br />
(Q fb<br />
)<br />
m W<br />
W<br />
Q W (Cs)<br />
sin 2 (e e MS<br />
)<br />
sin 2 W (N)<br />
g 2<br />
L<br />
(N)<br />
10<br />
g 2 R<br />
(N)<br />
10 2 10 3<br />
M H<br />
!GeV"
m W<br />
!GeV"<br />
80.5<br />
80.4<br />
March 2012<br />
LHC excluded<br />
LEP2 <strong>and</strong> Tevatron<br />
LEP1 <strong>and</strong> SLD<br />
68# CL<br />
80.3 m H<br />
!GeV" <br />
114 300 600 1000<br />
155 175 195<br />
m t<br />
!GeV"
6<br />
5<br />
4<br />
Theory uncertainty<br />
!# had<br />
=<br />
!# (5)<br />
0.02758±0.00035<br />
0.02749±0.00012<br />
incl. low Q 2 data<br />
!" 2<br />
3<br />
2<br />
1<br />
0<br />
Excluded<br />
30 100<br />
500<br />
m H<br />
[GeV]
6<br />
5<br />
4<br />
July 2011<br />
Theory uncertainty<br />
had<br />
=<br />
(5)<br />
0.02750#0.00033<br />
0.02749#0.00010<br />
incl. low Q 2 data<br />
m Limit<br />
= 161 GeV<br />
2<br />
3<br />
2<br />
1<br />
Excluded<br />
0<br />
30 100<br />
300<br />
m H<br />
!GeV"
6<br />
5<br />
4<br />
March 2012<br />
Theory uncertainty<br />
had<br />
=<br />
(5)<br />
0.02750#0.00033<br />
0.02749#0.00010<br />
incl. low Q 2 data<br />
m Limit<br />
= 152 GeV<br />
2<br />
3<br />
2<br />
1<br />
0<br />
LEP<br />
excluded<br />
40 100 200<br />
m H<br />
!GeV"<br />
LHC<br />
excluded
95% CL Limit on σ/σ SM<br />
10<br />
1<br />
ATLAS Private<br />
Obs.<br />
Exp.<br />
±1 σ<br />
±2 σ<br />
∫<br />
-1<br />
Ldt = 4.6-4.9 fb<br />
s<br />
= 7 TeV<br />
2011 Data<br />
-1<br />
10<br />
CLs Limits<br />
100 200 300 400 500 600<br />
m H<br />
[GeV]
95% CL Limit on σ/σ SM<br />
10 Obs.<br />
Exp.<br />
∫<br />
-1<br />
Ldt = 4.6-4.9 fb<br />
±1 σ<br />
± 2 σ<br />
s = 7 TeV<br />
1<br />
ATLAS Private<br />
2011 Data<br />
-1<br />
10<br />
CLs Limits<br />
110 115 120 125 130 135 140 145 150<br />
m H<br />
[GeV]
Local p<br />
0<br />
1<br />
-1<br />
10<br />
Obs. Asym w/o ESS<br />
Exp. Asym w/o ESS<br />
Obs. Toy w/ ESS<br />
1σ<br />
2σ<br />
-2<br />
10<br />
-3<br />
10<br />
ATLAS Private<br />
∫<br />
Ldt = 4.6-4.9 fb<br />
s=7TeV<br />
-1<br />
3σ<br />
105 110 115 120 125 130 135 140 145 150 155<br />
m H<br />
[GeV]<br />
(c)
Significance, !<br />
10<br />
9<br />
8<br />
7<br />
6<br />
5<br />
4<br />
3<br />
2<br />
1<br />
-1<br />
10fb<br />
-1<br />
10fb<br />
-1<br />
5fb<br />
s=7 TeV<br />
s=8 TeV<br />
s=7 TeV<br />
s=8 TeV<br />
0<br />
100 120 150 200 300 400 500<br />
5fb -1<br />
ATLAS Preliminary (Simulation)<br />
m H [GeV]
Significance, !<br />
10<br />
9<br />
8<br />
7<br />
6<br />
5<br />
4<br />
3<br />
2<br />
1<br />
Last Year<br />
-1<br />
10fb<br />
-1<br />
10fb<br />
-1<br />
5fb<br />
s=7 TeV<br />
s=8 TeV<br />
s=7 TeV<br />
s=8 TeV<br />
0<br />
100 120 150 200 300 400 500<br />
5fb -1<br />
ATLAS Preliminary (Simulation)<br />
m H [GeV]
Significance, !<br />
10<br />
9<br />
8<br />
7<br />
6<br />
5<br />
4<br />
3<br />
2<br />
1<br />
Now<br />
Last Year<br />
-1<br />
10fb<br />
-1<br />
10fb<br />
-1<br />
5fb<br />
s=7 TeV<br />
s=8 TeV<br />
s=7 TeV<br />
s=8 TeV<br />
0<br />
100 120 150 200 300 400 500<br />
5fb -1<br />
ATLAS Preliminary (Simulation)<br />
m H [GeV]
4th of July