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Understanding the Matter-AntimatterAsymmetry of the Universe
Search for the Origin of Mass - the God Particle
Romulus GodangThe University of Mississippi
January 30, 2007Oxford, Mississippi
January 30, 2007
Oxford, Mississippi
Understanding the Matter-Antimatter Asymmetry of the Universe (page 1)
Search for the Origin of Mass - the God Particle
Romulus Godang
The University of Mississippi
Fundamental Particle
� What is the world made of ?
• In ancient times, people sought to organize the world
into fundamental elements: earth, air, fire, and water.
. Who first classified these fundamental elements ?
↪→ Greek thinker Empedocles (500 BC)
• Are they really the fundamental elements ?
January 30, 2007
Oxford, Mississippi
Understanding the Matter-Antimatter Asymmetry of the Universe (page 2)
Search for the Origin of Mass - the God Particle
Romulus Godang
The University of Mississippi
Fundamental Particle ...
� The ancient Chinese believed 5 basic elements:
• Wood
• Metal
• Earth
• Fire
• Water
� The ancient India proclaimed 5 basic elements:
• Space
• Air
• Fire
• Water
• Earth
January 30, 2007
Oxford, Mississippi
Understanding the Matter-Antimatter Asymmetry of the Universe (page 3)
Search for the Origin of Mass - the God Particle
Romulus Godang
The University of Mississippi
Is the Atom or Nucleus Fundamental ?
� Fundamental building blocks mean objects that are simple and structureless
� Scientists originally thought the nucleus was fundamental BUT
later they discovered that nucleus was made of protons and neutrons
January 30, 2007
Oxford, Mississippi
Understanding the Matter-Antimatter Asymmetry of the Universe (page 4)
Search for the Origin of Mass - the God Particle
Romulus Godang
The University of Mississippi
The Birth of the Universe
� After the Big bang exploded with enormous energy, the universe beganto cool-down that has lasted until our own time
� BUT we don’t know what made the Big Bang happen in the first place
January 30, 2007
Oxford, Mississippi
Understanding the Matter-Antimatter Asymmetry of the Universe (page 5)
Search for the Origin of Mass - the God Particle
Romulus Godang
The University of Mississippi
The Standard Model Theory
� All the known matter particles are composites of 6 quarks and 6 leptons
and they interact by exchanging force carrier particles:
↪→ Electromagnetic (γ), Weak (Z0, W±), and Strong (gluons)
↪→ Gravity (not yet in the model...)
January 30, 2007
Oxford, Mississippi
Understanding the Matter-Antimatter Asymmetry of the Universe (page 6)
Search for the Origin of Mass - the God Particle
Romulus Godang
The University of Mississippi
The Standard Model Theory...
� Hadrons are composite particles made of quarks:
• Baryons are any hadron which is made of three quarks (qqq)
↪→ proton (uud) and antiproton (uud)
• Mesons contain one quark (q) and one antiquark (q)
↪→ B0 (db) and B0 (db)
January 30, 2007
Oxford, Mississippi
Understanding the Matter-Antimatter Asymmetry of the Universe (page 7)
Search for the Origin of Mass - the God Particle
Romulus Godang
The University of Mississippi
Looking for New Particles
� All new particles are named with Greek letters
� We have discovered about 200 particles
� Enrico Fermi (Nobel 1938) said to his student
Leon Lederman (Nobel 1988): ”Young man, if
I could remember the names of these particles,
I would have been a botanist!”
� All measurements are combined and listed in one book by
Particle Data Group (PDG) at Berkeley University.
� PDG is an international collaboration charged with summarizing Particle Physics
and related areas of Cosmology and Astrophysics since 1957.
� 2006 PDG published 1200-page book, all years it has been cited in 24,000 times
� U. Miss has significantly contributed to and member of PDG (R. Godang)
January 30, 2007
Oxford, Mississippi
Understanding the Matter-Antimatter Asymmetry of the Universe (page 8)
Search for the Origin of Mass - the God Particle
Romulus Godang
The University of Mississippi
What Do We Know about Matter and Antimatter ?
� Antimatter is a mirror image of matter
• Particle and antiparticle have identical mass and spin BUT opposite charges
Neutral bosons (e.g. Z0, γ) have their own antiparticles
� The antimatter introduced by Paul Dirac (Nobel Prize 1933) in 1928
Dirac’s equation ↪→ electron with ± energy
1932 Carl Anderson discovered the positron in a cloud chamber
Frederic and Irene Curie found positrons emission
� The Big Bang produced matter and antimatter in equal numbers
� Our universe is the absence of antimatter (we live in a universe of matter)
� What happened to the antimatter...?
January 30, 2007
Oxford, Mississippi
Understanding the Matter-Antimatter Asymmetry of the Universe (page 9)
Search for the Origin of Mass - the God Particle
Romulus Godang
The University of Mississippi
What Happened to the Antimatter ?
� How do we know there is no antimatter around ?
• When a matter and antimatter meet, they annihilate into pure energy,
leaving only photons and neutrinos
• The fact: we don’t see this kind of energy in our daily life
� Can we see the evidence of antimatter ?
� The magnetic field makes negative particles curl left, positive particles curl right
January 30, 2007
Oxford, Mississippi
Understanding the Matter-Antimatter Asymmetry of the Universe (page 10)
Search for the Origin of Mass - the God Particle
Romulus Godang
The University of Mississippi
Why the Universe is Made Exclusively of Matter ?
� Andrei Sakharov (1967):
• Baryon violating interactions
• Thermal non-equilibrium situation
• CP violation
� Testing the Sakharov’s criteria:
• There is no direct evidence that baryon number is violated
• There is a prediction of proton decay: p→ e+ + π0
but the predicted proton lifetime is ∼ 1030 year (not observed)
• In thermal equilibrium the particle density depends only on
the particle mass and temperature.
They are identical in CPT theorem ↪→ NO asymmetry
January 30, 2007
Oxford, Mississippi
Understanding the Matter-Antimatter Asymmetry of the Universe (page 11)
Search for the Origin of Mass - the God Particle
Romulus Godang
The University of Mississippi
CP Violation in Weak Interaction
� C (Charge Conjugation Invariance)
• Charge conjugation invariance is broken in weak interaction
• Right-handed neutrinos (left-handed antineutrinos) are not seen
� P (Parity) = the flip in the sign of all spatial coordinates
• Parity is broken in weak interaction
• There is no left-handed antiparticles
� CP: Charge Conjugation with Parity Invariance
• CP is conserved in weak interaction (left-handed neutrino) but...
Christension, Cronin, Fitch and Turlay have discovered CP violation
in Kaon system (1964) ↪→ confirmed by KTEV (Fermilab) and NA48 (CERN)
January 30, 2007
Oxford, Mississippi
Understanding the Matter-Antimatter Asymmetry of the Universe (page 12)
Search for the Origin of Mass - the God Particle
Romulus Godang
The University of Mississippi
The B Meson Factories
� BABAR at Stanford Linear Accelerator Center
� Another B-factory machine is at KEKB (Tsukuba) in Japan
January 30, 2007
Oxford, Mississippi
Understanding the Matter-Antimatter Asymmetry of the Universe (page 13)
Search for the Origin of Mass - the God Particle
Romulus Godang
The University of Mississippi
CP Violation in B Meson
� BABAR and Belle directly measured CP violation in B system
BABAR : e+ (3.1 GeV) - e− (9 GeV) Belle : e+ (3.5 GeV) - e− (8 GeV)
In 1999 BABAR and Belle had first colliding beam
In 2001 BABAR and Belle reported the first measurement of direct
CP violation in B meson ↪→ fundamental matter-antimatter asymmetry
January 30, 2007
Oxford, Mississippi
Understanding the Matter-Antimatter Asymmetry of the Universe (page 14)
Search for the Origin of Mass - the God Particle
Romulus Godang
The University of Mississippi
The BABAR Collaboration
U. Mississippi group: L. Cremaldi, V. Eschenburg, R. Godang, R. Kroeger
J. Reidy, D. Sanders, D. Summers, and H. Zhao
January 30, 2007
Oxford, Mississippi
Understanding the Matter-Antimatter Asymmetry of the Universe (page 15)
Search for the Origin of Mass - the God Particle
Romulus Godang
The University of Mississippi
Physics at B Factories
d
d
b
−e
+e
b
B0
B0
γ∗ϒ(4S)
9.44 9.46
Mass (GeV/c2)
0
5
10
15
20
25
σ (e
+e- →
Had
rons
)(nb
) ϒ(1S)
10.00 10.020
5
10
15
20
25
ϒ(2S)
10.34 10.370
5
10
15
20
25
ϒ(3S)
10.54 10.58 10.620
5
10
15
20
25
ϒ(4S)
� All B physics based on Υ (4S) decays including CP violation measurement
� U. Miss published B(Υ (4S)→ B0B0) in PRL 95, 042001, 2005 (R. Godang)
B(Υ (4S)→ B0B0) ≡ f00 = 0.487± 0.010stat ± 0.008syst
-8 -6 -4 -2 0 2 M2ν (GeV2/c4)
0
20000
40000
60000
80000
100000
120000
Can
dida
tes/
(0.1
7 G
eV2 /c
4 )
data, single tags
B- 0 signal
BB- peaking
BB- combinatoric
-8 -6 -4 -2 0 20
100
200
300
400
500
600
M22ν (GeV2/c4)
Can
dida
tes/
(0.1
7 G
eV2 /c
4 )
data, double tags
B- 0 signal
BB- peaking
BB- combinatoric
January 30, 2007
Oxford, Mississippi
Understanding the Matter-Antimatter Asymmetry of the Universe (page 16)
Search for the Origin of Mass - the God Particle
Romulus Godang
The University of Mississippi
The CKM Matrix
� In SM, quark can change flavor by weak interactions:
d′
s′
b′
=
Vud Vus VubVcd Vcs VcbVtd Vts Vtb
dsb
Cabibbo-Kobayashi-Maskawa (CKM) matrix
[Weak eigenstates] = [VCKM ] [quark mass eigenstates]
The CKM matrix contains real and imaginary numbers (complex numbers)
• Wolfenstein’s CKM matrix form:
VCKM =
1− 12λ2 λ Aλ3(ρ− iη)
−λ 1− 12λ2 Aλ2
Aλ3(1− ρ− iη) −Aλ2 1
• Four independent parameters: A, ρ, η, and λ ∼ 0.22 (expansion parameter)
• A, ρ, η are real numbers and can be measured in B decays
January 30, 2007
Oxford, Mississippi
Understanding the Matter-Antimatter Asymmetry of the Universe (page 17)
Search for the Origin of Mass - the God Particle
Romulus Godang
The University of Mississippi
The CKM Matrix...
� By applying the unitarity condition (scalar product of any two rows or columns):
V ∗ubVud + V ∗cbVcd + V ∗tbVtd = 0
� CKM matrix can be presented by a triangle in the complex plane
B KSψ
B π π+ -
B ργB
0 B
0mixing
BS ρKS
B+
Dcp0 K
+
B ππ, Κπl
V
V
V Vtd tb
ud
ub
V Vcd cb*
**
γ
α
β
b u ν
b c ν
l
• It is very important to measure the CKM angles and its sides!
• We need to measure them precisely in order to search for New Physics
January 30, 2007
Oxford, Mississippi
Understanding the Matter-Antimatter Asymmetry of the Universe (page 18)
Search for the Origin of Mass - the God Particle
Romulus Godang
The University of Mississippi
The Unitarity Triangle (UT)
� The UT sides Ru and Rt can be expressed:
R t
(ρ,η)
γ
α
βρ
η
Ru
(0,0) (1,0)
Ru =
∣∣∣∣VudV
∗ub
VcdV∗cb
∣∣∣∣ =
√ρ2 + η2 Rt =
∣∣∣∣VtdV
∗tb
VcdV∗cb
∣∣∣∣ =
√(1− ρ)2 + η2
� The angles α, β, and γ are defined by
α = arg
[− VtdV
∗tb
VudV∗ub
], β = arg
[−VcdV
∗cb
VtdV∗tb
], γ = arg
[−VudV
∗ub
VcdV∗cb
]
� B factories and other experiments measure (α = π − β − γ)
cosγ = ρ/Ru , sinγ = η/Ru
cosβ = (1− ρ)/Rt , sinβ = η/Rt
January 30, 2007
Oxford, Mississippi
Understanding the Matter-Antimatter Asymmetry of the Universe (page 19)
Search for the Origin of Mass - the God Particle
Romulus Godang
The University of Mississippi
How to Measure the UT
� The Unitarity Triangle plane for the relevant observables:
-2
-1.5
-1
-0.5
0
0.5
1
1.5
2
-2 -1.5 -1 -0.5 0 0.5 1 1.5 2
εK
εK
K0→π0νν
ε,/εK , K0
L→π0νν
∆md
|Vub/Vcb|
sin 2α
sin 2α
sin 2β
sin 2β
K+→π+νν
K+→π+νν
sin γ sin γ
ρ
ηα
βγ
� Sin 2β (CP violation) measurement is the main goal of BABAR and Belle
� Surprisingly BABAR and Belle discovered several other new particles:
massive particle Y(4260) (2005) and Ds (2317) (2003)
January 30, 2007
Oxford, Mississippi
Understanding the Matter-Antimatter Asymmetry of the Universe (page 20)
Search for the Origin of Mass - the God Particle
Romulus Godang
The University of Mississippi
CP Violation in B System
� The time evolving B0 or B0 to its final CP eigenstates:
afCP =Γ(B0
phys(t)→fCP )−Γ(B0phys(t)→fCP )
Γ(B0phys(t)→fCP )+Γ(B0
phys(t)→fCP )
afCP =1−|λfCP |2cos(∆mB t)−2=mλfCP sin(∆mB t)
1+|λfCP |2
where: λfCP = qp
AfCPAfCP
, AfCP = amplitude of final CP eigenstates
qp
= −∆mB− i2 ∆ΓB
2(M12− i2 Γ12), where p and q are the complex coefficients
� There are 3 ways to measure CP Violation in B decays:
• Direct CP violation in B decays (B0 and B± decays)
| AfCPAfCP
| 6= 1
• CP violation in pure mixing (only B0 decays)
| qp| 6= 1
• CP violation in the interference between decays with or without mixing
|λfCP | = 1,=m(λfCP ) 6= 1
January 30, 2007
Oxford, Mississippi
Understanding the Matter-Antimatter Asymmetry of the Universe (page 21)
Search for the Origin of Mass - the God Particle
Romulus Godang
The University of Mississippi
CP Violation in B System...
January 30, 2007
Oxford, Mississippi
Understanding the Matter-Antimatter Asymmetry of the Universe (page 22)
Search for the Origin of Mass - the God Particle
Romulus Godang
The University of Mississippi
How to measure CP Violation in B System
� The time-dependent CP violation asymmetry:
ACP (∆t) ≡ f+(∆t)− f−(∆t)
f+(∆t) + f−(∆t)
= −ηf sin2β sin (∆md ∆t),
where
ηf = ±1, CP eigenvalue of the final state f
∆md = the B0 −B0 oscillation frequency
∆t = trec − ttag, βγ = 0.56, ∆z ≈ βγc∆t|∆z| = βγcτB0 ≈ 250µm
� β = arg[−VcdV ∗cbVtdV ∗tb
]
β is the angle of the UT of the CKM matrix
� The direct measurement of sin2β is the CP asymmetry
January 30, 2007
Oxford, Mississippi
Understanding the Matter-Antimatter Asymmetry of the Universe (page 23)
Search for the Origin of Mass - the God Particle
Romulus Godang
The University of Mississippi
CP Violation Result
� The number of B0(NB0) and B0(NB0) tags
� The asymmetry (NB0 −NB0)/(NB0 +NB0) as a function of ∆t
January 30, 2007
Oxford, Mississippi
Understanding the Matter-Antimatter Asymmetry of the Universe (page 24)
Search for the Origin of Mass - the God Particle
Romulus Godang
The University of Mississippi
The Current CP Violation Status
ACP Averages
HF
AG
Jan
2006
HF
AG
Jan
2006
HF
AG
Jan
2006
HF
AG
Jan
2006
HF
AG
Jan
2006
HF
AG
Jan
2006
DC
P K
AC
P+
DC
P K
AC
P-
D* C
P K
AC
P+
D* C
P K
AC
P-
DC
P K
* A
CP
+
DC
P K
* A
CP
-
-1.4 -1.2 -1 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1 1.2 1.4
BaBar 0.35 ± 0.13 ± 0.04
Belle 0.07 ± 0.14 ± 0.06
Average 0.23 ± 0.10
BaBar -0.06 ± 0.13 ± 0.04
Belle -0.11 ± 0.14 ± 0.05
Average -0.08 ± 0.10
BaBar -0.10 ± 0.23 +-00..0034
Belle -0.27 ± 0.25 ± 0.04
Average -0.18 ± 0.17
Belle 0.26 ± 0.26 ± 0.03
Average 0.26 ± 0.26
BaBar -0.08 ± 0.19 ± 0.08
Belle -0.02 ± 0.33 ± 0.07
Average -0.06 ± 0.18
BaBar -0.26 ± 0.40 ± 0.12
Belle 0.19 ± 0.50 ± 0.04
Average -0.08 ± 0.32
H F A GH F A GJan 2006
PRELIMINARY
January 30, 2007
Oxford, Mississippi
Understanding the Matter-Antimatter Asymmetry of the Universe (page 25)
Search for the Origin of Mass - the God Particle
Romulus Godang
The University of Mississippi
The Current CP Violation Status...
sin(2βeff)/sin(2φe1ff)
HF
AG
HE
P 2
005
HF
AG
HE
P 2
005
HF
AG
HE
P 2
005
HF
AG
HE
P 2
005
HF
AG
HE
P 2
005
HF
AG
HE
P 2
005
HF
AG
HE
P 2
005
HF
AG
HE
P 2
005
HF
AG
HE
P 2
005
b→ccs
φ K
0η′
K0
f 0 K
S
π0 KS
π0 π0 K
S
ω K
S
K+ K
- K0
KS K
S K
S
-3 -2 -1 0 1 2 3
World Average 0.69 ± 0.03BaBar 0.50 ± 0.25 +-
00..0074
Belle 0.44 ± 0.27 ± 0.05Average 0.47 ± 0.19BaBar 0.36 ± 0.13 ± 0.03Belle 0.62 ± 0.12 ± 0.04Average 0.50 ± 0.09BaBar 0.95 +-
00..2332 ± 0.10
Belle 0.47 ± 0.36 ± 0.08Average 0.75 ± 0.24BaBar 0.35 +-
00..3303 ± 0.04
Belle 0.22 ± 0.47 ± 0.08Average 0.31 ± 0.26BaBar -0.84 ± 0.71 ± 0.08Average -0.84 ± 0.71BaBar 0.50 +-
00..3348 ± 0.02
Belle 0.95 ± 0.53 +-00..1125
Average 0.63 ± 0.30BaBar 0.41 ± 0.18 ± 0.07 ± 0.11Belle 0.60 ± 0.18 ± 0.04 +-
00..1192
Average 0.51 ± 0.14 +-00..1018
BaBar 0.63 +-00..2382 ± 0.04
Belle 0.58 ± 0.36 ± 0.08Average 0.61 ± 0.23
H F A GH F A GHEP 2005
PRELIMINARY
January 30, 2007
Oxford, Mississippi
Understanding the Matter-Antimatter Asymmetry of the Universe (page 26)
Search for the Origin of Mass - the God Particle
Romulus Godang
The University of Mississippi
The Unitarity Triangle Sides
� B factories has improved our understanding of CP violation :
♦ sin 2β = 0.687± 0.032 (a precision measurement of 4.7%)
↪→ This precision outstripped the other measurements
� As for today measurements |Vub| and |Vcb| are complementary to sin 2β
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
-0.4 -0.2 0 0.2 0.4 0.6 0.8 1
excluded at CL > 0.95
γ
α
excluded at CL > 0.95
sin 2β
sol. w/ cos 2β < 0(excl. at CL > 0.95)
α
βγ
ρ
η
excl
uded
are
a ha
s C
L > 0.95 C K M
f i t t e rEPS 2005
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
-0.4 -0.2 0 0.2 0.4 0.6 0.8 1
excluded at CL > 0.95
α
∆md
εK
γ ∆ms & ∆md
|Vub/Vcb|
excluded at CL > 0.95
sin 2β
sol. w/ cos 2β < 0(excl. at CL > 0.95)
α
βγ
ρ
η
excl
uded
are
a ha
s C
L > 0.95 C K M
f i t t e rEPS 2005
♦ Using only angle measurements ♦Without angle measurements
� It is clear that we have to make the green ring ( |Vub||Vcb| ) thinner
in order to make a stringent test on the Standard Model
� We need to improve a precision of |Vub| (especially) and |Vcb|
January 30, 2007
Oxford, Mississippi
Understanding the Matter-Antimatter Asymmetry of the Universe (page 27)
Search for the Origin of Mass - the God Particle
Romulus Godang
The University of Mississippi
Semileptonic B Decays
♦ Why do we use semileptonic B Decays ?
�
� ��� � ���
��
�
���� � � ��� � �
� Simple theoretical description at parton level
� B flavor can be identified from charge of lepton
� Coupling at W− is proportional to |Vub| and |Vcb|which is directly related in its decay rate :
• Γ(b→ u`ν) =G2F
192π2 |Vub|2m5b
• Γ(b→ c`ν) =G2F
192π2 |Vcb|2m2b(mb −mc)
3
♦ Experimental Approaches :
� Sensitive to strong interactions in B decays
• Exclusive measurements
need form factors to describe the B transition
• Inclusive measurements
need Operator Product Expansion (OPE) and b mass to extract |Vxb|
�
����� �
������
�
January 30, 2007
Oxford, Mississippi
Understanding the Matter-Antimatter Asymmetry of the Universe (page 28)
Search for the Origin of Mass - the God Particle
Romulus Godang
The University of Mississippi
The Unitarity Triangle Status
� The current average angle results:
α = (92.1± 5.1)◦; β = (24.6± 1.7)◦; γ = (63.1±5.0)◦
� A precision measurement of |Vub||Vcb| would significantly improve
the constraints on the Unitary Triangle in SM
=⇒ It could benchmark for New Physics
� Current precision of |Vub| and |Vcb| measurements :
• (∆|Vub||Vub| ) = (3.3exp ± 2.9model ± 4.7SF ± 4.0th)% = 7.6%
• (∆|Vcb||Vcb| ) = 2%. (OPE fit of E` and MX moments by BABAR )
=⇒ It contributes directly to a precision of (∆|Vtd||Vtd| )
� BABAR has double the data in 2006 (0.5 ab−1)
We hope to quadruple the data by 2008 (1 ab−1)
January 30, 2007
Oxford, Mississippi
Understanding the Matter-Antimatter Asymmetry of the Universe (page 29)
Search for the Origin of Mass - the God Particle
Romulus Godang
The University of Mississippi
Search for Higgs Particle
How the elementary particles get their mass ?
� Higgs mechanism (Peter Higgs, 1964) play a central role in the unification
of electromagnetic and weak interaction by providing W± and Z0 bosons
� It implies the existence of a single neutral scalar particle so called
“Higgs particle” yet Leon Lederman called it “God particle”
� The challenge: Higgs mass is a free parameter in the SM
↪→ what is the Higgs mass range ?
� The first search of Higgs was done by LEP, CERN (2003)
↪→ yield a lower limit: MH > 114.4 GeV (C.L. only)
� Can Fermilab (D0 and/or CDF) discover the Higgs particle
before the more powerful collider, LHC turn on (2007) ?
(U. Miss at D0: B. Quinn and A. Melnitchouk)
January 30, 2007
Oxford, Mississippi
Understanding the Matter-Antimatter Asymmetry of the Universe (page 30)
Search for the Origin of Mass - the God Particle
Romulus Godang
The University of Mississippi
Search for Higgs Boson Status
� January 8, 2007: CDF measured the mass of W :
MW = 80, 413± 48 MeV
↪→ the new average MW = 80, 398± 25 MeV
→ upper limit of MH down from 166 GeV to 153 GeV
� Tevatron is only capable of finding Higgs if MH ≤ 170 GeV
→ Fermilab has a good change to find Higgs!
Higgs mass (GeV)100 120 140 160 180 200
) (p
b)
(*)
WW
→B
R(H
×σ
-110
1
10
210
Exc
lud
ed a
t L
EP
Standard Model
4th Generation Model
ν lνl→(*)WW→H
95% CL LimitExpectedObserved
-1DØ, 320 pb
Higgs mass (GeV)100 120 140 160 180 200
) (p
b)
(*)
WW
→B
R(H
×σ
-110
1
10
210
110 120 130 140 150 160 170 180 190 200
-110
1
10
210
)2Higgs Mass (GeV/c110 120 130 140 150 160 170 180 190 200
) (p
b)
*W
W→
x B
R(H
Hσ95
% C
.L.
-110
1
10
210
Standard Model
4th Generation Model
Expected Limit
95% C.L. Limit
Exc
lud
ed L
EP
January 30, 2007
Oxford, Mississippi
Understanding the Matter-Antimatter Asymmetry of the Universe (page 31)
Search for the Origin of Mass - the God Particle
Romulus Godang
The University of Mississippi
Search Higgs at Muon Collider
� Unique features of a Muon Collider (µ+ − µ−):
• Bremsstrahlung radiation effect is negligible (scales by m−4µ )
so it does not limit their circular acceleration to reach multi-TeV energies
• Direct s-channel coupling (Mandelstam) to Higgs boson resonances is
40,000 (mµ/me)2 > in (µ+µ− → h) than in (e+e− → h)
=⇒ R(µ+µ−)higgs � R
(e+e−)higgs
h
b
b
µ+
µ−
( t )
(t )
~mµ ~mb (mt)
• U. Miss at Muon Collider : D. Summers, L. Cremaldi, R. Godang, S. Bracker
January 30, 2007
Oxford, Mississippi
Understanding the Matter-Antimatter Asymmetry of the Universe (page 32)
Search for the Origin of Mass - the God Particle
Romulus Godang
The University of Mississippi
Heavy Neutral Higgs Bosons
� In MSSM, the heavy Higgs bosons are largely degenerate
� The Higgs boson cross section in s-channel:
σh(√s) = 4πΓ(h→µµ)Γ(h→X)
(s−m2h)2 + m2
h(Γhtot)2 =⇒ σ√s = (2 MeV )
(R
0.003%
) ( √s
100 GeV
)
� The resonances are clearly overlapping (separated by ∼ 1 GeV )
� Muon Collider could separate out these states with energy resolution:
R = 0.01% and R = 0.06%
January 30, 2007
Oxford, Mississippi
Understanding the Matter-Antimatter Asymmetry of the Universe (page 33)
Search for the Origin of Mass - the God Particle
Romulus Godang
The University of Mississippi
LHC Detectors
� LHC: p− p collisions with CM-energy√s = 14 TeV
� CMS Collaboration: 2000 scientists with 155 institutes in 37 countries
↪→ Search for Higgs is one of the main goals in CMS
↪→ Search for Black Holes: M. Cavaglia, R. Godang, L Cremaldi, D. Summers
January 30, 2007
Oxford, Mississippi
Understanding the Matter-Antimatter Asymmetry of the Universe (page 34)
Search for the Origin of Mass - the God Particle
Romulus Godang
The University of Mississippi
The CMS Experiment
U. Miss: L. Cremaldi, R. Godang, R. Kroeger, D. Sanders, D. Summers
January 30, 2007
Oxford, Mississippi
Understanding the Matter-Antimatter Asymmetry of the Universe (page 35)
Search for the Origin of Mass - the God Particle
Romulus Godang
The University of Mississippi
CATFISH: New MC Generator
� We introduce a new MC generator so called CATFISH
CATFISH (Collider grAviTational FIeld Simulator for black Holes)
� New features of CATFISH compared to other BH generators :
• CATFISH is more flexible and user friendly
• It includes different final BH decay modes with
possibility of remnant formation
• It includes Graviton field emissivities
� CATFISH authors: M. Cavaglia, R. Godang, L. Cremaldi, D. Summers
� The paper has been submitted for a publication
January 30, 2007
Oxford, Mississippi
Understanding the Matter-Antimatter Asymmetry of the Universe (page 36)
Search for the Origin of Mass - the God Particle
Romulus Godang
The University of Mississippi
CATFISH Website
� CATFISH is well documented and available for public
http://www.phy.olemiss.edu/GR/catfish/
January 30, 2007
Oxford, Mississippi
Understanding the Matter-Antimatter Asymmetry of the Universe (page 37)
Search for the Origin of Mass - the God Particle
Romulus Godang
The University of Mississippi
BH Events Shape in CATFISH
� BH events are expected to be highly spherical due to
the spherical nature of Hawking evaporation process
0.00 0.25 0.50 0.75 1.00
Sphericity
10-1
1
101
102
103
104
Num
ber
of E
vent
s
M★ = 1 TeV, n = 6
Mmin = 1 TeV
np = 2, BD
np = 4, BD
np = 2, YR
np = 4, YR
0.00 0.25 0.50 0.75 1.00
R2 ≡ H2/H0
10-1
1
101
102
103
104
105
Num
ber
of E
vent
s
M★ = 1 TeV, n = 6
Mmin = 1 TeV
np = 2, BD
np = 4, BD
np = 2, YRnp = 4, YR
� Experimentally one needs to distinguish between BH events shape
with qq events as BH-background (back-to-back events shape)
• (left) Sphericity BH events shape, → S > 0.30 (depends on Mmin)
• (right) Fox-Wolfram moment, → R2 < 0.50
January 30, 2007
Oxford, Mississippi
Understanding the Matter-Antimatter Asymmetry of the Universe (page 38)
Search for the Origin of Mass - the God Particle
Romulus Godang
The University of Mississippi
The Higgs Production at CMS
g
g g fusion :
g
g
g
t t fusion :
t Ho
Ho
t
t
t
t
t
t
q
q
WW, ZZ fusion :
q
q
q
q
Ho
Ho
W, Z bremsstrahlungq
Ho production at hadron colliders:
W,Z
W,Z
W,Z
W,Z
But : BR ( H Z¡Z¡ 4l–) = 1.4 ¥ 10—3
BR ( H Z¡Z¡ 4µ–) = 3 ¥ 10—4
gg H
qq Hqq
gg,qq Hbb
gg,qq Htt
qq HZ
qq’ HW
107
106
105
104
103
102
10-1
10-2
10-3
10-4
10
1
0 200 400 600 800 1000
MH (GeV)
σ (p
b)
σ(pp H+X)
s = 14 TeV
mt = 175 GeV
CTEQ4M
D_D
_118
6 .c
NLO QCD
M. Spira et al.
even
ts fo
r 10
5 pb
-1January 30, 2007
Oxford, Mississippi
Understanding the Matter-Antimatter Asymmetry of the Universe (page 39)
Search for the Origin of Mass - the God Particle
Romulus Godang
The University of Mississippi
The Higgs Discovery at CMS
� The relative light Higgs mass MH < 120 GeV
� For MH < 150 GeV , the most promising channel:
H0 → γγ (dominated by energy resolution)
� But the branching fraction is small
� The decay width is about few tens keV only
ECAL performance is very crucial in this analysis
� We are working on ECAL and HCAL simulation
(GFLASH): R. Kroeger and R. Godang
1
1
50 100 200 500 1000
50 100 200 500 1000
10—1
10—1
10—2
10—3
10—2
102
10
10—3
MH [GeV]
MH [GeV]
Γ(H
) [G
eV
]B
R(H
)
WW
ZZ
Zγγγ
τ+τ—
gg tt
cc
SM HiggsBranching ratios and total decay width
D_D
_ 20
61 c
bb
January 30, 2007
Oxford, Mississippi
Understanding the Matter-Antimatter Asymmetry of the Universe (page 40)
Search for the Origin of Mass - the God Particle
Romulus Godang
The University of Mississippi
The Higgs Discovery at CMS...
� 3 channels cover Higgs mass range
• H0 → γγ
• H0 → Z0Z0
• H0 →W±W∓
� We expected to have about
10 fb−1 data for 1 year running
� We hope to discover
Standard Model Higgs in 2008 ?
� U. Miss proposed to measure
H0 →W+W−, (W+W− → `+`−νν)
� More data are needed to study the Higgs’ properties
102
10
1
10—1
100 200 300 400 500 600
MHiggs [GeV]
H → γγH → ZZ
H → WW
LHC 14 TeV (SM NLO Cross Sections)
Dis
cove
ry L
um
ino
sity
[fb
—1]
D_
D_
12
85
c
5σ Higgs Signals (statistical errors only)
January 30, 2007
Oxford, Mississippi
Understanding the Matter-Antimatter Asymmetry of the Universe (page 41)
Search for the Origin of Mass - the God Particle
Romulus Godang
The University of Mississippi
Summary
� CP Violation in B system has been observed
α = (92.1± 5.1)◦ β = (24.6± 1.7)◦ γ = (63.1± 5.0)◦
� Current precision of |Vub| and |Vcb| measurements :
• (∆|Vub||Vub| ) = (3.3exp ± 2.9model ± 4.7SF ± 4.0th)% = 7.6%
• BABAR is aiming to measure (∆|Vub||Vub| ) = 5%
• (∆|Vcb||Vcb| ) = 2%. (Partial Reconstruction method will confirm this)
• Many interesting physics analyses are available at BABAR
� Search for Higgs and BH at LHC is underway
� Using CATFISH, we hope to discover mini BH production at CMS
� New discoveries are waiting to be explored at LHC !
January 30, 2007
Oxford, Mississippi
Understanding the Matter-Antimatter Asymmetry of the Universe (page 42)
Search for the Origin of Mass - the God Particle
Romulus Godang
The University of Mississippi
Hopefully...
� Will the Higgs be discovered in 2008 ?
T H A N K S !
January 30, 2007
Oxford, Mississippi
Understanding the Matter-Antimatter Asymmetry of the Universe (page 43)
Search for the Origin of Mass - the God Particle
Romulus Godang
The University of Mississippi