niels tuning (1) physics of anti-matter lecture 6 n. tuning
TRANSCRIPT
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Niels Tuning (1)
Physics of Anti-matter
Lecture 6
N. Tuning
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Plan
1) Mon 3 Feb: Anti-matter + SM
2) Wed 5 Feb: CKM matrix + Unitarity Triangle
3) Mon 10 Feb: Mixing + Master eqs. + B0J/ψKs
4) Wed 12 Feb: CP violation in B(s) decays (I)
5) Mon 17 Feb: CP violation in B(s) decays (II)
6) Wed 19 Feb: CP violation in K decays + Overview
7) Mon 24 Feb: Mini-project (MSc. V. Syropoulos)
Wed 26 Feb: Exam
Niels Tuning (2)
Final Mark: 2/3*Exam + 1/6*Homework + 1/6*Mini project
In March: 7 Lectures on Flavour Physics by prof.dr. R. Fleischer
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Diagonalize Yukawa matrix Yij
– Mass terms
– Quarks rotate
– Off diagonal terms in charged current couplings
Niels Tuning (4)
RecapSM Kinetic Higgs Yukawa L L L L
0( , ) ...I I
Yuk Li L Rjd Ij id dY u
L
...2 2
Kinetic Li LiI I I
Li LIi
g gu W d d W u
L
5 5*1 1 ...2 2
ij iCKM i j j j i
g gu W d d uV VW
L
, , , , ...d u
s cL L
b tR R
Mass
m d m u
d s b m s u c t m c
m b m t
L
I
ICKM
I
d d
s V s
b b
SM CKM Higgs Mass L L L L
uI
dI
W
u
d,s,b
W
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Niels Tuning (5)
Why bother with all this?
• CKM matrix has origin in LYukawa
Intricately related to quark massed…
• Both quark masses and CKM elements show intriguing hierarchy
• There is a whole industry of theorist trying to postdict the CKM matrix based on arguments on the mass matrix
in LYukawa…
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Niels Tuning (6)
CKM-matrix: where are the phases?
u
d,s,b
W
• Possibility 1: simply 3 ‘rotations’, and put phase on smallest:
• Possibility 2: parameterize according to magnitude, in O(λ):
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This was theory, now comes experiment
• We already saw how the moduli |Vij| are determined
• Now we will work towards the measurement of the imaginary part– Parameter: η
– Equivalent: angles α, β, γ .
• To measure this, we need the formalism of neutral meson oscillations…
Niels Tuning (7)
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Meson Decays
• Formalism of meson oscillations:
• Subsequent: decay
0 ( )P t
Interference
P0 f P0P0 f
Interference(‘direct’) Decay
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Classification of CP Violating effects
1. CP violation in decay
2. CP violation in mixing
3. CP violation in interference
Niels Tuning (9)
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Classification of CP Violating effects
1. CP violation in decay
Example:
2. CP violation in mixing
Example:
3. CP violation in interference
Example:
Niels Tuning (10)
0
0B KB K
)sin()2sin()(00
00
mtNN
NNtA
fBfB
fBfBCP
B0→J/ψKs
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Remember!
Necessary ingredients for CP violation:
1) Two (interfering) amplitudes
2) Phase difference between amplitudes– one CP conserving phase (‘strong’ phase)
– one CP violating phase (‘weak’ phase)
Niels Tuning (11)
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Remember!
Niels Tuning (12)
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Niels Tuning (13)
CKM Angle measurements from Bd,u decays
• Sources of phases in Bd,u amplitudes*
• The standard techniques for the angles:
*In Wolfenstein phase convention.
Amplitude Rel. Magnitude Weak phase
bc Dominant 0
bu Suppressed γ
td (x2, mixing) Time dependent
2β
B0 mixing + single bc decay
B0 mixing + single bu decay
Interfere bc and bu in B± decay.
β
-i
-i
γ1 1
1 1 1
1 1
e
e
bu
td
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Classification of CP Violating effects
1. CP violation in decay
2. CP violation in mixing
3. CP violation in interference
Niels Tuning (14)
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Niels Tuning (15)
Other ways of measuring sin2β
• Need interference of bc transition and B0 –B0 mixing
• Let’s look at other bc decays to CP eigenstates:
cD
d
0 bB
d
cD
d
0,, ,s L
s dK K
d
0 bB
d
, 2 , ,...c
cJ S
c
All these decay amplitudes have the same phase
(in the Wolfenstein parameterization)
so they (should) measure the same CP violation
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CP in interference with BφKs
• Same as B0J/ψKs :
• Interference between B0→fCP and B0→B0→fCP
– For example: B0→J/ΨKs and B0→B0→ J/ΨKs
– For example: B0→φKs and B0→B0→ φKs
Niels Tuning (16)
+
e-iφ
Amplitude 2Amplitude 1
0
0 0 0
/ //
/ /
s
s
s
J K J KJ K
J KB B KJ K
AAq q p
p A p A q
* * *
/ * * *s
tb td cb cs cs cdJ K
tb td cb cs cs cd
V V V V V V
V V V V V V
sin 2 ( ) sin( )CPA t mt
( ) ( )( ) Im( )sin
( ) ( )B fB f
CP fB fB f
t tA t mt
t t
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CP in interference with BφKs: what is different??
• Same as B0J/ψKs :
• Interference between B0→fCP and B0→B0→fCP
– For example: B0→J/ΨKs and B0→B0→ J/ΨKs
– For example: B0→φKs and B0→B0→ φKs
Niels Tuning (17)
sin 2 ( ) sin( )CPA t mt
( ) ( )( ) Im( )sin
( ) ( )B fB f
CP fB fB f
t tA t mt
t t
+
e-iφ
Amplitude 2Amplitude 1
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Niels Tuning (18)
Penguin diagramsNucl. Phys. B131:285 1977
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Penguins??
Niels Tuning (19)
The original penguin: A real penguin: Our penguin:
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Funny
Niels Tuning (20)
Super Penguin: Penguin T-shirt:
Flying Penguin
Dead Penguin
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Niels Tuning (21)
The “b-s penguin”
B0J/ψKS B0φKS
… unless there is new physics!
• New particles (also heavy) can show up in loops:
– Can affect the branching ratio– And can introduce additional phase and affect the asymmetry
Asymmetry in SM
b s
μμ
“Penguin” diagram: ΔB=1
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Niels Tuning (22)
Hint for new physics??
sin2β
• sin2βbccs = 0.68 ± 0.03
sin2βpeng
B
J/ψ
Ks
b
d
c
c
s
d
φ
Ks
Bs
b
dd
sts?
• sin2βpeng = 0.52 ± 0.05
g,b,…?~~
S.T’Jampens, CKM fitter, Beauty2006
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Next… Something completely different? No, just K
1. CP violation in decay
2. CP violation in mixing
3. CP violation in interference
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Kaons…
Niels Tuning (24)
• Different notation: confusing!
K1, K2, KL, KS, K+, K-, K0
• Smaller CP violating effects
But historically important! Concepts same as in B-system, so you have a chance to understand…
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Neutral kaons – 60 years of history
… the θ0 must be considered as a "particle mixture" exhibiting two distinct lifetimes, that each lifetime is associated with a different set of decay modes, and that no more than half of all θ0's undergo the familiar decay into two pions.
1947 : First K0 observation in cloud chamber (“V particle”)1955 : Introduction of Strangeness (Gell-Mann & Nishijima) K0,K0 are two distinct particles (Gell-Mann & Pais)
1956 : Parity violation observation of long lived KL (BNL Cosmotron)1960 : m = mL-mS measured from regeneration1964 : Discovery of CP violation (Cronin & Fitch)
1970 : Suppression of FCNC, KL - GIM mechanism/charm hypothesis1972 : 6-quark model; CP violation explained in SM (Kobayashi & Maskawa)
1992-2000 : K0,K0 time evolution, decays, asymmetries (CPLear) 1999-2003 : Direct CP violation measured: ’ ≠ 0 (KTeV and NA48)
From G.CaponNiels Tuning (25)
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Intermezzo: CP eigenvalue
Niels Tuning (26)
• Remember:
– P2 = 1 (x -x x)
– C2 = 1 (ψ ψ ψ )
CP2 =1
• CP | f > = | f >
• Knowing this we can evaluate the effect of CP on the K0
CP|K0> = -1| K0>CP| K0> = -1|K0 >
• CP eigenstates:|KS> = p| K0> +q|K0>|KL> = p| K0> - q|K0>
|Ks> (CP=+1) → (CP= (-1)(-1)(-1)l=0 =+1)
|KL> (CP=-1) → (CP = (-1)(-1)(-1)(-1)l=0 = -1)
( S(K)=0 L(ππ)=0 )
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Niels Tuning (27)
Decays of neutral kaons
• Neutral kaons is the lightest strange particle it must decay through the weak interaction
• If weak force conserves CP then – decay products of K1 can only be a CP=+1 state, i.e.
|K1> (CP=+1) → (CP= (-1)(-1)(-1)l=0 =+1)
– decay products of K2 can only be a CP=-1 state, i.e.
|K2> (CP=-1) → (CP = (-1)(-1)(-1)(-1)l=0 = -1)
• You can use neutral kaons to precisely test that the weak force preserves CP (or not)– If you (somehow) have a pure CP=-1 K2 state and you observe it
decaying into 2 pions (with CP=+1) then you know that the weak decay violates CP…
( S(K)=0 L(ππ)=0 )
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Niels Tuning (28)
Designing a CP violation experiment
• How do you obtain a pure ‘beam’ of K2 particles?
– It turns out that you can do that through clever use of kinematics
• Exploit that decay of K into two pions is much faster than decay of K into three pions– Related to fact that energy of pions are large in 2-body decay
– 1 = 0.89 x 10-10 sec
– 2 = 5.2 x 10-8 sec (~600 times larger!)
• Beam of neutral Kaons automatically becomes beam of |K2> as all |K1> decay very early on…
Initial K0
beam
K1 decay early (into ) Pure K2 beam after a while!(all decaying into πππ) !
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Niels Tuning (29)
The Cronin & Fitch experiment
Incoming K2 beam
Decay of K2 into 3 pions
If you detect two of the three pionsof a K2 decay they will generallynot point along the beam line
Essential idea: Look for (CP violating) K2 decays 20 meters away from K0 production point
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Niels Tuning (30)
The Cronin & Fitch experiment
Incoming K2 beam
Decay pions
If K2 decays into two pions instead ofthree both the reconstructed directionshould be exactly along the beamline(conservation of momentum in K2 decay)
Essential idea: Look for K2 decays20 meters away from K0 production point
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Niels Tuning (31)
The Cronin & Fitch experiment
Incoming K2 beam
Decay pions
Result: an excess of events at =0 degrees!
K2 decays(CP Violation!)
Essential idea: Look for K2 decays20 meters away from K0 production point
K2 decays
Note scale: 99.99% of K decaysare left of plot boundary
• CP violation, because K2 (CP=-1)
changed into K1 (CP=+1)
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"for the discovery of violations of fundamental symmetry principles in the decay of neutral K mesons"
Val Logsdon Fitch 1/2 of the prize Princeton University Princeton, NJ, USA b. 1923
James Watson Cronin 1/2 of the prize University of Chicago Chicago, IL, USA b. 1931
The discovery emphasizes, once again, that even almost self evident principles in science cannot be regarded fully valid until they have been critically examined in precise experiments.
Nobel Prize 1980
Niels Tuning (32)
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Cronin & Fitch – Discovery of CP violation
• Conclusion: weak decay violates CP (as well as C and P)– But effect is tiny! (~0.05%)
– Maximal (100%) violation of P symmetry easily follows from absence of right-handed neutrino, but how would you construct a physics law that violates a symmetry just a tiny little bit?
• Results also provides us withconvention-free definition ofmatter vs anti-matter.
– If there is no CP violation, the K2 decaysin equal amounts to + e- e (a) - e+ e (b)
– Just like CPV introduces K2 ππ decays, it also introduces a slight asymmetry in the above decays (b) happens more often than (a)
– “Positive charge is the charged carried by the lepton preferentially produced in the decay of the long-lived neutral K meson” Niels Tuning (33)
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Intermezzo: Regeneration
• Different cross section for σ(p K0) than σ(pK0)
o Elastic scattering: same
o Charge exchange : same
o Hyperon production: more for K0 !
• What happens when KL-beam hits a wall ??
• Then admixture changes…: |KL> = p| K0> - q|K0>
Regeneration of KS !
• Could fake CP violation due to KS→π+π-…
00
21
2 KKK
00 pK
KKpK 000
strong interactions:must conserve strangeness
leave little free energy – unlikely!
pKnK
nKpK
0
0
Niels Tuning (34)
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KS and KL
2
2
,1
.1
S
L
K KK
K KK
KL and KS are not orthogonal:
0 0
0 0
,
.
S
L
K p K q K
K p K q K
2
2
2 1
2 1
1 ,
1 .
p
q
2
2 2
21
1 1S L
pK K
q
,Si tS SK t e K
.Li tL LK t e K
Usual (historical) notation in kaon physics:
Modern notation used in B physics:
Regardless of notation:
Niels Tuning (35)
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Three ways to break CP; e.g. in K0→ π+π-
1CP violation in decay: f
f
A
A
1CP violation in mixing: q
p
Aq
p A
2 20
0 2 2
2
2
2
2
22
21
K g t g t g t g t
K g t g
A
t t g tA g
0CP violation in interference mixing/decay: ff
f
Aq
p A
20
2
0
( ) ( )
1( ) ( )
K A g t g t
K A g t g t
Niels Tuning (36)
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Classification of CP Violating effects
1. CP violation in decay
2. CP violation in mixing
3. CP violation in interference
Niels Tuning (37)
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Time evolution
20
0 2
2 cos
2 cos
S L
S L
t t t
t t t
K N e e e m t
K N e e e m t
1
1
L
S
KpA qA
pA qA K
ie
2
0
2
0
1
1
1 12 cos sin
1 1
1
1
1 12 cos sin
1 1
S L
S L
t t
t
t t
t
e e
K
e m t m t
e e
K
e m t m t
Niels Tuning (38)
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B-system 2. CP violation in mixing K-system
CPLear (2003)
4
4
1
1T
q pN t N tA t
N t N t q p
BaBar, (2002)
X 0 0B B
CPLEAR, Phys.Rep. 374(2003) 165-270
36.6 1.6 10
0.9967 0.0008 1
TA t
q p
4
4
14
1e
ee
Te
I t q pA
I t
I t It
qt p
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B-system 2. CP violation in mixing K-system
NA48, (2001)
L(e) = (3.317 0.070 0.072) 10-3
4
4
1
1T
q pN t N tA t
N t N t q p
BaBar, (2002)
X 0 0B B
L
( ) ( )( )
( ) ( )L L
L L
K e K ee
K e K e
Niels Tuning (40)
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B-system 3.Time-dependent CP asymmetry
)sin()2sin()(00
00
mtNN
NNtA
fBfB
fBfBCP
B0→J/ψKs
BaBar (2002) Niels Tuning (41)
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B-system 3.Time-dependent CP asymmetry K-system
rate asymmetry
CPLear (PLB 1999)
)sin()2sin()(00
00
mtNN
NNtA
fBfB
fBfBCP
K0→π-π+B0→J/ψKs
),(),(
),(),()(
00
00
tfkRtfkR
tfkRtfkRtAf
~50/50 decay as Ks and KL + interference!
BaBar (2002)
K0
K0
_
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The Quest for Direct CP Violation
Indirect CP violation in the
mixing:
Direct CP violation in the
decay: ’
A fascinating 30-year long enterprise: “Is CP violation a peculiarity of kaons? Is it induced by a new superweak interaction?”
Niels Tuning (43)
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B system 1. Direct CP violation K system
)(
)(
)(
)(oo
s
ooL
oos
L
kAmp
kAmp
kAmp
kAmp
Different CP violation for the two decays Some CP violation in the decay!
B0→K+π-
BR(KL )
BR(Ks )
BR(KL oo)
BR(Ks oo)
oo
2
2
2 2 1 6Re
ε’≠ 0
B0→K-π+ K0→π-π+
K0→π0π0
K0→π-π+
K0→π0π0
Niels Tuning (44)
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Niels Tuning (45)
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Niels Tuning (46)
Hints for new physics?
φ
Ks
Bs
b
dd
stsg,b,…?
~~
1) sin2β≠sin2β ?
4th generation, t’ ?
3) βs≠0.04 ?
2) ACP (B0K+π-)≠ACP (B+K+π0) ?
4) P(B0s→B0
s) ≠ P(B0s←B0
s)
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Present knowledge of unitarity triangle
Niels Tuning (47)
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“The” Unitarity triangle
• We can visualize the CKM-constraints in () plane
![Page 49: Niels Tuning (1) Physics of Anti-matter Lecture 6 N. Tuning](https://reader036.vdocuments.site/reader036/viewer/2022062305/56649d355503460f94a0c3e5/html5/thumbnails/49.jpg)
Present knowledge of unitarity triangle
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I) sin 2β
)sin()2sin()(00
00
mtNN
NNtA
fBfB
fBfBCP
![Page 51: Niels Tuning (1) Physics of Anti-matter Lecture 6 N. Tuning](https://reader036.vdocuments.site/reader036/viewer/2022062305/56649d355503460f94a0c3e5/html5/thumbnails/51.jpg)
I) sin 2β
)sin()2sin()(00
00
mtNN
NNtA
fBfB
fBfBCP
![Page 52: Niels Tuning (1) Physics of Anti-matter Lecture 6 N. Tuning](https://reader036.vdocuments.site/reader036/viewer/2022062305/56649d355503460f94a0c3e5/html5/thumbnails/52.jpg)
II) ε and the unitarity triangle: box diagram
2
2
,1
.1
S
L
K KK
K KK
0 0
0 0
,
.
S
L
K p K q K
K p K q K
2
2
2 1
2 1
1 ,
1 .
p
q
CP violation in mixing
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II) ε and the unitarity triangle: box diagram
![Page 54: Niels Tuning (1) Physics of Anti-matter Lecture 6 N. Tuning](https://reader036.vdocuments.site/reader036/viewer/2022062305/56649d355503460f94a0c3e5/html5/thumbnails/54.jpg)
II) ε and the unitarity triangle: box diagram
Im(z2)=Im( (Rez+iImz)2)=2RezImz
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II) ε and the unitarity triangle
ρ Niels Tuning (55)
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III.) |Vub| / |Vcb|
• Measurement of Vub
– Compare decay rates of B0 D*-l+ and B0 -l+
– Ratio proportional to (Vub/Vcb)2
– |Vub/Vcb| = 0.090 ± 0.025
– Vub is of order sin(c)3 [= 0.01]
2 22
22 2
( ) ( / )
( / )( )ub
cb
l u b
c bl
b ul f m m
f m mb c
V
Vl
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IV.) Δmd and Δms
2
2
22
2
2
2
td
ts
Bd
Bs
td
ts
BdBd
BsBs
Bd
Bs
d
s
V
V
m
m
V
V
Bf
Bf
m
m
m
m
• Δm depends on Vtd
• Vts constraints hadronic uncertainties
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Present knowledge of unitarity triangle
Niels Tuning (58)
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Niels Tuning (59)
Hints for new physics?
φ
Ks
Bs
b
dd
stsg,b,…?
~~
1) sin2β≠sin2β ?
4th generation, t’ ?
3) βs≠0.04 ?
2) ACP (B0K+π-)≠ACP (B+K+π0) ?
4) P(B0s→B0
s) ≠ P(B0s←B0
s)
![Page 60: Niels Tuning (1) Physics of Anti-matter Lecture 6 N. Tuning](https://reader036.vdocuments.site/reader036/viewer/2022062305/56649d355503460f94a0c3e5/html5/thumbnails/60.jpg)
Niels Tuning (60)
More hints for new physics?
5) εK ? Treatment of errors… Input from Lattice QCD BK
Strong dependence on Vcb
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Niels Tuning (61)
More hints for new physics?
6) Vub: 2.9σ ??
BR(B+→τυ)=1.68 ± 0.31 10-4
Predicted: 0.764± 0.087 10-4
(If fBd off, then BBd needs to be off too, to make Δmd agree)
|Vub| from B→τνFrom: H.Lacker, and A.Buras, Beauty2011, Amsterdam
|Vub| from fit
|Vub| avg from semi-lep?
![Page 62: Niels Tuning (1) Physics of Anti-matter Lecture 6 N. Tuning](https://reader036.vdocuments.site/reader036/viewer/2022062305/56649d355503460f94a0c3e5/html5/thumbnails/62.jpg)
A.Buras, Beauty2011:
Niels Tuning (62)
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A.Buras, Beauty2011:
Niels Tuning (63)
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Standard Model: 25 free parameters
Strong interaction:s(mZ) 0.117
e
=1
2
3
neutrino mixing (4)
Electro-weak interaction:
e(0) 1/137.036mW 80.42 GeVmZ 91.188 GeVmH >114.3 GeV
Elementary particle masses (MeV):
me 0.51099890m 105.658357m 1777.0
mu 3mc 1200mt 174000
md 7ms 120mb 4300
m < 0.000003m < 0.19m < 18.2
e
u’d’s’
=uds
quark mixing (4)
Vijq Vij
l
mH >114.3 GeVCMS LHCb
Niels Tuning (64)
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The CKM matrix
'
'
'
ud us ub
cd cs cb
td ts tb
d V V V d
s V V V s
b V V V b
23
22
3 2
12
12
1 1L L
A id d
s A s
b bA i A
0.9738 0.0002 0.227 0.001 0.00396 0.00009
0.227 0.001 0.9730 0.0002 0.0422 0.0005
0.0081 0.0005 0.0416 0.0005 0.99910 0.00004
ud us ub
cd cs cb
td ts tb
V V V
V V V
V V V
β
-i
-i
γ1 1
1 1 1
1 1
e
e
• Couplings of the charged current:
• Wolfenstein parametrization:
• Magnitude: • Complex phases:
bW
ugVub
Niels Tuning (65)
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The CKM matrix
0.9738 0.0002 0.227 0.001 0.00396 0.00009
0.227 0.001 0.9730 0.0002 0.0422 0.0005
0.0081 0.0005 0.0416 0.0005 0.99910 0.00004
ud us ub
cd cs cb
td ts tb
V V V
V V V
V V V
β
-i
-i
γ1 1
1 1 1
1 1
e
e
• Couplings of the charged current:
• Wolfenstein parametrization
• Magnitude: • Complex phases:
0
( , ) ... ...I I IYuk
d u lij ij jL Rj iL iu Yd YdY
L
, ,2
CKMLW
L
d
u c t V s
b
gW
L
2I ILi LW i
gWu d
L
1)
2)
3)
Niels Tuning (66)
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• Complex phases:
The CKM matrix
0.9738 0.0002 0.227 0.001 0.00396 0.00009
0.227 0.001 0.9730 0.0002 0.0422 0.0005
0.0081 0.0005 0.0416 0.0005 0.99910 0.00004
ud us ub
cd cs cb
td ts tb
V V V
V V V
V V V
β
-i
-i
γ1 1
1 1 1
1 1
e
e
• Couplings of the charged current:
• Wolfenstein parametrization:
• Magnitude:
![Page 68: Niels Tuning (1) Physics of Anti-matter Lecture 6 N. Tuning](https://reader036.vdocuments.site/reader036/viewer/2022062305/56649d355503460f94a0c3e5/html5/thumbnails/68.jpg)
Remember the following:
• CP violation is discovered in the K-system
• CP violation is naturally included if there are 3 generations or more– 3x3 unitary matrix has 1 free complex parameter
• CP violation manifests itself as a complex phase in the CKM matrix
• The CKM matrix gives the strengths and phases of the weak couplings
• CP violation is apparent in experiments/processes with 2 interfering amplitudes with different strong and weak phase
– Often using “mixing” to get the 2nd decay process
• Flavour physics is powerful for finding new physics in loops!– Complementary to Atlas/CMS
Niels Tuning (68)
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Remember the following:
• CP violation is discovered in the K-system
• CP violation is naturally included if there are 3 generations or more– 3x3 unitary matrix has 1 free complex parameter
• CP violation manifests itself as a complex phase in the CKM matrix
• The CKM matrix gives the strengths and phases of the weak couplings
• CP violation is apparent in experiments/processes with 2 interfering amplitudes with different strong and weak phase
– Often using “mixing” to get the 2nd decay process
• Flavour physics is powerful for finding new physics in loops!– Complementary to Atlas/CMS
Niels Tuning (69)
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Personal impression:
• People think it is a complicated part of the Standard Model (me too:-). Why?
1) Non-intuitive concepts? Imaginary phase in transition amplitude, T ~ eiφ
Different bases to express quark states, d’=0.97 d + 0.22 s + 0.003 b
Oscillations (mixing) of mesons: |K0> ↔ |K0>
2) Complicated calculations?
3) Many decay modes? “Beetopaipaigamma…”
– PDG reports 347 decay modes of the B0-meson:
• Γ1 l+ νl anything ( 10.33 ± 0.28 ) × 10−2
• Γ347 ν ν γ <4.7 × 10−5 CL=90%
– And for one decay there are often more than one decay amplitudes…Niels Tuning (70)
2 2 220
20 2 2
2 2
2
1 2
f
f
B f A g t g t g t g t
B f A g t g t g t g t
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Backup
Niels Tuning (71)
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SLAC: LINAC + PEPII
PEP-II accelerator schematic and tunnel viewPEP-II accelerator schematic and tunnel view
4
3.10.56,
9
GeV
GeVe
S
e
Es M
E
LER
HER
Linac
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Coherent Time Evolution at the S
B-Flavor Tagging
Exclusive B Meson
Reconstruction
PEP-2 (SLAC)
Vertexing &Time DifferenceDetermination
Niels Tuning (73)
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LHCb: the Detectorp T
of
B-h
adro
n
η of B-hadron
• High cross section
• LHC energy
• Bs produced in large quantities
• Large acceptance
• b’s produced forward
• Small multiple scattering
• Large boost of b’s
• Trigger
• ↓ Low pT
• Leptons + hadrons (MUON, CALO)
• Particle identification (RICH)
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The well known triangle:
γ
α
β
γ β
qW
q’Vq’q
* * * 0ub ud cb cd tb tdV V V V V V * ** 0ub ud tb tdcb cdV V V VV V * * * 0ub ud cb cd tb tdV V V V V V * * * 0ub ud cb cd tb tdV V V V V V
β
-i
-i
γ1 1
1 1 1
1 1
e
e
CP phases:
• Measure the CKM triangle to unprecedented precision
• Measure very small Branching Ratios
Measuring the Quark Couplings
Niels Tuning (75)