Transcript Slide 1

CKM Physics & Beyond the Standard Model
Physics with Charm
Outline:
1) CKM Physics:
Charm’s role in testing the Standard Model
description of Quark Mixing & CP Violation:
Lifetimes
Hadronic Decays
Leptonic Decays
Semileptonic Decays

K-
K+
e+
2) Physics Beyond the Standard Model
D mixing
D CP Violation
D Rare Decays
(3770)D0 D0
D0K+-, D0K-e+
Outlook & conclusion
Not covered in this talk: D hadron spectroscopy & charmonium
see talk of Jin Shan.
ICHEP04 Plenary 8/20/04 Ian Shipsey
Ian Shipsey,
Purdue University
1
Big Questions in Flavor Physics
Dynamics of flavor?
Why generations?
Why a hierarchy of masses
& mixings?
Origin of Baryogenesis?
Sakharov’s criteria: Baryon number violation
CP violation
Non-equilibrium
3 examples: Universe, kaons, beauty but Standard Model CP
violation too small, need additional sources of CP violation.
Connection between flavor physics & electroweak symmetry breaking?
Extensions of the Standard Model (ex: SUSY) contain flavor &
CP violating couplings that should show up at some level in
flavor physics, but precision measurements and precision theory
are required to detect the new physics.
ICHEP04 Plenary 8/20/04 Ian Shipsey
2
Precision Quark Flavor Physics: charm’s role
2004


The Bd system unitarity triangle is limited by systematic errors from QCD:
Form factors in semileptonic () decay
Decay constants in B mixing
Vtd , Vts
Vub , Vcb
Bd
B
l

Bd

D system- the CKM matrix elements are known (tightly constrained to <1% by
the unitarity of the matrix).
Work back from measurements of absolute rates for leptonic and semileptonic
decays yielding decay constants and form factors to test QCD calculations.
In addition as Br(B D)~100% absolute D branching ratios normalize B physics.
ICHEP04 Plenary 8/20/04 Ian Shipsey
3
Precision theory + charm = large impact
2004
Theoretical
errors
dominate
width of
bands
precision QCD calculations
tested with precision charm
data
theory errors of a
few % on B system decay
constants & semileptonic
form factors
+
500 fb-1 @ BABAR/Belle
ICHEP04 Plenary 8/20/04 Ian Shipsey
4
Precision theory + charm = large impact
2004
Theoretical
errors
dominate
width of
bands
precision QCD calculations
tested with precision charm
data
theory errors of a
few % on B system decay
constants & semileptonic
form factors
+
500 fb-1 @ BABAR/Belle
ICHEP04 Plenary 8/20/04 Ian Shipsey
5
The Experiments
Results used in this talk have been obtained by the following Collaborations:
Beam
K-+
t
Fixed Target
E791
FOCUS
Hadron
Photon
~ 2  104 ~ 2  105
~ 40 fs
~ 40 fs
LEP
e e  Z 0
~ 104 /expt.
~ 100 fs
e e
CLEO
BaBar/Belle
e e
~ 106
~ 2  105
~ 140 fs
~ 160 fs
pp
CDF
pp
~ 106
~ 50 fs
The B Factories and CDF now have the largest charm samples.
New this year:
Beam
K-+
t
(Pilot run)
BESII
CLEO-c
ee  (3770)
3
~ 2.7 103 ~ 5.4 x10
Not
Not
applicable applicable
Exceptionally low background charm samples
were obtained at BESII & CLEO-c ideal for
measuring absolute charm branching ratios.
Note:K-+ is # reconstructed in published analyses, not total collected.
ICHEP04 Plenary 8/20/04 Ian Shipsey
6
Charm Hadron Lifetimes
Br

Lifetime needed to compare Br(expt) to  (theory)

Interpreted within O.P.E.
(Hc )  spect  O(1/ m ) PI ,WA,WS (Hc )  O(1/ m )
2
c
4
c
Spectator effects (PI.WA,WS) are O(1/mc3) but phase space enhanced
e
ve
Muon decay:
 
GF2 m5
192

3
D+
v
Naïve spectator model:
charm  (2  3) e, 
charm
ud
GF2 mc5
2

V
  charm  700 fs
cs
192 3
(D+) ~1,000 fs  (D0) ~400 fs.
ICHEP04 Plenary 8/20/04 Ian Shipsey
Ds+
baryons
Gross features of lifetime hierarchy can be explained
7
SELEX, FOCUS, CLEO
E791 E687
Charm Lifetimes
 (D  )
Charm
PDG2004
Dominated
By FOCUS
2002 results
x10
1040  7 fs
 ( Ds )
504  4 fs
 (D0 )
410.3  1.5 fs
 (  c )
442  26 fs
 ( c )
200  6 fs
 ( 0 c )
11213
10 fs
 ( c )
69  12 fs
 ( ps)
beauty
PDG2004
Lifetimes are PDG2004 except Ds
which is a PDG2004 + FOCUS average.
D+ 7 ‰, D0 4 ‰, Ds 8 ‰, c3%,  0 10%, +c 6 %,  c 17%
some lifetimes known as precisely as kaon lifetimes.
 ( D )
 2.5
0
 (D )
 ( B )
 1.1
0
 (B )
PDG2004
x1.3
 ( ps)
Charm quarks more
influenced by hadronic
environment than
beauty quarks.
Errors on lifetimes are not a limiting factor in the measurement of absolute rates.
ICHEP04 Plenary 8/20/04 Ian Shipsey
8
Status of Absolute Charm Branching Ratios
Br
Poorly known
Measured very precisely


decay constants
form factors
Key hadronic charm decay
modes used to normalize
B physics
Mode
PDG04 (%) Error (%)
0.080.17
100
0.05
D+

Ds+

0.60 ±0.14
24
D0
  e
0.390.23
0.11  .04
45
Do
K-+
D+
3.80±0.09
2.4
K-+ +
9.2±0.6
6.5
Ds+
f+
3.6±0.9
25
c
pK-+
5.0±1.3
26
J/ 
5.88 ±0.10
1.7
Charm produced at B Factories/Tevatron or at dedicated FT experiments allows relative rate
measurements but absolute rate measurements are hard because backgrounds are sizeable &
because # D’s produced is not well known.
#X Observed
Br ( D  X ) 
efficiency x #D's produced
ICHEP04 Plenary 8/20/04 Ian Shipsey
Backgrounds are large.
#D’s produced
is not well known.
9
1:
•
•
New Measurement of B(Ds+ f p+)
B0  Ds* D* : partial reconstruction
ICHEP ABS11-0952
Ds+ from Ds*+  Ds+ is not reconstructed
Pair D*- ( D0 -) &  , assume from B0 Ds*+D
Data sample:
124 million B pairs

Signal: 7414 ± 345
B0

S
0
D

K     , K S  

D This result independent
of B(Ds+ fp+)
(1.85 ± 0.09(stat) ± 0.16(syst) )%
mmiss  ( Ebeam  ED*  E )2  ( pB  pD*  p )2
2:
D
( DS )
Recoil mass
B(B0 Ds*+D*-) =
K   , K   0 ,
mES 
:
(A)
2
Ebeam
 ( pD*  pD* )2
s
B0  Ds* D* : full reconstruction
Ds+ f (K+K)  fully
B (B0 reconstructed
Ds*+ D*) x B (Ds+ f +) = (8.71  0.78(stat)) x10-4
•
Divide by (A)
Signal 212 ±19
12.5% total error (7.5%) syst
B(Ds+ f +) = (4.71 ± 0.47(stat) ±0.35(syst))% BIG improvement!
B(Ds+ f +) = (3.6 ± 0.9)% (PDG) CLEO Similar Partial recons. B0  Ds* D*

0
 
(25%)

(
D

f
)
/

(
D

K
 )
ICHEP04 Plenary 8/20/04 Ian Shipsey
s
10
Absolute Charm Branching Ratios at Threshold (CLEO-c)
CESR (10 GeV)
 CESR-c (3-4GeV)
CLEO III Detector
 CLEO-c Detector
CESR upgraded to CESR-c: 12 wigglers
(for damping at low energy)
6 last summer 6 this summer
9/03-3/04 6 wiggler Pilot Run L=4.6  1031 (as expected)
57.1 pb -1at  (3770) (6 MarkIII,  3 BESII)
Fall 2004 goal: 3 fb -1 at  (3770) ( DD) (60 data in hand)
Fall 2005 goal: 3 fb -1 at ~ 4140 MeV Ds Ds threshold
Fall 2006 1 billion J/
Minor modifications:
replaced silicon with 6 layer
low mass inner drift chamber
summer ’03. + B 1.5T 1.0T
ICHEP04 Plenary 8/20/04 Ian Shipsey
ICHEP ABS8-0775
11
Absolute Charm Branching Ratios at Threshold (CLEO-c)
• Operation at (3770)  DD
ICHEP ABS8-0775
1st CLEO-c DATA
57 pb-1 ~ 340,000 DD pairs
•Measurements use D tagging: exclusive reconstruction of 1 D
2
2
• D’s: large, low multiplicity, branching ratios ~1-15%
M D  Ebeam
 pD
• high reconstruction efficiency, favorable S/N
E  Ebeam  ED
 High net tagging efficiency: ~25% of all D’s produced are reconstructed (achieved).
D0  K  
Single
tags
DATA
(Prelim.)
~57 pb-1
D0 candidate Mass (GeV)
ICHEP04 Plenary 8/20/04 Ian Shipsey
D0  K   0
Single
tags
DATA
(Prelim.)
~57 pb-1
D0 candidate Mass (GeV)
12
Absolute Charm Branching Ratios at Threshold
ICHEP ABS8-0775
Preliminary
Doubly
Tagged
D+K-++,
D-K+--
Prelim.
DATA
~57 pb-1
D  K    , D  K   
D candidate mass (GeV)
Tagging effectively creates a single D beam
#X Observed
Br ( D  X ) 
efficiency for X  #D's Where # of D’s = # of tagged events
ICHEP04 Plenary 8/20/04 Ian Shipsey
13
Absolute Charm Hadronic Branching Ratios and   DD 
Xi
ICHEP ABS8-0775
D
Single
tagged D
e+
0
Double
tagged D
e
D0

Ni  2NDD Bii
K+
Ni2  ii

4 Nii  i2
N DD
Technique pioneered by Mark III
5 modes, combined 2 fit extract 5 Bi &
N(DD), convert to  with Ldt.
Parameter
(1.98  0.04  0.03)  10
D 0 D0 & D D yields convert to  with Ldt
BD  K  
0.0392  0.0008  0.0023
5

0

B D
B D 0  K    0
0
B D   K   

 K S0 


0.081  0.002  0.009
(1.48  0.06  0.04)  105

0.098  0.004  0.008
 B D  K  
    B D  K  
  BD  K   
K  
0
0
 K



K
0
S

0.0161  0.0008  0.0015

0
0.143  0.003  0.010
 K    
ND D

BD
BD
BD
B D



0


0





3.64  0.05  0.17

2.05  0.03  0.14
0.164  0.004  0.006
ICHEP04 Plenary 8/20/04 Ian Shipsey
+
D0
e+
e
D0
K+

Nii  NDD B 
2
i ii
  DD  required to estimate reach.
Fitted Value
ND0 D0
K-
 (D0 D0 ) =(3.47  0.07  0.15)nb
 ( D + D- ) =(2.59  0.11  0.11)nb
 ( DD) =(6.06  0.13  0.23)nb
CLEOc
 ( DD) =(5.0  0.5)nb (Mark III)
Cross section in agreement with Mark III
Meson factory figure of merit:
 (BB)  tag  Ldt=500fb-1
#B tags @B Factory

~1
#D tags @Charm Factory
 (DD)  tag  Ldt=3fb-1
BESII similar analysis using 8 modes.
but with less statistics comparison
14
Absolute
Hadronic
Branching
Ratio
Summary
BESII
CLEO-c.
%
D  K   
%
Most precise measurement.
D 0  K  
For many other modes
statistical precision is
similar to other
measurements entering
the PDG average.
%
%
 B / B(%)
Decay
PDG
Agreement BES /CLEOc /PDG is good.
Outlook (my estimate) for 3 fb-1
D0 D+ systematics limited.
ICHEP04 Plenary 8/20/04 Ian Shipsey
CLEO  c
D 0  K  
2.4
0.6
D   K   
6.1
0.7
DS  f
25% 12.5%( BABAR)
1.9 15
fD+from Absolute
Br(D+ 
B ( D   ) /  D  (const.) f

md  (const.)  f Bd
Hadronic
tag
2
D
2
BBd  Vtd
Vcd
2
D- D+   

|fD|2
|VCKM|2
l
2
Bd
2
Vtb
Bd

ICHEP ABS11-0776
Mark III <290 MeV
1 track  consistent no showers
MM 2  ( Ebeam  E )2  ( PDtag   P )2
Tags 28575
preliminary
Signal 8
CLEO-c
B  (3.5  1.4  0.6) 10 4
f D   (201  41  17) MeV
121  32
f D   (365 113
 28 ) MeV
8 signal
candidates
D   
-1
with
3fb
f D to 2.3%
f DsIan
to 1.9%
@ s ~ 4140MeV
ICHEP04: Plenary
8/20/04
Shipsey
3
• BES
• Lattice 2004
• CLEO-c
• Isospin Mass Splittings
• Potential Model
• Rel. Quark Model
• QCD Sum Rules
LQCD error 10%
• QCD Spectral Sum Rules
Expt. 22%
• MILC
• UKQCD
~57 pb-1
MM2 (GeV2 )
5400
preliminary
BESII
0.25
(2004)
0.092  0.01
B  (0.12 0,063
 0.009 )%
Bkgd 1.07  1.07
D  K 0 
BES I: 1 event (1998)
150
180
210
240
270
300
330
360
390
420
450
480
510
Charged D Decay Constant (MeV)
16
Absolute Charm Semileptonic Decay Rates
|VCKM|2
d
G
2 3
2 2

|
V
|
p
|
f
(q
)|
cs
K

2
3
dq
24
2
F
|f(q2)|2
I. Absolute magnitude & shape of form factors are a stringent test of theory.
II. Absolute charm semileptonic rate gives direct measurements of Vcd and Vcs.
III Key input to precise Vub
( B    FNAL unquenched)
Vub
V  (3.27  0.70  0.220.85 ) 103
ub
Typical exclusive
Vub presented
by A. Ali.
Stat
B
HQET
D
sys
b
c
0.51
FF
u
d
 l

Theory error
>20%.
 l
1) Measure D form factor in Dl. Tests LQCD D form factor calculation.
2) BaBar/Belle can extract Vub using tested LQCD calc. of B form factor.
3) But: need absolute Br(D l) and high quality d (D l)/dE neither exist.
ICHEP04 Plenary 8/20/04 Ian Shipsey
17
CLEO III
at 10 GeV
l
Kl
Dl/Kl
Use D*D
Observable: m=D*-D
Rate & Form Factor
 reconstruction
1st measurement of a form
ICHEP ABS8-0781
factor in Cabibbo suppressed
D semilpetonic decay.
2
2
3
d   D  P   GF Vcq PP
2 2

f
(
q
)

Note:
dq 2
24 3
absence
of kinematic
separation
d
dq 2
e
Ke
M (GeV)
pilnu/klnu
0.10
  e 
Cleo (04)
E687 (96)
0.14
Cleo (95)
  e 
  Ke0.12

0.08
A big advance in precision!
0.06
ICHEP04 Plenary 8/20/04 Ian Shipsey
  Ke 
f  (0)
K

f (0)
 0.082  .006  0.005 CLEO
(Measure of SU(3) breaking)
 0.86  0.07  0.05  0.01
stat
syst
CKM
18
tag  D
D   K / K * /  /   e

K-
CABIBBO ALLOWED
e


K+
e+
Absolute D0 Semileptonic
Branching Ratios at Threshold
ICHEP ABS8-0781
π+
CABIBBO SUPPRESSED
D0   e
Note:
D0  K  e kinematic
separation.
D0  K  e  
Umiss  Emiss  Pmiss
U miss
First
Observation
D0   e
D0  K *e 
U
ICHEP04 Plenary 8/20/04miss
Ian Shipsey
U miss
Preliminary
U miss
19
tag  D
Absolute D0 & D+ Semileptonic
D   K / K S0 /   e  Branching Ratios at BESII
D  KS0e
D0  K e
D0   e
U miss
GeV
Experiment
Hep-ex/0406028
Phys. Lett. B597
(2004) 39-46
( D0  K  e )
( D0  K 0 e )
KS0e recoil mass (GeV)
preliminary
BES II
MARK III
PDG2004
1.15  0.29  0.09
1.44  0.62
1.4  0.2
preliminary
Longstanding puzzle in charm decay, ratio should be unity (Isospin),
New BES II result moves ratio in the right direction.
ICHEP04 Plenary 8/20/04 Ian Shipsey
20
Absolute D0 & D+ Semileptonic Branching Ratios
Summary BESII & CLEO-c
D0  K e
%
D0   e
%
BES II/CLEO-c analyses in good agreement but statistics limited. For  e  CLEO-c
is already more precise than PDG. With 3fb-1 stat error on e will approach 1%.
D00e has been observed for the first time: useful for Grinstein’s Double Ratio.
Br  D 0  K  e  ve  (%)
Br  D 0    e  ve  (%)
Br  D   K 0 e  ve  (%)
BES
3.82  0.40  0.27
0.33  0.13  0.03
8.47  1.92  0.66
CLEO-c
3.52  0.10  0.25
0.25  0.03  0.02
--
3.4  0.5  0.4
0.390.23
0.11  0.04
6.02.2
1.3  0.7
3.58  0.18
0.390.23
0.11  0.04
6.7  0.9
Experiment
MARK III
PDG 04
B(D0   e )  (0.19  0.04  0.02)% B(D0  K *e )  (2.07  0.23  0.18)%
ICHEP04 Plenary 8/20/04 Ian Shipsey
21
Testing the Lattice with (semi)leptonic Charm Decays
D l
0
1fb-1
CLEO-c
MC
D0 Kl
U = Emiss - Pmiss
d D  l
dp
0
CLEO-c
MC
p (GeV/c)
Lattice QCD
d D0 l
dp
p (GeV/c)
CLEO-c/BESIII PS  PS & PS  V absolute form factor magnitudes & slopes to
a few%. Note: LQCD most precise where data is least but full q2 range calculable.
Need LQCD FF with few % precision before these measurements are made.
(D+ l / (D+ l independent of Vcd tests amplitudes ~2%
(Dsl / (Dsl independent of Vcs tests amplitudes ~ 2%
D0  K e  Vcs /Vcs = 1.6% (now ~10%)
3fb-1
D0   e Vcd /Vcd = 1.7% (now: 7%)
Tested lattice to calc. B semileptonic form factor, B factories use Blv for precise Vub
Blv shape is an additional cross check.
ICHEP04 Plenary 8/20/04 Ian Shipsey
22
Unitarity Tests Using Charm
 d '  Vud Vus Vub   d 
 
 
 s '   Vcd Vcs Vcb    s 
  
b '  
  Vtd Vts Vtb   b 
uc*=0
2nd row: |Vcd|2 + |Vcs|2 + |Vcb|2 = 1 ??
CLEO –c: test to ~3% (if theory D K/l good to few %)
& 1st column: |Vud|2 + |Vcd|2 + |Vtd|2 = 1 ?? with similar
precision to 1st row
(3fb-1)
uc*
|VubVcb*|
|VudVcd*|
|VusVcs*|
Compare ratio of long sides to 1.3%
ICHEP04 Plenary 8/20/04 Ian Shipsey
23
Charm Inclusive Semileptonic Decay at Threshold
From 57 pb-1 of (3770) CLEO-c data: Preliminary
(4S ) measurements
are systematics limited.
ICHEP ABS11-0777
CLEO-c DATA
CLEO-c DATA
PR PLOTS NO
Br YET
D+  Xe+
D0  Xe+
Electron Momentum (GeV/c)
Electron Momentum (GeV/c)
Stat. Uncertainty ~ 0.6%
Stat. Uncertainty ~0.5%
PDG: BR = (17.21.9)%
PDG: BR = (6.750.29)%
ICHEP04 Plenary 8/20/04 Ian Shipsey
24
Charm As a Probe of Physics Beyond the
Standard Model
Can we find violations of the Standard Model at low energies?
Example  Decay  missing energy
 W (100 GeV mass scale) from experiments at the MeV mass scale.
The existence of multiple fermion generations appears to originate at
high mass scales  can only be studied indirectly.
CP violation, mixing and rare decays  may investigate the physics at
these new scales through intermediate particles entering loops.
Why charm? in the charm sector the SM contributions to these effects
are small  large window to search for new physics
CP asymmetry≤10-3 D0 - D0 mixing ≤10-2
Rare decays ≤10-6
charm is the unique probe of the up-type quark sector (down quarks
in the loop).
High
statistics
instead
of
High
Energy
ICHEP04 Plenary 8/20/04 Ian Shipsey
25
D Mixing
Mixing has been fertile ground for discoveries:
Vcs
s
K
0
c Vcd
W
d
K
W
d
*
ud
V
s
*
us
u V
0
CKM factors c2
same order as kaon
i.e.s u
Mixing
rate 1
Mixing rate (1958) used to bound c quark mass  discovery(1974).
CPV part of transition , K (1964), was a crucial clue top quark existed  discovery (1994).
Vtb
Bd0
b
t
d
W
Vtd
d
t

Vtd* W Vtb*
b
Bd0
dominated by top  (mt2 - mc,u2) )/mW2  Large
B lifetime Cabibbo suppressed Vcb2
Mixing
Mixing also Cabibbo suppressed (Vtd2)
Mixing rate  early indication m top large rate 1
CKM factors c2 ~ 0.05
Mixing
(b-quark  VubVcb negligible)
rate 0.05
But D not Cabbibo suppressed (Vcs~1)
Additional suppression: Mixing  (ms2 - md2)/ mW2 = 0 SU(3) limit.
2 x [SU(3) breaking]2<O(10-3)
SM
mixing
small


c
ICHEP04 Plenary 8/20/04 Ian Shipsey
10-2 possible
26
mixing rate = |amplitude|2
Theoretical “Guidance”
mixing rate = |amplitude|2
current
experimental
sensitivity
SM Mixing Predictions
x mixing: Channel for New Physics.
x
M

y (long-range) mixing: SM background.
y=/2

y
2
x=M/
New Physics Mixing Predictions
New physics will enhance x but not y.
Rmix 
x=M/
(A. Petrov, hep/ph 0311371)
ICHEP04 Plenary 8/20/04 Ian Shipsey
1
2
x
2
 y2 
SM mixing predictions ~ bounded by box
diagram rate & expt. sensitivity. New Physics
predictions span same large range  mixing
is not a clear indication of New Physics.
No CP-violating effects expected in SM.
CP violation in mixing would therefore
be an unambiguous signal of New Physics.
27
Status of y
 CP   CP 

2 CP   CP 
Easier, measure CP-even
decay relative to D0->K-+:
(1/2 CP even ½ CP odd)
I take f=0 in the average:
yCP  (0.9  0.4)%
Belle 03
0.00
y
Belle 01
6.00
1
BABAR
CLEO
FOCUS
Early FOCUS measurement
with non zero yCP:
Y  y cos f , Y  x sin f
E791
yCP
 D0  K   

1
0


 D  K K 
The observables become:
YCP (%)
y
More recent analyses allow for   D0  K  K    D0  K  K  
CP violation comparing:
  D0       D0     
No evidence for CPV is found.
-6.00
x
yCP
ICHEP04 Plenary 8/20/04 Ian Shipsey
E791
(0.8  2.9  1.0)%
FOCUS
(3.4  1.4  0.7)%
CLEO
Belle 01
(1.1  2.5  1.4)%
(0.5  1.0  0.8)%
BABAR
(0.8  0.4
Belle 03
+0.5
-0.4)%
(1.15 0.69  0.38)%
28
Search for D Mixing in Semileptonic Decays
x2  y 2
Two new measurements presented at this conference sensitive to
RS Right-Sign unmixed decays
D*+
D*-
D0 +tag
K-e+
D0
•Flavor at decay is tagged by lepton
The mixing rate is given by
-


  t
WS (t )   exp   t
 
 D0 

 

 D0
tag
K+e-
WS Wrong-sign mixed decays
D*+
D*-
D0 +tag
D0
K+e-
D0 -tag
D0
•D*+ decays: D*+  D0
•Flavor at birth is tagged by pion from D*
decay
K-e+
ICHEP04 Plenary 8/20/04 Ian Shipsey




2
 x2  y 2 


4




 Quadratic time
t
 RS (t )   exp  
 dependence
 D0 



Belle 140 fb-1
D0  K (e /  )
mixing
rate
ICHEP ABS11-0703
Neutrino reconstruction
29
Search for D Mixing in Semileptonic Decays
unmixed
m  m( D* )  ( D0 )
Nunmix  40198  329
Rmix
mixed
Nmix  19  67
Nunmix  unmix


 (0.20  0.70) 103 (stat)
N mix
 mix
Rmix  1.4 103 at 90% CL (stat + sys)
ICHEP04 Plenary 8/20/04 Ian Shipsey
30
Search for D Mixing in Semileptonic Decays
ICHEP ABS11-0629
• Unbinned extended maximum likelihood fit to transverse lifetime and M = M(D*)-M(D0) with
15 floated parameters DK and K* e v continuum events 80fb-1 ON 7.1fb-1 OFF
mixed
M projection
Unmixed
M signal region
D0 signal
Peaking D+
Random D+
Random D0
Zero Life
Note very
different
horizontal
& vertical
scales
m  m( D* )  ( D0 )
Unmixed D0 yield: 49620 ± 324 evts (stat)
Rmix  Nmix / Nunmix
R mix 0.0023 0.0012 stat
0
•N(mix): 114 ± 61
0.0004 syst
R mix 0.0042 90% C.L.
ICHEP04 Plenary 8/20/04 Ian Shipsey
m  m( D )  ( D )
*
(~5% probability of getting
a larger result for Rmix=0)
31
D Mixing Semileptonic Summary
Year
Expt.
R mix
90% C.L.
Rmix 
1
2
x
2
 y2 
FOCUS result is unpublished
M. Hosack Fermilab Thesis 2002-25.
ICHEP04 Plenary 8/20/04 Ian Shipsey
2004 Belle
 1.4 10-3
2004 BABAR
<4.2 10-3
2002 FOCUS
<1.3110-3
2002 CLEO
 8.6 10-3
1996 E791
 5.0 10-3
BABAR & Belle are adding
more data and expect to publish
improved upper limits soon.
32
Vcs Vcd ~ cos 4  c
Search for D Mixing in DK
2
ICHEP ABS11-0704
W+
Sensitive to both x and y, and linear in y.
Best constraints come from this mode.
“right-sign” (RS)
=> Cabibbo-favored decays
“wrong-sign” (WS) => Mixing or doubly
Cabibbo-suppressed decays.
D0
doubly
Cabibbo
suppressed
(RD)
K  
mixing
(x2+y2)
D0
Cabibbo
Favored
(CF)
“Wrong sign”
CP Violating effects are measured
by fitting D0 and D0 separately.
ICHEP04 Plenary 8/20/04 Ian Shipsey
2
D0
c
u
Vcd Vus ~ sin 4  c
2
2
W+
D0
c
u
u
+
d
s
Ku
u
K+
s
d 
u
Need to fit proper decay time in order to
distinguish mixing (both x and y) from doubly
Cabibbo-suppressed (DCS) decays:


r  t    RD  RD y t  14  x2  y2  t 2  e t


DCS
interference
mixing


Complication: phase difference, K,
between CF and DCS amplitudes can
lead to observable quantities x’ and y’,
related to x and y by a rotation.
33
The Wrong Sign Rate
90 fb1
Observables:
S/B~1
0.30
0.40
x2 statistics of previous
measurements.
K  
K  
Rws [%]
AD [%]
E791 (66)
5.6K
not quoted
0.680.34
0.33  0.07

ALEPH (67)
1038
19
1.84  0.59  0.07

FOCUS (68)
37K
150
0.404  0.085  0.025

CLEO (61)
13.5K
45
0.3320.063
0.065  0.040
 219
20  1
Belle (63)
83K
845
0.371  0.018
8.0  7.7
BaBar (62)
120K
430
Average
( D  K  )
4

(0.371

0.018)%
~
tan
c
0
 
( D  K  )
B( D0  K   ) ~ 1.4 104
0

BABAR
0.50
Belle
D0  K  
845  40
FOCUS
0.60
CLEO
RWS (%)
0.70
Wrong sign
RWS 
E791
D*  D0 
Right sign : D0  K   228K
3 cut on Q

ICHEP04 Plenary 8/20/04 Ian Shipsey
0.357  0.022  0.027 9.5  6.1  8.3
0.368  0.021
RWS  (0.368  0.021)%
34
Simulation
Data
Fit to WS
Courtesy : Ji Lin
(decay)
(Mixing)
This is a substantial improvement on previous results.
ICHEP04 Plenary 8/20/04 Ian Shipsey
35
Mixing Summary
Combining all results:
CP conservation
is assumed.
No statistically
significant evidence
for mixing has yet been
found.
2004 update for ICHEP
World
95%CL
x-y
World
95% CL y
CDF expect a mixing
result using D K
soon.
Important to measure
 can be done at a
charm factory.
G. Burdman and I. Shipsey
Ann. Rev. Nucl. Part. Sci. 53 431 (2003)
arXivhep-ph/0310076 (updated August 20 2004).
ICHEP04 Plenary 8/20/04 Ian Shipsey
36
CPV in D Decays
I’ll ignore CP violation in mixing (as it is negligible).
CPV via interference between mixing & decay (D0 only)
(
D0
f
D0
) ≠ 
Time dependent since
mixing is involved
Experiment concentrates on this
Direct CPV:
ACP
f
D0
Very small in charm since mixing is suppressed
(i.e. good hunting ground for New Physics).
(

D0
A1ei1
) ≠ 
f
D
A2ei 2
A1*ei1

f
D
* i 2
2
Ae
( f )  ( f )
2 ImA1 A2* sin(1   2 )
3



10
( f )  ( f ) A1 2  A2 2  2 ReA1 A2*cos (1   2 )
2 weak amplitudes with phase difference
ICHEP04 Plenary 8/20/04 Ian Shipsey
strong phase-shift
37
Direct CP Violation
Acp 
Im VcdVud* VcsVus* 
2
In Standard Model Direct CPV only for Singly
Cabibbo suppressed decays.
1) Consider D0 → 
(same for K+K, K+K, f,K*K
K+K0, , 0, etc...)
W+
c
D0
u
u 
sin  PT
d 
D 0c
u
ICHEP04 Plenary 8/20/04 Ian Shipsey
u 
d
d 
u
P
 103
T
*
cd ud
1 3
I  ,
2 2
different
weak
phases
different
strong
phases
are likely
V V
Suppressed…
u
W+
s
A2 4 sin  PT
Standard Model Contribution ACP ~ 10-3
New Physics up to ~1%
If CP~1% observed:is it NP or hadronic
enhancement of SM? Strategy: analyze
many channels to elucidate source of CPV.
Since this decay is
Singly Cabibbo
d
P
T
…we can modify
it’s topology in
a simple way to
get a penguin.
Vcs*Vus
I 
1
2
38
Search for Direct CP Violation in D  K K 




ICHEP ABS11-0629
79.9 fb-1
Three ACP measurements: (1) KK (2) f , (3) KK ~43,000 events
relative to Ds+  KK as control [Cabibbo favored hence no CP].
D /D K K 


s



D / Ds  K  K  
M(KK)
ACP ( K  K   )
%
For f & K * K
significant
improvement
over previous
measurements.
% Ian Shipsey
ICHEP04 Plenary 8/20/04
%
39
Search for Direct CP Violation in D0     , K  K 
ICHEP ABS11-0535
D0
D0
KK
8190 140
8030 140

366069
367468
Mode
D* to tag D0 flavor. Measure relative to D0K
Cabibbo allowed mode (Acp=0) as control).
123pb-1
D 0    
16220
7334  97
ACPKK(%)
D0  K  K 
1
0.00
ACP KK  (1.2 1.0)%
-5.00
ACPpipi(%)
ACP D
0
  
CLEO
(0.0  2.2  0.8)%
(1.9  3.2  0.8)%
E791
(1.0  4.9  1.2)%
(4.9  7.8  2.5)%
FOCUS
(0.1  2.2  1.5)%
(4.8  3.9  2.5)%
CDF
(2.0  1.7  0.6)%
(1.0  1.3  0.6)%
ICHEP04 Plenary 8/20/04 Ian Shipsey
-6.00
CDF
 K K 
FOCUS
0
1
E791
0.00
Cleo
6.00
ACP D
FOCUS
D*  D 0  ,
E791
D*  D 0  ,
Cleo
5.00
CDF
Time integrated
Most recent (& precise) result.
ACP  (1.3 1.2)%
Time dependent measurements can
distinguish direct & indirect CPV.
CDF plan this. BABAR/Belle (2003)
found no evidence for indirect CP
at the 1% level (see y status slide).
40
Rare Decays
FCNC modes are suppressed by the GIM mechanism:
D0  e e  (B
D0      (B
10-23 )
310-13 )
The lepton flavor violating mode D0  e
is strictly forbidden.
Beyond the Standard Model, New Physics may enhance these, e.g.,
R-parity violating SUSY:
B  D 0  e  e   up to 10-10

BD

 up to 10
B D 0      up to 10-6
0
 e
(Burdman
-6
et al., Phys. Rev. D66, 014009).
ICHEP04 Plenary 8/20/04 Ian Shipsey
41
Search for D  e e ,   , e 
0
 


ICHEP ABS11-0964
121.6 fb-1
Search channels
Reference channel:~ 10,000
events in search window
(depending on final state).
Large backgrounds,
only D0 final states are
tractable in e+e- at
10 GeV so far.
Use D*D0 tag.
Measure relative to
D  .
3 evt
D*  D0 
D0    
1 evt
mode
0 evt
mass(+,-) (GeV)
W+
D0
c
u

prev
e e
u
+
m(
d
c
0
d -D

u
u
standard model rate ~ 10-3
ICHEP04 Plenary 8/20/04 Ian Shipsey
 
1.2 6.2
    1.3 2.5
)
e   0.81 8.1
W+
s,d,b
ULx106

+e+
-e-
standard model rate ~ 10-13 (10-23 )
Big
Improvement!
D0  e  
forbidden.
42
Rare Decay Summary
Sets MSSM constraint
Presented at
this conference
Close to Long Distance Predictions
August
2004
For D+ all charged
final states are
well-suited to fixed
target experiments
FOCUS has best limits
Expt. sensitivity 10-5-10-6
Just beginning to confront
models of New Physics in
an interesting way.
Still plenty of room
for New Physics.
Outlook: bright
CDF, B factories,
charm factories,
BTeV.
1023
ICHEP04 Plenary 8/20/04 Ian Shipsey
43
BEPCII/BESIII Project
Design
• Two ring machine
• 93 bunches each
• Luminosity
1033 cm-2 s-1 @1.89GeV
6 1032 cm-2 s-1 @1.55GeV
6 1032 cm-2 s-1 @ 2.1GeV
• New BESIII
Status and Schedule
• Most contracts signed
• Linac installed
2004
• Ring installed
2005
• BESIII in place
2006
• Commissioning
BEPCII/BESIII
ICHEP04 Plenary 8/20/04 Ian Shipsey
beginning of 2007
44
Summary
New Physics searches in D mixing, D CP violation and in rare decays by
BABAR, Belle and CDF have become considerably more sensitive in the past year,
however all results are null.
In charm’s role as a natural testing ground for QCD techniques there has been
solid progress. The start of data taking at the 3770) by BESII and CLEO-c
(and later BESIII) promises an era of precision absolute charm branching ratios.
The precision with which the charm decay constant fD+ is known has already improved
from 100% to ~20%. A reduction in errors for decay constants and form factors to
the few % level is promised.
This comes at a fortuitous time, recent breakthroughs in precision lattice QCD
need detailed data to test against. Charm can provide that data. If the lattice passes
the charm test it can be used with increased confidence by:
BABAR/Belle/CDF/D0//LHC-b/ATLAS/CMS/BTeV to achieve precision determinations
of the CKM matrix elements Vub, Vcb, Vts, and Vtd thereby maximizing the sensitivity
of heavy quark flavor physics to physics beyond the Standard Model.
Charm is enabling quark flavor physics to reach its full potential. Or in pictures….
ICHEP04 Plenary 8/20/04 Ian Shipsey
45
Precision theory + charm = large impact
2004
ICHEP04 Plenary 8/20/04 Ian Shipsey
Theoretical
errors
dominate
width of
bands
46
Precision theory + charm = large impact
2004
precision QCD calculations
tested with precision charm
data
theory errors of a
few % on B system decay
constants & semileptonic
form factors
+
500 fb-1 @ BABAR/Belle
ICHEP04 Plenary 8/20/04 Ian Shipsey
47
• Results I did not have time to cover:
• Measurement of B  Ds*  Ds 0  B  Ds*  Ds   [11-0953]
• Relative BF of Cabibbo-suppressed


c
decay modes [11-0963]
• Study of 0c   K  and 0c    [11-0938]
(See excellent talk by Matt Charles in Parallel Session 11 HQ(5) for details.)
For more detail on results presented see talks in HQ(5) & HQ(6) by: Alex Cerri, Matt Charles,
Jiangchuan Chen, Yongsheng Gao, Ji Lin, Milind Purohit, Gang Rong, and Anders Ryd.
Two recent
reviews:
S. Bianco, F. L. Fabbri, D. Benson & I. Bigi, hep-ex/0309021.
G. Burdman & I. Shipsey, Ann. Rev. Nucl. Part. Sci., 2003, hep-ph/0310076.
Thanks to the BABAR, Belle, BES II, CDF, CLEO/CLEO-c, and FOCUS collaborations for
producing such beautiful results. For their help providing plots and information for this talk thanks to:
BABAR: Matt Charles, Milind Purohit, Jeff Richman.
Belle: Tom Browder, Ji Lin, Bruce Yablsey.
BESII: Jiangchuan Chen, Fred Harris, Gang Rong, Li Weiguo.
CDF: Alex Cerri, Stefano Giagu.
CLEO-c Yongsheng Gao, Nabil Meena, Anders Ryd, Batbold Sanghi, Seunghee Son, Victor Pavlunin.
FOCUS: John Cumalat, Will Johns, Daniele Pedrini, Jim Wiss.
CKM Fitter: Andreas Hoecker, Lydia Roos.
ICHEP04 Plenary 8/20/04 Ian Shipsey
48
Additional Slides
ICHEP04 Plenary 8/20/04 Ian Shipsey
49
Precision Quark Flavor Physics
high precision determination Vub, Vcb, Vts, Vtd, Vcs, Vcd, & associated phases.
The Over-constrain the “Unitarity Triangles” - Inconsistencies  New physics !
goal
status
Vud, Vus & Vcb best determined due to flavor symmetries: I, SU(3), HQS.
Charm (Vcd & Vcs) beauty (Vub, Vtd, Vts) poorly determined. theoretical errors dominate.
Vud/Vud 0.1%
CKM
Matrix
Current
Status:
1 Free/bound
n
e

p
Vcd/Vcd 7%


Nc
Vtd/Vtd =36%
Bd
Solution
ei
K
l



Vcs/Vcs =16%
l
D
Vus/Vus =1%
1D
l

K
Vts/Vts 39%
Bd Bs
Bs
Vub/Vub 17%
l
i
e

B

Vcb/Vcb 5%
l
B

D
Vtb/Vtb 29%
1
t
W
b
Precision measurements in charm, especially absolute rates can calibrate QCD techniques
that will enable precise new measurements at Bfactories/Tevatron to be translated into
greatly improved CKM precision.
ICHEP04 Plenary 8/20/04 Ian Shipsey
50
Bd & Bs mixing & Charm Decay Constants
Bd  Bd mixing
Vtb
ALEPH,CDF,DELPHI,
L3,OPAL.BABAR/BELLE,
ARGUS/CLEO
Bs  Bs mixing
Vtd
ALEPH,CDF,
DELPHI,OPAL.SLD
 2 (lattice)
2
Vtd
Vtd Vtd

Vcb Vts
Vtb
md  (const.) f B2d BBd Vtd
M d  0.502  0.007 ps
-1
2
M d  BBd f Bd   Vtd 
 


M s  BBs f Bs   Vts 


2
Vtb
M d
M d
 /  ~ 6  8%??
2
 1.4%
Typical
fB2BB = (223  33 12)2 MeV2 Lattice
value
|Vtd|.|Vtb| = (9.2  1.4  0.5) 10 –3
World
Average
ms<14.5/ps
f Bd f Bs inaccessible
Dominant error.
|fD|2
|VCKM|2
l
f D f Ds accessible
B( D   ) /  D  (const.) f

(s)
(s)
2
D(s )
Vcd ( s )
(15-20% error) Lattice  fB/fBs & fD/fDs with small errors
fD/fDs (expt.) tests fD/fDs (LQCD) & gives
if f Bd Bd was known to 3%
confidence to fB/fBs (LQCD): precise Vtd / Vts
Vtd Vtb would be known to ~5%
fB/fD (LQCD) & fD (expt.) +Md precise Vtd
Same for Vts
ICHEP04 Plenary 8/20/04 Ian Shipsey

2
51
Role of precision absolute charm branching ratios
ALEPH, DELPHI,
L3,OPAL.BABAR/BELLE,
ARGUS/CLEO
Vcb Zero recoil in B  D*l+ & B  Dl+
d
2
*
2 2
3
(
B

D

)

F
(
q
)
V
V

(41.6

0.9

1.8
)

10
cb
cb
exp
theo
dq 2
2
2
F (q  qmax )  0.91  0.04
As B Factory data sets grow,
& calculation of F improve
a limiting systematic:
Lattice &
sum rule
(HFAG Summer 2004)
dB(DK)/dB(DK)
 dVcb/Vcb=1.2%
  Bo  D*+ h  
HQET spin symmetry test:
1
o
+ 
 B  D h 
Test factorization with B  DDs
Understanding charm content of B decay (nc)
Precision Z bb and Z cc (Rb & Rc)
At LHC/LC H  bb H  cc
ICHEP04 Plenary 8/20/04 Ian Shipsey
52
 CKM matrix elements Vcs Vcd at BESII
Vcd sinc
Vcs ~1
1.3%
but depends on Vcd/Vcd 7% D
P Vcs/Vcs =16%
13%
D
W  hadronsVud ,Vus,Vub
l

d    c, c  s  

G
 W  cs
D
W  v Vcd ,Vcb
(cc)
K
l


(D0  K e )  1.53| Vcs |2 | fK (0) |2 1011 s1
( D0   e )  3.01| Vcd |2 | f (0) |2 1011 s1
BES use current
theoretical predictions with
errors estimated at ~10%
f K (0)
f  (0)
Vcs/Vcs ~10%
Best
Determination
with Kl
Vcd/Vcd =23%
Not yet
competitive
Note: Goal of lattice QCD
few % error on
f K (0)
f  (0)
ICHEP04 Plenary 8/20/04 Ian Shipsey
Vcs
Vcd
|Vcs|(Expt) (theory)
|Vcd|(Expt) (theory)
BES(QCDSR)
1.0  0.05  0.15
0.25  0.05  0.05
BES(LQCD(1 )
1.1  0.060.06
0.13
0.26  0.050.03
0.04
BES(LQCD(2))
1.18  0.060.09
0.08
0.29  0.06  0.03
0.97  0.11(Wcs)
0.224  0.012
PDG2004
53
ISGW2
E687
E653
CLEO
R2
E791
ECL
UKQCD
BBD
BKS
LMMS
BKS
SPQR
APE
0.5
ISGW2
E653
3
1.0
ECL
AW/GS
2
E687
2.0
CLEO
2.5
circa 2004
Focus
BBD
3.0
R2
E791
UKQCD
LANL
BKS
Stech
KS
ISGW
20
Results are getting very precise and more
calculations are needed. Absolute values
of indivudual form factiors soon with
improved precision promised by CLEO-c.
ICHEP04 Plenary 8/20/04 Ian Shipsey
LMMS
0.5
BKS
APE
LMMS
LANL
1
1.5
LMMS
0
ISGW2
0.2
E691 E653
0.4
E791
0.6
Focus
1
0.8
15
WSB
1.2
10
E687
1.4
5
BEAT
1.6
2
circa 1999
0
0
R2
0
2.5
SPQR
0.5
3
1.5
KS
1
E691
Focus
1.5
BEAT
E791
E687
2
ISGW2
ISGW
WSB
2.5
E653
Rv
3
AW/GS
Stech
D+  K* & Ds  f form factor ratios
0.0
0
1
4
5
6
7
8
9
Dsfl form factor should be within
10% of D K*l R2 for Dsfl
was  2 higher than D K*l until
FOCUS (2004) .
54
Search for D0     
Search channel:
3 events in
search window
Reference channel:with similar
kinematics.
18 events
6 events
3 evt
J /     
mass(+,-) (GeV)
B(J/+,-) = (5.88 ±0.10) %
+need to know relative production crosssection
for J/ and D
ICHEP04 Plenary 8/20/04 Ian Shipsey
D0
c
u
mass(+,-) (GeV)
W+
+
s,d,b

-
BR(D0+) < 2.010-6
(90% CL)
hep-ex/0405059,
55
Three Types of CP Violation
Decay (AD)
|Af|  |Af |
2
D
SM  10 SCS only
Mixing (AM)
D0
2
D0
SM: Small because
mixing is small
2
D0
D0

f
SM: Extremely small
Interference
between mixing
and decay (f)

f
3
f
D0
+
2
D
D0
f
2
D0
f
2
D0

f
D0
f
D0
+
f
Experiments focus mostly on AD
ICHEP04 Plenary 8/20/04 Ian Shipsey
56