Transcript DOE 2003 Presenttion

m2(p+p0) (GeV2)
UIUC – HEP: CLEO Task
m2(p+p-) (GeV2)
Mats Selen
Aug 5, 2004
M. Selen, DOE Visit, 2004
1
Involvement in CLEO-c:
• CLEO Spokesman
• CLEO Run Manager
• Trigger Hardware
• Physics (of course)
: Mats (with David Cassel)
: Topher
: Topher, Norm, Paras
: Everyone
Analyses:
DSp (BR, double partial recon)
D0K-en (Mixing Analysis)
D0KSp0p0 (BR & Dalitz Analysis)
D0K+K-p0 (BR & Dalitz Analysis)
D0p+p-p0 (Dalitz Analysis)
: Jeremy (GG - finished)
: Chris (MS - finishing)
: Norm, Bob, Topher, Mats
: Paras, Bob (MS)
: Charles (MS – finished*)
New UIUC Involvement: Jim Wiss & Doris Kim
• Expertise in Dalitz analyses and SL decays
• Already involved with several analysis
• Very interested in D  Kpe (more later)
M. Selen, DOE Visit, 2004
2
Drift Chamber Crates
Gates
DR3 - TQT
G / CAL
ASUM
QVME
DM/CTL
STTR(12)
Endcap CC
TILE(8)
TIM
TIM
DM/CTL
Axial tracker
QVME
Stereo tracker
ASUM
AXTR(16) AXX(16)
Barrel CC
Analog
TILE (16)
DFC
TIM
DM/CTL
TRCR
TRCR
CCGL
CC Digital
TCTL
SURF
DAQ
L1D
AXPR
TPRO(4)
Flow control & Gating
CLEO
Mixer/Shaper
Boards
Level 1 decision
Mixer/Shaper Crates (24)
ctrl.
The CLEO-c
Trigger
TIM
DM/CTL
TPRO(2)
SURF
TIM
DM/CTL
M. Selen, DOE Visit, 2004
3
What it Looks Like
(all more or less alike to untrained eye)
M. Selen, DOE Visit, 2004
4
DSp
(Jeremy Williams, GG)
CLEO-II.V
• Badly measured at present: World average B(DSp ) = (3.6 ± 0.9)%
• Calibrates other DS decays: Equivalent of D0K-p+ for D0 decays.
Some DS branching fractions
M. Selen, DOE Visit, 2004
Some D0 branching fractions
5
Double Partial Reconstruction Approach:
N(DSp)
Need to evaluate
N(DS)
Look for
(1)
(2)
B0  DS*+ D*DS 
DS 
ps D0
ps (Kp…) Use to find N(D*S) from B DS* D*
DS 
ps D0
(p…)  ps D0
Use to find N(D*) from B DS* D*
Using the fact that N(D*S) = N(D*) from B DS* D*
to relate (1) and (2) and find B(DSp)
M. Selen, DOE Visit, 2004
6
Signal
Background
Total
M. Selen, DOE Visit, 2004
7
Preliminary new CLEO results:
B(DSp ) = (2.45 ± 0.42 ± 0.19)%
M. Selen, DOE Visit, 2004
8
D0 Ken (Mixing)
Chris Sedlack & MS
CLEO-II.V
D*+  p+ D0; D0  K- e+n Right Sign Signal (RS)
D*+  p+ D0; D0  D0; D0  K+ e-n Wrong Sign Signal (WS)
Some other p+ ; D0  K+ e-n Example of Wrong Sign Background
Hard part: Telling WS signal from background
Chris’ solution: Neural Net looking at a variety of kinematic vars.
M. Selen, DOE Visit, 2004
9
Training &
Evaluating
the Nets:
WS Signal
M. Selen, DOE Visit, 2004
r
WS Background
r
10
Fit for mixed & unmixed yields
using proper lifetime distribution:
Get signal and background shapes from MC.
RMIX = 1.1 ± 0.76 %
Example fit of partial data sample
Studying cuts & systematics before
opening the box on rest of data
M. Selen, DOE Visit, 2004
11
D0 Ksp0p0 Dalitz
S/(S+B) ~ 70%
S ~ 700
CLEO-II.V+III
• Complement KSp-p+ analyses
• Good place to search for low mass pp
• No r p0p0 to get in the way!
• Norm re-writing code
• Switching to CLEO-c data
m2(p0p0) (GeV2)
(Norm, BIE & MS)
m2(KSp0)RS (GeV2)
K*(890) + K0(1430) + f0 + NR + s
K*(890) + K0(1430) + f0 + NR
Lots more work
to do !
0
1
m2(p0p0) (GeV2)
M. Selen, DOE Visit, 2004
2
0
1
m2(p0p0) (GeV2)
2
12
D0K-K+p0 Dalitz
(Paras Naik, BIE & MS)
CLEO-III

New method for measuring CKM phase  by looking at B–
→ D0 K–, where D0 → K* K.



Phys.Rev. D67 (2003) 071301, Grossman, Ligeti, & Soffer
Needs a measurement of the strong phase difference dD between D0 →
K*+ K– and D0 → K*– K+.
D0 → K+ K– p0 is a great place to measure dD via interference!
– Phys.Rev. D68 (2003) 054010, Rosner & Suprun


Dalitz analysis - Resonant substructure
Previous D0 → K+ K– p0 branching ratio measurement
(CLEO II) can be revisited.
Vud Vub*
a
Vtd Vtb*

b
Vcd Vcb*
M. Selen, DOE Visit, 2004
B(D0  K+ K– p0) = (0.14  0.04)%
CLEO II result / PDG Value, 151 ± 42 events, 2.7 fb-1
Phys.Rev. D54 (1996) 4211, Asner, et al.
13
Data and Dalitz Plot
Both D0’s and D0’s plotted
CLEO III (4S) Region: 8.965/fb
D*+ → p+ D0
“K+” is really K- for a D0, etc…
Dominant resonances:
K+ K– p0
K* (892 MeV/c2)

 (1019 MeV/c2)
DATA
726 points
K Km p0
signal region
(after selection criteria)
Signal Fraction  77.4%
Signal Events  565
(in the signal region)
mK+p02 (GeV/c2)2
DATA

K*+
K*-
mK+K-p0 (GeV/c2)
M. Selen, DOE Visit, 2004
mK-p02 (GeV/c2)2
14
mK+K-2 (GeV/c2)2
Dalitz Fit Projections

K*+
DATA
M. Selen, DOE Visit, 2004
K*-
mK+p02 (GeV/c2)2
mK-p02 (GeV/c2)2
15
CLEO III
Dalitz Plot Fit
Preliminary!!!
Errors only from fit statistics
Resonance
amplitude a
phase q
K*(892)+
Fixed to 1
Fixed to 0
K*(892)-
0.5220  0.0541
331.28  10.10
 (1020)
0.6157  0.0573
102.80  13.27
nonresonant
5.8390  0.4506
223.10 
7.88
Just when things were humming along…
- disk crash
- still recovering, taking opportunity to rewrite much
of analysis code (i.e. make it better etc).
M. Selen, DOE Visit, 2004
16
D0p-p+p0
CLEO-II.V
m2(p+p0) (GeV2)
(Charles Plager)
** PRD in the works **
Amplitude
Phase
Fit Fraction
r+p-
1 (fixed)
0 (fixed)
76.5±1.8±4.8
r0p0
0.56±0.02±0.07
10±3±3
23.9±1.8±4.6
r-p+
0.65±0.03±0.04
-4±3±4
32.3±2.1±2.2
NR
1.03±0.17±0.31
77±8±11
2.7±0.9±1.7
S/(S+B) ~ 80%
S ~ 1100
No contribution from s(500) at ~1% level
0
1
2
m2(p+p-) (GeV2)
M. Selen, DOE Visit, 2004
3
0
1
m2(p+p0)
2
(GeV2)
m2(p+p-) (GeV2)
3
0
1
m2(p-p0)
2
(GeV2)
3
17
The Future of Charm Physics: CLEO-c
CLEO-c
Under
way !
y(3770) – 3 fb-1
30 million DD events, 6 million tagged D decays
(310 times MARK III)
S ~ 4140 MeV – 3 fb-1
1.5 million DsDs events, 0.3 million tagged Ds decays
(480 times MARK III, 130 times BES)
y(3100), 1 fb-1 & y(3686)
~1 Billion J/y decays
(170 times MARK III, 20 times BES II)
M. Selen, DOE Visit, 2004
18
CLEO-c
M. Selen, DOE Visit, 2004
What’s new ?
19
The Future of Charm Physics: CLEO-c
Heavy Flavor Physics: “overcome QCD roadblock”
• CLEO-c: precision charm absolute Br measurements
Leptonic decays  decay constants
Semileptonic decays Vcd, Vcs, V_CKM unitarity check, form factors
Absolute D Br’s normalize B physics
Test QCD techniques in c sector, apply to b sector
 improved Vub, Vcb, Vtd, Vts
Physics beyond SM will have nonperturbative sectors
• CLEO-c: precise measurements of quarkonia spectroscopy &
decay provide essential data to calibrate theory.
Physics beyond SM: where is it?
• CLEO-c: D-mixing, charm CPV, charm/tau rare decays.
M. Selen, DOE Visit, 2004
20
CLEO-c will soon have
50x more data than this!
M. Selen, DOE Visit, 2004
21
K+
Single & Double Tagging:
K-
D0
e+
e-
D0
pp+
M. Selen, DOE Visit, 2004
22
Absolute D branching ratios (S & D tagging)
M. Selen, DOE Visit, 2004
23
Absolute D branching ratios (S & D tagging)
M. Selen, DOE Visit, 2004
24
Tagging cleans things SL decays up a lot:
Dpe
M. Selen, DOE Visit, 2004
25
SL branching fractions with CLEO-c now (57.2 pb-1)
M. Selen, DOE Visit, 2004
26
A first analysis for Doris & Jim
Studying hadronic physics in charm semileptonic decay
0. The lack of final state interactions makes semileptonic decay a
particularly clean environment for studying hadronic physics. An
example is the complicated physics of broad s-wave resonances.
1. FOCUS was able to observe s-wave interference with the dominant
K*(896) channel in D+Kpmn and determine the phase shift near the
K* pole but FOCUS did not attempt to measure the variation of swave phase with Kp mass because of backgrounds.
2. How well can Cleo-c follow the s-wave phase and amplitude variation
given a yield comparable to FOCUS but with greatly reduced
backgrounds?
3. What can we learn about interference in other 4 body semileptonic
decay?
27
Interference in D+ K* mn
F-B asymmetry
Focus “K*” signal
Data
MC
-15% F-B
asymmetry!
matches
model
m( Kp 
K* mn interferes with S- wave Kp
and creates a forward-backward
asymmetry in the K* decay angle
with a mass variation due to the
varying BW phase
The S-wave amplitude is
about 7% of the (H0) K* BW
with a 45o relative phase
The same relative
phase as LASS
M. Selen, DOE Visit, 2004
28
Learning more about the s-wave amplitudes
const amp
LASS amp
G
G
Focus was limited to the K* peak
region because serious non-charm
backgrounds dominate out of this
region. There is almost no
discrimination between a constant and
the expected s-wave amplitude from
scattering experiments in the narrow
region probed by Focus.
M. Selen, DOE Visit, 2004
eventsCosV
25 MeV bins
const amp
LASS amp
Im
BW
a
Re
M(Kp)
The higher Kp mass is where the
amplitude variation is most interesting.
As the s-wave phase shift passes 900 ,
the cosV asymmetry should reverse.
We need the background free
environment of CLEO-c to see this
29
Related SL physics
1. Does s-wave interference occur in decays such as Dren?
The FOCUS environment has far too much background to see this
2. What is the q2 dependence of form factors that describe the coupling to
the s-wave piece? This might provide additional LQCD tests.
The FOCUS q2 resolution is too poor to resolve this
3. For that matter-- what is the q2 dependence of the K* helicity amplitudes
All experimentalists have been assuming the spectroscopic pole forms
But we know the spectroscopic poles are wrong for DKen
A journey of 1000 miles begins with a single step….
Doris and Jim are
starting to learn the
ropes of doing a
CLEO-c analysis
Doris is spending
about half of her time
at Cornell
M. Selen, DOE Visit, 2004
Data
MC
From 60 pb-1
CLEO-c
Even a totally
un-cut sample has a
beautiful K* signal that
is well simulated
mKp
30
Summary
Involvement in CLEO-c:
• CLEO Spokesman
• CLEO Run Manager
• Trigger Hardware
• Physics
: Mats (with David Cassel)
: Topher
: Topher, Norm, Paras
: Everyone
Analyses:
DSp (BR, double partial recon)
D0K-en (Mixing Analysis)
D0KSp0p0 (BR & Dalitz Analysis)
D0K+K-p0 (BR & Dalitz Analysis)
D0p+p-p0 (Dalitz Analysis)
: Jeremy (GG - finished)
: Chris (MS - finishing)
: Norm, Bob, Topher, Mats
: Paras, Bob (MS)
: Charles (MS – finished*)
New UIUC Involvement: Jim Wiss & Doris Kim
Future looks great!
M. Selen, DOE Visit, 2004
31