Title: Interference Effects in D Meson Decays
1Interference Effects in D Meson Decays
- D. Cinabro
- Wayne State University
- FPCP 2006, 12 April
2Why Interference Effects?
- Provide unique information
- Phases and amplitudes are otherwise inaccessible
- Need these to extract fundamental parameters (CKM
elements for example) from other measurements - Challenge and input for QCD
3Outline
- New results (since summer 2005) are thin
- D?KK?0 Dalitz analysis for D?KK strong phase
from CLEO-III - D?3? Dalitz analysis from CLEO-c
- Quantum Correlations in D0D0 decays from the ?
for phases and mixing parameters from CLEO-c
_
4CLEO Data Sets
- CLEO-III data on ?(4S), 9/fb with charm produced
in continuum or from B decay - CLEO-c data on the ?, 281/pb, which
corresponds to 1.4M D pairs.
5CLEOc Detector
- Venerable CsI Calorimeter 2.2 resolution on 1
GeV photon, 5 on 100 MeV, ?p/p 0.6 at 1 GeV,
RICH particle ID
6CLEO-III D?KK?0
- Motivation is to extract strong phase difference
in D?KK - See Grossman, Ligeti, and Soffer (PRD
67(2003)07130) and Rosner and Suprun
(PRD68(2003)054010) for how this helps measure
CKM ? (?3) in charged B decay
7D?KK?0 Charged D Tag
- 600 Signal SB41, Soft ? tag gives D0 flavor
8D?KK?0
- Both charges of K and ? contributions clearly
visible - Interference between Ks is also clear
9D?KK?0
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12CLEO-III D?KK?0
- Preliminary
- ?D?KK 332o8o11o, large interference
- A(D?K-K)/ A(D?KK-) 0.520.050.04
- Precision limited by non-K contributions to the
decays - Observed branching fractions consistent with
previous measurements
13CLEO-c D?3? Dalitz
First time doing a Dalitz analysis that has been
done by E791 and FOCUS (previously concentrated
on modes with ?0) 2600 signal on SB of 21
(E791 1200, FOCUS 1500) Mbc ?Ebeam2 p3?2, ?E
Ebeam - E3?
__________
14D?3? Dalitz
- Symmetry under interchange of like-sign pions
- Dalitz analysis on high mass versus low mass
unlike-sign pion combinations - Big vertical stripe is Ks?
15D?3? Dalitz
- Worry that efficiency will be difficult in
corners of the Dalitz plot since D starts nearly
at rest. - Looks good, changes are smooth.
- Model with both MC bin-by-bin and polynomial fit.
16D?3? Dalitz
- Backgrounds from sidebands (offset in ?E to
insure that it remains on the Dalitz plot) - Add in Ks, ?, f0(1370) to represent possible
resonance contributions
17D?3? Dalitz Many potential contributions
18D?3? Dalitz
f2?
??
??
f0?
19D?3? Dalitz
FF in E791 CLEOc
?? 33.63.9 20.02.5
?? 46.39.2 41.82.9
f2? 19.42.5 18.22.7
f0(980)? 6.21.4 4.10.9
f0(1500)? ---------- 3.41.3
Non-res 7.86.6 lt3.5
?(1450)? 0.70.8 lt2.4
Prob(?2) 96.3 27.8
20CLEO-c D?3? Dalitz
- Still preliminary
- Need to consider other models of ?? S-wave (for
example replace ? and f0 contributions by
generalized ?? interaction) to compare with FOCUS
which used the K-matrix - Broad agreement with E791 (? contribution, first
observation for CLEO)
21CLEO-c TQCA
- K-? vs semileptonic measures isolated decay rate
and tags flavor of decaying D - Different sensitivity to mixing vs DCSD
- D decays to CP eigenstates also interfere and
opposite semileptonics to get isolated rate,
flavor tags for yet another dependence on y and
strong phase - CP eigenstate vs CP eigenstate shows maximal
correlations
- The Quantum Correlation Analysis
- ee???D0D0 is C -1
- K-? vs K?- interfere and thus sensitive to DCSD
and strong phase - Time integrated rate depends on both cos?D?K? and
mixing parameter y ??/2? - K-? vs K-? forbidden unless there is mixing.
-
22TQCA
See PRD 73 034024 (2006) hep-ph/0507238 by
Asner and Sun
RM (x2y2)/2 r Amp DCS/Amp CF
f l CP CP-
f RM/r2
f 1r2(2-(2cos?)2)
l- 1 1
CP 1r (2cos?) 1 0
CP- 1-r (2cos?) 1 2 0
X 1 ry (2cos?) 1 1-y 1y
-
And measure branching fractions simultaneously
23TQCA Single Tags in Data
K-?
K?-
KK
Ks?0
Ks?0?0
??
24TQCA Double Tags in Simulation
M(K-?)
M(K-?)
M(K?-)
M(K-?)
M(KK)
M(KK)
M(K-?)
M(KK)
25TQCASemileptonics
Opposite K? Flavor Tag
Opposite CP- Tag
Signal
Backgrounds
Electron Momentum (GeV)
Electron Momentum (GeV)
26TQCA
CP tags vs CP tags clearly shows Quantum
Correlation
No QC Data K-K ?-? Ks?0?0 Ks?0
K-K 5.20.4 -2.21.9 4.50.3 0.10.9 5.70.4 1.61.3 16.00.6 39.66.3
?-? 1.10.2 0.21.4 2.20.2 1.61.3 5.80.4 14.03.7
Ks?0?0 1.20.2 1.01.0 7.30.4 19.04.4
Ks?0 9.70.5 3.01.7
CP
CP-
C P
CP-
27TQCA
K-? vs K-?
K-? vs K?-
Data clearly favors QC interpretation
showing constructive and destructive
interference and no effect as predicted
CP vs CP
CP- vs CP-
CP vs CP-
K? vs CP
K? vs CP-
28Parameter CLEO TQCA PDG or CLEOc
y -0.0570.066? 0.0080.005
r2 -0.0280.069? (3.740.18)X10-3
r (2cos?D?K? ) 0.1300.082?
RM (1.741.47?)x10-3 lt 1x10-3
B(D?K?) (3.800.029?) (3.910.12)
B(D?KK) (0.3570.029?) (0.3890.012)
B(D???) (0.1250.011?) (0.1380.005)
B(D?Ks?0?0) (0.9320.087?) (0.890.41)
B(D?Ks?0) (1.270.09?) (1.550.12)
B(D0?Xe?) (6.210.42?) (6.460.21)
29CLEO-c TQCA
- Obviously still preliminary, but very promising
- Systematics look tractable (lt stats)
- Number of CP tags is limit so working on adding
more - C fraction lt 0.060.05? on ?
- Ultimate sensitivity with projected CLEO-c data
set y 0.012, x2 0.0006, cos?D?K? 0.13,
x(sin?D?K?) 0.024 (needs C1 initial state from
running above the ?)
30Conclusions
- Unique information from interference effects in D
decays - All since summer 2005 from CLEO
- ?D?KK 332o8o11o and A(D?K-K)/
A(D?KK-) 0.520.050.04 in D?KK?0 Dalitz - D?3? Dalitz agrees with E791 on need for low
mass ?? S-Wave contribution - CLEO TQCA sensitive to D mixing parameters and
?D?K?