Transcript Prezentacja programu PowerPoint

On quasi-two-body components
B+  D0D0K+
of
J.Brodzicka, H.Palka INP Krakow
BGM
(for 250fb-1)
June 7, 2005
 B+  D0D0K+
Looser LR cut applied LR>0.01 to obtain larger signal yield for Dalitz plot analysis
(previously: LR>0.04  S=151 ± 18 BF=( 1.13 ± 0.14)10-3 )
S =
234 ± 30
S/B = 0.25
for Mbc >5.273 GeV (3)
0.16 ) 10-3
BF=(1.25 ± 0.16 –+ 0.26
Systematic error contributions to BF
for E<18MeV (3)
Fitting method:
2-dim Mbc vs. E unbinned likelihood fit
J.Brodzicka, H.Palka INP Krakow
BGM
June 7, 2005
Dalitz plot and projections for B+  D0D0K+
For Mbc > 5.277 GeV E<7.5 MeV
( 1.5 signal region )
J.Brodzicka, H.Palka INP Krakow
LR > 0.01
Background: elliptical strip 6 to 10
in Mbc, E, surrounding the signal region
BGM
June 7, 2005
Background-free invariant mass distributions
2-dim Mbc vs. E fits in 2-body inv. mass bins
reflection
Signal / 50 MeV
Signal / 50 MeV
reflection
(3770) (4160) +DsJ(2700)
M( D0 K+ )
Signal / 50 MeV
DsJ(2700) +(4160)
B signal in mass bins
M( D0K+ )
M( D0D0 )
Background-free spectra are very consistent
with the Dalitz-plot projections
over the estimated background.
J.Brodzicka, H.Palka INP Krakow
fitted B Signal
BGM
June 7, 2005
Estimation of the resonance contributions
(3770)
Breit Wigner
+ threshold function
(4160)
for
cos  DD  0.
DsJ(2700)
(4160) in ½ helicity distr:
34 ± 6 events
(for 2nd half helicity distr:
20% smaller efficiency)
fitted B Signal
for M(D0D0)>3.85 GeV
(to remove (3770) reflection
from high m(D0K+) region)
Lower curve: MC predicted
(4160) reflection
+ non-resonant component
described by 3-body MC
Phase Space
Non-resonant component : NNR = 37 ± 13
J.Brodzicka, H.Palka INP Krakow
BGM
June 7, 2005
Explanation of 2-body mass spectra
Contributions from quasi-two-body components:
(normalized to measured yields and superimposed by adding histograms)
B+ (4160) K+
B+ (3770) K+
B+ D0 DsJ+(2700)
2/n.d.f =20/21
J.Brodzicka, H.Palka INP Krakow
(Shapes predicted by MC simulations generated
with parameters of contributing resonances
obtained in the analysis)
2/n.d.f =18/21
2/n.d.f =24/22
BGM
June 7, 2005
Various decay models predictions versus data
MC simulations of the Dalitz plot based on the determined strenghts of the
quasi-two-body components: B+D0DsJ+(2700), B+(4160)K+ and B+(3770)K+
fitted B Signal
MC simulations for:
non-coherent approach (no interference)
maximal constructive interference
between DsJ(2700) and (4160)
maximal destructive interference
between DsJ(2700) and (4160)
Interference between (4160) and (3770)
is found to be negligible.
J.Brodzicka, H.Palka INP Krakow
None hypothesis can be rejected.
It is taken into account
as source of systematic error,
mainly on DsJ(2700) yield and
parameters (see Table).
BGM
June 7, 2005
Systematics on DsJ(2700):
Systematics on (4160):
(4160) is estimated
from region without
interference with
DsJ(2700)
Systematics on non-resonant component:
 from DsJ(2700) and (4160) yields and parameters : NNR : +40% -27%
Systematics on (3770) yield:
 range of fitting, fit parameterization: N: ± 3%
J.Brodzicka, H.Palka INP Krakow
BGM
June 7, 2005
Angular distribution
in the helicity frames of DsJ(2700), (4160) and (3770)
Background-free cos distribution obtained using 2-dim Mbc vs. E fit in each cos bin
GeV
(4160) region:
(3770) region:
3.95<M(D0D0)<4.25 GeV
M(D0D0)<3.85 GeV
Eff. corrected signal
Eff. corrected signal
2.5<M(D0K+)<2.9
Eff. corrected signal
DsJ(2700) region:
cos  DK
cos  DD
cos  DD
DsJ(2700) spin hypotheses:
J=1 2/n.d.f = 3.8/4
J=2 2/n.d.f = 4.5/4
J=0 2/n.d.f = 9.4/4
(4160) spin hypothesis:
J=1 2/n.d.f = 1.3/3
(3770) spin hypothesis:
J=1 2/n.d.f = 2.6/5
(4160) reflection
fitted B Signal
corrected for acceptance
DsJ(2700) reflection
J.Brodzicka, H.Palka INP Krakow
BGM
June 7, 2005
fitted B signal
not corrected for
acceptance
Signal
Signal
Angular distributions in various decay models versus data
cos  DK
cos  DD
MC simulations for:
non-coherent approach (no interference)
maximal constructive interference
between DsJ(2700) and (4160)
maximal destructive interference
between DsJ(2700) and (4160)
J.Brodzicka, H.Palka INP Krakow
The effect of maximal interferences
is minor in angular distributions.
BGM
June 7, 2005
Estimation of contributions from other resonances in D0 K+
The M( D0 K+ ) Dalitz-plot projection is fitted
DsJ+(2573) spin-2 state
N / 10MeV
Fitted functions:
BW(DsJ(2573))+BW(DsJ(2700))+Linear background
with BW’s parameters fixed:
M(DsJ(2573))=2573MeV
(DsJ(2573))=15MeV
M(DsJ(2700))=2713MeV
(DsJ(2700))=130MeV
M( D0 K+ )
N / 2 MeV
SELEX DsJ+(2632) state
N(DsJ(2573))= 1.6 ± 4.4
Fitted functions:
G(DsJ(2632))+Linear background
with Gaussian parameters fixed:
M(DsJ(2632))=2632MeV
(DsJ(2632))=5MeV
N(DsJ(2632))= -2.3 ± 2.2
M( D0 K+ )
J.Brodzicka, H.Palka INP Krakow
BGM
June 7, 2005
Branching fractions of components of
BF(
BF(
BF(
BF(
B+
B+
B+
B+




D0DsJ+(2700)
(4160)K+ )
(3770)K+ )
D0D0K+ NR )
B+  D0D0K+
) = ( 0.65 ± 0.10 +0.12 –0.15) 10-3
= ( 0.26 ± 0.04 ± 0.03) 10-3
= ( 0.19 ± 0.03 ± 0.03) 10-3
= ( 0.14 ± 0.05 +0.06 –0.04) 10-3
90%C.L upper limits: BF( B+  D0DsJ+(2632) ) = 5.710-6
BF( B+  D0DsJ+(2573) ) = 1.610-4
BF( B+  X,Y(3940)K+ ) = 1.1 10-4
( B+  X,Y(3940)K+ from events counting
in background free M(D0D0) distribution
in mass interval 3.85-4.0 GeV)
J.Brodzicka, H.Palka INP Krakow
BGM
June 7, 2005
Summary
 B+  D0D0K+ proceeds dominantly via
quasi-two-body channel B+  D0DsJ+(2700)
 in ~30% through the color suppressed channels:
B+  (4160)K+ B+  (3770)K+
 confirmation of the (3770) production
 first observation of the charmonium (4160) production in B decays
 DsJ+(2700)  D0 K+ is new cs resonance with:
M = 2713 ± 10
+11
- 5
MeV
Favoured spin-parity: 1-
Γ = 129 ± 31
+83
-55
MeV
Interpretation of DsJ+(2700) :
 the cs radial excitation 23S1 state
(potential model predicts m=2720 MeV for this state)
 the chiral doubler state 1- to the 1+ DsJ(2536)
(predicted at m=2721 ± 10 MeV)
Plan
 publish this result
J.Brodzicka, H.Palka INP Krakow
BGM
June 7, 2005
J.Brodzicka, H.Palka INP Krakow
BGM
June 7, 2005