resonances in decay for 400fb -1 dc meeting april 10th, 2006

Resonances Resonances inin decay decay for 400fbfor 400fb-1-1

DC MeetingDC Meeting

April 10th, 2006April 10th, 2006

J.Brodzicka, H.Palka INP KrakJ.Brodzicka, H.Palka INP Krakóóww

BB++ D D00DD00KK++

Dalitz Dalitz plot plot projections projections forforwith 20MeV binningwith 20MeV binning

Background

B+ D0D0K+

For 1.5 E-Mbc signal region

LR > 0.01

J.Brodzicka, H.Palka INP Krakow DC February 6th, J.Brodzicka, H.Palka INP Krakow DC February 6th, 20062006

DsJ(2700) is not split upno significant narow states are seen besides (3770)

J.Brodzicka, H.Palka INP Krakow DC April 10th, 2006J.Brodzicka, H.Palka INP Krakow DC April 10th, 2006

BB++ D D00DD00KK++ candidates with Dcandidates with D00(’s) from the mass sideband(’s) from the mass sideband

no LR cut no LR cut D mass sideband: D mass sideband: ||M(M(DD) - 1.865 GeV) - 1.865 GeV|| >15 MeV (~2 >15 MeV (~2σσ))

for Mbc > 5.273 GeV (3)

for E<20MeV (3)

both D’s from both D’s from mass sidebandmass sideband

at least one D from at least one D from mass sidebandmass sideband

no peaking backgroundno peaking background


for Mbc>5.277GeV (1.5)

for E<10MeV (1.5)

both D from both D from mass sidebandmass sideband

at least one D from at least one D from mass sidebandmass sideband

BB++ D D00DD00KK++ candidates with Dcandidates with D00(’s) from the mass sideband(’s) from the mass sideband

Two-body mass distributions for Two-body mass distributions for BB++ D D00DD00KK++ candidates candidates with Dwith D00(’s) from the mass sideband(’s) from the mass sideband


one D from one D from mass sidebandmass sideband

for Mbc > 5.273 GeV (3) and E<20MeV (3)

Mass spectra shapes consistent with Mass spectra shapes consistent with background estimated from background estimated from EE--MMbcbc sidebandsideband


both D from both D from mass sidebandmass sideband

for Mbc > 5.273 GeV (3) and E<20MeV (3)



for Mbc > 5.277 GeV (1.5) and E<10MeV (1.5) one D from one D from mass sidebandmass sideband


for Mbc > 5.277GeV and E<10 MeV ( 1.5 signal region )


Dalitz plot forDalitz plot for corrected for acceptance corrected for acceptance( with correction( with correction conserving number of events observed )conserving number of events observed )

B+ D0D0K+

DDsJsJ(2700)(2700)~2.5 GeV ~2.5 GeV

Dalitz plot forDalitz plot for corrected for acceptance corrected for acceptance( scaled to BF(( scaled to BF(BB++ D D00DD00KK++) by effective efficiency obtained) by effective efficiency obtained ))


for Mbc > 5.277GeV and E<10 MeV ( 1.5 signal region )

B+ D0D0K+


Mass distributions corrected for acceptanceMass distributions corrected for acceptance(using large ~700K (using large ~700K BB++ D D00DD00KK++ MC sample) MC sample)

Events from 1.5 E-Mbc signal region

Background from 6 < d <10 strip surrounding the E-Mbc signal region


BackgroundBackground-free-free invariant invariant mass mass distributionsdistributions corrected for acceptance corrected for acceptance

B signal in mass binsB signal in mass bins obtained from obtained from 22--dim Mdim Mbcbc--E fitE fitss in in two-body two-body inv. mass binsinv. mass bins

fitted fitted B B SignalSignalcorrected for acceptancecorrected for acceptance

Dalitz plots for various decay models forDalitz plots for various decay models for


BB++ D D00DD00KK++

MC studies based on the relative contributions from the resonant components and 3-body decay obtained from data analysis (non coherent approach)

no interference

max constructive interf.

DsJ(2700) and (4160)

max destructive interf.

DsJ(2700) and (4160)

Generated distributionsGenerated distributions

How interference between DsJ(2700) and (4160) (states crossing in the Dalitz plot) influences the DsJ parametres


non-coherent approach

no interference

max constructive interf. = 0

between DsJ(2700) and (4160)

max destructive interf. = 180


Comparison of mass spectra in various decay models Comparison of mass spectra in various decay models for for BB++ D D00DD00KK++

Generated distributionsGenerated distributions


Dalitz plots for various decay models forDalitz plots for various decay models forBB++ D D00DD00KK++

Reconstructed distributionsReconstructed distributions

no interference


DsJ(2700) and (4160)


DsJ(2700) and (4160)



no interference





Comparison of mass spectra in various decay models Comparison of mass spectra in various decay models for for BB++ D D00DD00KK++

Reconstructed distributionsReconstructed distributions



no interference





Comparison of mass spectra in various decay models Comparison of mass spectra in various decay models with data distributionswith data distributions

datadata

interference effects do not influence interference effects do not influence the 2-body mass distributions substantiallythe 2-body mass distributions substantially decay model is not decideddecay model is not decided

Interference related systematics on DInterference related systematics on DsJsJ parameters parameters


(to remove (3770) reflection

from high M(D0K+) region)

for M(D0D0)>3.85 GeV

BW + MC predicted (4160) reflection + non-resonant component described by 3-body MC

no interference



Uncertainty on:Uncertainty on:Yield: +4 %Yield: +4 %M: +3 -8 MeV M: +3 -8 MeV ΓΓ: +36 -30 MeV : +36 -30 MeV

Fits like in data analysis:Fits like in data analysis:


11-- stronglystrongly favouredfavoured

Comparison with the DsJ(2700) spin hypotheses:

J=1 2/n.d.f = 6.7/5 ~cos2θ J=2 2/n.d.f = 249.9/5 ~(1-3cos2θ)2

J=0 2/n.d.f = 184.7/4 flat

Angular distribution Angular distribution in the DsJ(2700) helicity frame in the DsJ(2700) helicity frame

fitted fitted B B SignalSignalcorrected for acceptancecorrected for acceptance

DsJ(2700) region: 2.57 < M(D0K+) < 2.84 GeV

BackupsBackups


Dalitz plot and projections forDalitz plot and projections for Background: elliptical strip 6 to 10

in Mbc, E, surrounding the signal region

B+ D0D0K+

For Mbc > 5.277GeV E<10 MeV

( 1.5 signal region )

LR > 0.01


(4160(4160))

(3770)(3770)

DDsJsJ(2700)(2700)

(3770)(3770) (4160)(4160)

DDsJsJ(2700)(2700)

DDsJsJ(2700) (2700) (3770)(3770)

(4160(4160))

(3770)(3770)(4160(4160))

DDsJsJ(2700)(2700)


BackgroundBackground-free-free invariant invariant mass mass distributionsdistributions22--dim Mdim Mbcbc--E fitE fitss in in 2-body 2-body inv. mass binsinv. mass bins B signal in mass binsB signal in mass bins

DsJ(2700) +(4160) reflection

(4160) +DsJ(2700) reflection

(3770)

Background-free mass spectra are very consistent with the Dalitz-plot projections over the estimated background.

fitted B Signal

Estimation of the resonance contributionsEstimation of the resonance contributions

(4160)

(3770) DsJ(2700)

(to remove (3770) reflection

from high M(D0K+) region)

for M(D0D0)>3.85 GeV

Lower curve: MC predicted (4160) reflection + non-resonant component described by 3-body MC

.0cos DDfor (4160) in ½ helicity distr: 24 ± 11 events (~2σ)(for 2nd half helicity distr: 20% smaller efficiency)

Breit Wigner functions+ threshold function

DsJ(2700) parametersconsistent with previousestimations

Z(3930)

J.Brodzicka, H.Palka INP BAM February 27th, 2006J.Brodzicka, H.Palka INP BAM February 27th, 2006

Non-resonant component yieldNon-resonant component yield: 47 ± 32: 47 ± 32

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)

Explanation ofExplanation of 2-body mass spectra2-body mass spectra

Shapes predicted by MC simulations

DDsJsJ++((2702700)0), , ((3773770)0) are not the full story, but the ‘fit’ is acceptable are not the full story, but the ‘fit’ is acceptable

J.Brodzicka, H.Palka INP BAM February 27th, 2006J.Brodzicka, H.Palka INP BAM February 27th, 2006

resonances in decay for 400fb -1 dc meeting april 10th, 2006

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