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a 0 (980) and f 0 (980) mixing and analysis of J/ Ψ -> Φ ηη. Wang Yadi 2009.09.07. outline. a 0 (980) and f 0 (980) mixing J/ Ψ -> Φ a 0 (980)-> Φ ηπ 0 analysis of J/ Ψ -> Φ ηη systemic error of η and π 0 selections summary and future work. a 0 (980)-f 0 (980) mixing. - PowerPoint PPT Presentation
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Wang Yadi2009.09.07
a0(980) and f0(980) mixingand analysis of J/ Ψ->Φηη
outline
a0(980) and f0(980) mixing
J/Ψ->Φa0(980)-> Φηπ0
analysis of J/ Ψ->Φηη
systemic error of η and π0 selections
summary and future work 2009.09.072
a0(980)-f0(980) mixing
Motivation A possible way to distinguish the nature of
a0/f0 : a0(980)-f0(980) mixing
~200M J/psi @ BES3 (based on BOSS 6.5.0) Event selection Background analysis
2009.09.073
KK q2q2
Model predictions Estimations from relevant measured parameters
For a very recent prediction from chiral unitary approach,cf. Hanhart, Kubis & Pelaez, Phys.Rev. D76 074028
No firm direct observation of a0-f0 mixing available !
||2 : 0.01~0.2
2009.09.074
J.J.Wu, Q.Zhao & B.S.Zou, PR D75(2007)114012 :
2×108 J/ events with BES3 detector
search for a narrow peak ( 987.4 – 995.4 ) MeV
in isospin forbidden processBR(J/ f0(980) a0(980) 0 ) ~ (0.2-20)*10-6
0-(1--)->0-(1--)+0+(0++)-> 0-(1--)+ 1-(0++)
2009.09.075
Event selection
two charged tracks: |Rxy |<5cm, |z|<20cm
Number of isolated photons: 4<= N<=20 Ebarral>30MeV , Eendcap>50MeV; 0<Time<14 θγcharged>20o
K+,K- are identified (dE/dx+TOF) prob_K>prob_pi & prob_K>0.001
looping with all isolated photons: To reconstruct candidates:
21C() <=9; |cosθ|<0.95 ； M() ~ (0.457,
0.607)GeV To reconstruct 0 candidates:
21C() <=9; |cosθ|<0.95; M() ~ (0.075, 0.175)GeV
0
1 2
,
| |cos
E E
p
decay angle
2009.09.076
Event selection
if there are more than one distinct or 0 candidates, the combination gives min 2
6C(K+K-0) is retained 2
6C(K+K-0) <50; 2
6C(K+K-0) <= 26C(K+K-);
26C(K+K-0) <= 2
6C(K+K-0 0);
mass window of |m(K+K-)-m|<=0.012 GeV/c2;
mass window of a0(980) (when fitting)0.92 GeV/c2 <=M(0)<=1.05 GeV/c2;
2009.09.077
blue --- Inclusive MC blue --- J/ ψ-> Ф π0η blue --- J/ ψ->
Ф f_2(1270)-> Ф η η
2 06 ( )C KK
Red --- signal J/Ψ->Φa0(980)->Φηπ0
2009.09.078
blue --- J/ ψ->K*K η
M(K+K-) distribution
blue --- J/ ψ-> Ф π0η blue --- Inclusive MC
Red --- signal J/Ψ->Φa0(980)->Φηπ0
2009.09.079
Double Gaussian fit
σ1~2.1MeVσ2~6.4MeV
σ ~ 3.7MeVM ~ 1.0197GeV
distribution of M(K+K-)
2009.09.0710
Mass resolution of a0: 5.4 MeV
Output : M~0.9846GeV σ~8.6MeVInput : M~0.9847GeV σ~8.0MeVEff ~ 12.2%
distribution of M(π0 η)
2009.09.0711
number efficiency
total 40000 100.0%
Ncharged = 2; Q =0 26739 66.85%
Nγ >= 4 18301 45.75%
Pass Pid
NK+ =1; NK- = 1
15052 37.63%
Pass 4C: 14871 37.18%
Pass vtxfit: 11550 28.88%
Pass 6C: 5894 14.74%
χ6C(KKπη) <50 5587 13.97%
χ6C(KKπη) < χ6C(KKπ π)
χ6C(KKπη) < χ6C(KKη η)
5587 13.97%
|M(KK)-1.02|<0.01 4979 12.45%
0.92<M(πη)<1.05 4876 12.19%
cut flow for J/ψ->Фa0(980)(8MeV)
2009.09.0712
background analysis
exclusive channels
inclusive channels
2009.09.0713
channel sample exist efficiency Branch ratio normalized to 2E8 J/psi data
signal : J/ψ->Фa0(980)(8MeV) 40000 4876 12.19%
J/ψ->γ*(KKbar) ->Фa0(980) 20000 2564 12.82% 7.05E-7 18.1
J/ ψ->K*Kbar 20000 0 0.00% 1.95E-3 0
J/ ψ->ωK+K- 20000 0 0.00% 3.5E-6 0
J/ ψ->ω π0π0 20000 0 0.00% 2.96E-3 0
J/ ψ->Фf_’2(1525)-> Ф η η 20000 3 0.015% 6.33E-4 19.0
J/ ψ-> Ф π0π0 20000 1 0.005% 2.69E-4 2.7
J/ ψ-> Ф η 20000 0 0.00% 1.45E-4 0
J/ ψ-> Ф η ‘-> Ф η π0π0 20000 1 0.005% 1.56E-5 0.2
J/ ψ-> Ф η ‘-> Ф ωγ-> Ф π0 γ γ 20000 158 0.79% 5.2E-7 0.8
J/ψ->ηh_1(01400), h_1(1400)->K*K 20000 229 1.15%
exclusive background analysis
2009.09.0714
channel sample exist efficiency Branch ratio normalized to 2E8 J/psi data
J/ ψ-> Ф f 0(980)-> Ф π0π0 20000 4 0.02% 4.0E-5 1.6
J/ ψ-> Фf(1285)-> Ф a0(980) π0 20000 1 0.005% 5.3E-6 0.05
J/ ψ-> Ф f_2(1270)-> Фπ0π0 20000 2 0.01% 1.47E-4 2.9
J/ ψ-> Ф f_2(1270)-> Ф η η 20000 4 0.02% 2.2E-7 0.01
J/ ψ-> π+π-π0 20000 0 0.00% 2.05E-2 0
J/ ψ->K+K-π0π0 20000 0 0.00% 2.39E-3 0
J/ ψ-> Ф η f 0(980)-> Ф η π0π0 20000 0 0.00% 1.57E-5 0
J/ ψ->γηc->γK+K- π0 20000 0 0.00% 8.99E-4 0
J/ ψ->K*K η 20000 16 0.08% 3.72E-4 59.52
J/ ψ-> Ф KsKl-> Фπ0π0 Kl 20000 0 0.00% 1.35E-4 0
J/ ψ-> Ф η η (PHSP) 20000 4 0.02%
J/ ψ-> Ф ηπ0 (PHSP) 20000 2526 12.63%
exclusive background analysis
2009.09.0715
channel Branch ratio exsit
J/ψ->ηh_1(01400), h_1(1400)->K*K 24
J/ ψ-> Ф π0π0 2.69E-4 9
J/ ψ->K*K η 8
J/ ψ-> K+K-a0(980) 1
J/ ψ->K*_0(1425) K η 1
J/ ψ-> Ф f 0(980) 4.0E-5 1
J/ ψ-> Ф η f 0(980)-> Ф η π0π0 1.57E-5 1
J/ ψ->γK*K ->γKK π0 2.81E-4 1
J/ ψ-> Ф f ‘(1350)-> Ф π0π0 5.37E-5 1
J/ ψ->K*_2(1426) K η 1
90M J/Ψ inclusive backgrounds analysis
2009.09.0716
4 main backgrounds
J/ψ->γ*(KKbar) ->Фa0(980)
J/ψ->ηh_1(1400), h_1(1400)->K*K
J/ ψ-> Ф π0π0
J/ ψ->K*K η
2009.09.0717
distribution of M(π0 η) in data
red --- M(K+K-) ~ (1.008 ~ 1.032)GeVblue---M(K+K-) ~ (1.560 ~ 1.032) GeV
next step is fitting :
bkg ~ c1*RooChebychev + c2*sideband + c3*bkg1 + c4*bkg2
bkg1 ~ J/Ψ->Φ a0(980) ->Φηπ0
bkg2 ~ J/Ψ->Φ f0(980) ->Φπ0π0
signal ~ shape of J/psi -> Φ a0 (8MeV)
2009.09.0718
analysis of J/Ψ-> Φ η η
event selection is the same as J/Ψ-> Φ η π0 ,
except :
26C(K+K-) <50;
26C(K+K-) <= 2
6C(K+K-0) 2
6C(K+K-) <= 26C(K+K-0 0)
2009.09.0719
blue --- inclusive MC blue --- J/Ψ->Φηη blue --- J/ ψ-> Ф f_2(1270)-> Фπ0π0
distribution of Χ6C2(k+k-ηη)
Red --- signal J/Ψ->ηΦ*(1680)->ΦηηPink --- signal J/Ψ->ηY(2175)->Φηη
2009.09.0720
blue --- inclusive MC blue --- J/Ψ->Φηη blue --- J/ ψ-> Ф f_2(1270)-> Фπ0π0
distribution of M(K+K-)
Red --- signal J/Ψ->ηΦ*(1680)->ΦηηPink --- signal J/Ψ->ηY(2175)->Φηη
2009.09.0721
number efficiency
total 20000 100.00%
Ncharged = 2; Q =0 11143 55.72%
Nγ >= 4 8589 42.95%
Pass Pid
NK+ =1; NK- = 1
5646 28.23%
Pass 4C: 5517 27.59%
Pass vtxfit: 3671 18.36%
Pass 6C: 1517 7.59%
χ6C(KKπη) <50 1458 7.29%
χ6C(KKπη) < χ6C(KKπ π)
χ6C(KKπη) < χ6C(KKη η)
1457 7.29%
|M(KK)-1.02|<0.01 1324 6.62%
cut flow for J/ψ-> η Ф (1680)
2009.09.0722
number efficiency
total 20000 100.00%
Ncharged = 2; Q =0 11696 58.48%
Nγ >= 4 9050 45.25%
Pass Pid
NK+ =1; NK- = 1
6301 31.51%
Pass 4C: 6153 30.77%
Pass vtxfit: 4251 21.26%
Pass 6C: 1758 8.79%
χ6C(KKπη) <50 1679 8.40%
χ6C(KKπη) < χ6C(KKπ π)
χ6C(KKπη) < χ6C(KKη η)
1678 8.39%
|M(KK)-1.02|<0.01 1502 7.51%
cut flow for J/ψ-> η Y(2175)
2009.09.0723
background analysis
exclusive channels
inclusive channels
2009.09.0724
channel sample exist efficiency Branch ratio normalized to 2E8 J/psi data
signal_1: J/ψ->η Ф (1680) 20000 1324 6.62%
signal_2: J/ψ->η Y(2175) 20000 1502 7.51%
J/ψ->γ*(KKbar) ->Фa0(980) 20000 0 0.00% 7.05E-7 0
J/ ψ->K*Kbar 20000 0 0.00% 1.95E-3 0
J/ ψ->ωK+K- 20000 0 0.00% 3.5E-6 0
J/ ψ->ω π0π0 20000 0 0.00% 2.96E-3 0
J/ ψ->Фf_’2(1525)-> Ф η η 20000 1813 9.07% 6.33E-4 114.8
J/ ψ-> Ф π0π0 20000 2 0.01% 2.69E-4 5.4
J/ ψ-> Ф η 20000 0 0.00% 1.45E-4 0
J/ ψ-> Ф η ‘-> Ф η π0π0 20000 0 0.00% 1.56E-5 0
J/ ψ-> Ф η ‘-> Ф ωγ-> Ф π0 γ γ 20000 0 0.00% 5.2E-7 0
exclusive background analysis
2009.09.0725
channel sample exist efficiency Branch ratio normalized to 2E8 J/psi data
J/ ψ-> Ф f 0(980)-> Ф π0π0 20000 0 0.00% 4.0E-5 0
J/ ψ-> Фf(1285)-> Ф a0(980) π0 20000 2 0.01% 5.3E-6 0.1
J/ ψ-> Ф f_2(1270)-> Фπ0π0 20000 3 0.015% 1.47E-4 4.4
J/ ψ-> Ф f_2(1270)-> Ф η η 20000 1952 9.76% 2.2E-7 4.3
J/ ψ-> π+π-π0 20000 0 0.00% 2.05E-2 0
J/ ψ->K+K-π0π0 20000 0 0.00% 2.39E-3 0
J/ ψ-> Ф η f 0(980)-> Ф η π0π0 20000 0 0.00% 1.57E-5 0
J/ ψ->γηc->γK+K- π0 20000 0 0.00% 8.99E-4 0
J/ ψ->K*K η 20000 0 0.00% 3.72E-4 0
J/ ψ-> Ф KsKl-> Фπ0π0 Kl 20000 0 0.00% 1.35E-4 0
J/ψ->Фa0(980)(8MeV) 20000 1574 7.87%
J/ ψ-> Ф ηπ0 (PHSP) 20000 3 0.015%
exclusive background analysis
2009.09.0726
90M J/Ψ inclusive MC background analysis
channel Branch ratio exsit
J/Ψ->Φf0(1500)->Φηη 8.32E-6 75
J/Ψ->Φf2’(1525)->Φηη 6.26E-6 50
J/Ψ->Φηη 34
J/Ψ->Φf2(1275)->Φηη 1.25E-7 2
J/Ψ->Φπ0π0 2.69E-4 1
J/ ψ->γη(2225)->γΦΦ->γγηΦ 7.29E-7 1
J/Ψ->Φf2(1275)->Φπ0π0 5.55E-5 1
J/ψ->γΦΦ->γγηΦ 1
J/Ψ->Φf0(1500),
Φ->K+K-unkown, f0(1500)->ηη
1
2009.09.0727
3 main backgrounds
J/Ψ->Φf0(1500)->Φηη
J/Ψ->Φf2’(1525)->Φηη
J/Ψ->Φηη
2009.09.0728
distribution of M(ηΦ)compare signal and data
J/ψ->η Ф (1680)
data
2009.09.0729
J/ψ->η Y(2175)
data
distribution of M(ηΦ)compare signal and data
2009.09.0730
π0,η selection’s systematic error
π0 selections:
decay angle : cosθ<0.95;
0.075GeV < Mγγ < 0.175GeV;
η selections:
decay angle : cosθ<0.95;
0.457GeV < Mγγ < 0.647GeV;
2009.09.0731
π0 systematic error
Initial cuts:good charged tracks: N=2 , using PID;good neutral: N>=2;4C chisq<999
Final cuts:
Nγ<4;
Mπ+γγ >1.2GeV & Mπ+π->1.2GeV;
3.00GeV < Eπ+π-γγ < 3.14GeV;
Ptr12 >0.001, Ptr2
2 >0.001;
Ptr2 = 4pmiss
2×sin2(σ/2)
J/ψ->ρ- π+
2009.09.0732
Without Pi0 selections
With Pi0 selections
Without Pi0 selections
With Pi0 selections
Eff_MC= 98.48%
Eff_data = 99.17%
the systematic error is about 1%
2009.09.0733
η systematic error
Initial cuts:good charged tracks: N=2 , using PID;good neutral: N>=2;4C chisq<999
Final cuts:Nγ = 2;3.00GeV < Eπ+π-γγ < 3.14GeV;Ptr1
2 >0.001, Ptr22 >0.01;
Ptr2 = 4pmiss
2×sin2(σ/2)
J/ψ->p pbar η
2009.09.0734
Without η selections
With η selections
Without η selections
With η selections
Eff_MC = 95.53%
Eff_data = 96.55%
the systematic error is about 1%
2009.09.0735
Summary
a preliminary analysis of a0(980)-f0(980) mixing
structures observed in Mφη
determination of the preliminary systemic error of π0 ,η
2009.09.0736
Future work
full analysis of φπ0η (a0-f0 mixing), φηη
determination of systemic error of π0 ,η selection in different momentum region and with different Eγ1, Eγ2
Thanks!2009.09.0737
2009.09.0738
backup
inclusive VS data M(phi , eta )
2009.09.0739
phi f0(1500) VS dataM(eta phi)
2009.09.0740
phi f2(1525) VS dataM(eta phi)
2009.09.0741
phi eta eta VS dataM(eta phi)
2009.09.0742
J/ψ->Фa0(980)(8MeV) J/Ψ->Φηη
maybe i should not use the sideband bkg to fit M(eta,pi0) and M(eta,phi)should i try to use some bkgs + signal + RooChebychev
2009.09.0743
