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Status report on h physics. 2 nd Kloe Physics Workshop June 10 th -12 th , 2002 Otranto (LE). F. Ambrosino, T. Capussela, C. Di Donato , F.Perfetto. Status report on h physics. Correction factor to the observed cross sections ( h - h paper) Dalitz plot h p + p - p 0
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Status report on h physics 2nd Kloe Physics Workshop June 10th-12th, 2002 Otranto (LE) F. Ambrosino, T. Capussela, C. Di Donato, F.Perfetto
Status report on h physics • Correctionfactor to theobserved • cross sections (h-h paper) • Dalitz plot h p+p-p0 • Study of f h g p+p-gg
e+e-Pg Thecorrection factor to the observed cross sections due to the interference between the amplitudes A(f h(h)g) andA(r h(h)g) at s = mf R.R.Akhmetshin et al., Phys. Lett. B 434 426 (1998)
2 sPg(s)= s (0) BP + SAV FPg (s) a s3/2 3 V=r,w,f m3VmVGV eidV FPg (m2V) m2V-s-is GV(s) V AV= • e+e-Pg The Born cross section of the process:
s(0)V = s (m2V) • 12p BVe+e-BVPg • m2V e+e-VPg = e+e-Pg For r meson see Gounaris-Sakurai model (Phys. Rev. Lett. 21 (1968) 244)
BR(f hg) = (6.100.610.43)•10-5 p+p- 3g (6.700.58 )•10-5 p+p- 7g +0.89 -0.92 e+e-Pg • sPg(s)=C•|Af+Ar|2 with P=h,h • sfhgsfhg • sfhgsfhg meas = Kr Kr =0,95 meas
Dalitz plot h p+p-p0 • f hg p+ p- p0g • Topological selection • Kinematic fit • Fit to dalitz plot: efficiency and resolution study already done (h-h paper)
Dalitz variable |M(x,y)|2= N0f(x,y) Nij=N0eij|M(xi,yj)|2dxidyj X X=3(T+-T-)/Q Y=(3T0/Q)-1 Q = T++T-+T0
p+ p+ r p- p- h/h h/h g g f p+ p- g g Relevant for the box anomaly: h/h p+ p- gdecays are dominated by the r meson; chiral theory expects an anomalous contribution
f p+ p- g g • Careful spectral shape measurement • in order to study the anomalous • contribution(Holstein hep-ph/0112150) • h p+ p- g • BRfhgp+p-gg = 6.16•10-4 • PDG’00: 18K events (’73) • L = 200 pb-1 means ~385K events
Topological selection • One charged vertex r<4 cm and |z|<8 cm • two prompt neutral clusters e=56% Mpp (MeV) Eg (MeV)
Main background • f p+ p- p0BR = 15.31% • e = 63% S/B = 3.5x10-3 Mpp (MeV) Eg (MeV)
S/B comparison g prompt p+p- Eg (MeV) Mpp (MeV) Eg (MeV) Mpp (MeV)
Background rejection Mp+p-g> 500 MeV cosqgg < 0.20 h ppg cosqgg cosqgg f ppp cosqgg Mppg (MeV)
M pp tracks ehg = 45% S/B=0.14 Ncut/Ntop Mpp (MeV) Mpp (MeV)
Background rejection Mgg > 200 MeV Mp+p- < 560 MeV Mgg (MeV) Mgg (MeV) Mgg (MeV) Mpp (MeV)
M pp tracks ehg = 45% S/B=2 Ncut/Ntop Mpp (MeV) Mpp (MeV)
f p+ p- g g • A first look at the p+ p- g g final state • Kinematic fit • likelihood to improve S/B without • deforme the shape of the distributions
Conclusions • h-hpaper submitted • first look at dalitz ploth p+p-p0 • f p+ p- g g: likelihood function either to improve S/B either to have distribution with shape not biased
M pp tracks ehg = 45% S/B=2 Mpp (MeV)