A Monte-Carlo Generator Photon Jets （MCGPJ） to simulate Bhabha scattering as well as production of two charged muons and two photons events is discussed. The theoretical precision of the cross ...sections with radiative corrections （RC） is estimated to be smaller than 0.2%. The Next Leading Order （NLO） radiative corrections proportional to α are treated exactly, whereas the all logarithmically enhanced contributions, related to photon jets emitted in the collinear region, are taken into account in frame of the Structure Function approach. Numerous tests of the MCGPJ as well as a detailed comparison with other MC generators are presented.
We report here measurement of the cross section of e+e- → π+π-ψ ( 2S ) between 4.0 and 5.5 GeV, based on an analysis of initial state radiation events in a 980fb-1 data sample recorded with the Belle ...detector. The properties of the Y ( 4360 ) and Y ( 4660 ) states are determined. Fitting the mass spectrum of π+π-ψ ( 2S ) with two coherent Breit-Wigner functions, we discover two solutions with identical mass and width but different couplings to electron-positron pairs: MY ( 4360 ) = ( 4347±6±3 ) MeV / c2 , Γ Y ( 4360 ) = ( 103±9±5 ) MeV , MY ( 4660 ) = ( 4652±10±8 ) MeV / c2 , Γ Y ( 4660 ) = ( 68±11±1 ) MeV ; and B Y ( 4360 ) → π+π-ψ ( 2S ) · Γ Y ( 4360 ) e+e-= ( 10.9±0.6±0.7 ) eV and B Y ( 4660 ) → π+π-ψ ( 2S ) · Γ Y ( 4660 ) e+e-= ( 8.1±1.1±0.5 ) eV for one solution; or B Y ( 4360 ) → π+π-ψ ( 2S ) · Γ Y ( 4360 ) e+e-= ( 9.2±0.6±0.6 ) eV and B Y ( 4660 ) → π+π=ψ ( 2S ) · Γ Y ( 4660 ) e+e-= ( 2.0±0.3±0.2 ) eV for the other. Here, the first errors are statistical and the second systematic. Evidence for a charged charmoniumlike structure at 4.05GeV / c2 is observed in the π±ψ ( 2S ) intermediate state in the Y ( 4360 ) decays. decays.
The cross section of the process
e
+
e
−
→
K
S
K
L
π
0
has been studied with the CMD-3 detector at the VEPP-2000 electron-positron collider in the center-of-mass energy range from 1.1 to 2 GeV. ...Preliminary results on the total cross section of the process are presented.
The ϕ(1020) meson leptonic width has been determined from the combined analysis of 4 major decay modes of the resonance (ϕ→K+K−,KL0KS0,π+π−π0,ηγ) studied with the CMD-2 detector at the VEPP-2M e+e− ...collider. The following value has been obtained: Γ(ϕ→e+e−)=1.235±0.006±0.022 keV. The ϕ(1020) meson parameters in four main decay channels have been also recalculated: B(ϕ→K+K−)=0.493±0.003±0.007, B(ϕ→KLKS)=0.336±0.002±0.006, B(ϕ→π+π−π0)=0.155±0.002±0.005, B(ϕ→ηγ)=0.0138±0.0002±0.0002.
We report preliminary results on the cross section of the process e
+
e
−
→ φ(1020)η measured at 30 center-of-mass energy points in the range from 1.59 up to 2.0 GeV. Data analysis is based on the ...integrated luminosity of 22 pb
−1
collected with the CMD-3 detector in 2011–2012. The obtained cross section agrees with the BaBar measurement and has better statistical accuracy.
The preliminary results of measurement of the
e
+
e
−
→ π
+
π
−
π
0
cross section in the 1.05–2 GeV center-of-mass energy range with 30 pb
–1
of experimental data collected using the CMD-3 detector ...are presented. The parameters of resonant states ω(1420) and ω(1650) are obtained.
We present the results of an amplitude analysis of B¯0→J/ψK-π+ decays. A new charged charmoniumlike state Zc(4200)+ decaying to J/ψπ+ is observed with a significance of 6.2σ. The mass and width of ...the Zc(4200)+ are 4196+31-29+17-13 MeV/c2 and 370+70-70+70-132 MeV, respectively; the preferred assignment of the quantum numbers is JP=1+. In addition, we find evidence for Zc(4430)+→J/ψπ+. The analysis is based on a 711 fb-1 data sample collected by the Belle detector at the asymmetric-energy e+e- collider KEKB.
We analyze the data on
e
+
e
−
collisions at c.m.s. energies between 0.32 and 2 GeV collected in 2011–2013 with the CMD3 detector operating at the VEPP-3
e
+
e
−
collider of the Budker Institute of ...Nuclear Physics. The data correspond to an integrated luminosity of nearly 60 pb
-1
. Preliminary results
e
+
e
−
→
K
+
K
−
n
π (
n
= 1, 2, 3) on the reactions with two charged kaons in the final state are presented, and the procedure for estimating the integrated luminosity for each energy setting is described.
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