Measurements of the cross sections for e+e−→hadrons at 3.650, 3.6648, 3.773 GeV and the branching fraction for ψ(

Measurements of the observed cross sections for e+e−→ exclusive light hadrons containing KS0 meson a

“…I and II, where the first error is statistical and the second systematic. In the measurements of the observed cross sections, the systematic errors arise from the uncertainties in integrated luminosity of the data set (2.1% [4,5]), photon selection (2.0% per photon), tracking efficiency (2.0% per track), particle identification (0.5% per pion or kaon), kinematic fit (1.5%), K 0 S reconstruction (1.1% [27]), branching fractions quoted from PDG [33] (0.03% for B(π 0 → γγ) and 0.07% for B(K 0 S → π + π − )), Monte Carlo modeling (6.0% [19,20,21]), Monte Carlo statistics (1.4% ∼ 4.4%), background subtraction (0.0% ∼ 3.0%) and fit to mass spectrum (0.4% ∼ 8.5%). Adding these uncertainties in quadrature yields the total systematic error ∆ sys for each mode at √ s = 3.773 and 3.650 GeV.…”

“…To understand the possible excess of the ψ(3770) cross section relative to the DD cross section, BES and CLEO Collaborations made many efforts to study the ψ(3770) non-DD decays. The CLEO Collaboration measured the e + e − → ψ(3770) → non-DD cross section to be +0.41 measured the branching fraction for ψ(3770) → non−DD decay to be (15 ± 5)% [4,5,6,7,8], which indicates that, contrary to what is generally expected, the ψ(3770) might substantially decay into non−DD final states or there are some new structure or physics effects which may partially be responsible for the largely measured non-DD branching fraction of the ψ(3770) decays [9,10]. BES Collaboration observed the first non−DD decay mode for ψ(3770) → J/ψπ + π − , and measured its decay branching fraction to be B[ψ(3770) → J/ψπ + π − ] = (0.34 ± 0.14 ± 0.09)% [11,12].…”

Measurements of the observed cross sections for e+e−→light hadrons at s=3.773 and

“…In the measurements of the observed cross sections for e + e − → light hadrons, the systematic error arises mainly from the uncertainties in luminosity (∼2.1% [4,5]), photon selection (∼2.0% per photon), tracking efficiency (∼2.0% per track), particle identification (∼0.5% per pion or kaon, ∼2.0% per proton), kinematic fit (∼1.5%), Monte Carlo statistics (∼(1.1∼3.2)%), branching fractions quoted from PDG [20] (∼1.22% for B(φ → K + K − ), ∼0.03% for B(π 0 → γγ) and ∼0.66% for B(η → γγ)), background subtraction (∼(0.0∼4.8)%), fit to mass spectrum (∼3.8%), and Monte Carlo modeling (∼6.0%). Adding these uncertainties in quadrature yields the total systematic error ∆ sys for each final state at √ s = 3.773 and 3.650 GeV, respectively, which are shown in the sixth columns of Tabs.…”

“…However, it is difficult to understand for a long time that the observed cross section σ obs DD for DD production at the peak of ψ(3770) resonance is less than the observed cross section σ obs ψ(3770) for ψ(3770) production [2,3]. Recently, BES Collaboration directly measured the branching fraction for ψ(3770) → non−DD to be (16.1 ± 1.6 ± 5.7)% [4] and (16.4 ± 7.3 ± 4.7)% [5] with two different data samples and different methods. These imply that the ψ(3770) might substantially decay into non−DD final states.…”

Study ofe+e−→ppAblikim1, Yang2, Zhang3 et al. 2014Phys. Rev. DSelf Cite160120View full textAdd to dashboardCite

“…However, the BES collaboration measured the total non-DD branching fraction to be (14.7±3.2)% neglecting interference effects [7][8][9][10]. The CLEO collaboration measured the non-DD branching fraction to be (−3.3±1.4 +6.6 −4.8 )% taking into account interference between electromagnetic resonant and electromagnetic non-resonant (continuum) amplitude assuming no interference with the three-gluon amplitude [11].…”