We report on a precision measurement of the cross section for the reaction e+e−→π+π− in the mass range 0.30<Mππ<1.00 GeV/c2 with the initial state radiation (ISR) method, using 817 pb−1 of data at ...e+e− center-of-mass energies near 3.77 GeV and 586 pb−1 of data at e+e− center-of-mass energies near 4.17 GeV, collected with the CLEO-c detector at the CESR e+e− collider at Cornell University. The integrated cross sections in the range 0.30<Mππ<1.00 GeV/c2 for the process e+e−→π+π− are determined with a statistical uncertainty of 0.7% and a systematic uncertainty of 1.6%. The leading-order hadronic contribution to the muon anomalous magnetic moment calculated using these measured e+e−→π+π− cross sections in the range Mππ=0.30 to 1.00 GeV/c2 is calculated to be (500.6±3.6(stat)±8.0(syst))×10−10.
Using e+e− annihilation data taken at the CESR collider with the CLEO-c detector, measurements of hyperon pair production cross sections and elastic and transition electromagnetic form factors have ...been made at the charmonium resonances: ψ(2S), s=3.69 GeV, |Q2|=13.6 GeV2, L=48 pb−1; ψ(3770), s=3.77 GeV, |Q2|=14.2 GeV2, L=805 pb−1; and ψ(4170), s=4.17 GeV, |Q2|=17.4 GeV2, L=586 pb−1. Results with good statistical precision are obtained with high efficiency particle identification. Systematics of pair production cross sections, and form factors with respect to the number of strange quarks in the hyperons are studied, and evidence is presented for the effects of diquark correlations in comparative results for Λ0 and Σ0, both of which have the same uds quark content but different isospin.
The electromagnetic structure of the lightest hadrons, proton, pion, and kaon is studied by high-precision measurements of their form factors for the highest timelike momentum transfers of ...|Q2|=s=14.2 and 17.4 GeV2. Data taken with the CLEO-c detector at sqrts=3.772 and 4.170 GeV, with integrated luminosities of 805 and 586 pb(-1), respectively, have been used to study e+ e- annihilations into π+ π-, K+ K-, and pp. The dimensional counting rule prediction that at large Q2 the quantity Q2F(Q2) for pseudoscalar mesons is nearly constant, and should vary only weakly as the strong coupling constant αS(Q2) is confirmed for both pions and kaons. However, the measurements are in strong quantitative disagreement with the predictions of the existing quantum chromodynamics-based models. For protons, it is found that the timelike form factors continue to remain nearly twice as large as the corresponding spacelike form factors measured in electron elastic scattering, in significant violation of the expectation of their equality at large Q2. Further, in contrast to pions and kaons, a significant difference is observed between the values of the corresponding quantity |Q4|G(M)(|Q2|)/μ(p) for protons at |Q2|=14.2 and 17.4 GeV2. The results suggest the constancy of |Q2|G(M)(|Q2|)/μ(p), instead, at these large |Q2|.
This work shows how it is possible to reconstruct SuperKEKB’s beam parameters using a Neural Network with beamstrahlung signal from the Large Angle Beamstrahlung Monitor (LABM) as input. We describe ...the device, the model, and discuss the results.
Respirable crystalline silica (RCS), in the form of quartz and cristobalite from occupational sources, was classified by the International Agency for Research on Cancer (IARC) as carcinogenic to ...humans (category 1). In addition, RCS has recently been included in the Directive (EU) 2017/2398 about carcinogens and mutagens at work. Numerous studies suggest that the toxicity of quartz is conditioned by density and distribution of surface silanol groups, and it has been widely demonstrated at lab scale that masking these silanol groups significantly reduces silica toxicity. Based on these findings, a detoxifying, wet-coating method, using organosilanes as coating agent for reactive surface silanols, was previously developed and tested at industrial scale. In the present work, a new dry-coating process (patent pending) also using organosilanes was developed and applied to detoxify quartzes from different industrial branches. Dry-coating efficiency and stability were assessed and confirmed by both in-vitro tests (lactate dehydrogenase release and alkaline comet assay) and an intratracheal instillation study in rats. Finally, industrial trials were performed by different quartz end users (elastomers, foundry, adhesives, pigments and glazes) to evaluate the technical and economic feasibility of implementing this dry-coating process at industrial scale. From the obtained results, it can be drawn that the proposed methodology seems to represent a promising strategy to significantly reduce the risk associated with the handling of RCS-bearing materials. This RCS coating approach shows enough flexibility to be adapted to different industrial processes without significantly interfering with product quality.
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•A new dry coating technology of quartzes allows RCS toxicity to be reduced.•The coating process was tested by 5 different quartz end-users.•The physico-chemical results were technically and economically assessed at industrial scale.•Reduction of toxicity was confirmed by in-vitro and in-vivo tests.
Using 805 pb−1 of e+e− annihilation data taken with the CLEO-c detector at ψ(3770), s=3770 MeV, we report the first measurements of the electromagnetic form factors of the Λ0, Σ0, Σ+, Ξ0, Ξ−, and Ω− ...hyperons for the large timelike momentum transfer of |Q2|=14.2 GeV2. The form factors for the different hyperons are found to vary by nearly a factor two. It is found that |GM(Λ0)|=1.66(24)×|GM(Σ0)|. The Λ0 and Σ0 hyperons have the same uds quark content, but differ in their isospin, and therefore the spin of the ud quark pair. It is suggested that the spatial correlation implied by the singlet spin–isospin configuration in the Λ0 is an example of strong diquark correlations in the Λ0, as anticipated by Jaffe and Wilczek. Improved measurements of the branching fractions of ψ(2S)→pp¯ and hyperon–antihyperon pairs are also reported.
Quantum-correlated ψ(3770)→DD¯ decays collected by the CLEO-c experiment are used to perform first measurements of F+, the fractional CP-even content of the self-conjugate decays D→π+π−π0 and ...D→K+K−π0. Values of 0.968±0.017±0.006 and 0.731±0.058±0.021 are obtained for π+π−π0 and K+K−π0, respectively. It is demonstrated how modes of this sort can be cleanly included in measurements of the unitarity triangle angle γ using B∓→DK∓ decays. The high CP-even content of D→π+π−π0, in particular, makes this a promising mode for improving the precision on γ.
Statistical analysis using all moments of the likelihood
L
(
y
|
α
)
(
y being the data and
α
being the fit parameters) is presented. The relevant plots for various data fitting situations are ...presented. The goodness of fit (GOF) parameter (currently the
χ
2
) is redefined as the isoprobability level in a multidimensional space. Many useful properties of statistical analysis are summarized in a new statistical principle which states that the most common likelihood, and not the tallest, is the best possible likelihood, when comparing experiments or hypotheses.
We present a new measurement of the Cabibbo-Kobayashi-Maskawa matrix element |Vcb| from B0→D*−ℓ+νℓ decays, reconstructed with the full Belle data set of 711 fb−1 integrated luminosity. Two form ...factor parametrizations, originally conceived by the Caprini-Lellouch-Neubert (CLN) and the Boyd, Grinstein and Lebed (BGL) groups, are used to extract the product F(1)ηEW|Vcb| and the decay form factors, where F(1) is the normalization factor and ηEW is a small electroweak correction. In the CLN parametrization we find F(1)ηEW|Vcb|=(35.06±0.15±0.56)×10−3, ρ2=1.106±0.031±0.007, R1(1)=1.229±0.028±0.009, R2(1)=0.852±0.021±0.006. For the BGL parametrization we obtain F(1)ηEW|Vcb|=(34.93±0.23±0.59)×10−3, which is consistent with the world average when correcting for F(1)ηEW. The branching fraction of B0→D*−ℓ+νℓ is measured to be B(B0→D*−ℓ+νℓ)=(4.90±0.02±0.16)%. We also present a new test of lepton flavor universality violation in semileptonic B decays, B(B0→D*−e+ν)B(B0→D*−μ+ν)=1.01±0.01±0.03. The errors quoted correspond to the statistical and systematic uncertainties, respectively. This is the most precise measurement of F(1)ηEW|Vcb| and form factors to date and the first experimental study of the BGL form factor parametrization in an experimental measurement.
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