The e^+e^- → 3(π^+π^-), 2(π^+π^-π^0) and K^+K^-2(π^+π^-) cross sections at center-of-mass energies from production threshold to 4.5 GeV measured with initial-state radiation

We study the processes e^+e^- → 3(π^+π^-)γ, 2(π^+π^-π^0)γ and K^+K^-2(π^+π^-)γ, with the photon radiated from the initial state. About 20 000, 33 000 and 4000 fully reconstructed events, respectively, have been selected from 232  fb^(-1) of BABAR data. The invariant mass of the hadronic final state defines the effective e^+e^- center-of-mass energy, so that these data can be compared with the corresponding direct e^+e^- measurements. From the 3(π^+π^-), 2(π^+π^-π^0) and K^+K^-2(π^+π^-) mass spectra, the cross sections for the processes e^+e^- → 3(π^+π^-), e^+e^- → 2(π^+π^-π^0) and e^+e^- → K^+K^-2(π^+π^-) are measured for center-of-mass energies from production threshold to 4.5 GeV. The uncertainty in the cross section measurement is typically 6%–15%. We observe a structure at 1.9 GeV in both cross sections and a resonance structure with mass 1645 ± 0.008  GeV/c^2 and width 0.114 ± 0.014  GeV when the ω(782)η final state is extracted. We observe the J/ψ in all these final states and measure the corresponding branching fractions

Search for the decay B^+ → τ^+ν_τ

We search for the rare leptonic decay B^+ → τ^+ν_τ in a sample of 232 × 10^6 BB̅ pairs collected with the BABAR detector at the SLAC PEP-II B-Factory. Signal events are selected by examining the properties of the B meson recoiling against the semileptonic decay B^- → D^9*0)ℓ^-ν̅_ ℓ. We find no evidence for a signal and set an upper limit on the branching fraction of B(B^+ → τ^+ν_τ)<2.8 × 10^9-4) at the 90% confidence level. We combine this result with a previous, statistically independent BABAR search for B+→τ+ντ to give an upper limit of B(B^+ → τ^+ν_τ)<2.6 × 10^(-4) at the 90% confidence level

Measurement of time-dependent CP asymmetries in B^0→D^((*)±)π^∓ and B^0→D^±ρ^∓ decays

We present updated results on time-dependent CP asymmetries in fully reconstructed B^0→D^((*)±)π^∓ and B^0→D^±ρ^∓ decays in approximately 232×10^6 Υ(4S)→BB events collected with the BABAR detector at the PEP-II asymmetric-energy B factory at SLAC. From a time-dependent maximum-likelihood fit we obtain for the parameters related to the CP violation angle 2β+γ: a^(Dπ)=-0.010±0.023±0.007, c_(lep)^(Dπ)=-0.033±0.042±0.012, a^(D*π)=-0.040±0.023±0.010, c_(lep)D^(*π)=0.049± 0.042±0.015,a^(Dρ)=-0.024±0.031±0.009, c_(lep)^(Dρ)=-0.098±0.055±0.018, where the first error is statistical and the second is systematic. Using other measurements and theoretical assumptions, we interpret the results in terms of the angles of the Cabibbo-Kobayashi-Maskawa unitarity triangle and find |sin⁡(2β+γ)|>0.64  (0.40) at 68% (90%) confidence level

Branching fraction limits for B^0 decays to η′η, η′π^0 and ηπ^0

We describe searches for decays to two-body charmless final states η′η, η′π^0 and ηπ^0 of B^0 mesons produced in e^+e^- annihilation. The data, collected with the BABAR detector at the Stanford Linear Accelerator Center, represent 232 × 10^6 produced BB̅ pairs. The results for branching fractions are, in units of 10^(-6) (upper limits at 90% C.L.): B(B^0 → η′η)=0.2^(+0.7)_(-0.5) ± 0.4(<1.7), B(B^0 → ηπ^0) = 0.6^(+0.5)_(-0.4) ± 0.1(<1.3), and B(B^0 → η′π^0) = 0.8^(+0.8)_(-0.6) ± 0.1(<2.1). The first error quoted is statistical and the second systematic

Logistic regression for simulating damage occurrence on a fruit grading line

Many factors influence the incidence of mechanical damage in fruit handled on a grading line. This makes it difficult to address damage estimation from an analytical point of view. During fruit transfer from one element of a grading line to another, damage occurs as a combined effect of machinery roughness and the intrinsic susceptibility of fruit. This paper describes a method to estimate bruise probability by means of logistic regression, using data yielded by specific laboratory tests. Model accuracy was measured via the statistical significance of its parameters and its classification ability. The prediction model was then linked to a simulation model through which impacts and load levels, similar to those of real grading lines, could be generated. The simulation output sample size was determined to yield reliable estimations. The process makes it possible to derive a suitable line design and the type of fruit that should be handled to maintain bruise levels within European Union (EU) Standards. A real example with peaches was carried out with the aid of the software implementation SIMLIN®, developed by the authors and registered by Madrid Technical University. This kind of tool has been demanded by inter-professional associations and grading lines designers in recent year

Measurement of CP observables for the decays B^± → D^0_(CP)K^±

We present a study of the decay B^- → D^0_(CP)K^± and its charge conjugate, where D^0_CP) is reconstructed in CP-even, CP-odd, and non-CP flavor eigenstates, based on a sample of 232 x 10^6 Y(4S) → BB decays collected with the BABAR detector at the PEP-II e^+e^- storage ring. We measure the partial-rate charge asymmetries A_(CP±) and the ratios R_(CP±) of the B → D^0K decay branching fractions as measured in CP^± and non-CP D^0 decays: A_(CP±) 0:35 ± 0.13(stat) ± 0.04(syst), A_(CP-)= -0.06 ± 0.13(stat) ± 0.04(syst), R_(CP+) = 0.90 ± 0.12(stat) ± 0.049syst), and R_(CP-) = 0:86 ± 0.10(stat) ± 0.05(syst)

Network Topology of an Experimental Futures Exchange

Many systems of different nature exhibit scale free behaviors. Economic systems with power law distribution in the wealth is one of the examples. To better understand the working behind the complexity, we undertook an empirical study measuring the interactions between market participants. A Web server was setup to administer the exchange of futures contracts whose liquidation prices were coupled to event outcomes. After free registration, participants started trading to compete for the money prizes upon maturity of the futures contracts at the end of the experiment. The evolving `cash' flow network was reconstructed from the transactions between players. We show that the network topology is hierarchical, disassortative and scale-free with a power law exponent of 1.02+-0.09 in the degree distribution. The small-world property emerged early in the experiment while the number of participants was still small. We also show power law distributions of the net incomes and inter-transaction time intervals. Big winners and losers are associated with high degree, high betweenness centrality, low clustering coefficient and low degree-correlation. We identify communities in the network as groups of the like-minded. The distribution of the community sizes is shown to be power-law distributed with an exponent of 1.19+-0.16.Comment: 6 pages, 12 figure

Search for the rare decays B^0 → D_s^((*)+)a-_(0(2))

We have searched for the decays B^0 → D_s^+a^-_0, B^0 → D_s^(*+)a^-_0, B^0 → D_s^+a^-_2 and B^0 → D_s^(*+)a^-_2 in a sample of about 230 × 10^6 Υ(4S) → BB̅ decays collected with the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. We find no evidence for these decays and set upper limits at 90% C.L. on the branching fractions: B(B^0 → D_s^+a^-_0)<1.9 × 10^(-5), B(B^0 → D_s^(*+)a^-_0)<3.6 × 10^(-5), B(B^0 → D_s^+a^-_2)<1.9 × 10^(-4), and B(B^0 → D_s^(*+)a^-_2)<2.0 × 10^(-4)

Discerning Aggregation in Homogeneous Ensembles: A General Description of Photon Counting Spectroscopy in Diffusing Systems

In order to discern aggregation in solutions, we present a quantum mechanical analog of the photon statistics from fluorescent molecules diffusing through a focused beam. A generating functional is developed to fully describe the experimental physical system as well as the statistics. Histograms of the measured time delay between photon counts are fit by an analytical solution describing the static as well as diffusing regimes. To determine empirical fitting parameters, fluorescence correlation spectroscopy is used in parallel to the photon counting. For expedient analysis, we find that the distribution's deviation from a single Poisson shows a difference between two single fluor moments or a double fluor aggregate of the same total intensities. Initial studies were performed on fixed-state aggregates limited to dimerization. However preliminary results on reactive species suggest that the method can be used to characterize any aggregating system.Comment: 30 pages, 5 figure