Final Measurement of the

This Letter reports one of the most precise measurements to date of the antineutrino spectrum from a purely ^{235}U-fueled reactor, made with the final dataset from the PROSPECT-I detector at the High Flux Isotope Reactor. By extracting information from previously unused detector segments, this analysis effectively doubles the statistics of the previous PROSPECT measurement. The reconstructed energy spectrum is unfolded into antineutrino energy and compared with both the Huber-Mueller model and a spectrum from a commercial reactor burning multiple fuel isotopes. A local excess over the model is observed in the 5-7 MeV energy region. Comparison of the PROSPECT results with those from commercial reactors provides new constraints on the origin of this excess, disfavoring at 2.0 and 3.7 standard deviations the hypotheses that antineutrinos from ^{235}U are solely responsible and noncontributors to the excess observed at commercial reactors, respectively.

Nonfuel Antineutrino Contributions in the High Flux Isotope Reactor.

Reactor neutrino experiments have seen major improvements in precision in recent years. With the experimental uncertainties becoming lower than those from theory, carefully considering all sources of ν ¯ e is important when making theoretical predictions. One source of ν ¯ e that is often neglected arises from the irradiation of the nonfuel materials in reactors. The ν ¯ e rates and energies from these sources vary widely based on the reactor type, configuration, and sampling stage during the reactor cycle and have to be carefully considered for each experiment independently. In this article, we present a formalism for selecting the possible ν ¯ e sources arising from the neutron captures on reactor and target materials. We apply this formalism to the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory, the ν ¯ e source for the the Precision Reactor Oscillation and Spectrum Measurement (PROSPECT) experiment. Overall, we observe that the nonfuel ν ¯ e contributions from HFIR to PROSPECT amount to 1% above the inverse beta decay threshold with a maximum contribution of 9% in the 1.8-2.0 MeV range. Nonfuel contributions can be particularly high for research reactors like HFIR because of the choice of structural and reflector material in addition to the intentional irradiation of target material for isotope production. We show that typical commercial pressurized water reactors fueled with low-enriched uranium will have significantly smaller nonfuel ν ¯ e contribution.

Measurement of the Antineutrino Spectrum from

This Letter reports the first measurement of the ^{235}U ν[over ¯]_{e} energy spectrum by PROSPECT, the Precision Reactor Oscillation and Spectrum experiment, operating 7.9 m from the 85 MW_{th} highly enriched uranium (HEU) High Flux Isotope Reactor. With a surface-based, segmented detector, PROSPECT has observed 31678±304(stat) ν[over ¯]_{e}-induced inverse beta decays, the largest sample from HEU fission to date, 99% of which are attributed to ^{235}U. Despite broad agreement, comparison of the Huber ^{235}U model to the measured spectrum produces a χ^{2}/ndf=51.4/31, driven primarily by deviations in two localized energy regions. The measured ^{235}U spectrum shape is consistent with a deviation relative to prediction equal in size to that observed at low-enriched uranium power reactors in the ν[over ¯]_{e} energy region of 5-7 MeV.

Dentin biomodification potential depends on polyphenol source.

Although proanthocyanidins (PACs) modify dentin, the effectiveness of different PAC sources and the correlation with their specific chemical composition are still unknown. This study describes the chemical profiling of natural PAC-rich extracts from 7 plants using ultra high pressure/performance liquid chromatography (UHPLC) to determine the overall composition of these extracts and, in parallel, comprehensively evaluate their effect on dentin properties. The total polyphenol content of the extracts was determined (as gallic acid equivalents) using Folin-Ciocalteau assays. Dentin biomodification was assessed by the modulus of elasticity, mass change, and resistance to enzymatic biodegradation. Extracts with a high polyphenol and PAC content from Vitis vinifera, Theobroma cacao, Camellia sinensis, and Pinus massoniana induced a significant increase in modulus of elasticity and mass. The UHPLC analysis showed the presence of multiple types of polyphenols, ranging from simple phenolic acids to oligomeric PACs and highly condensed tannins. Protective effect against enzymatic degradation was observed for all experimental groups; however, statistically significant differences were observed between plant extracts. The findings provide clear evidence that the dentin bioactivities of PACs are source dependent, resulting from a combination of concentration and specific chemical constitution of the complex PAC mixtures.

First measurement of the form factors in the decays D0 → ρ- e+ ν(e) and D+ → ρ0 e+ ν(e).

The beauty to up quark coupling constant |V(ub)| can be extracted from B → ρ e+ ν(e) combined with the form factors for D → K* e+ ν(e) and B → V ℓ+ ℓ- and D → ρ e+ ν(e). Using the entire CLEO-c ψ(3770) → DD event sample, corresponding to an integrated luminosity of 818 pb(-1) and approximately 5.4×10(6) DD events, we measure the form factors for the decays D0 → ρ- e+ ν(e) and D+ → ρ0 e+ ν(e) for the first time and the branching fractions with improved precision. A four-dimensional unbinned maximum likelihood fit determines the form factor ratios to be V(0)/A1(0)=1.48±0.15±0.05 and A2(0)/A1(0)=0.83±0.11±0.04. Assuming Cabibbo-Kobayashi-Maskawa unitarity, the known D meson lifetimes, and our measured branching fractions we obtain the form factor normalizations A1(0), A2(0), and V(0). We also present a measurement of the branching fraction for D+ → ω e+ ν(e) with improved precision.

Observation of the h(c)(1P) Using e+ e- collisions above the DD threshold.

Using 586 pb(-1) of e+ e- collision data at E(c.m.) = 4170 MeV, produced at the Cornell Electron Storage Ring collider and collected with the CLEO-c detector, we observe the process e+ e- → π+ π- h(c)(1P). We measure its cross section to be 15.6±2.3±1.9±3.0 pb, where the third error is due to the external uncertainty on the branching fraction of ψ(2S) → π0 h(c)(1P), which we use for normalization. We also find evidence for e+ e- → ηh(c)(1P) at 4170 MeV at the 3σ level and see hints of a rise in the e+ e- → π+ π- h(c)(1P) cross section at 4260 MeV.

J/psi and psi(2S) Radiative Transitions to eta_{c}.

Using 2.45x10;{7} psi(2S) decays collected with the CLEO-c detector at the Cornell Electron Storage Ring we present the most precise measurements of magnetic dipole transitions in the charmonium system. We measure B(psi(2S)-->gammaeta_{c})=(4.32+/-0.16+/-0.60)x10;{-3}, B(J/psi-->gammaeta_{c})/B(psi(2S)-->gammaeta_{c})=4.59+/-0.23+/-0.64, and B(J/psi-->gammaeta_{c})=(1.98+/-0.09+/-0.30)%. We observe a distortion in the eta_{c} line shape due to the photon-energy dependence of the magnetic dipole transition rate. We find that measurements of the eta_{c} mass are sensitive to the line shape, suggesting an explanation for the discrepancy between measurements of the eta_{c} mass in radiative transitions and other production mechanisms.

Observation of D+ --> etae + nue.

Using a 281 pb-1 data sample collected at the psi(3770) resonance with the CLEO-c detector at the Cornell Electron Storage Ring, we report the first observation of D+ --> etae + nue. We also set upper limits for D+ --> eta'e + nue and D + --> varphie + nue that are about 2 orders of magnitude more restrictive than those obtained by previous experiments.

Search for lepton flavor violation in upsilon decays.

In this Letter, we describe a search for lepton flavor violation (LFV) in the bottomonium system. We search for leptonic decays Upsilon(nS)-->mutau (n=1, 2, and 3) using the data collected with the CLEO III detector. We identify the tau lepton using its leptonic decay nu_{tau}nu[over ]_{e}e and utilize multidimensional likelihood fitting with probability density function shapes measured from independent data samples. We report our estimates of 95% C.L. upper limits on LFV branching fractions of Upsilon mesons. We interpret our results in terms of the exclusion plot for the energy scale of a hypothetical new interaction versus its effective LFV coupling in the framework of effective field theory.

Observation of chicJ radiative decays to light vector mesons.

Using a total of 2.74 x 10(7) decays of the psi(2S) collected with the CLEO-c detector, we present a study of chi(cJ)-->gammaV, where V=rho(0), omega, phi. The transitions chi(c1)-->gammarho(0 and chi(c1)-->gammaomega are observed with B(chi(c1)-->gammarho(0))=(2.43+/-0.19+/-0.22) x 10(-4) and B(chi(c1)-->gammaomega)=(8.3+/-1.5+/-1.2) x 10(-5). In the chi(c1)-->gammarho(0) transition, the final state meson is dominantly longitudinally polarized. Upper limits on the branching fractions of other chi(cJ) states to light vector mesons are presented.

Search for very light CP-odd Higgs Boson in radiative decays of Upsilon(1S).

We search for a non-SM-like CP-odd Higgs boson (a(1)(0)) decaying to tau(+)tau(-) or mu(+)mu(-) in radiative decays of the Upsilon(1S). No significant signal is found, and upper limits on the product branching ratios are set. Our tau(+)tau(-) results are almost 2 orders of magnitude more stringent than previous upper limits. Our data provide no evidence for a Higgs state with a mass of 214 MeV decaying to mu(+)mu(-), previously proposed as an explanation for 3 Sigma(+)-->pmu(+)mu(-) events observed by the HyperCP experiment. Our results constrain NMSSM models.

Measurement of the eta'-meson mass using J/psi-->gammaeta'.

We measure the mass of the eta;{'} meson using psi(2S)-->pi;{+}pi;{-}J/psi, J/psi-->gammaeta;{'} events acquired with the CLEO-c detector operating at the CESR e;{+}e;{-} collider. Using three decay modes, eta;{'}-->rho;{0}gamma, eta;{'}-->pi;{+}pi;{-}eta with eta-->gammagamma, and eta;{'}-->pi;{+}pi;{-}eta with eta-->pi;{+}pi;{-}pi;{0}, we find M_{eta;{'}}=957.793+/-0.054+/-0.036 MeV, in which the uncertainties are statistical and systematic, respectively. This result is consistent with but substantially more precise than the current world average.

Precision measurement of the mass of the hc(1P1) state of charmonium.

A precision measurement of the mass of the h_{c}(1P1) state of charmonium has been made using a sample of 24.5x10;{6} psi(2S) events produced in e;{+}e;{-} annihilation at the Cornell Electron Storage Ring (CESR). The reaction used was psi(2S)-->pi;{0}h_{c}, pi;{0}-->gammagamma, h_{c}-->gammaeta_{c}, and the reaction products were detected in the CLEO-c detector. Data have been analyzed both for the inclusive reaction and for the exclusive reactions in which eta_{c} decays are reconstructed in 15 hadronic decay channels. Consistent results are obtained in the two analyses. The averaged results of the present measurements are M(h_{c})=3525.28+/-0.19(stat.)+/-0.12(syst.) MeV, and B(psi(2S)-->pi;{0}h_{c})xB(h_{c}-->gammaeta_{c})=(4.19+/-0.32+/-0.45)x10;{-4}. Using the ;{3}P_{J} centroid mass, DeltaM_{hf}(1P) identical withM(chi_{cJ})-M(h_{c})=+0.02+/-0.19+/-0.13 MeV.

Observation of J/psi-->3gamma.

We report the first observation of the decay J/psi-->3gamma. The signal has a statistical significance of 6sigma and corresponds to a branching fraction of B(J/psi-->3gamma)=(1.2+/-0.3+/-0.2)x10;{-5}, in which the errors are statistical and systematic, respectively. The measurement uses psi(2S)-->pi;{+}pi;{-}J/psi events acquired with the CLEO-c detector operating at the CESR e;{+}e;{-} collider.

Study of the decays D0-->pi{-}e{+}nu{e}, D{0}-->K{-}e{+}nu{e}, D{+}-->pi{0}e{+}nu{e}, and D{+}-->K0e{+}nu{e}.

By using 1.8x10{6} DDpairs, we have measured B(D{0}-->pi{-}e{+}nu{e})=0.299(11)(9)%, B(D{+}-->pi{0}e{+}nu{e})=0.373(22)(13)%, B(D{0}-->K{-}e{+}nu{e})=3.56(3)(9)%, and B(D{+}-->K{0}e{+}nu{e})=8.53(13)(23)% and have studied the q;{2} dependence of the form factors. By combining our results with recent lattice calculations, we obtain |V{cd}|=0.217(9)(4)(23) and |V{cs}|=1.015(10)(11)(106).

Measurement of the absolute branching fraction of Ds+ --> tau+ nutau decay.

Using a sample of tagged D(s)(+) decays collected near the D(s)(*+/-)D(s)(-/+) peak production energy in e(+)e(-) collisions with the CLEO-c detector, we study the leptonic decay D(s)(+)-->tau(+)nu(tau) via the decay channel tau(+)-->e(+)nu(e)nu(tau). We measure B(D(s)(+)-->tau(+)nu(tau))=(6.17+/-0.71+/-0.34)%, where the first error is statistical and the second systematic. Combining this result with our measurements of D(s)(+)-->mu(+)nu(mu) and D(s)(+)-->tau(+)nu(tau) (via tau(+)-->pi(+)nu(tau)), we determine f(D(s))=(274+/-10+/-5) MeV.

First observation of the decay Ds+-->pn.

Using e+e--->Ds*-Ds+ data collected near the peak Ds production energy, Ecm=4170 MeV, with the CLEO-c detector, we present the first observation of the decay Ds+-->pn. We measure a branching fraction B(Ds+-->pn)=(1.30+/-0.36(-0.16)+0.12)x10(-3). This is the first observation of a charmed meson decaying into a baryon-antibaryon final state.

Measurement of prominent eta-decay branching fractions.

The decay psi(2S) --> etaJ/psi is used to measure, for the first time, all prominent eta-meson branching fractions with the same experiment in the same dataset, thereby providing a consistent treatment of systematics across branching fractions. We present results for eta decays to gamma gamma, pi(+)pi(-)pi(0), 3pi(0), pi(+)pi(-)gamma and e(+)e(-)gamma, accounting for 99.9% of all eta decays. The precision of several of the branching fractions and their ratios is improved. Two channels, pi(+)pi(-)gamma and e(+)e(-)gamma, show results that differ at the level of three standard deviations from those previously determined.

Measurement of the eta-meson mass using psi(2S) --> etaJ/psi.

We measure the mass of the eta meson using psi(2S) --> etaJ/psi events acquired with the CLEO-c detector operating at the CESR e(+)e(-) collider. Using the four decay modes eta --> gamma gamma, 3pi(0), pi(+)pi(-)pi(0), and pi(+)pi(-)gamma, we find M(eta) = 547.785 +/- 0.017 +/- 0.057 MeV, in which the first uncertainty is statistical and the second systematic. This result has an uncertainty comparable to the two most precise previous measurements and is consistent with that of NA48, but is inconsistent at the level of 6.5 sigma with the much smaller mass obtained by GEM.

Observation of Upsilon(3S)-->tau+tau- and tests of lepton universality in Upsilon decays.

Using data collected with the CLEO III detector at the CESR e+e- collider, we report on a first observation of the decay Upsilon(3S)-->tau+tau-, and precisely measure the ratio of branching fractions of Upsilon(nS), n=1, 2, 3, to tau+tau- and mu+mu- final states, finding agreement with expectations from lepton universality. We derive absolute branching fractions for these decays, and also set a limit on the influence of a low mass CP-odd Higgs boson in the decay of the Upsilon(1S).