K. Randrianarivony

Model-independent determination of the strong-phase difference between D0 and D⊃̄0→KS,L0h+h- (h=π, K) and its impact on the measurement of the CKM angle γ/Φ3

We report the first determination of the relative strong-phase difference between D0→KS,L0K+K- and D 0→KS,L0K+K-. In addition, we present updated measurements of the relative strong-phase difference between D0→KS,L0π+π- and D 0→KS,L0π+π-. Both measurements exploit the quantum coherence between a pair of D0 and D 0 mesons produced from ψ(3770) decays. The strong-phase differences measured are important for determining the Cabibbo-Kobayashi-Maskawa angle γ/ϕ3 in B-→K-D˜0 decays, where D˜0 is a D0 or D 0 meson decaying to KS0h+h- (h=π, K), in a manner independent of the model assumed to describe the D0→KS0h+h- decay. Using our results, the uncertainty in γ/ϕ3 due to the error on the strong-phase difference is expected to be between 1.7° and 3.9° for an analysis using B-→K-D˜0, D˜0→KS0π+π- decays, and between 3.2° and 3.9° for an analysis based on B-→K-D˜0, D˜0→KS0K+K- decays. A measurement is also presented of the CP-odd fraction, F-, of the decay D0→KS0K+K- in the region of the ϕ→K+K- resonance. We find that in a region within 0.01  GeV2/c4 of the nominal ϕ mass squared F->0.91 at the 90% confidence level.

Observation of the hc(1P) Using e+e- Collisions above the DD̄ 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.

Study of ψ(2S) decays to γpp̄, π0pp̄, and ηpp̄, and search for pp̄ threshold enhancements

The decays of {psi}(2S) into {gamma}pp, {pi}{sup 0}pp, and {eta}pp have been studied with the CLEO-c detector using a sample of 24.5x10{sup 6} {psi}(2S) events obtained from e{sup +}e{sup -} annihilations at {radical}(s)=3686 MeV. The data show evidence for the excitation of several N{sup *} resonances in p{pi}{sup 0} and p{eta} channels in {pi}{sup 0}pp and {eta}pp decays, and f{sub 2} states in {gamma}pp decay. Branching fractions for decays of {psi}(2S) to {gamma}pp, {pi}{sup 0}pp, and {eta}pp have been determined. No evidence for pp threshold enhancements was found in the reactions {psi}(2S){yields}Xpp, where X={gamma}, {pi}{sup 0}, {eta}. We do, however, find confirming evidence for a pp threshold enhancement in J/{psi}{yields}{gamma}pp as previously reported by BES.

Measurement of the pseudoscalar decay constant fDs using Ds+→τ+ν, τ+→ρ+ν̄ decays

Analyzing 600 pb of ee collisions at 4170 MeV center-of-mass energy with the CLEOc detector, we measure the branching fraction B(D s → τ ν) = (5.52 ± 0.57 ± 0.21)% using the τ → ρν decay mode. Combining with other CLEO measurements of B(D s → τ ν) we determine the pseudoscalar decay constant fDs = (259.7 ± 7.8± 3.4) MeV consistent with the value obtained from our D s → μ ν measurement of (257.6± 10.3± 4.3) MeV. Combining these measurements we find a value of fDs = (259.0± 6.2± 3.0) MeV, that differs from the most accurate prediction based on unquenched lattice gauge theory of (241 ± 3) MeV by 2.4 standard deviations. We also present the first measurements of B(D s → K ππ) = (1.00 ± 0.18 ± 0.04)%, and B(D s → π ππ) = (0.65 ± 0.13 ± 0.03)%, and measure a new value for B(D s → ηρ ) = (8.9 ± 0.6 ± 0.5)%. PACS numbers: 13.20.Fc, 12.38.Gc, 14.40.LbAnalyzing 600 pb ―1 of e + e ― collisions at 4170 MeV center-of-mass energy with the CLEO-c detector, we measure the branching fraction B(D + s → τ + ν) = (5.52 ± 0.57 ± 0.21)% using the τ + → ρ + ν decay mode. Combining with other CLEO measurements of B(D + s → τ + ν) we determine the pseudoscalar decay constant f Ds = (259.7 ± 7.8 ± 3.4) MeV consistent with the value obtained from our D + s → μ + ν measurement of (257.6 ± 10.3 ± 4.3) MeV. Combining these measurements we find a value of f Ds = (259.0 ± 6.2 ± 3.0) MeV, that differs from the most accurate prediction based on unquenched lattice gauge theory of (241 ± 3) MeV by 2.4 standard deviations. We also present the first measurements of B(D + s → K 0 π + π 0 ) = (1.00 ± 0.18 ± 0.04)%, and B(D + s → π + π 0 π 0 ) (0.65 ± 0.13 ± 0.03)%, and measure a new value for B(D + s → ηρ + ) = (8.9 ± 0.6 ± 0.5)%.

Amplitude analysis of D0→K+K-π+π-

We present an amplitude analysis of the decay D-0 -> K- pi(+)pi(+)pi(-) based on a data sample of 2.93 fb(-1) acquired by the BESIII detector at the psi(3770) resonance. With a nearly background free sample of about 16000 events, we investigate the substructure of the decay and determine the relative fractions and the phases among the different intermediate processes. Our amplitude model includes the two-body decays D-0 -> (K) over bar*(0)rho(0), D-0 -> K- a(1)(+) (1260) and D-0 -> K-1(-)(1270)pi(+), the three-body decays D-0 -> K-1(-)*(0)pi(+)pi(-) and D-0 -> K- pi(+)rho(0), as well as the four-body nonresonant decay D-0 -> K- pi(+)pi(+)pi(-). The dominant intermediate process is D-0 -> K(-)a(1)(+)(1260)accounting for a fit fraction of 54.6%.

Studies of the decays D0→KS0K−π+ and D0→KS0K+π−

The first measurements of the coherence factor RK⁰SKπ and the average strong–phase difference δK⁰SKπD in D⁰ → K⁰S K∓π± decays are reported. These parameters can be used to improve the determination of the unitary triangle angle in B⁻ → D¯K⁻ decays, where D¯ is either a D⁰ or a D¯⁰ meson decaying to the same final state, and also in studies of charm mixing. The measurements of the coherence factor and strong-phase difference are made using quantum-correlated, fully reconstructed D⁰D¯⁰ pairs produced in e⁺e⁻ collisions at the ψ(3770) resonance. The measured values are RK⁰SKπ = 0.73 ± 0.08 and δK⁰SKπD = (8.3 ± 15.2)° for an unrestricted kinematic region and RK*K = 1.00 ± 0.16 and δK*KD = (26.5 ± 15.8)° for a region where the combined K⁰Sπ± invariant mass is within 100 MeV/c² of the K*(892)± mass. These results indicate a significant level of coherence in the decay. In addition, isobar models are presented for the two decays, which show the dominance of the K*(892)± resonance. The branching ratio B(D⁰ → K⁰S K⁺π⁻)/B(D⁰ → K⁰S K⁻π⁺) is determined to be 0.592 ± 0.044(stat.) ± 0.018(syst.), which is more precise than previous measurements.J. Insler, H. Muramatsu, C. S. Park, L. J. Pearson, E. H. Thorndike, S. Ricciardi, C. Thomas, 3 M. Artuso, S. Blusk, R. Mountain, T. Skwarnicki, S. Stone, J. C. Wang, L. M. Zhang, G. Bonvicini, D. Cinabro, M. J. Smith, P. Zhou, T. Gershon, P. Naik, J. Rademacker, K. W. Edwards, K. Randrianarivony, R. A. Briere, H. Vogel, P. U. E. Onyisi, J. L. Rosner, J. P. Alexander, D. G. Cassel, S. Das, R. Ehrlich, L. Gibbons, S. W. Gray, D. L. Hartill, D. L. Kreinick, V. E. Kuznetsov, J. R. Patterson, D. Peterson, D. Riley, A. Ryd, A. J. Sadoff, X. Shi, W. M. Sun, J. Yelton, P. Rubin, N. Lowrey, S. Mehrabyan, M. Selen, J. Wiss, J. Libby, M. Kornicer, R. E. Mitchell, D. Besson, T. K. Pedlar, D. Cronin-Hennessy, J. Hietala, S. Dobbs, Z. Metreveli, K. K. Seth, A. Tomaradze, T. Xiao, D. Johnson, S. Malde, L. Martin, A. Powell, G. Wilkinson, D. M. Asner, G. Tatishvili, J. Y. Ge, D. H. Miller, I. P. J. Shipsey, B. Xin, G. S. Adams, J. Napolitano, and K. M. Ecklund

First measurement of the form factors in the decays D0→ρ- e+νe and D+→ρ0e+νe

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.

Diamond detector irradiation tests at TRIUMF

Polycrystalline chemical vapour deposition (pCVD) diamond detectors are being considered for an upgrade of Forward Calorimetry in the ATLAS detector at the CERN LHC. In order to determine their radiation hardness, four detectors were continuously monitored during irradiation with 500 MeV protons at TRIUMF to a fluence of 2.25 x 1017 protons/cm2. All four detectors worked at the end of the irradiation period. The detector response A as a function of fluence has been fitted to a sum of two exponentials and to a function A = ao/(1+a1) where ao is the initial response and is the fluence with a1 = 9.8 x 10−17 ± 3.2 x 10−18 cm2/proton. At the end of irradiation the response had reduced to five percent of the original value. The time resolution was found to be ~ 250 picoseconds.

Search for Rare and Forbidden Decays of Charm and Charmed-Strange Mesons to Final States h^+- e^-+ e^+

We have searched for flavor-changing neutral current decays and lepton-number-violating decays of D{sup +} and D{sub s}{sup +} mesons to final states of the form h{sup {+-}}e{sup {-+}}e{sup +}, where h is either {pi} or K. We use the complete samples of CLEO-c open-charm data, corresponding to integrated luminosities of 818 pb{sup -1} at the center-of-mass energy E{sub CM}=3.774 GeV containing 2.4x10{sup 6} D{sup +}D{sup -} pairs and 602 pb{sup -1} at E{sub CM}=4.170 GeV containing 0.6x10{sup 6} D{sub s}{sup *{+-}}D{sub s}{sup {-+}} pairs. No signal is observed in any channel, and we obtain 90% confidence level upper limits on branching fractions B(D{sup +}{yields}{pi}{sup +}e{sup +}e{sup -})<5.9x10{sup -6}, B(D{sup +}{yields}{pi}{sup -}e{sup +}e{sup +})<1.1x10{sup -6}, B(D{sup +}{yields}K{sup +}e{sup +}e{sup -})<3.0x10{sup -6}, B(D{sup +}{yields}K{sup -}e{sup +}e{sup +})<3.5x10{sup -6}, B(D{sub s}{sup +}{yields}{pi}{sup +}e{sup +}e{sup -})<2.2x10{sup -5}, B(D{sub s}{sup +}{yields}{pi}{sup -}e{sup +}e{sup +})<1.8x10{sup -5}, B(D{sub s}{sup +}{yields}K{sup +}e{sup +}e{sup -})<5.2x10{sup -5}, and B(D{sub s}{sup +}{yields}K{sup -}e{sup +}e{sup +})<1.7x10{sup -5}.

Search for the decay J/ψ → γ + invisible

A search for J/ψ radiative decay to weakly interacting neutral final states was performed using the CLEO-c detector at the Cornell Electron Storage Ring. J/ψ events were selected by observing the hadronic decay ψ (2S) → π + π - J/ψ. A total of 3.7 X 10 6 J/ψ events were used to study the decay J/ψ → y + X, where X is a narrow state that is invisible to the detector. No significant signal was observed, and upper limits on the branching fraction were set for masses m X up to 960 MeV/c 2 . The upper limit corresponding to m X = 0 is 4.3 × 10- 6 at the 90% confidence level.