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Harris, F. A.

Publications and source records attributed to Harris, F. A..

At least 19 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2024

Observation of J / ψ decays to e + e − e + e − and e + e − μ + μ −

Using a data sample of 4.481 × 10 8 ψ ( 3686 ) events collected with the BESIII detector, we report the first observation of the four-lepton-decays J / ψ → e + e − e + e − and J / ψ → e + e − μ + μ − utilizing the process ψ ( 3686 ) → π + π − J / ψ . The branching fractions are determined to be [ 5.48 ± 0.31 ( stat ) ± 0.45 ( syst ) ] × 10 − 5 and [ 3.53 ± 0.22 ( stat ) ± 0.13 ( syst ) ] × 10 − 5 , respectively. The results are consistent with theoretical predictions. No significant signal is observed for J / ψ → μ + μ − μ + μ − , and an upper limit on the branching fraction is set at 1.6 × 10 − 6 at the 90% confidence level. A C P asymmetry observable is constructed for the first two channels, which is measured to be ( − 0.012 ± 0.054 ± 0.010 ) and ( 0.062 ± 0.059 ± 0.006 ) , respectively. No evidence for C P violation is observed in this process. Published by the American Physical Society 2024

Astronomy & Astrophysics↗
DOE OSTI2022

Observation of the doubly Cabibbo-suppressed decays $D^+ → K^+π^0π^0$ and $D^+ → K^+π^0η$

By analyzing e + e - annihilation data corresponding to an integrated luminosity of 2.93 fb -1 collected at the center-of-mass energy of 3.773 GeV with the BESIII detector, we report the first observations of the doubly Cabibbo-suppressed decays D + → K + π 0 π 0 and D + → K + π 0 η. The branching fractions of D + → K + π 0 π 0 and D + → K + π 0 η are measured to be (2.1 ± 0.4 stat ± 0.1 syst ) x 10 -4 and (2.1 ± 0.5 stat ± 0.1 syst ) x 10 -4 with statistical significances of 8.8σ and 5.5σ, respectively. In addition, we search for the subprocesses D + → K * (892) + π 0 and D + → K * (892)+η with K * (892) + → K + π 0 . The branching fraction of D + → K * (892) + η is determined to be (4.4$^{+1.8}_{-1.5stat}$ ± 0.2 syst ) x 10 -4 , with a statistical significance of 3.2σ. No significant signal for D + → K * (892) + π 0 is found and we set an upper limit on the branching fraction of this decay at the 90% confidence level to be 5.4 x 10 -4 .

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2022

Amplitude analysis and branching fraction measurement of $D_s^+$ →$K^–K^+π^+π^+π^–$

Using $e^+e^–$ annihilation data corresponding to a total integrated luminosity of 6.32 fb –1 collected at the center-of-mass energies between 4.178 and 4.226 GeV with the BESIII detector, we perform an amplitude analysis of the decay $D_s^+$ →$K^–K^+π^+π^+π^–$ and determine the relative fractions and phases of different intermediate processes. Absolute branching fraction of $D_s^+$ →$K^–K^+π^+π^+π^–$ decay is measured to be (6.60 ± 0.47 stat. ± 0.38 syst. ) x 10 –3 . The dominant intermediate process is $D_s^+$ → $a_1$(1260) + $\phi, \phi$ → $K^–K^+ a_1$(1260) + → $ρπ^+$, $ρ → π^+π^–$, with a branching fraction of (5.15 ± 0.41 stat. ± 0.32 syst. ) x 10 –3 .

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2022

Study of the processes $χ_{cJ}$ → $Ξ^–\overline{Ξ}^+$ and $Ξ^0 \overline{Ξ} ^0$

Using 448.1 x 10 6 $\psi$(3686) decays collected with the BESIII detector at the BEPCII $e^+e^-$ storage rings, the branching fractions and angular distributions of the decays $χ_{cJ}$ → $Ξ^–\overline{Ξ}^+$ and $Ξ^0 \overline{Ξ} ^0$ (J = 0, 1, 2) are measured based on a partial-reconstruction technique. The decays $χ_{c1}$ → $Ξ^0 \overline{Ξ} ^0$ and $χ_{c2}$ → $Ξ^0 \overline{Ξ} ^0$ are observed for the first time with statistical significances of 7σ and 15σ, respectively. The results of this analysis are in good agreement with previous measurements and have significantly improved precision.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2022

Number of J/ψ events at BESIII*

Using inclusive decays of $J/\psi $, a precise determination of the number of $J/\psi $ events collected with the BESIII detector was performed. For the two data sets taken in 2009 and 2012, the numbers of $J/\psi $ events were recalculated to be $ (224.0 \pm 1.3)\times10^6 $ and $ (1088.5 \pm 4.4)\times10^6 $, respectively; these numbers are in good agreement with the previous measurements. For the $J/\psi $ sample taken in 2017–2019, the number of events was determined to be $ (8774.0 \pm 39.4)\times10^{6} $. The total number of $J/\psi $ events collected with the BESIII detector was determined to be $ (10087 \pm 44)\times10^{6} $, where the uncertainty is dominated by systematic effects, and the statistical uncertainty is negligible.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2022

Search for new hadronic decays of $h_c$ and observation of $h_c$ → $p\overline{p}η$

A search for the hadronic decays of the $h_c$ meson to the final states $p\overline{p}π^+π^-π^o$, $p\overline{p}η$, and $p\overline{p}π^o$ via the process $\psi$(3686) → $π^oh_c$ is performed using (4.48 ± 0.03) x 10 8 $\psi$(3686) events collected with the BESIII detector. The decay channel $h_c$ → $p\overline{p}η$ is observed for the first time with a significance greater than 5σ and a branching fraction of (6.41 ± 1.74 ± 0.53 ± 1.00) x 10 -4 , where the uncertainties are statistical, systematic, and that from the branching fraction of $\psi$(3686) → $π^oh_c$. Strong evidence for the decay $h_c$ → $p\overline{p}π^+π^-π^o$ is found with a significance of 4.9σ and a branching fraction of (3.84 ± 0.83 ± 0.69 ± 0.58) x 10 -3 . The significances include systematic uncertainties. No clear signal of the decay $h_c$ → $p\overline{p}π^o$ is found, and an upper limit of 6.59 x 10 -4 on its branching fraction is set at the 90% confidence level.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2022

Search for the decay $h_c$ → $π^0J/ψ$

A search for the decay $h_c$ → $π^0J/ψ$ is performed using a sample of hc produced in the reaction $e^+e^-$ → $π^+π^-h_c$. The data samples were collected with the BESIII detector at center-of-mass energies between 4.189 and 4.437 GeV, corresponding to a total integrated luminosity of 11 fb -1 . No significant signal is observed. Upper limits on the branching ratio $\mathcal{B}$($h_c$ →$π^oJ/ψ$)/$\mathcal{B}$($h_c$ →$γη_c$ →$γK^+K_-π^o$) and on the branching fraction $\mathcal{B}$($h_c$ →$π^oJ/ψ$) are determined to be 7.5 x 10 -2 and 4.7 x 10 -4 at 90% confidence level, respectively. The latter is derived from the former using the measured branching fraction of the normalization channel. This is the first determination of the upper limit of the decay $h_c$ → $π^0J/ψ$

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2022

Amplitude analysis and branching-fraction measurement of $\mathrm{D}^+_s$ → $π^+π^oη'$

Using data collected with the BESIII detector in $e^+e^-$ collisions at center-of-mass energies between 4.178 and 4.226 GeV and corresponding to 6.32 fb -1 of integrated luminosity, we report the amplitude analysis and branching-fraction measurement of the $\mathrm{D}^+_s$ → $π^+π^oη'$ decay. We find that the dominant intermediate process is $\mathrm{D}^+_s$ →$ρ^+η'$ and the significances of other resonant and nonresonant processes are all less than 3σ. The upper limits on the branching fractions of S-wave and P-wave nonresonant components are set to 0.10% and 0.74% at the 90% confidence level, respectively. In addition, the branching fraction of the $\mathrm{D}^+_s$ → $π^+π^oη'$ decay is measured to be (6.15 ± 0.25(stat.) ± 0.18(syst.))%, which receives significant contribution only from $\mathrm{D}^+_s$ →$ρ^+η'$ according to the amplitude analysis.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗