arXiv subjects

C. H. Heinz

Publications and source records attributed to C. H. Heinz.

6 recordsLinked to original sources

arXiv2023

Search for $\barΛ$-$Λ$ oscillations in the decay $J/ψ\to p K^- \barΛ+c.c.$

We report the first search for $\barΛ$--$Λ$ oscillations in the decay $J/ψ\to p K^- \barΛ + c.c.$ by analyzing $1.31\times10^9$ $J/ψ$ events accumulated with the BESIII detector at the BEPCII collider. The $J/ψ$ events are produced using $e^+e^-$ collisions at a center of mass energy $\sqrt{s}= 3.097$~GeV. No evidence for hyperon oscillations is observed. The upper limit for the oscillation rate of $\barΛ$ to $Λ$ hyperons is determined to be $\mathcal{P}(Λ)=\frac{\mathcal{B}(J/ψ\to pK^-Λ+c.c.)}{\mathcal{B}(J/ψ\to pK^-\barΛ+c.c.)}<4.4\times10^{-6}$ corresponding to an oscillation parameter $δm_{Λ\barΛ}$ of less than $3.8\times10^{-18}$~GeV at the 90\% confidence level.

hep-ex↗

arXiv2022

Search for the decay $D^{0} \to π^{0} ν\barν$

We present the first experimental search for the rare charm decay $D^{0} \to π^{0} ν\barν$. It is based on an $e^+e^-$ collision sample consisting of $10.6\times10^{6}$ pairs of $D^0\bar{D}^0$ mesons collected by the BESIII detector at $\sqrt{s}$=3.773 GeV, corresponding to an integrated luminosity of 2.93~fb$^{-1}$. A data-driven method is used to ensure the reliability of the background modeling. No significant $D^{0} \to π^{0} ν\barν$ signal is observed in data and an upper limit of the branching fraction is set to be $2.1\times 10^{-4}$ at the 90$\%$ confidence level. This is the first experimental constraint on charmed-hadron decays into dineutrino final states.

hep-ex↗

arXiv2021

Measurement of the Born cross sections for $e^+e^- \to η^\prime π^{+}π^{-}$ at center-of-mass energies between $2.00$ and $3.08$ GeV

The Born cross sections for the process $e^+e^- \to η^\prime π^{+}π^{-}$ at different center-of-mass energies between $2.00$ and $3.08$ GeV are reported with improved precision from an analysis of data samples collected with the BESIII detector operating at the BEPCII storage ring. An obvious structure is observed in the Born cross section line shape. Fit as a Breit-Wigner resonance, it has a statistical significance of $6.3σ$ and a mass and width of $M=(2111\pm43\pm25)$~MeV/$c^2$ and $Γ=(135\pm34\pm30)$~MeV, where the uncertainties are statistical and systematic, respectively. These measured resonance parameters agree with the measurements of BABAR in $e^+e^- \to η^\prime π^{+}π^{-}$ and BESIII in $e^+e^- \to ωπ^0$ within two standard deviations.

hep-ex↗

arXiv2021

Study of $e^+e^- \to 2(p\bar{p})$ at center-of-mass energies between 4.0 and 4.6 GeV

Using data taken at 23 center-of-mass energies between 4.0 and 4.6 GeV with the BESIII detector at the BEPCII collider and with a total integrated luminosity of approximately $15$ fb$^{-1}$, the process $e^+e^-\to 2(p \bar{p})$ is studied for the first time. The Born cross sections for $e^+e^-\to 2(p \bar{p})$ are measured, and no significant structure is observed in the lineshape. The baryon pair ($pp$ and $\bar{p}\bar{p}$) invariant mass spectra are consistent with phase space, therefore no hexaquark or di-baryon state is found.

hep-ex↗

arXiv2021

Cross section measurement of $e^+e^- \to p\bar{p}η$ and $e^+e^- \to p\bar{p}ω$ at center-of-mass energies between 3.773 GeV and 4.6 GeV

Based on $14.7~\textrm{fb}^{-1}$ of $e^+e^-$ annihilation data collected with the BESIII detector at the BEPCII collider at 17 different center-of-mass energies between $3.7730~\textrm{GeV}$ and $4.5995~\textrm{GeV}$, Born cross sections of the two processes $e^+e^- \to p\bar{p}η$ and $e^+e^- \to p\bar{p}ω$ are measured for the first time. No indication of resonant production through a vector state $V$ is observed, and upper limits on the Born cross sections of $e^+e^- \to V \to p\bar{p}η$ and $e^+e^- \to V \to p\bar{p}ω$ at the $90\%$ confidence level are calculated for a large parameter space in resonance masses and widths. For the current world average parameters of the $ψ(4230)$ of $m=4.2187~\textrm{GeV}/c^{2}$ and $Γ=44~\textrm{MeV}$, we find upper limits on resonant production of the $p\bar{p}η$ and $p\bar{p}ω$ final states of $7.5~\textrm{pb}$ and $10.4~\textrm{pb}$ at the $90\%$ CL, respectively.

hep-ex↗

arXiv2020

Erratum to "Measurement of the $e^+e^-\toπ^+π^-$ cross section between 600 and 900 MeV using initial state radiation"

In Phys. Lett. B 753, 629-638 (2016) [arXiv:1507.08188] the BESIII collaboration published a cross section measurement of the process $e^+e^-\to π^+ π^-$ in the energy range between 600 and 900 MeV. In this erratum we report a corrected evaluation of the statistical errors in terms of a fully propagated covariance matrix. The correction also yields a reduced statistical uncertainty for the hadronic vacuum polarization contribution to the anomalous magnetic moment of the muon, which now reads as $a_μ^{ππ\mathrm{, LO}}(600 - 900\,\mathrm{MeV}) = (368.2 \pm 1.5_{\rm stat} \pm 3.3_{\rm syst})\times 10^{-10}$. The central values of the cross section measurement and of $a_μ^{ππ\mathrm{, LO}}$, as well as the systematic uncertainties remain unchanged.

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