1 Ocak 2019 Dergi makalesi Açık Erişim

CERN İşbirliği

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<oai_dc:dc xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd">
  <dc:creator>CERN İşbirliği</dc:creator>
  <dc:date>2019-01-01</dc:date>
  <dc:description>Using 16 energy points of ${e}^{+}{e}^{-}$ annihilation data collected in the vicinity of the $J/\psi $ resonance with the BESIII detector and with a total integrated luminosity of around $100\phantom{\rule{0.25em}{0ex}}{\text{pb}}^{-1}$, we study the relative phase between the strong and electromagnetic amplitudes of $J/\psi $ decays. The relative phase between $J/\psi $ electromagnetic decay and the continuum process (${e}^{+}{e}^{-}$ annihilation without the $J/\psi $ resonance) is confirmed to be zero by studying the cross section lineshape of ${\mu }^{+}{\mu }^{-}$ production. The relative phase between $J/\psi $ strong and electromagnetic decays is then measured to be ${\left(84.9±3.6\right)}^{\circ }$ or ${\left(-84.7±3.1\right)}^{\circ }$ for the $2\left({\pi }^{+}{\pi }^{-}\right){\pi }^{0}$ final state by investigating the interference pattern between the $J/\psi $ decay and the continuum process. This is the first measurement of the relative phase between $J/\psi $ strong and electromagnetic decays into a multihadron final state using the lineshape of the production cross section. We also study the production lineshape of the multihadron final state $\eta {\pi }^{+}{\pi }^{-}$ with $\eta \to {\pi }^{+}{\pi }^{-}{\pi }^{0}$, which provides additional information about the phase between the $J/\psi $ electromagnetic decay amplitude and the continuum process. Additionally, the branching fraction of $J/\psi \to 2\left({\pi }^{+}{\pi }^{-}\right){\pi }^{0}$ is measured to be $\left(4.73±0.44\right)\text{%}$ or $\left(4.85±0.45\right)\text{%}$, and the branching fraction of $J/\psi \to \eta {\pi }^{+}{\pi }^{-}$ is measured to be $\left(3.78±0.68\right)×{10}^{-4}$. Both of them are consistent with the world average values. The quoted uncertainties include both statistical and systematic uncertainties, which are mainly caused by the low statistics.</dc:description>
  <dc:identifier>https://aperta.ulakbim.gov.trrecord/105997</dc:identifier>
  <dc:identifier>oai:zenodo.org:105997</dc:identifier>
  <dc:rights>info:eu-repo/semantics/openAccess</dc:rights>
  <dc:rights>http://www.opendefinition.org/licenses/cc-by</dc:rights>
  <dc:source>Physics Letters B 791 C</dc:source>
  <dc:title>Measurement of the phase between strong and electromagnetic amplitudes of / Decays</dc:title>
  <dc:type>info:eu-repo/semantics/article</dc:type>
  <dc:type>publication-article</dc:type>
</oai_dc:dc>