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تسجيل مستخدم جديدPionic Deuterium
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The strong interaction shift and broadening in pionic deuterium have been remeasured with high statistics by means of the (3p-1s) X-ray transition using the cyclotron trap and a high-resolution crystal spectrometer. Preliminary results are (-2325+/-31) meV (repulsive) for the shift and (1171+23/-49} meV for the width, which yields precise values for the pion-deuteron scattering length and the threshold parameter for pion production.
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The strong interaction shift $epsilon$ and broadening {Gamma} in pionic deuterium have been determined in a high statistics study of the {pi}D(3p - 1s) X-ray transition using a high-resolution crystal spectrometer. The pionic deuterium shift will pro
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We report a search for d^* dibaryon production by double-radiative capture on pionic deuterium. The experiment was conducted at the TRIUMF cyclotron using the RMC cylindrical pair spectrometer, and detected gamma-ray coincidences following pion stops
in liquid deuterium. We found no evidence for narrow dibaryons, and obtained a branching ratio upper limit, BR < 6.7 times 10^{-6} (90% C.L.), for narrow d^* production in the mass range from 1920 to 1980 MeV. Replaced with Physics Letter B accepted version and corrected normalization.
The hadronic shift in pionic hydrogen has been redetermined to be $epsilon_{1s}=7.086,pm,0.007(stat),pm,0.006(sys)$,eV by X-ray spectroscopy of ground state transitions applying various energy calibration schemes. The experiment was performed at the
high-intensity low-energy pion beam of the Paul Scherrer Institut by using the cyclotron trap and an ultimate-resolution Bragg spectrometer with bent crystals.
Exclusive and kinematically complete high-statistics measurements of the double pionic fusion reaction $dd to ^4$He$pi^0pi^0$ have been performed in the energy range 0.8 - 1.4 GeV covering thus the region of the ABC effect, which denotes a pronounced
low-mass enhancement in the $pipi$-invariant mass spectrum. The experiments were carried out with the WASA detector setup at COSY. Similar to the observation in the basic $pn to d pi^0pi^0$ reaction, the data reveal a correlation between the ABC effect and a resonance-like energy dependence in the total cross section. The maximum occurs at m=2.37 GeV + 2$m_N$, i.e. at the same position as in the basic reaction. The observed resonance width $Gamma approx$ 160 MeV can be understood from broadening due to Fermi motion of the nucleons in initial and final nuclei together with collision damping. Differential cross sections are described equally well by the hypothesis of a $pn$ resonance formation during the reaction process.
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