Near-threshold π− photoproduction on the deuteron

Abstract

The first experimental investigation of the near-threshold cross section for incoherent π − photoproduction on the deuteron γd → π − pp is presented. The total cross section has been measured using an unpolarized tagged-photon beam, a liquid-deuterium target, and three large NaI(Tl) spectrometers. The experimental technique involved detection of the ∼131 MeV gamma ray resulting from the radiative capture of photoproduced π − in the target. The data are compared to theoretical models that give insight into the elementary reaction γn → π − p and pion-nucleon and nucleon-nucleon final-state interactions.

On the Photoproduction Reactions $γd\toπNN$

“…The reaction γd → π − pp. Recently, the PIONS@MAX-lab Collaboration (MAXlab, Lund, Sweden) has reported data on the total cross sections of incoherent chargedpion photoproduction γd → π − pp close to threshold [44,45]. This study is focused on a determination of the total γn → π − p cross sections on a "neutron" target, utilizing the deuteron measurements, where model-dependent nuclear (FSI) corrections play a critical role.…”

“…Figure 8: Total cross sections of the reaction γd → π − pp: blue filled circles are the MAX-lab data [44,45]; E γ is the photon energy in the laboratory frame; the statistical and systematic uncertainties from Table II of Ref. [44,45] are summed in quadrature. The green short dotted curve shows the result, obtained with the IA amplitude M a .…”

“…[45,46]. The total cross sections of the reaction γd → π − pp, measured by PIONS@MAX-lab Collaboration [44,45] are shown in Fig. 8.…”

“…In present paper, we review our results of theoretical study of the incoherent reactions γd → πNN , performed earlier in our papers [34,[40][41][42][43][44][45][46]. We briefly discuss the theoretical model used for the reactions of interest.…”

Total cross section of the reaction <i>γd → π^–pp</i> in the threshold energy region

“…Только в одном эксперименте измерялось полное сечение реакции γd → p + nn при энергиях до 22 МэВ выше порога [5]. Недавно были выполнены первые измерения полного сечения реакции γd → ppp в пороговой области энергий E γ < 160 МэВ [6]. В этой же работе приведены предсказания теоретической модели В. Е. Тарасова и др.…”