Spectroscopy of pionic atoms in ${}^{122}\text{S}\mathbf{n}(\text{d},{}^3\text{H}\mathbf{e})$ reaction and angular dependence of the formation cross sections

Abstract

We observed the atomic $1s$ and $2p$ states of ${\pi }^{-}$ bound to ${}^{121}\mathrm{Sn}$ nuclei as distinct peak structures in the missing mass spectra of the ${}^{122}\mathrm{Sn}(d,{}^3\mathrm{He})$ nuclear reaction. A very intense deuteron beam and a spectrometer with a large angular acceptance let us achieve potential of discovery, which includes capability of determining the angle-dependent cross sections with high statistics. The $2p$ state in a Sn nucleus was observed for the first time. The binding energies and widths of the pionic states are determined and found to be consistent with previous experimental results of other Sn isotopes. The spectrum is measured at finite reaction angles for the first time. The formation cross sections at the reaction angles between 0 and $2^{\circ }$ are determined. The observed reaction-angle dependence of each state is reproduced by theoretical calculations. However, the quantitative comparison with our high-precision data reveals a significant discrepancy between the measured and calculated formation cross sections of the pionic $1s$ state.

References in corpus (10)

• In-medium nuclear interactions of low-energy hadrons
• Hadron properties in the nuclear medium
• Precision spectroscopy of pionic 1s states of Sn nuclei and evidence for partial restoration of chiral symmetry in the nuclear medium
• In-medium chiral perturbation theory beyond the mean-field approximation
• Chiral Dynamics of Deeply Bound Pionic Atoms
• In-medium Pion and Partial Restoration of Chiral Symmetry
• Precision Spectroscopy of Deeply Bound Pionic Atoms and Partial Restoration of Chiral Symmetry in Medium
• Pionic Atom Spectroscopy in the (d,3He) reaction at finite angles
• Simultaneous Measurements of the $p+d\to (A=3)+\pi$ Reactions
• Testing in-medium $\pi N$ dynamics on pionic atoms

Cited by in corpus (6)

• Recent Progress in QCD Condensate Evaluations and Sum Rules
• Chiral symmetry restoration at high matter density observed in pionic atoms
• Search for ${\eta }^{\prime }$ bound nuclei in the ${}^{12}\mathrm{C}(\gamma ,p)$ reaction with simultaneous detection of decay products
• Structure of double pionic atoms
• The ${\eta }^{\prime }N$ interaction from the ${\eta }^{\prime }p$ correlation function
• Feasibility of an experimental search for a resonance of a pion and a light nucleus