Search for ${\eta }^{\prime }$ bound nuclei in the ${}^{12}\mathrm{C}(\gamma ,p)$ reaction with simultaneous detection of decay products

Abstract

We measured missing mass spectrum of the ${}^{12}\mathrm{C}(\gamma ,p)$ reaction for the first time in coincidence with potential decay products from ${\eta }^{\prime }$ bound nuclei. We tagged an ($\eta +p$) pair associated with the ${\eta }^{\prime }N\to \eta N$ process in a nucleus. After applying kinematical selections to reduce backgrounds, no signal events were observed in the bound-state region. An upper limit of the signal cross section in the opening angle $\cos {\theta }_{lab}^{\eta p}<-0.9$ was obtained to be 2.2 nb/sr at the 90$\%$ confidence level. It is compared with theoretical cross sections, whose normalization ambiguity is suppressed by measuring a quasifree ${\eta }^{\prime }$ production rate. Our results indicate a small branching fraction of the ${\eta }^{\prime }N\to \eta N$ process and/or a shallow ${\eta }^{\prime }$-nucleus potential.

7 pages, 4 figures

References in corpus (10)

• Observation of a new particle in the search for the Standard Model Higgs boson with the ATLAS detector at the LHC
• Observation of a new boson at a mass of 125 GeV with the CMS experiment at the LHC
• η- and η'-mesic nuclei and U_A(1) anomaly at finite density
• Analysis of U${}_A$(1) symmetry-breaking and restoration effects on the scalar-pseudoscalar spectrum
• Feasibility Study of Observing eta' Mesic Nuclei with (p,d) Reaction
• Determination of the eta'-proton scattering length in free space
• Measurement of excitation spectra in the ${}^{12}$C$(p,d)$ reaction near the ${\eta }^{\prime }$ emission threshold
• Determination of the real part of the η'-Nb optical potential
• Photoproduction of eta-mesons off nuclei for Eg < 2.2 GeV
• ${\eta }^{\prime }$ meson under partial restoration of chiral symmetry in nuclear medium

Cited by in corpus (8)

• SPring-8 LEPS2 beamline: A facility to produce a multi-GeV photon beam via laser Compton scattering
• $\eta$ and ${\eta }^{\prime }$ mesons in nuclear matter and nuclei
• Spectral function of the ${\eta }^{\prime }$ meson in nuclear medium based on phenomenological models
• Revisiting ${\eta }^{\prime }(958)$ nuclear states
• The ${\eta }^{\prime }N$ interaction from the ${\eta }^{\prime }p$ correlation function
• Direct measurement of the in-medium ${\eta }^{\prime }$ mass spectrum through the $\gamma \gamma$ decay channel
• Backward-angle electroproduction of ${\eta }^{\prime }$ mesons off protons at $W=2.13\text{GeV}$ and $Q^2=0.46{\left(\text{GeV}/c\right)}^2$
• Feasibility of the observation of ${\eta }^{\prime }$ mesic nuclei in the semi-exclusive ${}^{12}$C($p,dp$) reaction