Experimental measurement of sizes of emission sources for deuterons and $\alpha$ particles in ${}^{16}\mathrm{O}-p$ collisions at $3.25A\mathrm{GeV}/c$

The sizes of emission sources of deuterons and $\alpha$ particles were determined in minimum bias ${}^{16}\mathrm{O}-p$ collisions at $3.25A\mathrm{GeV}/c$ from the analysis of experimental one-dimensional correlation functions of these particles, based on a theoretical model assuming the simultaneous excitation and decay of sources (of identical particles), whose coordinates are distributed according to a Gaussian function. The peak was observed in the experimental correlation function of the pairs of $\alpha$ particles in the region of $q<25\mathrm{MeV}/c$, which was deduced to be due to decays of unstable ${}^8\mathrm{Be}$ and ${}^9\mathrm{B}$ nuclei at various kinetic energies. This result does not contradict the popular assumption of other authors about the existence of the $\alpha$-condensate state in the ${}^{16}\mathrm{O}$ nucleus since unstable ${}^8\mathrm{Be}$ and ${}^9\mathrm{B}$ nuclei themselves can probably be formed from decay of the $\alpha$-condensate state of the oxygen nucleus if such a state does exist.

Figure 1

The one-dimensional correlation function $\mathbb{C}\left(q\right)$ given in (1) for deuterons, emitted in ${}^{16}\mathrm{O}-p$ collisions at $3.25A\mathrm{GeV}/c$. The solid curve is the result of a minimum ${\chi }^2$ fitting of the experimental $\mathbb{C}\left(q\right)$ spectrum by the function in (2).

Figure 2

The one-dimensional correlation function $\mathbb{C}\left(q\right)$ given in (1) for $\alpha$ particles, emitted in ${}^{16}\mathrm{O}-p$ collisions at $3.25A\mathrm{GeV}/c$. The solid curve is the result of a minimum ${\chi }^2$ fitting of the experimental $\mathbb{C}\left(q\right)$ spectrum by the function in (2).

Figure 3

The distribution on excitation energies of the pairs of $\alpha$ particles in ${}^{16}\mathrm{O}-p$ collisions at $3.25A\mathrm{GeV}/c$. The solid curve is the background distribution.