Formation Of Light Nuclei Research Articles

On nuclear coalescence in small interacting systems

The formation of light nuclei can be described as the coalescence of clusters of nucleons into nuclei. In the case of small interacting systems, such as dark matter and e^+e^- annihilations or pp collisions, the coalescence condition is often imposed only in momentum space and hence the size of the interaction region is neglected. On the other hand, in most coalescence models used for heavy ion collisions, the coalescence probability is controlled mainly by the size of the interaction region, while two-nucleon momentum correlations are either neglected or treated as collective flow. Recent experimental data from pp collisions at LHC have been interpreted as evidence for such collective behaviour, even in small interacting systems. We argue that these data are naturally explained in the framework of conventional QCD inspired event generators when both two-nucleon momentum correlations and the size of the hadronic emission volume are taken into account. To include both effects, we employ a per-event coalescence model based on the Wigner function representation of the produced nuclei states. This model reproduces well the source size for baryon emission and the coalescence factor B_2 measured recently by the ALICE collaboration in pp collisions.

Formation of light nuclei at chemical freezeout: Description within a statistical thermal model

The thermal description of light nuclei at the chemical freeze-out has been investigated. First, I have verified the equilibration of the light nuclei and then introduced a new method to investigate the light nuclei formation. One can study the proximity between the phase space density of light nuclei ratios and their hadronic constituents e.g $\bar{d}/d$ and $(\bar{p}\bar{n}/pn)$. I have found that with the exclusion of the decay feed-down from the hadronic yields in the thermal model, the hadronic representations have good agreement with the light nuclei ratios. I have performed a similar analysis with the ratio of $\Lambda$-hypernuclei and $^3 He$, which is related to the ratio $\Lambda/p$. In this context, the strangeness population factor $S_3$ has been studied also. These results indicate that the nuclei and hypernuclei formation may occur near the standard chemical freeze-out and before the decay of the hadronic resonances. This method will serve as a guideline to discuss the light nuclei formation and the inclusion of decay into their hadronic constituents.

Correlations between production of charged pions and formation of light nuclei in 16Op collisions at 3.25AGeV/c

Correlations between production of charged pions and formation of light nuclei in collisions of oxygen nuclei with protons at [Formula: see text][Formula: see text]GeV/[Formula: see text] were investigated. It was deduced that the mechanisms of formation of light fragments with [Formula: see text] and the processes of generation of charged pions do not depend on each other.

Formation of Light Nuclei in the Expanding Universe

Formation of Light Nuclei in the Expanding Universe