Exact flavor conservation at the quark level in causal clusters: strange particles, protons and light nuclei in small collision systems

The suppression of strange hadrons in pp and p--Pb collisions at the LHC, including the $ϕ$ meson, has recently been described by the exact conservation of strangeness imposed on the quarks of a causally connected cluster before hadronization. Here we extend this approach to the light flavors. The numbers of up and down quarks and antiquarks are conserved in the same cluster, and the suppression of a baryon or a nucleus depends only on how many light quarks of each flavor it contains. With the strangeness sector fixed by the previous analysis, a single constant, the ratio $r$ of light to strange quark abundances, determines the multiplicity dependence of protons, deuterons, He and hypertriton in pp and p--Pb collisions. Including the finite size of the nuclei, one obtains a very good fit of the data for $r=3.76\pm0.38$, i.e.\ strange quarks about 0.27 times as abundant as light quarks per flavor, close to the value known from string fragmentation