Characteristics of π⁻,$\bar p$, and antinuclei frompp collisions

Abstract

An investigation of inclusivepp→π⁻+⋯ in terms of the covariant Boltzmann factor (BF) including the chemical potential μ indicates a) that the temperatureT increases less rapidly than expected from Stefan's law, b) that a scaling property holds for the fibreball velocity of π⁻ secondaries, leading to a multiplicity law like ∼E ^1/2_cm at high energy, and c) that μ_π is related to the quark mass: μ_π=2m _q −m _π the quark massm _q determined by$T_{\pi ^ - }$ at$\bar pp$ threshold beingm _q =3T_π≃330 MeV. Because ofthreshold effects $T_{\bar p}< T_{\pi ^ - }$, whereas${{\mu _p } \mathord{\left/ {\vphantom {{\mu _p } {\mu _{\pi ^ - } }}} \right. \kern-\nulldelimiterspace} {\mu _{\pi ^ - } }} \simeq {3 \mathord{\left/ {\vphantom {3 2}} \right. \kern-\nulldelimiterspace} 2}$ as expected from the quark contents of$\bar p$ and π. The antinuclei$\bar d$ and${{\bar t} \mathord{\left/ {\vphantom {{\bar t} {\overline {He^3 } }}} \right. \kern-\nulldelimiterspace} {\overline {He^3 } }}$ observed inpp events are formed by coalescence of$\bar p$ and$\bar n$ produced in thepp collision. Semi-empirical formulae are proposed to estimate multiplicities of π⁻,$\bar p$ and antinuclei.