Bound-free pair production in relativistic nuclear collisions from the NICA to the HE LHC colliders

TL;DR

This paper investigates bound-free electron-positron pair production in relativistic heavy ion collisions across various colliders, providing a universal formula for cross sections and assessing implications for collider operation and magnet quenching.

Contribution

It introduces an approximate universal formula for the total cross section of bound-free pair production in relativistic heavy ion collisions, with accuracy estimates and detailed predictions for future collider experiments.

Findings

Cross sections range from 10 to 70 barns for heavy ion collisions.

Estimated accuracy of the formula is better than 30% at NICA energies.

Predicted cross sections are a few millibarns for proton-ion collisions.

Abstract

We consider the electron-positron pair production in relativistic heavy ion collisions, in which the produced electron is captured by one of the nuclei resulting, thus, in the formation of a hydrogen--like ion. These ions emerge from the collision point and hit the vacuum chamber wall inside superconducting magnets. Therefore, this process may be important for the problems of beam life time and for the quenching the irradiated magnet. A theoretical investigation for such a bound-free pair production (BFPP) at the colliders from NICA to HE LHC is presented. We obtain an approximate universal formula for the total cross section of the process. We compare it with the results of available numerical calculations and estimate that an accuracy of our calculations is better than $30$ % at the energies of the NICA collider and becomes of the order of a few percent for the RHIC and HE LHC colliders. Based on the obtained results, the detailed calculations are performed for future experiments at the NICA collider. We find that the expected BFPP cross sections for the Au$^{79+}$-Au$^{79+}$ and Bi$^{83+}$-Bi$^{83+}$ collisions are in the range from $10$ to $70$ barn, while for the p-Au$^{79+}$ and p-Bi$^{83+}$ collisions they are in the range of a few mbarn.