Supercritically charged objects and electron-positron pair creation

Abstract

We investigate the stability and e + e − pair creation of supercritical charged superheavy nuclei, udQM nuggets, strangelets, and strangeon nuggets based on Thomas-Fermi approximation. The model parameters are fixed by reproducing their masses and charge properties reported in earlier publications. It is found that udQM nuggets, strangelets, and strangeon nuggets may be more stable than 56 Fe at A > ∼ 315, 5 × 10 4 , and 1.2 × 10 8 , respectively. For those stable against neutron emission, the most massive superheavy element has a baryon number ∼965, while udQM nuggets, strangelets, and strangeon nuggets need to have baryon numbers larger than 39, 433, and 2.7 × 10 5 . The e + e − pair creation will inevitably start for superheavy nuclei with charge numbers Z ≥ 177, udQM nuggets with Z ≥ 163, strangelets with Z ≥ 192, and strangeon nuggets with Z ≥ 212. A universal relation Q/Re = (me − μe) /α is obtained at a given electron chemical potential μe, where Q is the total charge and Re the radius of electron cloud. This predicts the maximum charge number by taking μe = −me. For supercritical charged objects with μe < −me, the decay rate for e + e − pair production is estimated based on the JWKB approximation. It is found that most positrons are emitted at t < ∼ 10 −15 s, while a long lasting positron emission is observed for large objects with R > ∼ 1000 fm. The emission and annihilation of positrons from supercritical charged objects may be partially responsible for the short γ-ray burst during the merger of binary compact stars, the 511 keV continuum emission, as well as the narrow faint emission lines in X-ray spectra from galaxies and galaxy clusters.

Unified Interacting Quark Matter and its Astrophysical Implications

“…With this being adequately included in a phenomenological quark-meson model, a recent study [4] demonstrated that u, d quark matter (udQM) is in general more stable than SQM, and it can be more stable than the ordinary nuclear matter at sufficiently large baryon number beyond the periodic table. This has been connected to a series of recent phenomenological explorations [5][6][7][8][9][10][11][12][13] and experimental searches [14][15][16].…”