Influence of long-range effects on low-energy cross sections of He and HeX: The lithium problem

Abstract

In this paper, we study the connection between the interaction and the low energy observables, in particular the cross section for He and HeX, the helium nucleus with a heavier particle attached, to explain problems with the observed lithium abundance in the big-bang nucleosynthesis. We treat the processes 4 He + 2 H → 6 Li + γ and 4 HeX − + 2 H → 6 Li + X − and primarily focus on the effects of the long-range part of the total potential on the cross section. Our results indicate that relatively small changes in the long-range part of the potential can have a profound affect. Additionally, we compare the relative impacts on the low energy cross section of the Coulomb barrier peak and the long-range part of the interaction. Our results confirm that the long-range potential dominantly influences the low energy observables.

Big Bang 6 Li nucleosynthesis studied deep underground (LUNA collaboration)

“…Assuming that observations will confirm a somewhat higher 6 Li abundance with respect to the computed CDM ( Lambda Cold Dark Matter ) model value, the only remaining possibilities to explain the discrepancy are very special astrophysical processes like stellar flare in-situ lithium production [41] . Other possibilities are unknown physical processes or new physics scenarios [42][43][44][45] .…”

First Direct Measurement of theH2(α,γ)LiAnders1, Trezzi2, Menegazzo3 et al. 2014Phys. Rev. Lett.10791130View full textAdd to dashboardCite

“…Pregalactic 6 Li production mechanisms have also been previously ruled out [32]. As a result, possible remaining scenarios explaining a global 6 Li= 7 Li level of a few percent as reported [7,8,10,33,34] may be, under very special conditions, a stellar flare in situ production of 6 Li [32] or nonstandard physics solutions [35][36][37][38]. Cosmic 6 Li is clearly a highly interesting probe of physics beyond the standard model.…”

Scattering of Klein-Gordon particles in the background of mixed scalar-vector generalized symmetric Woods-Saxon potential

“…The superposition of Coulomb and Woods-Saxon interaction can be described by Modified Woods-Saxon potential (MWSP) [33]. Recently in order to give a better description of the energy barrier at the surface of atomic nucleus that nucleons suffer, Generalized Symmetric Woods-Saxon potential (GSWSP) was proposed [34][35][36][37][38][39][40][41][42][43][44][45][46][47][48][49][50][51][52][53].…”