Possible solution to theLi7problem by the long lived stau

New results on catalyzed big bang nucleosynthesis with a long-lived negatively charged massive particle

“…The results from that study do not change by the implementation of the new cross sections adopted here. The larger destruction rate associated with the 7 Be X → 7 Li+X 0 decay followed by the 7 Li(p,α) 4 He and 7 Li(X − ,γ) 7 Li X (p,2α)X − reactions [5,7] or a further conversion of 7 Li X by the weak interaction [12] shifts the contours of the 7 Li abundance toward smaller values of Y X . In this case the parameter region which solves both the 6 Li and 7 Li problems is Y X ≈ 0.04 − 0.2 and τ X ≈ (1.4 − 2.6) × 10 3 s.…”

“…In the case where the reactions 7 Be X +p → 8 B * a X → 8 B X +γ [5] and 7 Be X + p → 8 B * (1 + , 0.770 MeV) X → 8 B X + γ [6] destroy 7 Be X , the DM mass is thus constrained to be m DM ≤ 4.5 GeV. On the other hand, when the 7 Be X → 7 Li+X 0 reaction [5,12] is included, the allowed mass range increases to m DM ≤ 20 − 110GeV.…”

“…Constraints on specific supersymmetric models through the catalyzed BBN calculation have been obtained in Refs. [3,11,12,44,45].…”

“…Of particular interest in this work is the apparent discrepancy between the inferred primordial abundances of 6 Li and 7 Li and the predictions of standard BBN. A popular model to resolve this discrepancy is the existence of an unstable negatively charged supersymmetric particle during the nucleosynthesis epoch [1][2][3][4][5][6][7][8][9][10][11][12][13]. Depending upon their abundance and lifetime [7], such particles can catalyze the nuclear reactions leading to enhanced 6 Li [1] and depleted 7 Li [5,6] as required by observations.…”

“…They affect the nucleosynthesis in a different way [1][2][3][4][5][6][7][8][9][10][11][12][13]. The X − particles become electromagnetically bound to positively charged nuclides with binding energies of ∼ O(0.1−1) MeV with the largest binding energies for heavier nuclei with larger charges.…”