Constraints on supersymmetric models from catalytic primordial nucleosynthesis of beryllium

Abstract

The catalysis of nuclear reactions by negatively charged relics leads to increased outputs of primordial 6 Li and 9 Be. In combination with observational constraints on the primordial fractions of 6 Li and 9 Be, this imposes strong restrictions on the primordial abundance and the lifetime of charged relics. We analyze the constraints from the catalysis of 9 Be on supersymmetric models in which the gravitino is the lightest supersymmetric particle and a charged slepton-such as the lighter stau-the next-to-lightest supersymmetric particle (NLSP). Barring the special cases in which the primordial fraction of the slepton NLSP is significantly depleted, we find that the 9 Be data require a slepton NLSP lifetime of less than 6 × 10 3 s. We also address the issue of the catalytic destruction of 6 Li and 9 Be by late forming bound states of protons with negatively charged relics finding that it does not lead to any significant modification of the limit on the slepton lifetime.

Thermal relic abundances of long-lived staus

“…Indeed, to decide on the cosmological viability of a SUSY model, one has to confront the associated Y e τ values with those constraints. In particular, for gravitino LSP scenarios with unbroken R-parity, restrictive cosmological constraints and implications thereof have been derived [48,39,40,41,57,42,32,93,36] often under the assumption that Y e τ can be described by (1.1). However, while (1.1) is quite reliable for τ 1 ≃ τ R [37,38,40,52], we have shown in the previous sections that Y e τ (for a given m e τ 1 ) can be about than two orders of magnitude smaller than (1.1).…”

“…5 in Ref. [36]. The uncertainty on the Y e τ limit associated with CBBN of 6 Li reflects the difficulties in quantifying an upper limit on the primordial 6 Li abundance; for more details on this issue, see [36] and references therein.…”

“…• The mere presence of the negatively charged τ 1 's at cosmic times of t 5 × 10 3 s can lead to ( 4 He τ 1 ) and ( 8 Be τ 1 ) bound states and can thereby allow for catalyzed BBN (CBBN) of 6 Li and 9 Be to abundances far above the ones obtained in standard BBN (SBBN) [33,34,35,36]. Indeed, confronting the abundances obtained in CBBN with observationally inferred bounds on the primordial abundances of 9 Be (and 6 Li) imposes restrictive upper limits of Y e [36] for n e τ 1 = n e τ * 1 .…”

“…Indeed, confronting the abundances obtained in CBBN with observationally inferred bounds on the primordial abundances of 9 Be (and 6 Li) imposes restrictive upper limits of Y e [36] for n e τ 1 = n e τ * 1 . For example, in gravitino LSP scenarios with the τ 1 LOSP being the next-to-lightest supersymmetric particle (NLSP) and conserved R-parity, the listed cosmological constraints have been confronted with representative values [37,38] Y e τ ≃ (0.4 − 1.5) × 10 −13 m e τ 1 100 GeV , (…”

“…[37] that have been obtained for the case of a purely 'right-handed' τ 1 ≃ τ R NLSP and a bino-like lightest neutralino, χ 0 1 ≃ B, with a mass of m e B = 1.1 m e τ 1 . Thereby, it has been found that the (C)BBN constraints impose the limit τ e τ 1 5 × 10 3 s [33,36] with severe implications in the colliderfriendly region of m e τ 1 < 1 TeV: (i) The τ e τ 1 limit disfavors the kinematical determination of m e G [39] and thereby both the determination of the Planck scale at colliders [16] and the method proposed to probe the maximum reheating temperature T R at colliders [27].…”