Thermal abundance of non-relativistic relics with Sommerfeld enhancement

Iminniyaz, Hoernisa; Kakizaki, Mitsuru

doi:10.1016/j.nuclphysb.2011.05.009

Cited by 12 publications

(9 citation statements)

References 57 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As already extensively discussed in the literature, the impact of Sommerfeld-enhanced annihilation rates on the DM relic density can be sizable both before [53][54][55][56][57][58] and after [17][18][19] kinetic decoupling. In this article, we have introduced a general framework that, for the first time, allows to consistently describe situations where DM an- 4 This would lead to the conclusion that this or very similar leptophilic models cannot account for the cosmic ray lepton excess without violating the gamma-ray constraints from clusters if Mcut ≤ 10 4 M [33].…”

Section: Discussionmentioning

confidence: 79%

Thermal decoupling and the smallest subhalo mass in dark matter models with Sommerfeld-enhanced annihilation rates

2012

View full text Add to dashboard Cite

We consider dark matter consisting of weakly interacting massive particles (WIMPs) and revisit in detail its thermal evolution in the early universe, with a particular focus on models where the annihilation rate is enhanced by the Sommerfeld effect. After chemical decoupling, or freeze-out, dark matter no longer annihilates but is still kept in local thermal equilibrium due to scattering events with the much more abundant standard model particles. During kinetic decoupling, even these processes stop to be effective, which eventually sets the scale for a small-scale cutoff in the matter density fluctuations. Afterwards, the WIMP temperature decreases more quickly than the heat bath temperature, which causes dark matter to reenter an era of annihilation if the cross-section is enhanced by the Sommerfeld effect. Here, we give a detailed and self-consistent description of these effects. As an application, we consider the phenomenology of simple leptophilic models that have been discussed in the literature and find that the relic abundance can be affected by as much two orders of magnitude or more. We also compute the mass of the smallest dark matter subhalos in these models and find it to be in the range O(10 −10 M ) − O(10 M ); even much larger cutoff values are possible if the WIMPs couple to force carriers lighter than about 100 MeV. We point out that a precise determination of the cutoff mass allows to infer new limits on the model parameters, in particular from gamma-ray observations of galaxy clusters, that are highly complementary to existing constraints from g − 2 or beam dump experiments.PACS numbers: 95.35.+d, 98.80.Cq, 95.30.Tg

show abstract

Section: Discussionmentioning

confidence: 79%

Thermal decoupling and the smallest subhalo mass in dark matter models with Sommerfeld-enhanced annihilation rates

2012

View full text Add to dashboard Cite

show abstract

“…The Sommerfeld effect in the calculations of thermal relic abundance has been studied extensively in the literature (see e.g. [48][49][50][51][52][53][54][55]). Let us first briefly describe the Sommerfeld corrections to the annihilation cross sections of the massive colored particles of our interest.…”

Section: Relic Abundance Calculationmentioning

confidence: 99%

Effects of QCD bound states on dark matter relic abundance

Liew

Luo

2017

J. High Energ. Phys.

View full text Add to dashboard Cite

We study scenarios where there exists an exotic massive particle charged under QCD in the early Universe. We calculate the formation and dissociation rates of bound states formed by pairs of these particles, and apply the results in dark matter (DM) coannihilation scenarios, including also the Sommerfeld effect. We find that on top of the Sommerfeld enhancement, bound-state effects can further significantly increase the largest possible DM masses which can give the observed DM relic abundance, by ∼ 30-100% with respect to values obtained by considering the Sommerfeld effect only, for the color triplet or octet exotic particles we consider. In particular, it indicates that the Bino DM mass in the right-handed stop-Bino coannihilation scenario in the Minimal Supersymmetric extension of the Standard Model (MSSM) can reach ∼ 2.5 TeV, even though the potential between the stop and antistop prior to forming a bound state is repulsive. We also apply the bound-state effects in the calculations of relic abundance of long-lived or metastable massive colored particles, and discuss the implications on the BBN constraints and the abundance of a super-weakly interacting DM. The corrections for the bound-state effect when the exotic massive colored particles also carry electric charges, and the collider bounds are also discussed.

show abstract

“…Later, the Sommerfeld enhancement and its implication on the relic density has been studied in the context of the minimal dark matter model [12,13], still referring to standard interactions and very massive WIMPs. More recently, in light of the PAMELA anomaly, several authors, including, e.g., [7,14,15,16,17,18,19,20,21,22,23,24,25], have considered a few aspects of the connection with WIMP DM, considering models for which a new dark force, carried by some yet-to-be-discovered light boson, provides a very large enhancement in the cross section. In our analysis we reconsider the case of supersymmetric DM, and discuss the effect in the general context of the minimal supersymmetric extension to the standard model (MSSM), with arbitrary Wino and Higgsino components in the lightest neutralino, 1 applying and developing the formalism introduced in Ref.…”

Section: Introductionmentioning

confidence: 99%

Relic densities including Sommerfeld enhancements in the MSSM

Hryczuk

Iengo

Ullio

2011

J. High Energ. Phys.

121

145

View full text Add to dashboard Cite

Abstract:We have developed a general formalism to compute Sommerfeld enhancement (SE) factors for a multi-state system of fermions, in all possible spin configurations and with generic long-range interactions. We show how to include such SE effects in an accurate calculation of the thermal relic density for WIMP dark matter candidates. We apply the method to the MSSM and perform a numerical study of the relic abundance of neutralinos with arbitrary composition and including the SE due to the exchange of the W and Z bosons, photons and Higgses. We find that the relic density can be suppressed by a factor of a few in a sizable region of the parameter space, mostly for Wino-like neutralino with mass of a few TeV, and up to an order of magnitude close to a resonance.

show abstract

Thermal abundance of non-relativistic relics with Sommerfeld enhancement

Cited by 12 publications

References 57 publications

Thermal decoupling and the smallest subhalo mass in dark matter models with Sommerfeld-enhanced annihilation rates

Thermal decoupling and the smallest subhalo mass in dark matter models with Sommerfeld-enhanced annihilation rates

Effects of QCD bound states on dark matter relic abundance

Relic densities including Sommerfeld enhancements in the MSSM

Contact Info

Product

Resources

About