Dark quarkonium formation in the early universe

M. Geller, S. Iwamoto, G. Lee*, Y. Shadmi, O. Telem

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

30 Scopus citations


The relic abundance of heavy stable particles charged under a confining gauge group can be depleted by a second stage of annihilations near the deconfinement temperature. This proceeds via the formation of quarkonia-like states, in which the heavy pair subsequently annihilates. The size of the quarkonium formation cross section was the subject of some debate. We estimate this cross section in a simple toy model. The dominant process can be viewed as a rearrangement of the heavy and light quarks, leading to a geometric cross section of hadronic size. In contrast, processes in which only the heavy constituents are involved lead to mass-suppressed cross sections. These results apply to any scenario with bound states of sizes much larger than their inverse mass, such as U(1) models with charged particles of different masses, and can be used to construct ultra-heavy dark-matter models with masses above the naïve unitarity bound. They are also relevant for the cosmology of any stable colored relic.

Original languageEnglish
Article number135
JournalJournal of High Energy Physics
Issue number6
StatePublished - 1 Jun 2018
Externally publishedYes


FundersFunder number
Lady Davis Foundation
Mainz Institute for Theoretical PhysicsNSF-PHY-1607611
Maryland Center for Fundamental Physics
Padova University
Samsung Science & Technology Foundation
United-States-Israel Binational Science Foundation
National Science FoundationPHY-1719877
National Science Foundation
Directorate for Mathematical and Physical Sciences1719877
Directorate for Mathematical and Physical Sciences
Bloom's Syndrome Foundation2014397
Bloom's Syndrome Foundation
Israel Science Foundation720/15
Israel Science Foundation
Planning and Budgeting Committee of the Council for Higher Education of IsraelPHY-1620074, 1937/12
Planning and Budgeting Committee of the Council for Higher Education of Israel


    • Phenomenological Models
    • QCD Phenomenology


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