Rapid thermal co-annihilation through bound states in QCD

Kim, Seyong; Laine, Mikko Sakari (2016). Rapid thermal co-annihilation through bound states in QCD. Journal of High Energy Physics, 2016(7), p. 143. Springer 10.1007/JHEP07(2016)143

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The co-annihilation rate of heavy particles close to thermal equilibrium, which plays a role in many classic dark matter scenarios, can be “simulated” in QCD by considering the pair annihilation rate of a heavy quark and antiquark at a temperature of a few hundred MeV. We show that the so-called Sommerfeld factors, parameterizing the rate, can be defined and measured non-perturbatively within the NRQCD framework. Lattice measurements indicate a modest suppression in the octet channel, in reasonable agreement with perturbation theory, and a large enhancement in the singlet channel, much above the perturbative prediction. The additional enhancement is suggested to originate from bound state formation and subsequent decay. Making use of a Green’s function based method to incorporate thermal corrections in perturbative co-annihilation rate computations, we show that qualitative agreement with lattice data can be found once thermally broadened bound states are accounted for. We suggest that our formalism may also be applicable to specific dark matter models which have complicated bound state structures.

Item Type:

Journal Article (Original Article)

Division/Institute:

10 Strategic Research Centers > Albert Einstein Center for Fundamental Physics (AEC)
08 Faculty of Science > Institute of Theoretical Physics

UniBE Contributor:

Laine, Mikko Sakari

Subjects:

500 Science > 530 Physics

ISSN:

1029-8479

Publisher:

Springer

Language:

English

Submitter:

Esther Fiechter

Date Deposited:

22 Aug 2016 12:35

Last Modified:

22 Aug 2016 12:35

Publisher DOI:

10.1007/JHEP07(2016)143

ArXiv ID:

1602.08105

BORIS DOI:

10.7892/boris.86110

URI:

https://boris.unibe.ch/id/eprint/86110

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