Related to Why is Anti-deuterium so important in the search for dark matter?. If the detection of anti-helium in the cosmic rays would be a signature of dark matter, is it possible to measure any light anti-nuclei in particle acceleration collisions? What would be the probability of observing these light anti-nuclei?
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A lot of effort in analysis of LHC data goes into trying to find supersymmetric particles , unsuccessfully at the moment. There are theoretical models for dark matter which assuming supersymmetry is what the WIMPs are about derives a signal of antideuterons from neutralino interactions, for example:
Antideuterons, ... As explained in Sect. II, they form when an antiproton and an antineutron merge together. The two antinucleons must be at rest with respect to each other in order for fusion to take place successfully.
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On the other hand, supersymmetric ̄D’s are manufactured at rest with respect to the Galaxy. In neutralino annihilations, antinucleons are predominantly produced with low energies. This feature is further enhanced by their subsequent fusion into antideuterons, hence a fairly flat spectrum for supersymmetric antideuterium nuclei as shown in Sect. IV. Below a few GeV/n, secondary antideuterons are quite suppressed with respect to their supersymmetric partners. That low–energy suppression is orders of magnitude more effective for antideuterons than for antiprotons. This makes cosmic–ray antideuterons a much better probe of s upersymmetric dark matter than antiprotons
So one has to first verify that supersymmetry is true, that neutralinos exist, and have enough of them to annihilate into antiprotons and antineutrons so that they can bind into deuterium.
As there is no experimental discovery of supesymmetry in the current accelerators, this whole scheme is highly theoretical for dark matter, and certainly cannot be explored in a particle accelerator setting, unless with very low energy beams in the way antihydrogen is generated at CERN, but this will have no connection with dark matter. (Considering the difficulties of controlling neutral beams antideuterium will be much more difficult as it needs antineutrons).
Edit after further search:
In heavy ion collisions, light nuclei have been created in Alice experiment .
The measurement by ALICE comparing the mass-to-charge ratios in deuterons/antideuterons and in helium-3/antihelium-3 confirms the fundamental symmetry known as CPT in these light nuclei.
This demonstrates the antiparticle production possibility in the quark gluon plasma, to explain antimatter creation in the early universe, not dark matter, as proposed by neutralino interactions .
So the answer is, antideuterons and antiheliums have been seen in accelerators, but their observation is related to antimatter production, not dark matter. The proposal for dark matter comes from supersymmetric theories combined with hypothesis dark matter is neutralinos.
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