The scalar hexaquark <i>uuddss</i> : a candidate to dark matter?
K. Azizi, S. S. Agaev, H. Sundu
Abstract
Abstract It is conventionally argued that dark matter (DM) has a non-baryonic nature, but if we assume that DM was frozen out before primordial nucleosynthesis and could not significantly impact primordial abundances this argument may be evaded. Then a hypothetical SU (3) flavor-singlet, highly symmetric, deeply bound neutral scalar hexaquark S = uuddss , which due to its features has escaped from experimental detection so far, may be considered as a candidate for a baryonic DM. In the present work we calculate the mass and coupling constant of the scalar six-quark particle S by means of the QCD sum rule method. Our predictions for its mass are <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mi>m</mml:mi> </mml:mrow> <mml:mrow> <mml:mi mathvariant="normal">S</mml:mi> </mml:mrow> </mml:msub> <mml:mo>=</mml:mo> <mml:mn>118</mml:mn> <mml:msubsup> <mml:mrow> <mml:mn>0</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>26</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>+</mml:mo> <mml:mn>40</mml:mn> </mml:mrow> </mml:msubsup> <mml:mspace class="nbsp" width="0.3333em"/> <mml:mi mathvariant="normal">M</mml:mi> <mml:mi mathvariant="normal">e</mml:mi> <mml:mi mathvariant="normal">V</mml:mi> </mml:math> ( m s = 95 MeV) and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mover accent="true"> <mml:mrow> <mml:mi>m</mml:mi> </mml:mrow> <mml:mo>̃</mml:mo> </mml:mover> </mml:mrow> <mml:mrow> <mml:mi mathvariant="normal">S</mml:mi> </mml:mrow> </mml:msub> <mml:mo>=</mml:mo> <mml:mn>123</mml:mn> <mml:msubsup> <mml:mrow> <mml:mn>9</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>28</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>+</mml:mo> <mml:mn>42</mml:mn> </mml:mrow> </mml:msubsup> <mml:mspace class="nbsp" width="0.3333em"/> <mml:mi mathvariant="normal">M</mml:mi> <mml:mi mathvariant="normal">e</mml:mi> <mml:mi mathvariant="normal">V</mml:mi> </mml:math> ( m s = 128 MeV). Although these values of mass would produce thermally the cosmological DM abundance, existence of this state may contradict the stability of the oxygen nuclei, which requires further thorough analysis.