Improved analysis of strong-interaction-stable doubly bottom tetraquarks on the lattice

We update earlier lattice results for the binding energies of the flavor antitriplet of strong-interaction-stable doubly bottom, <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"> <a:msup> <a:mi>J</a:mi> <a:mi>P</a:mi> </a:msup> <a:mo>=</a:mo> <a:msup> <a:mn>1</a:mn> <a:mo>+</a:mo> </a:msup> </a:math> tetraquarks, employing an extended sink construction which produces significantly improved ground-state effective-mass plateaus, as well as new, larger-volume ensembles which reduce possible finite-volume effects at lighter pion masses. The updated bindings are 115(17) MeV for the <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"> <c:mi>I</c:mi> <c:mo>=</c:mo> <c:mn>0</c:mn> </c:math> member of the antitriplet and 47(8) MeV for its <e:math xmlns:e="http://www.w3.org/1998/Math/MathML" display="inline"> <e:mi>I</e:mi> <e:mo>=</e:mo> <e:mn>1</e:mn> <e:mo>/</e:mo> <e:mn>2</e:mn> </e:math> partner. We also provide an update of our earlier study of the variable heavy mass dependence of binding in the <g:math xmlns:g="http://www.w3.org/1998/Math/MathML" display="inline"> <g:msup> <g:mn>1</g:mn> <g:mo>+</g:mo> </g:msup> </g:math> channel and new results on this dependence for binding in the <i:math xmlns:i="http://www.w3.org/1998/Math/MathML" display="inline"> <i:msup> <i:mn>0</i:mn> <i:mo>+</i:mo> </i:msup> </i:math> channel, accessible when the two heavy quarks have unequal masses. Implications of these results of potential relevance to experimental searches for signals of the production of doubly bottom tetraquarks and/or a possible bottom-charm partner of the <k:math xmlns:k="http://www.w3.org/1998/Math/MathML" display="inline"> <k:msub> <k:mi>T</k:mi> <k:mrow> <k:mi>c</k:mi> <k:mi>c</k:mi> </k:mrow> </k:msub> </k:math> are also discussed.