Lattice QCD study of positive parity dibaryons with maximal charm and strangeness

We present the ground-state energy spectra of dibaryons composed of single-flavor quarks, specifically systems with strangeness <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mi mathvariant="script">S</a:mi><a:mo>=</a:mo><a:mo>−</a:mo><a:mn>6</a:mn></a:math> and charm <d:math xmlns:d="http://www.w3.org/1998/Math/MathML" display="inline"><d:mi mathvariant="script">C</d:mi><d:mo>=</d:mo><d:mn>6</d:mn></d:math>. Our lattice QCD study is based on <g:math xmlns:g="http://www.w3.org/1998/Math/MathML" display="inline"><g:msub><g:mi>N</g:mi><g:mi>f</g:mi></g:msub><g:mo>=</g:mo><g:mn>2</g:mn><g:mo>+</g:mo><g:mn>1</g:mn><g:mo>+</g:mo><g:mn>1</g:mn></g:math> MILC ensembles with highly improved staggered quark sea quarks, spanning four lattice spacings and two spatial volumes. We employ valence quark propagators realized using a relativistic overlap action, evaluate correlation matrices with carefully designed operator bases, and extract reliable ground-state energy estimates in the <i:math xmlns:i="http://www.w3.org/1998/Math/MathML" display="inline"><i:mi>S</i:mi><i:mo>=</i:mo><i:mn>0</i:mn></i:math> and <k:math xmlns:k="http://www.w3.org/1998/Math/MathML" display="inline"><k:mi>S</k:mi><k:mo>=</k:mo><k:mn>2</k:mn></k:math> spin channels. We explore their binding characteristics and interaction dynamics by examining the energy separation between the dibaryon states and the corresponding two-baryon thresholds. These results contribute to a deeper understanding of single-flavor dibaryon states as a function of the quark masses. In the <m:math xmlns:m="http://www.w3.org/1998/Math/MathML" display="inline"><m:mi>S</m:mi><m:mo>=</m:mo><m:mn>0</m:mn></m:math> channel, the <o:math xmlns:o="http://www.w3.org/1998/Math/MathML" display="inline"><o:mrow><o:msub><o:mrow><o:mi mathvariant="normal">Ω</o:mi></o:mrow><o:mrow><o:mi>c</o:mi><o:mi>c</o:mi><o:mi>c</o:mi></o:mrow></o:msub><o:mtext>−</o:mtext><o:msub><o:mrow><o:mi mathvariant="normal">Ω</o:mi></o:mrow><o:mrow><o:mi>c</o:mi><o:mi>c</o:mi><o:mi>c</o:mi></o:mrow></o:msub></o:mrow></o:math> system exhibits a clear signal of a bound state, while the <s:math xmlns:s="http://www.w3.org/1998/Math/MathML" display="inline"><s:mrow><s:mi mathvariant="normal">Ω</s:mi><s:mtext>−</s:mtext><s:mi mathvariant="normal">Ω</s:mi></s:mrow></s:math> system lies very close to the threshold, making it difficult to draw definitive conclusions. For <w:math xmlns:w="http://www.w3.org/1998/Math/MathML" display="inline"><w:mi>S</w:mi><w:mo>=</w:mo><w:mn>2</w:mn></w:math>, both systems are found to be unbound.