Predictions for feed-down enhancements at the ΛcD¯ and Λc…

We demonstrate that triangle singularity (TS) and box singularity (BS) mechanisms can produce unique narrow enhancements at the <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:msub><a:mi mathvariant="normal">Λ</a:mi><a:mi>c</a:mi></a:msub><a:mover accent="true"><a:mi>D</a:mi><a:mo stretchy="false">¯</a:mo></a:mover></a:math> and <f:math xmlns:f="http://www.w3.org/1998/Math/MathML" display="inline"><f:msub><f:mi mathvariant="normal">Λ</f:mi><f:mi>c</f:mi></f:msub><f:msup><f:mover accent="true"><f:mi>D</f:mi><f:mo stretchy="false">¯</f:mo></f:mover><f:mo>*</f:mo></f:msup></f:math> thresholds in the invariant mass spectra of <k:math xmlns:k="http://www.w3.org/1998/Math/MathML" display="inline"><k:mi>J</k:mi><k:mo>/</k:mo><k:mi>ψ</k:mi><k:mi>p</k:mi></k:math> and <m:math xmlns:m="http://www.w3.org/1998/Math/MathML" display="inline"><m:mi>J</m:mi><m:mo>/</m:mo><m:mi>ψ</m:mi><m:mi>p</m:mi><m:mi>π</m:mi></m:math>, respectively. Taking into account that such mechanisms only depend on the initial <o:math xmlns:o="http://www.w3.org/1998/Math/MathML" display="inline"><o:msubsup><o:mi mathvariant="normal">Σ</o:mi><o:mi>c</o:mi><o:mrow><o:mo stretchy="false">(</o:mo><o:mo>*</o:mo><o:mo stretchy="false">)</o:mo></o:mrow></o:msubsup><o:msup><o:mover accent="true"><o:mi>D</o:mi><o:mo stretchy="false">¯</o:mo></o:mover><o:mrow><o:mo stretchy="false">(</o:mo><o:mo>*</o:mo><o:mo stretchy="false">)</o:mo></o:mrow></o:msup></o:math> interactions near threshold within the TS or BS kinematic regimes, the <x:math xmlns:x="http://www.w3.org/1998/Math/MathML" display="inline"><x:msub><x:mi mathvariant="normal">Λ</x:mi><x:mi>c</x:mi></x:msub><x:mover accent="true"><x:mi>D</x:mi><x:mo stretchy="false">¯</x:mo></x:mover></x:math> and <cb:math xmlns:cb="http://www.w3.org/1998/Math/MathML" display="inline"><cb:msub><cb:mi mathvariant="normal">Λ</cb:mi><cb:mi>c</cb:mi></cb:msub><cb:msup><cb:mover accent="true"><cb:mi>D</cb:mi><cb:mo stretchy="false">¯</cb:mo></cb:mover><cb:mo>*</cb:mo></cb:msup></cb:math> threshold enhancements can also acquire contributions from both the heavier pentaquark decays and the <hb:math xmlns:hb="http://www.w3.org/1998/Math/MathML" display="inline"><hb:msubsup><hb:mi mathvariant="normal">Σ</hb:mi><hb:mi>c</hb:mi><hb:mrow><hb:mo stretchy="false">(</hb:mo><hb:mo>*</hb:mo><hb:mo stretchy="false">)</hb:mo></hb:mrow></hb:msubsup><hb:msup><hb:mover accent="true"><hb:mi>D</hb:mi><hb:mo stretchy="false">¯</hb:mo></hb:mover><hb:mrow><hb:mo stretchy="false">(</hb:mo><hb:mo>*</hb:mo><hb:mo stretchy="false">)</hb:mo></hb:mrow></hb:msup></hb:math> scatterings of the continuum as a feed-down phenomenon. A search for these structures in the <qb:math xmlns:qb="http://www.w3.org/1998/Math/MathML" display="inline"><qb:mi>J</qb:mi><qb:mo>/</qb:mo><qb:mi>ψ</qb:mi><qb:mi>p</qb:mi></qb:math> and <sb:math xmlns:sb="http://www.w3.org/1998/Math/MathML" display="inline"><sb:mi>J</sb:mi><sb:mo>/</sb:mo><sb:mi>ψ</sb:mi><sb:mi>p</sb:mi><sb:mi>π</sb:mi></sb:math> spectra in both exclusive and semi-inclusive processes will provide a crucial evidence for the hadronic molecule nature of these observed pentaquarks and clarify the role played by the TS and BS in the near-threshold dynamics.