| Summary: | Inspired by the LHCb observation of hidden-charm pentaquarks, i.e., <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>P</mi><mi>c</mi></msub><mrow><mo>(</mo><mn>4312</mn><mo>)</mo></mrow></mrow></semantics></math></inline-formula>, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>P</mi><mi>c</mi></msub><mrow><mo>(</mo><mn>4440</mn><mo>)</mo></mrow></mrow></semantics></math></inline-formula>, and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>P</mi><mi>c</mi></msub><mrow><mo>(</mo><mn>4457</mn><mo>)</mo></mrow></mrow></semantics></math></inline-formula> in the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>J</mi><mo>/</mo><mi>ψ</mi><mi>p</mi></mrow></semantics></math></inline-formula> invariant mass spectrum, a calculation of the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>J</mi><mo>/</mo><mi>ψ</mi><mi>p</mi></mrow></semantics></math></inline-formula> scattering cross-section was performed using the quark-delocalization color screening model. The results show that <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>P</mi><mi>c</mi></msub><mrow><mo>(</mo><mn>4312</mn><mo>)</mo></mrow></mrow></semantics></math></inline-formula> can be identified as a hidden-charm molecular state <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mo>Σ</mo><mi>c</mi></msub><mi>D</mi></mrow></semantics></math></inline-formula> with <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msup><mi>J</mi><mi>P</mi></msup><mo>=</mo><msup><mfrac><mn>1</mn><mn>2</mn></mfrac><mo>−</mo></msup></mrow></semantics></math></inline-formula>. The two-peak structure can be reproduced around 4450 MeV, which corresponds to <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>P</mi><mi>c</mi></msub><mrow><mo>(</mo><mn>4440</mn><mo>)</mo></mrow></mrow></semantics></math></inline-formula> and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>P</mi><mi>c</mi></msub><mrow><mo>(</mo><mn>4457</mn><mo>)</mo></mrow></mrow></semantics></math></inline-formula>. They are the resonances molecular states <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mo>Σ</mo><mi>c</mi></msub><msup><mi>D</mi><mo>*</mo></msup></mrow></semantics></math></inline-formula> of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msup><mi>J</mi><mi>P</mi></msup><mo>=</mo><msup><mfrac><mn>1</mn><mn>2</mn></mfrac><mo>−</mo></msup></mrow></semantics></math></inline-formula> and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msup><mi>J</mi><mi>P</mi></msup><mo>=</mo><msup><mfrac><mn>3</mn><mn>2</mn></mfrac><mo>−</mo></msup></mrow></semantics></math></inline-formula>. Moreover, the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msubsup><mo>Σ</mo><mi>c</mi><mo>*</mo></msubsup><msup><mi>D</mi><mo>*</mo></msup></mrow></semantics></math></inline-formula> of both <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msup><mi>J</mi><mi>P</mi></msup><mo>=</mo><msup><mfrac><mn>1</mn><mn>2</mn></mfrac><mo>−</mo></msup></mrow></semantics></math></inline-formula> and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msup><mi>J</mi><mi>P</mi></msup><mo>=</mo><msup><mfrac><mn>3</mn><mn>2</mn></mfrac><mo>−</mo></msup></mrow></semantics></math></inline-formula> are possible molecular pentaquarks. Moreover, in the same theoretical frame, the calculation is extended to the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>P</mi><mi>c</mi></msub></mrow></semantics></math></inline-formula>-like molecular pentaquarks, denoted as <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>P</mi><mi>b</mi></msub></semantics></math></inline-formula>. Several hidden-bottom pentaquarks with masses above 11 GeV and narrow widths were obtained. All of these heavy pentaquarks are worth exploring in future experiments.
|
|---|