The observation of the $$P_{cs}(4459)$$ by the LHCb collaboration adds a new member to the set of known hidden-charm pentaquarks, which includes the $$P_c(4312)$$ , $$P_c(4440)$$ and $$P_c(4457)$$ . The $$P_{cs}(4459)$$ is expected to have the light-quark content of a $$\Lambda $$ baryon ( $$I=0$$ , $$S=-1$$ ), but its spin is unknown. Its closeness to the $${\bar{D}}^* \Xi _c$$ threshold – $$4478\,{\mathrm{MeV}}$$ in the isospin-symmetric limit – suggests the molecular hypothesis as a plausible explanation for the $$P_{cs}(4459)$$ . While in the absence of coupled-channel dynamics heavy-quark spin symmetry predicts the two spin-states of the $${\bar{D}}^* \Xi _c$$ to be degenerate, power counting arguments indicate that the coupling with the nearby $${\bar{D}} \Xi _c'$$ and $${\bar{D}} \Xi _c^*$$ channels might be a leading order effect. This generates a hyperfine splitting in which the $$J=\tfrac{3}{2}$$ $${\bar{D}}^* \Xi _c$$ pentaquark will be lighter than the $$J=\tfrac{1}{2}$$ configuration, which we estimate to be of the order of $$5-15\,{\mathrm{MeV}}$$ . We also point out an accidental symmetry between the $$P_{cs}(4459)$$ and $$P_c(4440/4457)$$ potentials. Finally, we argue that the spectroscopy and the $$J/\psi \Lambda $$ decays of the $$P_{cs}(4459)$$ might suggest a marginal preference for $$J = \tfrac{3}{2}$$ over $$J = \tfrac{1}{2}$$ .
{
"_oai": {
"updated": "2023-02-05T12:30:18Z",
"id": "oai:repo.scoap3.org:63742",
"sets": [
"EPJC"
]
},
"authors": [
{
"affiliations": [
{
"country": "China",
"value": "School of Physics, Beihang University, Beijing, 100191, China",
"organization": "Beihang University"
}
],
"surname": "Peng",
"given_names": "Fang-Zheng",
"full_name": "Peng, Fang-Zheng"
},
{
"affiliations": [
{
"country": "China",
"value": "School of Physics, Beihang University, Beijing, 100191, China",
"organization": "Beihang University"
}
],
"surname": "Yan",
"given_names": "Mao-Jun",
"full_name": "Yan, Mao-Jun"
},
{
"affiliations": [
{
"country": "France",
"value": "Centre d\u2019\u00c9tudes Nucl\u00e9aires, CNRS/IN2P3, Universit\u00e9 de Bordeaux, Gradignan, 33175, France",
"organization": "CNRS/IN2P3, Universit\u00e9 de Bordeaux"
}
],
"surname": "S\u00e1nchez S\u00e1nchez",
"given_names": "Mario",
"full_name": "S\u00e1nchez S\u00e1nchez, Mario"
},
{
"affiliations": [
{
"country": "China",
"value": "School of Physics, Beihang University, Beijing, 100191, China",
"organization": "Beihang University"
},
{
"country": "China",
"value": "International Research Center for Nuclei and Particles in the Cosmos and Beijing Key Laboratory of Advanced Nuclear Materials and Physics, Beihang University, Beijing, 100191, China",
"organization": "Beihang University"
}
],
"surname": "Pavon Valderrama",
"email": "mpavon@buaa.edu.cn",
"full_name": "Pavon Valderrama, Manuel",
"given_names": "Manuel"
}
],
"titles": [
{
"source": "Springer",
"title": "The $$P_{cs}(4459)$$ <math> <mrow> <msub> <mi>P</mi> <mrow> <mi>cs</mi> </mrow> </msub> <mrow> <mo>(</mo> <mn>4459</mn> <mo>)</mo> </mrow> </mrow> </math> pentaquark from a combined effective field theory and phenomenological perspective"
}
],
"dois": [
{
"value": "10.1140/epjc/s10052-021-09416-x"
}
],
"publication_info": [
{
"page_end": "16",
"journal_title": "European Physical Journal C",
"material": "article",
"journal_volume": "81",
"artid": "s10052-021-09416-x",
"year": 2021,
"page_start": "1",
"journal_issue": "7"
}
],
"$schema": "http://repo.scoap3.org/schemas/hep.json",
"acquisition_source": {
"date": "2023-02-05T12:30:16.118778",
"source": "Springer",
"method": "Springer",
"submission_number": "ce95fe4ea55011ed9a680e231c257137"
},
"page_nr": [
16
],
"license": [
{
"url": "https://creativecommons.org/licenses//by/4.0",
"license": "CC-BY-4.0"
}
],
"copyright": [
{
"holder": "The Author(s)",
"year": "2021"
}
],
"control_number": "63742",
"record_creation_date": "2021-07-29T18:30:16.189374",
"_files": [
{
"checksum": "md5:178225a3e053af1bde4ef4f9e51c4318",
"filetype": "xml",
"bucket": "e720b752-dfcf-4449-a9b3-2987320820ec",
"version_id": "0856a5b4-7ee1-4cf8-b775-7c207e8dc9f2",
"key": "10.1140/epjc/s10052-021-09416-x.xml",
"size": 37033
},
{
"checksum": "md5:816c047b54f0fe5f8650b38200f8186d",
"filetype": "pdf/a",
"bucket": "e720b752-dfcf-4449-a9b3-2987320820ec",
"version_id": "02ede649-8300-42d2-85fe-410757f2726c",
"key": "10.1140/epjc/s10052-021-09416-x_a.pdf",
"size": 475691
}
],
"collections": [
{
"primary": "European Physical Journal C"
}
],
"arxiv_eprints": [
{
"categories": [
"hep-ph",
"hep-ex",
"hep-lat",
"nucl-th"
],
"value": "2011.01915"
}
],
"abstracts": [
{
"source": "Springer",
"value": "The observation of the $$P_{cs}(4459)$$ <math> <mrow> <msub> <mi>P</mi> <mrow> <mi>cs</mi> </mrow> </msub> <mrow> <mo>(</mo> <mn>4459</mn> <mo>)</mo> </mrow> </mrow> </math> by the LHCb collaboration adds a new member to the set of known hidden-charm pentaquarks, which includes the $$P_c(4312)$$ <math> <mrow> <msub> <mi>P</mi> <mi>c</mi> </msub> <mrow> <mo>(</mo> <mn>4312</mn> <mo>)</mo> </mrow> </mrow> </math> , $$P_c(4440)$$ <math> <mrow> <msub> <mi>P</mi> <mi>c</mi> </msub> <mrow> <mo>(</mo> <mn>4440</mn> <mo>)</mo> </mrow> </mrow> </math> and $$P_c(4457)$$ <math> <mrow> <msub> <mi>P</mi> <mi>c</mi> </msub> <mrow> <mo>(</mo> <mn>4457</mn> <mo>)</mo> </mrow> </mrow> </math> . The $$P_{cs}(4459)$$ <math> <mrow> <msub> <mi>P</mi> <mrow> <mi>cs</mi> </mrow> </msub> <mrow> <mo>(</mo> <mn>4459</mn> <mo>)</mo> </mrow> </mrow> </math> is expected to have the light-quark content of a $$\\Lambda $$ <math> <mi>\u039b</mi> </math> baryon ( $$I=0$$ <math> <mrow> <mi>I</mi> <mo>=</mo> <mn>0</mn> </mrow> </math> , $$S=-1$$ <math> <mrow> <mi>S</mi> <mo>=</mo> <mo>-</mo> <mn>1</mn> </mrow> </math> ), but its spin is unknown. Its closeness to the $${\\bar{D}}^* \\Xi _c$$ <math> <mrow> <msup> <mrow> <mover> <mrow> <mi>D</mi> </mrow> <mrow> <mo>\u00af</mo> </mrow> </mover> </mrow> <mo>\u2217</mo> </msup> <msub> <mi>\u039e</mi> <mi>c</mi> </msub> </mrow> </math> threshold \u2013 $$4478\\,{\\mathrm{MeV}}$$ <math> <mrow> <mn>4478</mn> <mspace width=\"0.166667em\"></mspace> <mi>MeV</mi> </mrow> </math> in the isospin-symmetric limit \u2013 suggests the molecular hypothesis as a plausible explanation for the $$P_{cs}(4459)$$ <math> <mrow> <msub> <mi>P</mi> <mrow> <mi>cs</mi> </mrow> </msub> <mrow> <mo>(</mo> <mn>4459</mn> <mo>)</mo> </mrow> </mrow> </math> . While in the absence of coupled-channel dynamics heavy-quark spin symmetry predicts the two spin-states of the $${\\bar{D}}^* \\Xi _c$$ <math> <mrow> <msup> <mrow> <mover> <mrow> <mi>D</mi> </mrow> <mrow> <mo>\u00af</mo> </mrow> </mover> </mrow> <mo>\u2217</mo> </msup> <msub> <mi>\u039e</mi> <mi>c</mi> </msub> </mrow> </math> to be degenerate, power counting arguments indicate that the coupling with the nearby $${\\bar{D}} \\Xi _c'$$ <math> <mrow> <mover> <mrow> <mi>D</mi> </mrow> <mrow> <mo>\u00af</mo> </mrow> </mover> <msubsup> <mi>\u039e</mi> <mi>c</mi> <mo>\u2032</mo> </msubsup> </mrow> </math> and $${\\bar{D}} \\Xi _c^*$$ <math> <mrow> <mover> <mrow> <mi>D</mi> </mrow> <mrow> <mo>\u00af</mo> </mrow> </mover> <msubsup> <mi>\u039e</mi> <mi>c</mi> <mo>\u2217</mo> </msubsup> </mrow> </math> channels might be a leading order effect. This generates a hyperfine splitting in which the $$J=\\tfrac{3}{2}$$ <math> <mrow> <mi>J</mi> <mo>=</mo> <mstyle> <mfrac> <mn>3</mn> <mn>2</mn> </mfrac> </mstyle> </mrow> </math> $${\\bar{D}}^* \\Xi _c$$ <math> <mrow> <msup> <mrow> <mover> <mrow> <mi>D</mi> </mrow> <mrow> <mo>\u00af</mo> </mrow> </mover> </mrow> <mo>\u2217</mo> </msup> <msub> <mi>\u039e</mi> <mi>c</mi> </msub> </mrow> </math> pentaquark will be lighter than the $$J=\\tfrac{1}{2}$$ <math> <mrow> <mi>J</mi> <mo>=</mo> <mstyle> <mfrac> <mn>1</mn> <mn>2</mn> </mfrac> </mstyle> </mrow> </math> configuration, which we estimate to be of the order of $$5-15\\,{\\mathrm{MeV}}$$ <math> <mrow> <mn>5</mn> <mo>-</mo> <mn>15</mn> <mspace width=\"0.166667em\"></mspace> <mi>MeV</mi> </mrow> </math> . We also point out an accidental symmetry between the $$P_{cs}(4459)$$ <math> <mrow> <msub> <mi>P</mi> <mrow> <mi>cs</mi> </mrow> </msub> <mrow> <mo>(</mo> <mn>4459</mn> <mo>)</mo> </mrow> </mrow> </math> and $$P_c(4440/4457)$$ <math> <mrow> <msub> <mi>P</mi> <mi>c</mi> </msub> <mrow> <mo>(</mo> <mn>4440</mn> <mo>/</mo> <mn>4457</mn> <mo>)</mo> </mrow> </mrow> </math> potentials. Finally, we argue that the spectroscopy and the $$J/\\psi \\Lambda $$ <math> <mrow> <mi>J</mi> <mo>/</mo> <mi>\u03c8</mi> <mi>\u039b</mi> </mrow> </math> decays of the $$P_{cs}(4459)$$ <math> <mrow> <msub> <mi>P</mi> <mrow> <mi>cs</mi> </mrow> </msub> <mrow> <mo>(</mo> <mn>4459</mn> <mo>)</mo> </mrow> </mrow> </math> might suggest a marginal preference for $$J = \\tfrac{3}{2}$$ <math> <mrow> <mi>J</mi> <mo>=</mo> <mstyle> <mfrac> <mn>3</mn> <mn>2</mn> </mfrac> </mstyle> </mrow> </math> over $$J = \\tfrac{1}{2}$$ <math> <mrow> <mi>J</mi> <mo>=</mo> <mstyle> <mfrac> <mn>1</mn> <mn>2</mn> </mfrac> </mstyle> </mrow> </math> ."
}
],
"imprints": [
{
"date": "2021-07-29",
"publisher": "Springer"
}
]
}