Elliptic anisotropy of open-charm hadrons from parton scatterings in p -Pb collisions at energies available at the CERN Large Hadron Collider

The elliptic azimuthal anisotropy coefficient (<a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:msub><a:mi>v</a:mi><a:mn>2</a:mn></a:msub></a:math>) of open-charm hadrons at midrapidity (<b:math xmlns:b="http://www.w3.org/1998/Math/MathML"><b:mrow><b:mo>|</b:mo><b:mi>η</b:mi><b:mo><</b:mo><b:mn>1</b:mn><b:mo>|</b:mo></b:mrow></b:math>) was studied in <c:math xmlns:c="http://www.w3.org/1998/Math/MathML"><c:mi>p</c:mi></c:math>-Pb collisions at <d:math xmlns:d="http://www.w3.org/1998/Math/MathML"><d:mrow><d:msqrt><d:msub><d:mi>s</d:mi><d:mrow><d:mi>N</d:mi><d:mi>N</d:mi></d:mrow></d:msub></d:msqrt><d:mo>=</d:mo><d:mn>8.16</d:mn></d:mrow></d:math> TeV using a multiphase transport () model including an additional charm quark–antiquark pair production trigger. The model provides a simultaneous description of the measured <e:math xmlns:e="http://www.w3.org/1998/Math/MathML"><e:msub><e:mi>p</e:mi><e:mi mathvariant="normal">T</e:mi></e:msub></e:math> spectrum and <g:math xmlns:g="http://www.w3.org/1998/Math/MathML"><g:msub><g:mi>v</g:mi><g:mn>2</g:mn></g:msub></g:math> of the <h:math xmlns:h="http://www.w3.org/1998/Math/MathML"><h:msup><h:mi>D</h:mi><h:mn>0</h:mn></h:msup></h:math> meson, as well as the <i:math xmlns:i="http://www.w3.org/1998/Math/MathML"><i:msub><i:mi>v</i:mi><i:mn>2</i:mn></i:msub></i:math> of light flavor meson <j:math xmlns:j="http://www.w3.org/1998/Math/MathML"><j:msubsup><j:mi>K</j:mi><j:mrow><j:mi>s</j:mi></j:mrow><j:mn>0</j:mn></j:msubsup></j:math>. We found that the <k:math xmlns:k="http://www.w3.org/1998/Math/MathML"><k:msup><k:mi>D</k:mi><k:mn>0</k:mn></k:msup></k:math> and <l:math xmlns:l="http://www.w3.org/1998/Math/MathML"><l:msubsup><l:mi>K</l:mi><l:mrow><l:mi>s</l:mi></l:mrow><l:mn>0</l:mn></l:msubsup><l:mo> </l:mo><l:msub><l:mi>v</l:mi><l:mn>2</l:mn></l:msub></l:math> are both significantly affected by different parton scatterings among charm and light quarks. In addition, the predictions for the <m:math xmlns:m="http://www.w3.org/1998/Math/MathML"><m:msub><m:mi>v</m:mi><m:mn>2</m:mn></m:msub></m:math> of other charm hadrons including <n:math xmlns:n="http://www.w3.org/1998/Math/MathML"><n:msup><n:mi>D</n:mi><n:mo>+</n:mo></n:msup><n:mo>,</n:mo><n:mo> </n:mo><n:msubsup><n:mi>D</n:mi><n:mrow><n:mi>s</n:mi></n:mrow><n:mo>+</n:mo></n:msubsup></n:math>, and <o:math xmlns:o="http://www.w3.org/1998/Math/MathML"><o:msubsup><o:mi mathvariant="normal">Λ</o:mi><o:mrow><o:mi>c</o:mi></o:mrow><o:mo>+</o:mo></o:msubsup></o:math> in <q:math xmlns:q="http://www.w3.org/1998/Math/MathML"><q:mi>p</q:mi></q:math>-Pb collisions are given for the first time. The <r:math xmlns:r="http://www.w3.org/1998/Math/MathML"><r:msub><r:mi>v</r:mi><r:mn>2</r:mn></r:msub></r:math> of open-charm hadrons reasonably follows the number-of-constituent-quark (NCQ) scaling up to 2.5 GeV, strongly indicating the importance of partonic degrees of freedom for the collectivity of heavy flavors in high-multiplicity <s:math xmlns:s="http://www.w3.org/1998/Math/MathML"><s:mi>p</s:mi></s:math>-Pb collisions. These findings may hint at the formation of deconfined matter in small collision systems, and provide referential value for future measurements of azimuthal anisotropy at energies available at the CERN Large Hadron Collider. Published by the American Physical Society 2024