J/ψ elliptic and triangular flow in Pb-Pb collisions at $$ \sqrt{s_{\mathrm{NN}}} $$ = 5.02 TeV
抄録
<jats:title>A<jats:sc>bstract</jats:sc> </jats:title><jats:p>The inclusive J/<jats:italic>ψ</jats:italic> elliptic (<jats:italic>v</jats:italic><jats:sub>2</jats:sub>) and triangular (<jats:italic>v</jats:italic><jats:sub>3</jats:sub>) flow coefficients measured at forward rapidity (2<jats:italic>.</jats:italic>5 <jats:italic>< y <</jats:italic> 4) and the <jats:italic>v</jats:italic><jats:sub>2</jats:sub> measured at midrapidity (|<jats:italic>y</jats:italic>| <jats:italic><</jats:italic> 0<jats:italic>.</jats:italic>9) in Pb-Pb collisions at <jats:inline-formula><jats:alternatives><jats:tex-math>$$ \sqrt{s_{\mathrm{NN}}} $$</jats:tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msqrt> <mml:msub> <mml:mi>s</mml:mi> <mml:mi>NN</mml:mi> </mml:msub> </mml:msqrt> </mml:math></jats:alternatives></jats:inline-formula> = 5<jats:italic>.</jats:italic>02 TeV using the ALICE detector at the LHC are reported. The entire Pb-Pb data sample collected during Run 2 is employed, amounting to an integrated luminosity of 750 <jats:italic>μ</jats:italic>b<jats:sup><jats:italic>−</jats:italic>1</jats:sup> at forward rapidity and 93 <jats:italic>μ</jats:italic>b<jats:sup><jats:italic>−</jats:italic>1</jats:sup> at midrapidity. The results are obtained using the scalar product method and are reported as a function of transverse momentum <jats:italic>p</jats:italic><jats:sub>T</jats:sub> and collision centrality. At midrapidity, the J/<jats:italic>ψ v</jats:italic><jats:sub>2</jats:sub> is in agreement with the forward rapidity measurement. The centrality averaged results indicate a positive J/<jats:italic>ψ v</jats:italic><jats:sub>3</jats:sub> with a significance of more than 5<jats:italic>σ</jats:italic> at forward rapidity in the <jats:italic>p</jats:italic><jats:sub>T</jats:sub> range 2 <jats:italic>< p</jats:italic><jats:sub>T</jats:sub><jats:italic><</jats:italic> 5 GeV/<jats:italic>c</jats:italic>. The forward rapidity <jats:italic>v</jats:italic><jats:sub>2</jats:sub>, <jats:italic>v</jats:italic><jats:sub>3</jats:sub>, and <jats:italic>v</jats:italic><jats:sub>3</jats:sub><jats:italic>/v</jats:italic><jats:sub>2</jats:sub> results at low and intermediate <jats:italic>p</jats:italic><jats:sub>T</jats:sub> (<jats:italic>p</jats:italic><jats:sub>T</jats:sub> ≲ 8 GeV/<jats:italic>c</jats:italic>) exhibit a mass hierarchy when compared to pions and D mesons, while converging into a species-independent curve at higher <jats:italic>p</jats:italic><jats:sub>T</jats:sub>. At low and intermediate <jats:italic>p</jats:italic><jats:sub>T</jats:sub>, the results could be interpreted in terms of a later thermalization of charm quarks compared to light quarks, while at high <jats:italic>p</jats:italic><jats:sub>T</jats:sub>, path-length dependent effects seem to dominate. The J/<jats:italic>ψ v</jats:italic><jats:sub>2</jats:sub> measurements are further compared to a microscopic transport model calculation. Using a simplified extension of the quark scaling approach involving both light and charm quark flow components, it is shown that the D-meson <jats:italic>v</jats:italic><jats:sub>n</jats:sub> measurements can be described based on those for charged pions and J/<jats:italic>ψ</jats:italic> flow.</jats:p>
収録刊行物
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- Journal of High Energy Physics
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Journal of High Energy Physics 2020 (10), 2020-10
Springer Science and Business Media LLC