Prompt and non-prompt J/ψ production cross sections at midrapidity in proton-proton collisions at $$ \sqrt{\mathrm{s}} $$ = 5.02 and 13 TeV (2022)

A bstract The production of J /ψ is measured at midrapidity ( |y| &lt; 0 . 9) in proton-proton collisions at $$ \sqrt{s} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msqrt><mml:mi>s</mml:mi></mml:msqrt></mml:math> = 5 . 02 and 13 TeV, through the dielectron decay channel, using the ALICE detector at the Large Hadron Collider. The data sets used for the analyses correspond to integrated luminosities of $$ \mathcal{L} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>L</mml:mi></mml:math> int = 19.4 ± 0.4 nb − 1 and $$ \mathcal{L} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>L</mml:mi></mml:math> int = 32.2 ± 0.5 nb − 1 at $$ \sqrt{s} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msqrt><mml:mi>s</mml:mi></mml:msqrt></mml:math> = 5 . 02 and 13 TeV, respectively. The fraction of non-prompt J /ψ mesons, i.e. those originating from the decay of beauty hadrons, is measured down to a transverse momentum p T = 2 GeV /c (1 GeV /c ) at $$ \sqrt{s} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msqrt><mml:mi>s</mml:mi></mml:msqrt></mml:math> = 5 . 02 TeV (13 TeV). The p T and rapidity ( y ) differential cross sections, as well as the corresponding values integrated over p T and y , are carried out separately for prompt and non-prompt J /ψ mesons. The results are compared with measurements from other experiments and theoretical calculations based on quantum chromodynamics (QCD). The shapes of the p T and y distributions of beauty quarks predicted by state-of-the-art perturbative QCD models are used to extrapolate an estimate of the $$ \mathrm{b}\overline{\mathrm{b}} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>b</mml:mi><mml:mover><mml:mi>b</mml:mi><mml:mo>¯</mml:mo></mml:mover></mml:math> pair cross section at midrapidity and in the total phase space. The total $$ \mathrm{b}\overline{\mathrm{b}} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>b</mml:mi><mml:mover><mml:mi>b</mml:mi><mml:mo>¯</mml:mo></mml:mover></mml:math> cross sections are found to be $$ {\sigma}_{\mathrm{b}\overline{\mathrm{b}}} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mi>σ</mml:mi><mml:mrow><mml:mi>b</mml:mi><mml:mover><mml:mi>b</mml:mi><mml:mo>¯</mml:mo></mml:mover></mml:mrow></mml:msub></mml:math> = 541 ± 45 (stat . ) ± 69 $$ {\left(\mathrm{syst}.\right)}_{-12}^{+10} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msubsup><mml:mfenced><mml:mrow><mml:mtext>syst</mml:mtext><mml:mo>.</mml:mo></mml:mrow></mml:mfenced><mml:mrow><mml:mo>−</mml:mo><mml:mn>12</mml:mn></mml:mrow><mml:mrow><mml:mo>+</mml:mo><mml:mn>10</mml:mn></mml:mrow></mml:msubsup></mml:math> (extr . ) μ b and $$ {\sigma}_{\mathrm{b}\overline{\mathrm{b}}} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mi>σ</mml:mi><mml:mrow><mml:mi>b</mml:mi><mml:mover><mml:mi>b</mml:mi><mml:mo>¯</mml:mo></mml:mover></mml:mrow></mml:msub></mml:math> = 218 ± 37 (stat . ) ± 31 $$ {\left(\mathrm{syst}.\right)}_{-9.1}^{+8.2} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msubsup><mml:mfenced><mml:mrow><mml:mtext>syst</mml:mtext><mml:mo>.</mml:mo></mml:mrow></mml:mfenced><mml:mrow><mml:mo>−</mml:mo><mml:mn>9.1</mml:mn></mml:mrow><mml:mrow><mml:mo>+</mml:mo><mml:mn>8.2</mml:mn></mml:mrow></mml:msubsup></mml:math> (extr . ) μ b at $$ \sqrt{s} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msqrt><mml:mi>s</mml:mi></mml:msqrt></mml:math> = 13 and 5.02 TeV, respectively. The value obtained from the combination of ALICE and LHCb measurements in pp collisions at $$ \sqrt{s} $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msqrt><mml:mi>s</mml:mi></mml:msqrt></mml:math> = 13 TeV is also provided.