Measurement of the $B^{\pm}$ production cross-section in pp collisions at $\sqrt{s} =$ 7 and 13 TeV

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Abstract

The production of $B^{\pm}$ mesons is studied in $pp$ collisions at centre-of-mass energies of 7 and 13 TeV, using $B^{\pm}\rightarrow J/\psi K^{\pm}$ decays and data samples corresponding to 1.0 fb$^{-1}$ and 0.3 fb$^{-1}$, respectively. The production cross-sections summed over both charges and integrated over the transverse momentum range $0<p_{\text{T}}< 40$ GeV/$c$ and the rapidity range $2.0<y<4.5$ are measured to be $\sigma(pp \rightarrow B^{\pm} X, \sqrt{s} = \text{7 TeV}) = 43.0 \pm 0.2 \pm 2.5 \pm 1.7\mu b,$ $\sigma(pp \rightarrow B^{\pm} X, \sqrt{s} = \text{13 TeV}) = 86.6 \pm 0.5 \pm 5.4 \pm 3.4\mu b,$ where the first uncertainties are statistical, the second are systematic, and the third are due to the limited knowledge of the $B^{\pm}\rightarrow J/\psi K^{\pm}$ branching fraction. The ratio of the cross-section at 13 TeV to that at 7 TeV is determined to be $2.02\pm0.02\text{(stat)}\pm0.12\text{(syst)}$. Differential cross-sections are also reported as functions of $p_{\text{T}}$ and $y$. All results are in agreement with theoretical calculations based on the state-of-art fixed next-to-leading order quantum chromodynamics.

 Invariant mass distributions of $B ^\pm$ candidates in the range ${3.5< p_{\mathrm{ T}} <4.0 {\mathrm{\,GeV\!/}c} }$ and ${2.5 Tables and captions  Summary of relative systematic uncertainties on the integrated production cross-sections at {$\sqrt{s}=$7} and$13\mathrm{\,TeV} $, and the ratio of the cross-sections$R(13\mathrm{\,TeV} /7\mathrm{\,TeV} )$. Table_1.pdf [27 KiB] HiDef png [115 KiB] Thumbnail [18 KiB] tex code Measured$\varepsilon_{\text{tot}}$of$ B ^\pm$events at$7\mathrm{\,TeV} $, in the bins of$ B ^\pmp_{\mathrm{ T}}$and$y$. The efficiencies and uncertainties are in percent. Table_2.pdf [35 KiB] HiDef png [247 KiB] Thumbnail [41 KiB] tex code Measured$\varepsilon_{\text{tot}}$of$ B ^\pm$events at$13\mathrm{\,TeV} $, in the bins of$ B ^\pmp_{\mathrm{ T}}$and$y$. The efficiencies and uncertainties are in percent. Table_3.pdf [35 KiB] HiDef png [239 KiB] Thumbnail [41 KiB] tex code Measured$ B ^\pm$double-differential cross-section (in units of$\mathrm{ \,nb}$) at$7\mathrm{\,TeV} $, as a function of$p_{\mathrm{ T}}$and$y$, in the rapidity regions of$2.0

Created on 16 February 2019.Citation count from INSPIRE on 21 February 2019.