Measurement of the $B^{+}$ production cross section in $p\overline{p}$ collisions at $\sqrt{s}=1960\mathrm{GeV}$

We present a new measurement of the $B^{+}$ meson differential cross section $d\sigma /d{p}_T$ at $\sqrt{s}=1960\mathrm{GeV}$. The data correspond to an integrated luminosity of $739{\mathrm{pb}}^{-1}$ collected with the upgraded CDF detector (CDF II) at the Fermilab Tevatron collider. $B^{+}$ candidates are reconstructed through the decay $B^{+}\to J/\psi K^{+}$, with $J/\psi \to {\mu }^{+}{\mu }^{-}$. The integrated cross section for producing $B^{+}$ mesons with $p_T\ge 6\mathrm{GeV}/c$ and $|y|\le 1$ is measured to be $2.78\pm 0.24\mu \mathrm{b}$.

Figure 1

Invariant mass distribution of all $B^{\pm }$ candidates. The line represents a fit to the data using a first order polynomial plus a Gaussian function in order to estimate the background and the $B^{\pm }$ signal, respectively.

Figure 2

Invariant mass distribution of $B^{\pm }$ candidates with $6\le p_T\le 9\mathrm{GeV}/c$. The line represents the best fit to the data described in the text.

Figure 3

Invariant mass distribution of $B^{\pm }$ candidates with $9\le p_T\le 12\mathrm{GeV}/c$. The line represents the best fit to the data described in the text.

Figure 4

Invariant mass distribution of $B^{\pm }$ candidates with $12\le p_T\le 15\mathrm{GeV}/c$. The line represents the best fit to the data described in the text.

Figure 5

Invariant mass distribution of $B^{\pm }$ candidates with $15\le p_T\le 25\mathrm{GeV}/c$. The line represents the best fit to the data described in the text.

Figure 6

Invariant mass distribution of $B^{\pm }$ candidates with $p_T\ge 25\mathrm{GeV}/c$. The line represents the best fit to the data described in the text.

Figure 7

Invariant mass distribution of a CMUP muon paired with all charged tracks in the event with (a) or without (b) a CMU stub. Lines represent the fits described in the text.

Figure 8

Invariant mass distribution of a CMUP muon paired with all CMU muons in the event with (a) or without (b) a L1 CMU primitive. Lines represent the fits described in the text.

Figure 9

Transverse momentum distributions in the data ($•$) and simulation (solid histogram). The simulation is normalized to the $B^{\pm }\to {\mu }^{+}{\mu }^{-}{K}^{\pm }$ signal observed in the data (see text).

Figure 10

Rapidity distributions of $B^{\pm }$ mesons in the data ($•$) and simulation (solid histogram). The simulation is normalized to the $B^{\pm }\to {\mu }^{+}{\mu }^{-}{K}^{\pm }$ signal observed in the data (see text).

Figure 11

Measurements of the $B^{+}$ differential cross section ($|y^{B^{+}}|\le 1$) at the Tevatron are compared to NLO and FONLL theoretical predictions. The FONLL result utilizes the CTEQ6M fits to the parton distribution functions, and nonperturbative fragmentation functions consistent with the accuracy level of the calculation [36]. The NLO prediction, used to evaluate the kinematical acceptance of this experiment and to compare different measurements of the $b$ quark cross section at the Tevatron in Ref. [5], uses the ${\mathrm{MRSD}}_0$ [6] fits and the Peterson fragmentation model with $ϵ=0.006$ (see text). The result of this experiment ($•$) is shown together with those of ($△$) Ref. [26] and ($\circ$) Ref. [9]; the result of Ref. [9] has been increased by 10% to account for the expected increase of the cross section from $\sqrt{s}=1.8$ to 1.96 TeV [1]. For each experiment, errors are the sum in quadrature of statistical and systematic uncertainties.