Inclusive production of a heavy-light dijet system in hybrid high-energy and collinear factorization

We propose the study of the inclusive hadroproduction of a heavy-flavored jet in association with a light jet, as a probe channel of strong interactions at high energies. We build up a hybrid factorization that encodes genuine high-energy effects, provided by a partial next-to-leading BFKL resummation, inside the standard collinear structure of the cross section. We present a detailed analysis of different distributions, shaped on kinematic ranges typical of experimental analyses at the Large Hadron Collider, and differential in rapidity, azimuthal angle and transverse momentum. The fair stability that these distributions exhibit under higher-order corrections motivates our interest toward future studies. Here, the hybrid factorization could help to deepen our understanding of heavy-flavor physics in wider kinematic ranges, like the ones accessible at the Electron-Ion Collider.

Figure 1

Pictorial representation of (a) the Mueller–Navelet jet production and of (b) the inclusive heavy-light dijet hadroproduction in hybrid high-energy/collinear factorization.

Figure 2

Pictorial representation of (a) an inclusive single forward emission in hybrid high-energy/collinear factorization and of (b) an inclusive single central emission in pure high-energy factorization. The red blob in panel (a) refers to collinear PDFs, while sea green ones in both panels denote the hard part of the impact factor describing the emission of a generic object in (a) forward or (b) central regions of rapidity. The unintegrated gluon distributions, depicted in violet, encode nonperturbative information about the gluon content in the proton at high energies (small-$x$) and are connected to the impact factor via Reggeon lines. Gluon-induced emissions from the collinear region in panel (a), not shown here, are encoded in the sea green blob.

Figure 3

Hybrid factorization for the heavy-light dijet production with a light-quark jet produced in the lower fragmentation region (gluon jet not shown here). The high-energy resummed partonic cross section is convoluted with collinear PDFs.

Figure 4

Feynman diagrams relevant for the calculation of the LO impact factor describing the hadroproduction of a heavy-flavored jet. Zigzag lines stand for Reggeized gluons.

Figure 5

Feynman diagrams relevant for the calculation of the LO impact factor describing the hadroproduction of a light jet. Zigzag lines stand for Reggeized gluons.

Figure 6

$\mathrm{\Delta }Y$-dependence of the $\phi$-summed cross section, $C_0$, in the $b\text{-jet}$ (left) and $c\text{-jet}$ (right) channels and for $\sqrt{s}=14\mathrm{TeV}$. Shaded bands provide with the combined uncertainty coming from scale variation and numerical integration(s).

Figure 7

$\mathrm{\Delta }Y$-dependence of $R_{nm}\equiv C_n/C_m$ ratios, in the $b\text{-jet}$ channel and for $\sqrt{s}=14\mathrm{TeV}$. Shaded bands provide with the combined uncertainty coming from scale variation and numerical integration(s).

Figure 8

$\mathrm{\Delta }Y$-dependence of $R_{nm}\equiv C_n/C_m$ ratios, in the $c\text{-jet}$ channel and for $\sqrt{s}=14\mathrm{TeV}$. Shaded bands provide with the combined uncertainty coming from scale variation and numerical integration(s).

Figure 9

LLA (upper) and NLA (lower) azimuthal distribution in the $b\text{-jet}$ (left) and $c\text{-jet}$ (right) channels, for three distinct values of the final-state rapidity interval, $\mathrm{\Delta }Y$, and for $\sqrt{s}=14\mathrm{TeV}$. Shaded bands provide with the combined uncertainty coming from scale variation and numerical integration(s).

Figure 10

Transverse-momentum distribution of the $b$-jet (left) and of the $c$-jet (right) at $\mathrm{\Delta }Y=3$ (upper) and $\mathrm{\Delta }Y=5$ (lower), for $35\mathrm{GeV}<|{\overrightarrow{p}}_J|<60\mathrm{GeV}$ and $\sqrt{s}=14\mathrm{TeV}$. Shaded bands provide with the combined uncertainty coming from scale variation and numerical integration(s).