Double parton scatterings in b-quark pairs production at the LHC

TL;DR

The paper investigates the production of two b-bbar pairs at the LHC, focusing on the role of double parton scattering (DPS) relative to single parton scattering (SPS). It uses k_t-factorization with two unintegrated gluon density prescriptions, calibrates a K-factor against TEVATRON data, and applies a DPS framework with sigma_eff to quantify bbbarbbbar production, comparing it to LO SPS predictions computed with MadGraph. The results indicate DPS dominates the integrated cross section at LHC energies (especially at low p_T), with cross sections around 1 μb at 14 TeV, implying DPS is a powerful channel to study multi-parton interactions and the gluon content of the proton. The work highlights DPS as a tool to study three-dimensional proton structure and motivates experimental searches at ALICE and LHCb acceptances.

Abstract

A sizable rate of events where two pairs of b-quarks are produced contemporarily is foreseen at the CERN LHC, as a consequence of the large parton luminosity. At very high energies both single and the double parton scatterings contribute to the process, the latter mechanisms, although power suppressed, giving the dominant contribution to the integrated cross section.

Figures (6)

• Figure 1: $p \bar{p}\rightarrow b\bar{b}$ production cross section as a function of $p_t^{min}$ at ${\sqrt s}=1.8$ TeV, with the $b$-quark within the rapidity range $|y_b|< 1$, experimental data from ref.Abbott:1999se, and at ${\sqrt s}=14$ TeV with the $b$-quark within the pseudo-rapidity range $|\eta|< 0.9$ .
• Figure 2: Normalized rapidity ($y$) and pseudorapidity ($\eta$) distributions for $b\bar{b}$ production at ALICE. With the $k_t$ factorization approach (dashed histograms) and at the lowest order in pQCD multiplied by the $K$-factor (continuous histograms).
• Figure 3:
• Figure 4: $b\bar{b} b \bar{b}$ production cross section at ${\sqrt s}=14$ TeV and at ${\sqrt s}=5.5$ TeV as a function of $p_t^{min}$ with all the four $b$-quarks in the pseudo-rapidity interval $|\eta|< 0.9$ .
• Figure 5: $b\bar{b} b \bar{b}$ production with the two equal sign $b$-quarks in the pseudo-rapidity interval $|\eta_b|<0.9$. $\eta$-distributions and $y_b$-distributions at ${\sqrt s}=14$ TeV and at ${\sqrt s}=5.5$ TeV. The continuous histograms refer to the contribution of double parton scatterings while the dashed histograms to the single parton scatterings.