Like-Sign W Boson Production at the LHC as a Probe of Double Parton Scattering

Abstract

Double parton scattering, i.e. two parton hard scattering processes in the same hadron-hadron collision, may constitute an important background for Higgs and other new particle searches at the LHC. We point out that like-sign W pair production provides a relatively clean way of searching for, and calibrating, double parton scattering at the LHC.

Figures (5)

• Figure 1: Examples of Feynman diagrams for the $uu \to W^+W^+dd$ scattering process, ${\cal O}(\alpha_S^2 \alpha_W^2)$ (a) and ${\cal O}(\alpha_W^4)$ (b-f).
• Figure 2: Total cross sections for single $W$ and $W$ pair production in $pp$ and $p\bar{p}$ collisions. The dashed and dot-dashed lines correspond to single parton scattering, and the solid lines to double parton scattering assuming $\sigma_{\rm eff} = 14.5$ mb.
• Figure 3: Transverse momentum distributions for $W^+W^+$, $W^-W^-$, $W^+W^-$ (dashed, dot-dashed and dotted lines, respectively) single parton scattering and $W^+W^+$, $W^-W^-$ double parton scattering (solid lines) at the LHC. The double scattering predictions are obtained using the $p_T$-space resummation method KS (with neither smearing nor matching included).
• Figure 4: Jet transverse momentum distributions in like-sign single scattering $WW$ production.
• Figure 5: The dependence of the ratio ${\cal R}$ of like-sign to opposite-sign $W$ pair event rates on the effective cross section $\sigma_{\rm eff}$ at the LHC.