Electroweak-correction effects in gauge-boson pair production at the LHC

TL;DR

This paper computes leading-logarithmic electroweak ${\cal O}(\alpha)$ corrections to high-energy hadronic production of gauge-boson pairs, specifically $pp\to WZ$ and $pp\to W\gamma$, at the LHC. Using the leading-pole approximation, the authors separate production and decay into factorizable corrections (with DPA for $WZ Z$ and SPA for $W\gamma$) and implement these into Monte Carlo predictions, neglecting non-factorizable and real-emission contributions. They find that electroweak corrections are negative and grow with the hard-scattering energy, lowering cross sections by roughly $5$–$20\%$ in the region of large transverse momentum and small gauge-boson rapidity separation, with the size depending on cuts and observables. The study highlights the importance of including electroweak Sudakov-like logarithms in precision LHC analyses and demonstrates the reliability of the LPA/DPA framework for these processes in the high-energy regime. The findings have direct implications for SM tests and for constraining new physics in di-boson channels, where backgrounds and kinematic distributions are sensitive to such corrections.

Abstract

We have studied the effect of one-loop logarithmic electroweak radiative corrections on WZ and $Wγ$ production processes at the LHC. We present analytical results for the leading-logarithmic electroweak corrections to the corresponding partonic processes du -> WZ, Wgamma. Using the leading-pole approximation we implement these corrections into Monte Carlo programs for $pp\to lν_l l'\bar l', lν_lγ$. We find that electroweak corrections lower the predictions by 5-20% in the physically interesting region of large transverse momentum and small rapidity separation of the gauge bosons.

Figures (12)

• Figure 1: Lowest-order angular distributions for the process $\bar{{\rm d}$ d$}{\rm u}$ u$\rightarrow{\rm W}$ W$^+_\lambda{\rm Z}$ Z$_{\lambda^\prime}$ at $E_{{\rm CM}}=500\,{\rm GeV}$. Here $\lambda ,\lambda^\prime$ denote the transverse (T) or longitudinal (L) helicities.
• Figure 2: Born cross sections for the process $\bar{{\rm d}$ d$}{\rm u}$ u$\rightarrow{\rm W}$ W$^+_\lambda{\rm Z}$ Z$_{\lambda^\prime}$ as a function of $E_{{\rm CM}}$ with $\lambda ,\lambda^\prime$ as in Fig. \ref{['fi:WZ_born_theta']}. From left to right, the three legends refer to the left-side curves and to the right-side ones respectively, as explained in the text.
• Figure 3: Lowest-order distributions in the invariants $\sqrt{\hat{s}}$ and $\sqrt{|\hat{r}|}$ as defined in the text for the full process ${\rm p}$ p${\rm p}$ p$\rightarrow l\nu_ll^\prime\bar{l^\prime}$ at $\sqrt{s}=14\,{\rm TeV}$. Standard cuts and $P_{{\rm T}}(l^\prime\bar{l^\prime})>300\,{\rm GeV}$ are applied.
• Figure 4: Born cross section for the full process ${\rm p}$ p${\rm p}$ p$\to l\nu_ll^\prime\bar{l^\prime}$ at $\sqrt{s}=14\,{\rm TeV}$ as a function of the cut on the transverse momentum of the reconstructed ${\rm Z}$ Z$$ boson. Standard cuts are applied.
• Figure 5: Born cross section for the process ${\rm p}$ p${\rm p}$ p$\to l\nu_ll^\prime\bar{l^\prime}$ at $\sqrt{s}=14\,{\rm TeV}$ as a function of the upper cut $M^{{\rm cut}}$ on the two invariant masses, $M(ij)$, of the leptonic pairs which could reconstruct ${\rm W}$ W$$ and ${\rm Z}$ Z$$ bosons, as explained in the text. Standard cuts and $P_{{\rm T}}(l^\prime\bar{l^\prime})>800\,{\rm GeV}$ are applied.