Leptoquark Pair Production in Hadronic Interactions

TL;DR

This paper computes the pair-production cross sections of scalar and vector leptoquarks in hadronic collisions within a model-independent framework governed by gluon couplings, including anomalous vector couplings $κ_G$ and $λ_G$. It derives complete partonic cross sections for $gg$ and $qar{q}$ initial states, employing a factorization of color-group and Lorentz structures, and extends the results to hadronic environments by convolving with parton densities and incorporating direct and resolved photon contributions for ep and γγ-initiated processes. The authors provide extensive numerical predictions for Tevatron and LHC energies and discuss how cross sections and distributions depend on $M_ ext{LQ}$ and the anomalous couplings, highlighting regions where the cross section is minimized or enhanced. They also present projected discovery reach across multiple collider modes, including future $e^+e^-$ and γγ colliders, showing that hadron colliders offer the broadest mass reach while photon- and lepton-based facilities provide complementary sensitivity, especially for higher leptoquark charges. Overall, the work establishes a largely gauge-driven, model-independent framework for leptoquark searches and mass bounds across current and future high-energy colliders.

Abstract

The scalar and vector leptoquark pair production cross sections in hadronic collisions are calculated. In a model independent analysis we consider the most general C and P conserving couplings of gluons to both scalar and vector leptoquarks described by an effective low--energy Lagangian which obeys SU(3)_c invariance. Analytrical expressions are derived for the differential and integral scattering cross sections including the case of anomalous vector leptoquark couplings, $κ_G$ and $λ_G$, to the gluon field. Numerical predictions are given for the kinematic range of the TEVATRON and LHC. The pair production cross sections are also calculated for the resolved photon contributions to $ep \rightarrow e \overlineΦ ΦX$ at HERA and LEP $\otimes$ LHC, and for the process $γγ\rightarrow Φ\overline ΦX$ at possible future $e^+e^-$ linear colliders and $γγ$ colliders. Estimates of the search potential for scalar and vector leptoquarks at present and future high energy colliders are given.