Estimated constraints on t-channel Leptoquark exchange from LHC contact interaction searches

Understand

The t-channel exchange of a first generation leptoquark could contribute to the cross-section for q q-bar to e+e-.

• The leptoquark is off-shell, so this process can be sensitive to leptoquarks beyond the mass reach of pair production searches at the LHC (currently m_{LQ}> 830 GeV).
• We attempt to analytically translate ATLAS bounds on $ (\bar{q} \gamma ^\mu q) (\bar{e} \gamma _\mu e) $ contact interactions to the various scalar leptoquarks, and obtain a bound on their quark-lepton coupling of order $\lambda^2 \leq (m_{LQ}/2$ TeV)$^2$.
• The greatest difficulty in this translation is that the leptoquarks do not induce the contact interaction studied by ATLAS, so the interference with the Standard Model is different.