The physics potential of the LHC depends heavily on our ability to provide accurate simulations of both signal and background processes. The process of running full NLO-events plus a shower plus detector simulation plus cuts is, however, a lengthy one. In order to avoid re-running the entire sequence for the MSSM, anomalous HVV couplings, or for a spin-2 particle, as opposed to a Standard Model (SM) Higgs boson, it was proposed that SM Higgs events were simply reweighted for different BSM scenarios. REPOLO – REweighting POwheg events at Leading Order – uses the VBFNLO framework and reweights each SM event by a factor \begin{eqnarray} \frac{|\mathcal{M}_{\text{BSM}}|^{2}}{|\mathcal{M}_{\text{SM}}|^{2}} . \nonumber \end{eqnarray}

The method does, however, have severe limitations, as a single event with a high reweighting factor (i.e. where $|\mathcal{M}_{\text{SM}}|^{2} \ll |\mathcal{M}_{\text{BSM}}|^{2}$) can destroy a distribution. This means that, in practice, only SM-like distributions can be safely reweighted using REPOLO.

Due to this limitation, REPOLO is only semi-public. To obtain a copy of the source code, please email

** vbfnlo(at)particle.uni-karlsruhe.de **

so that we can discuss whether REPOLO is a suitable tool for the situation.

The REPOLO manual is available here.