Using Drell-Yan to probe the underlying event in Run II at Collider Detector at Fermilab (CDF)

Tuning Monte Carlo generators: The Perugia tunes

“…Tuning to one and predicting the other is therefore not only feasible but simultaneously a powerful cross-check on the universality properties of the modelling. Additional important quantities to consider for further model tests and tuning would be event shapes at hadron colliders [52,68], observables involving explicit jet reconstructionincluding so-called "charged jets" [22] (a jet algorithm run on a set of charged tracks, omitting neutral energy), which will have fluctuations in the charged-to-neutral ratio overlaid on the energy flow and therefore will be more IR than full jets, but still less so than individual particles, and "EM jets" (a jet algorithm run on a set of charged tracks plus photons), which basically adds back the π 0 component to the charged jets and hence is less IR sensitive than pure charged jets while still remaining free of the noisy environment of hadron calorimeters -explicit underlyingevent, fragmentation, and jet structure (e.g., jet mass, jet shape, jet-jet separation) observables in events with jets [7,[21][22][23][24][25]51,[69][70][71][72][73][74], photon + jet(s) events (including the important γ + 3-jet signature for double-parton interactions [9,11]), Drell-Yan events [21,74,75], and observables sensitive to the initial-state shower evolution in DIS (see, e.g., [38,76]). …”

The Development of MPI Modeling in Pythia

“…Notable is the CDF study on the production of γ + 3 jets [77], which came to be the first generally accepted proof of the existence of DPS. Studies of the pedestal effect eventually also became quite sophisticated [78][79][80][81], providing differential information on activity in towards, away and transverse regions in azimuth relative to the trigger, including a Z 0 trigger. All of these observations were in qualitative agreement with Pythia predictions.…”

root_s_hat_min: a global inclusive variable for determining the mass scale of new physics in events with missing energy at hadron colliders

“…Ideally, this information should be measured from real data, using some Standard Model process as a standard candle. For example, Drell-Yan can provide the relevant information for a q q initial state [59], while t t can be used to study the gg initial state. Alternatively, one may calculate the ISR effects from first principles in QCD.…”