Related papers: Measurement of the Underlying Event and Minimum Bi…
The Large Hadron Collider (LHC) at CERN in Geneva (Switzerland) will go in operation in the coming months and will soon enable us to analyze the highest energy collisions ever produced at an accelerator. Beyond Standard Model searches at…
Measurements of Underlying Event activity using proton-proton collision data collected by the CMS detector will be presented. To check the energy dependence of the underlying event activity, results are compared with previous measurements…
Experimental measurements of observables sensitive to the underlying event (UE) in $Z$-boson events have been performed by both ATLAS and CMS experiments at the LHC. However, in the busy LHC environment, these observables receive…
New sets of parameters ("tunes") for the underlying-event (UE) modeling of the PYTHIA8, PYTHIA6 and HERWIG++ Monte Carlo event generators are constructed using different parton distribution functions. Combined fits to CMS UE proton-proton…
We present recent results on Minimum Bias, MPI and DPS, Diffractive and Exclusive studies using data collected during Run 1 of the LHC. The measurements include data collected in pp collisions at $\sqrt s = 7$, and $8$ TeV by the CMS…
This chapter summarizes minimum-bias measurements at the Large Hadron Collider. In particular, the pseudorapidity density, the transverse-momentum spectra, the multiplicity distribution, the correlation of average transverse momentum and…
For comparison of inclusive jet cross sections measured at hadron-hadron colliders to next-to-leading order (NLO) parton-level calculations, the energy deposited in the jet cone by spectator parton interactions must first be subtracted. The…
From particle identification to the discovery of the Higgs boson, deep learning algorithms have become an increasingly important tool for data analysis at the Large Hadron Collider (LHC). We present an innovative end-to-end deep learning…
Recent measurements dedicated to improving the understanding of modelling top quark pair (${\text{t}\overline{\text{t}}}$) production at the LHC are summarised. These measurements, performed with proton-proton collision data collected by…
The early physics program at the ATLAS experiment includes measuring the basic properties of proton proton collisions, such as charged particle multiplicities, in order to constrain phenomenological models of soft interactions in the LHC…
There is strong theoretical motivation for the study of events with 2 same-sign leptons, jets, and missing transverse energy (MET) at the Large Hadron Collider (LHC). There are many compelling models, for instance, supersymmetry and extra…
In view of the approaching LHC operation the feasibility and accuracy of QCD measurements with the CMS experiment at the Large Hadron Collider (LHC) involving hadrons and jets are discussed. This summary is based on analyses performed at…
We define a new set of observables to probe the structure of the underlying event in hadron collisions. We use the conventional definition of the `transverse region' in jet events and, for a fixed window in jet $p_\perp$, propose to measure…
We summarise the motivation for, and the status of, the tools developed by CEDAR/MCnet for validating and tuning Monte Carlo event generators for the LHC against data from previous colliders. We then present selected preliminary results…
The analysis of the momentum difference between charged hadrons in high-energy proton-proton collisions is performed in order to study coherent particle production. The observed correlation pattern agrees with a model of a helical QCD…
This paper presents measurements of charged-particle distributions sensitive to the properties of the underlying event in events containing a $Z$ boson decaying into a muon pair. The data were obtained using the ATLAS detector at the LHC in…
Recent CMS soft QCD results in proton-proton collisions at three LHC center-of-mass energies are highlighted. The properties of minimum bias events such as charged particle transverse momentum spectra, event-by-event multiplicity…
Soft QCD contributes to all observables at the LHC, due to the presences of underlying event (UE) and pile-up in all events. Both these processes are dominated by multi-parton interactions (MPI), i.e. the result of proton collisions…
Event-shape observables measured using charged particles in inclusive $Z$-boson events are presented, using the electron and muon decay modes of the $Z$ bosons. The measurements are based on an integrated luminosity of $1.1 {\rm fb}^{-1}$…
Distributions sensitive to the underlying event are studied in events containing one or more charged-particle jets produced in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector at the Large Hadron Collider (LHC). These measurements…