Conveners
Monte Carlo, MB & UE
- Guy Paic (Universidad Nacional Autonoma (MX))
Monte Carlo, MB & UE
- Valentina Mariani (Universita e INFN, Perugia (IT))
Monte Carlo, MB & UE
- Philip Ilten (University of Birmingham (GB))
Monte Carlo, MB & UE
- There are no conveners in this block
This talk focuses on the recent implementation of the Mueller dipole formalism in Pythia 8. We show how the dipole formalism can be used to assign spatial vertices to the MPIs in Pythia 8. This allows us to study geometric quantities such as initial state eccentricities, connected to flow coefficients measured at the LHC. In this work we show comparisons to pp, pPb and PbPb data from the LHC...
New measurements on particle production as a function of the charged-particle multiplicity in pp collisions have been reported by the ALICE Collaboration. The novelty of the results relies on the use of transverse spherocity for event classification in either pencil-like or isotropic events, which turn out to be sensitive to the main hard scattering or underlying event, respectively. Results...
The talk will present the results obtained by the CMS collaboration on minimum bias processes and the so-called underlying event. An overview of what we learned during the whole Run 2 of the LHC will be provided.
The interaction force between Lund strings contributes to the flow effects in high-multiplicity pp and AA collisions. Hence, it is important to know how much push can this force exert on the strings, whose effects might be observed in the system as a whole. In this talk, we present our shoving mechanism implemented in the Lund string model. This mechanism, along with rope hadronization and...
Results from LHCb measuring bulk properties of minimum bias events, as well the inelastic cross-section will be summarized. Using these results, a tuning campaign for Pythia 8, specific to the LHCb fiducial volume, is underway and explores some of the newly available colour reconnection models. Some highlights from this tuning campaign will be presented.
Bose-Einstein correlations of charged hadrons provide a tool to investigate the space-time structure of the hadron emitting source. In CMS we measure charged hadrons over a broad multiplicity range, from a few particles up to about 250 reconstructed charged hadrons in proton-proton collisions 13 TeV. Different analysis techniques were used to investigate the dependence on simulations when...
A new set of CMS underlying-event tunes is presented for the PYTHIA 8 event generator. The tunes use the NNPDF3.1 parton distribution functions at leading (LO), next-to-leading (NLO), or next-to-next-to-leading (NNLO) order in perturbative QCD, and the strong coupling amd PDF evolution at LO or NLO. Comparisons of the predictions of the new tunes are provided for observables sensitive to the...
We present a model for generating spacetime coordinates in the Monte Carlo event generator Herwig 7, and perform colour reconnection by minimizing a boost-invariant distance measure of the system. We compare the model to a series of soft physics observables. We find reasonable agreement with the data, suggesting that pp-collider colour reconnection may be able to be applied in larger systems.
With current large cosmic ray observatories, precise data of extensive air shower cascades is recorded up to primary particle energies of 10^{20}eV. While there is significant progress in understanding cosmic rays in general, and also particle physics in the air shower cascades, there are also tantalizing open questions. The most interesting one is the "muon mystery", which is a strong hint...
Various recent measurements of high-multiplicity pp and p-A collisions at LHC energies have revealed, surprisingly, that these small collision systems exhibit some features of the quark-gluon-plasma, e.g. collective behaviour and strangeness enhancement, formerly thought to be achievable only in heavy-ion collisions. A promising method to narrow down the origin of this behaviour is to study...
Recent progress in the development of the general purpose Monte Carlo generator Herwig 7 will be presented. A focus will be given to progress in modeling underlying event and minimum bias.
The correlation between the near side and transverse side has been studied with Pythia. Strong correlations between the two regions occur at high multiplicities of above dN/deta of 50 charged particles. The changes occurring in the spectra obtained subtracting the transverse side spectra are reported. We conclude that the results indicate the possibility of parton energy loss in pp collisions.
A measurement of charged-particle distributions sensitive to the properties of the
underlying event is presented for an inclusive sample of events containing a Z-boson,
decaying to a muon pair. The measurement is done using proton-proton collision data
collected by the ATLAS experiment at √s=13 TeV. Unfolded differential cross sections
are presented for charged particle multiplicity and...
In this talk, we present four measurements that probe the internal structure of jets using
data collected by the ATLAS experiment. First, a measurement of the properties of jet
fragmentation using charged particle tracks is presented, including charged particle
multiplicity, jet charge, the summed fragmentation function, the momentum transverse
to the jet axis, and the radial profile of...
