172 citations · 290 across the 25 of their papers we have counts for
31 papers · 1 filter
New parton distribution functions of the real photon
Madhav Chithirasreemadam, Vadim Guzey, Felix Hekhorn +2
Precise determination of the partonic structure of real photons has attracted renewed interest in view of ongoing studies of high-energy photon-induced processes in ultraperipheral…
Taking dimuon production in DIS to NNLO precision
Ilkka Helenius, Hannu Paukkunen, Sami Yrjänheikki
We present an updated calculation of dimuon production in neutrino-nucleus collisions - an important constraint of the relatively poorly-known strange-quark distribution - at next-…
Multiplicative NLO matching in DIS with Pythia 8
Ilkka Helenius, Joni O. Laulainen, Christian T. Preuss
We present a new multiplicative next-to-leading order (NLO) matching scheme in Pythia 8 for deep-inelastic scattering (DIS) processes in electron-proton collisions. The implementat…
Associated + charm production: indications for PDF analysis
Ville Alanko, Ilkka Helenius, Hannu Paukkunen
The strange quark and antiquark contents of the proton remain weakly constrained compared to the other light quarks, particularly the asymmetry between the two. Production of a $W^…
Towards new D meson fragmentation functions
Manuel Epele, Felix Hekhorn, Ilkka Helenius +2
The Heavy Meson (Hymn) collaboration presents a new extraction of D meson fragmentation functions using experimental data from LEP and LHC. We focus particularly on kinematical reg…
Simultaneous production of a boson and a charmed hadron at the LHC in general-mass variable-flavour-number scheme
Ville Alanko, Ilkka Helenius, Hannu Paukkunen
The simultaneous production of a boson and a charmed hadron in proton-proton collisions offers a potential probe for constraining the strange quark parton distribution func…
VALO1.0: New real-photon parton distributions with Monte Carlo uncertainties
Madhav Chithirasreemadam, Vadim Guzey, Felix Hekhorn +2
Performing a global QCD analysis of data on the photon structure function in scattering, we determine new leading order (LO) and next-to-leading (NLO) parton…
Inclusive charm and bottom quark pair production cross sections at hadron colliders at next-to-next-to-leading-order accuracy
David d'Enterria, Felix Hekhorn, Ilkka Helenius +2
The inclusive cross sections for charm () and bottom () quark-antiquark pair production in proton-proton, proton-a…
Multiplicative matching of neutral current deep-inelastic scattering processes at next-to-leading order in PYTHIA 8
Ilkka Helenius, Joni O. Laulainen, Christian T. Preuss
We introduce a method for matching the neutral-current deep inelastic scattering process with parton showers in Pythia 8, at first order in the strong coupling. The implementation,…
Dimuon production in neutrino-nucleus collisions at next-to-next-to-leading order in perturbative QCD
Ilkka Helenius, Hannu Paukkunen, Sami Yrjänheikki
Charm production in charged-current neutrino-nucleus deep-inelastic scattering (DIS), measured through dimuon final states, remains an important constraint of strangeness in global…
Dimuon production in DIS with charm-mass effects
Ilkka Helenius, Hannu Paukkunen, Sami Yrjänheikki
Dimuon production in neutrino-nucleus collisions, an important constraint of strangeness in global parton distribution function analyses, is typically calculated by assuming it to…
Improving the description of dimuon production in neutrino-nucleus collisions using the SACOT- scheme
Hannu Paukkunen, Ilkka Helenius, Sami Yrjänheikki
Dimuon production in deeply inelastic scattering between neutrinos and nuclei plays an important role in constraining the strange-quark parton distribution functions (PDFs). Here,…
Multi-Jet Production in Deep Inelastic Scattering with Pythia
Ilkka Helenius, Joni O. Laulainen, Christian T. Preuss
We introduce multi-jet merging for deep inelastic scattering in the Vincia parton shower in the Monte Carlo event generator Pythia 8. Merging combines event samples of different pa…
Multi-Jet Merging in Deep Inelastic Scattering with Pythia
Joni Laulainen, Ilkka Helenius, Christian T. Preuss
We aim to improve the modelling of deep inelastic scattering by implementing multi-jet merging capabilities in Vincia parton shower in the general-purpose Monte Carlo event generat…
Modelling the underlying event in photon-initiated processes
J. M. Butterworth, I. M. Helenius, J. J. Juan Castella +3
Modelling the underlying event in high-energy hadronic collisions is important for physics at colliders. This includes lepton colliders, where low-virtuality photons accompanying t…
Dijet photoproduction and transverse-plane geometry in ultra-peripheral nucleus-nucleus collisions
Kari J. Eskola, Vadim Guzey, Ilkka Helenius +2
We present new NLO pQCD predictions for the inclusive photoproduction of dijets in ultra-peripheral (UPC) lead-lead collisions at 5.02 TeV with a realistic impact-parameter depende…
Dimuon production in neutrino-nucleus collisions -- the SIDIS approach
Ilkka Helenius, Hannu Paukkunen, Sami Yrjänheikki
Dimuon production is in many global parton distribution function analyses calculated by assuming that it is proportional to inclusive charm production. As this assumption breaks do…
Global fits of proton PDFs with non-linear corrections from gluon recombination
Pit Duwentäster, Vadim Guzey, Ilkka Helenius +1
We present numerical studies of the leading non-linear corrections to the DGLAP evolution equations of parton distribution functions (PDFs) resulting from gluon recombination, whic…
Les Houches 2023: Physics at TeV Colliders: Standard Model Working Group Report
J. Andersen, B. Assi, K. Asteriadis +81
This report presents a short summary of the activities of the "Standard Model" working group for the "Physics at TeV Colliders" workshop (Les Houches, France, 12-30 June, 2023).
Hadron-ion collisions in Pythia and the vector-meson dominance model for photoproduction
Ilkka Helenius, Marius Utheim
We present an extension to the Pythia Monte Carlo event generator that enables simulations of collisions between a generic hadron beam on a nuclear target with energy variation in…
Photoproduction in general-purpose event generators
Ilkka Helenius, Peter Meinzinger, Simon Plätzer +1
We compare the three general-purpose Monte Carlo event generators, HERWIG, PYTHIA, and SHEPRA for jet photoproduction processes in and collisions. Due to the lower en…
Dimuons from neutrino-nucleus collisions in the semi-inclusive DIS approach
Ilkka Helenius, Hannu Paukkunen, Sami Yrjänheikki
We present a next-to-leading order perturbative QCD calculation of dimuon production in neutrino-nucleus collisions. This process is typically calculated by assuming it to be propo…
Spatial resolution of dijet photoproduction in near-encounter ultraperipheral nuclear collisions
Kari J. Eskola, Vadim Guzey, Ilkka Helenius +2
We present next-to-leading order perturbative QCD predictions for inclusive dijet photoproduction in ultra-peripheral nucleus-nucleus collisions (UPCs) within the impact-parameter…
Proton PDFs with non-linear corrections from gluon recombination
Pit Duwentäster, Vadim Guzey, Ilkka Helenius +1
We present numerical studies of the leading non-linear corrections to the Dokshitzer-Gribov-Lipatov-Altarelli-Parisi evolution equations of parton distribution functions (PDFs) res…