201 citations · 907 across the 41 of their papers we have counts for
39 papers · 1 filter
Lossy Lorentz boosts at ultra-relativistic energies: Numerical study and source survey of high-energy physics software
Christian Bierlich
Most high-energy-physics software packages implement Lorentz boosts for themselves. At sufficiently large boosts, these routines can return finite, plausible-looking four-vectors w…
Pythia-Contrib: a modular contribution framework for the Pythia 8 event generator
Benoit Assi, Christian Bierlich, Rikab Gambhir +6
Pythia is a general-purpose Monte Carlo event generator used in particle, astroparticle, and nuclear physics, by theorists and experimentalists, to simulate particle collisions. Be…
The PYTHIA Facility
Christian Bierlich, Leif Lönnblad, Torbjörn Sjöstrand
The development and operation of large-scale particle physics facilities rely not only on accelerators and detectors, but also on sustained, high-precision simulation infrastructur…
HDSense: An efficient method for ranking observable sensitivity
Benoît Assi, Christian Bierlich, Rikab Gambhir +6
Identifying which observables most effectively constrain model parameters can be computationally prohibitive when considering full likelihoods of many correlated observables. This…
Iterative HOMER with uncertainties
Anja Butter, Ayodele Ore, Sofia Palacios Schweitzer +10
We present iHOMER, an iterative version of the HOMER method to extract Lund fragmentation functions from experimental data. Through iterations, we address the information gap betwe…
Simplifying Strangeness Fluctuations through Balance Functions in Proton-Proton Collisions
Christian Bierlich, Peter Christiansen
Recent measurements of event-by-event fluctuations of multistrange baryons and kaons in proton-proton collisions by ALICE have been proposed as sensitive probes to distinguish betw…
Characterizing the hadronization of parton showers using the HOMER method
Benoit Assi, Christian Bierlich, Philip Ilten +6
We update the HOMER method, a technique to solve a restricted version of the inverse problem of hadronization -- extracting the Lund string fragmentation function from data…
Describing Hadronization via Histories and Observables for Monte-Carlo Event Reweighting
Christian Bierlich, Phil Ilten, Tony Menzo +5
We introduce a novel method for extracting a fragmentation model directly from experimental data without requiring an explicit parametric form, called Histories and Observables for…
Going against the flow: Revealing the QCD degrees of freedom in hadronic collisions
Christian Bierlich, Peter Christiansen, Gösta Gustafson +3
In collisions between heavy nuclei, such as those at the Large Hadron Collider (LHC) at CERN, hydrodynamic models have successfully related measured azimuthal momentum anisotropies…
Robust Independent Validation of Experiment and Theory: Rivet version 4 release note
Christian Bierlich, Andy Buckley, Jonathan Butterworth +5
The Rivet toolkit is the primary mechanism for phenomenological preservation of collider-physics measurements, containing both a computational core and API for analysis implementat…
A test of strangeness quantum number conservation in proton-proton collisions
Christian Bierlich, Stefano Cannito, Valentina Zaccolo
The study delves into the production of (multi-)strange hadrons in proton-proton collisions at LHC. Novel observables are proposed to distinguish between EPOS4, based on core-coron…
String interactions as a source of collective behaviour
Christian Bierlich
The discovery of collective effects in small collision systems, have spurred a renewed interest in hadronization models, also as a source for collective effects all the way to larg…
Open charm production cross section from combined LHC experiments in collisions at TeV
Christian Bierlich, Jeremy Wilkinson, Jiayin Sun +3
Open charm production in proton-proton collisions represents an important tool to investigate some of the most fundamental aspects of Quantum Chromodynamics, from the partonic mech…
Towards a data-driven model of hadronization using normalizing flows
Christian Bierlich, Phil Ilten, Tony Menzo +5
We introduce a model of hadronization based on invertible neural networks that faithfully reproduces a simplified version of the Lund string model for meson hadronization. Addition…
The dynamic hadronization of charm quarks in heavy-ion collisions
Christian Bierlich, Gösta Gustafson, Leif Lönnblad +1
The PYTHIA8/ANGANTYR model for heavy ion collisions was recently updated with a mechanism for \textit{global colour reconnection}. The colour reconnection model used is QCD colour…
Reweighting Monte Carlo Predictions and Automated Fragmentation Variations in Pythia 8
Christan Bierlich, Philip Ilten, Tony Menzo +5
This work reports on a method for uncertainty estimation in simulated collider-event predictions. The method is based on a Monte Carlo-veto algorithm, and extends previous work on…
Strangeness enhancement across collision systems without a plasma
Christian Bierlich, Smita Chakraborty, Gösta Gustafson +1
We present novel rope hadronization results for strange hadron enhancement in pp, pPb, and PbPb collisions using PYTHIA/Angantyr at LHC energies. With the rope model for string fra…
A comprehensive guide to the physics and usage of PYTHIA 8.3
Christian Bierlich, Smita Chakraborty, Nishita Desai +11
This manual describes the PYTHIA 8.3 event generator, the most recent version of an evolving physics tool used to answer fundamental questions in particle physics. The program is m…
Data and Analysis Preservation, Recasting, and Reinterpretation
Stephen Bailey, Christian Bierlich, Andy Buckley +15
We make the case for the systematic, reliable preservation of event-wise data, derived data products, and executable analysis code. This preservation enables the analyses' long-ter…
Jet modifications from colour rope formation in dense systems of non-parallel strings
Christian Bierlich, Smita Chakraborty, Gösta Gustafson +1
We revisit our rope model for string fragmentation that has been shown to give a reasonable description of strangeness and baryon enhancement in high-multiplicity pp events at the…
Hyperfine splitting effects in string hadronization
Christian Bierlich, Smita Chakraborty, Gösta Gustafson +1
We revisit the recipe for hadron formation in the Lund string hadronization model. Given an incoming quark or quark-diquark pair, weights for hadron formation are updated to take h…
Hadronic Rescattering in pA and AA Collisions
Christian Bierlich, Torbjörn Sjöstrand, Marius Utheim
In a recent article we presented a model for hadronic rescattering, and some results were shown for pp collisions at LHC energies. In order to extend the studies to pA and AA colli…
Setting the string shoving picture in a new frame
Christian Bierlich, Smita Chakraborty, Gösta Gustafson +1
Based on the recent success of the \angantyr model in describing multiplicity distributions of the hadronic final state in high energy heavy ion collisions, we investigate how far…
New opportunities at the photon energy frontier
Jaroslav Adam, Christine Aidala, Aaron Angerami +72
Ultra-peripheral collisions (UPCs) involving heavy ions and protons are the energy frontier for photon-mediated interactions. UPC photons can be used for many purposes, including p…