Computational Tools for High Energy Physics and Cosmology
IP2I, Lyon
Computational Tools for High Energy Physics and Cosmology workshop will be a hybrid in-person/online event at the Institut de Physique des 2 Infinis de Lyon (IP2I), Lyon, France, from Nov 22-26, 2021.
This workshop aims to review the state-of-the-art tools for high energy physics and cosmology.
The workshop consists of short sessions over 5 days together with software demo and several discussion sessions.
The following themes will be covered at the workshop:
- Higgs and Collider physics
- Dark matter
- Cosmology
- Flavour physics and precision tests
- General tools (Fitting tools, recast tools, spectrum generators, etc...)
The program will consist of both invited talks and contributed talks and tutorials.
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Dark MatterConvener: Genevieve Belanger
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1
Welcome and IntroductionSpeaker: Nazila Mahmoudi (Universite Claude Bernard Lyon I (FR))
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2
Review of Dark Matter ToolsSpeaker: Andreas Goudelis (LPTHE - Paris)
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3
Photon-axion oscillations with ELMAG
ELMAG is a Monte Carlo program made to simulate electromagnetic cascades initiated by high-energy photons interacting with the extragalactic background light. Photons propagating in an external magnetic field may further oscillate into axions or axion-like particles (ALPs). We have implemented axions into ELMAG, complementing thereby the usual description of photon-axion oscillations with a Monte Carlo treatment of high-energy photon propagation and interactions. Such oscillations will lead to characteristic features in the energy spectrum of high-energy photons from astrophysical sources that can be used to probe the existence of ALPs. In this talk, the implementation of axions into ELMAG is discussed. Furthermore, the expected signatures of photon-axion oscillations are reviewed and the importance of a proper treatment of magnetic fields are stressed.
Speakers: Michael Kachelriess, Mr Jonas Tjemsland (NTNU) -
12:30
Break
- 4
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5
Studying dark matter with MadDM: Lines and loops
Automated tools for the computation of amplitudes and cross sections have become the backbone of phenomenological studies beyond the standard model. We present the latest developments in MadDM, a calculator of dark-matter observables based on MadGraph5_aMC@NLO. The new version enables the fully automated computation of loop-induced annihilation processes, relevant for indirect detection of dark matter. Of particular interest is the electroweak annihilation into $\gamma X$, where $X=\gamma$, $Z$, $h$ or any new unstable particle even under the dark symmetry. These processes lead to the sharp spectral feature of monochromatic gamma lines: a smoking-gun signature for dark matter annihilation in our Galaxy. MadDM provides the predictions for the respective fluxes near Earth and derives constraints from the gamma-ray line searches by Fermi-LAT and HESS. As an application, we present the implications for the parameter space of the Inert Doublet model and a top-philic $t$-channel mediator model.
Speaker: Daniele Massaro (Alma Mater Studiorum - Università di Bologna / Université Catholique de Louvain) -
6
Estimating QCD uncertainties on anti-proton spectra from dark-matter annihilation
In this talk, I discuss the progress on the particle physics modeling of anti-proton spectra from dark matter indirect detection searches and the QCD uncertainties on these predictions. First, I discuss the challenges in the measurements of baryon differential yields at LEP and the way we used to deal with these. Then, we discuss the up-to date fits of the fragmentation function including baryon component and the resulting QCD uncertainties. The results of this study will be published on Zenodo and GitHub.
Speaker: Dr Adil Jueid (Korea Institute for Advanced Study) -
7
DarkHistorySpeaker: Hongwan Liu (Massachusetts Institute of Technology)
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1
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Tutorials and demos
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8
Tutorial for SuperIso Relic In-Person: Amphi Dirac (Online: main zoom room)
In-Person: Amphi Dirac
Online: main zoom room
Speaker: Alexandre Arbey (Lyon U. & CERN TH) -
9
Tutorial for MicrOMEGAs In-person: Amphi Dirac (Online: secondary zoom room)
In-person: Amphi Dirac
Online: secondary zoom room
Speaker: Alexander Pukhov (SINP, MSU)
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8
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Higgs, Flavour and PrecisionConvener: Nishita Desai (Tata Institute of Fundamental Research)
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10
Review on Higgs ToolsSpeaker: Heidi Rzehak (Paul-Scherrer-Institut)
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11
Two-loop Prediction of the Anomalous Magentic Moment of the Muon in the Two-Higgs Doublet Model with GM2Calc 2
We present an extension of the $\texttt{GM2Calc}$ software to perform the calculation of new physics contributions to the anomalous magnetic moment of the muon ($a_\mu^\text{BSM}$) for the two-Higgs doublet model (2HDM). The 2HDM is one of the simplest and phenomenologically-rich extensions of the Standard Model. It is one of the few single field extensions that can give large contributions to the anomalous magnetic moment of the muon. In particular it has been shown that the inclusion of two-loop corrections are essential and when included this model can explain the long standing discrepancy between the Standard Model prediction and the experimental measurement. We implement all significant two-loop contributions for the general, flavour violating, 2HDM as well as for the flavour aligned 2HDM and the type I, II, X and Y flavour conserving variants. $\texttt{GM2Calc}$ 2 also provides an uncertainty estimate of the two-loop calculation of $a_\mu^\text{BSM}$ in the 2HDM. Input parameters can be provided in either the gauge basis or the mass basis, and we provide an easy to use command-line input with an SLHA-like interface to specify these. The interface also allows one to select between different 2HDM types and choose which corrections to apply. In addition we also provide interfaces in C++, C, $\texttt{Python}$ and $\texttt{Mathematica}$, to make it easy to interface to other codes. Thus, $\texttt{GM2Calc}$ 2 can be used as a standalone tool for studies of $a_\mu$ in the 2HDM, or to explore the 2HDM phenomenology more broadly it can be used in combination with other codes via its interfaces.
Speaker: Douglas Jacob (Monash University) - 12
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13
Likelihood analysis of the general 2HDM with Gambit's FlavBit
We present a likelihood analysis of the general two Higgs doublet model, using the most important currently measured flavour observables, in view of the anomalies in charged current tree-level and neutral current one-loop rare decays of $B$ mesons in $b\to c l \overline{\nu}$ and $b\to s\mu^{+}\mu^{-}$ transitions, respectively. Our analysis predicts values for $\mathrm{BR}(h\to \tau\mu)$ between $10^{-2}$ and $10^{-4}$ which are within the future sensitivity at the High Luminosity LHC. We also find that the predictions for the $\tau\rightarrow3\mu$ and $\tau\to\mu\gamma$ decays are well within the projected limits at the Belle II experiment with a discovery potential for $\mathrm{BR}(\tau\rightarrow3\mu)\sim 10^{-9}$ and $\mathrm{BR}(\tau\rightarrow\mu\gamma)\sim 10^{-9}-10^{-8}$. Using the latest measurement of the Fermilab Muon $g-2$ Collaboration, we also perform a simultaneous fit to the muon anomalous magnetic moment and both observables related to flavour changing currents and leptonic decays of mesons, finding solutions at the $1\sigma$ level.
Speaker: Cristian Felipe Sierra Fonseca (Monash University) -
10:30
Break
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14
EOS: A High-Energy Physics Software for Flavour Observables
EOS is an open-source software for a variety of computational tasks in flavour physics. Its use cases include theory predictions within the Standard Model (SM) of particle physics and beyond, inference of theory parameters from experimental or theoretical likelihoods, and simulation of pseudo events for a number of signal processes. EOS ensures high performance computations through a C++ backend and ease of usability through a Python frontend.
In this interactive tutorial we provide Jupyter Python notebooks that introduce the basic EOS classes and provide examples for each of the three use cases.Speaker: Meril Reboud (TUM) -
15
HiggsTools: a toolbox for BSM scalar phenomenology
The codes HiggsBounds and HiggsSignals compare model predictions of BSM models with extended scalar sectors to searches for additional scalars and measurements to the 125GeV Higgs boson. We present a unification and extension of the functionalities provided by both codes into the new HiggsTools framework. The codes have been re-written in modern C++ with a native python interface for easy interactive use. We discuss the user interface for providing model predictions, now part of the new sub-library HiggsPredictions, which also provides access to many tabulated cross sections and BRs in reference models such as the SM. HiggsBounds now implements experimental limits purely through json data files and can better handle clusters of BSM particles of similar mass, even for complicated search topologies. In HiggsSignals, the treatment of different types of measurements has been unified, both in the χ2 computation and in the data file format used to implement experimental results.
Speaker: Jonas Wittbrodt (Lund University) -
16
Higgs-mass predictions with FeynHiggs
FeynHiggs is a public tool for the prediction of Higgs-boson properties in the Minimal Supersymmetric Standard Model (MSSM). Focussing on the mass of the SM-like Higgs, I will discuss the status and recent developments of FeynHiggs. In the effective-field-theory calculation, this includes improvements that are relevant for multi-scale hierarchies, addressing the case where the gluino is much heavier than the sfermions and the case of non-SM-like light Higgs bosons. In the fixed-order calculation, this concerns a complete overhaul of the two-loop corrections, significantly improving numerical stability and thus enhancing the range of applicability for scenarios with heavy SUSY particles.
Speaker: Sebastian Paßehr (RWTH Aachen University)
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10
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Tutorials and demos
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17
Tutorial for GUM/GAMBIT In-Person: Amphi Dirac (Online: main zoom room)
In-Person: Amphi Dirac
Online: main zoom room
Speaker: Christopher Chang (The University of Queensland)
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17
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Tutorials and demos
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18
Tutorial for HiggsTools In-Person: Amphi Dirac (Online: main zoom room)
In-Person: Amphi Dirac
Online: main zoom room
Speaker: Jonas Wittbrodt (Lund University) -
19
Tutorial for EOS In-Person: Amphi Dirac (Online: secondary zoom room)
In-Person: Amphi Dirac
Online: secondary zoom room
Speakers: Meril Reboud (TUM), Meril Reboud (Centre National de la Recherche Scientifique (FR))
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18
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CosmologyConvener: Alexandre Arbey (Lyon U. & CERN TH)
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20
Review on Tools for Cosmological Phase TransitionsSpeaker: Graham White
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21
Overview on CMB CodesSpeaker: Antony Lewis (University of Sussex)
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22
Beyond the Standard Model with BlackHawk v2.0
We will present the new version of BlackHawk v2.0. BlackHawk is a public code designed to compute the Hawking radiation spectra of (primordial) black holes. In the version 2.0, we have added several non-standard black hole metrics: charged, higher dimensional and polymerized black holes, on top of the usual rotating (Kerr) black holes. BlackHawk also embeds some additional scripts and numerical tables that can prove useful in e.g. dark matter studies. We will describe these new features and provide some examples of the capabilities of the code, with an overview of the work already published.
Speaker: Jérémy Auffinger (Institut de Physique des 2 Infinis - Lyon - FRANCE) -
10:20
Buffer for overruns or discussions
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10:30
Break
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23
MiMeS, the Misalignment Mechanism Solver
We introduce a C++ header-only library that is used to solve the axion equation of motion, MiMeS. MiMeS makes no assumptions regarding the cosmology and the mass of the axion, which allows the user to consider various cosmological scenarios and axion-like models. MiMeS also includes a convenient python interface that allows the library to be called without writing any code in C++, with minimal overhead.
Speaker: Dimitrios Karamitros (Manchester University) -
24
A new cosmic muon generator for cosmic-ray muon applications
Cosmic rays, thanks to their ubiquity and high penetration capability, have been successfully used in scientific research ever since their discovery.
As soon as their knowledge improved, applications in the civil/environmental field were also developed: muon radiography (or muography, based on the flux attenuation) and muon tomography (based on the scattering angle) have been used to study the inner structure of volcanoes, to seek hidden rooms in Egyptian pyramids, to search for heavy metals in containers, and so on.
And besides these imaging techniques, cosmic ray muons are also widely used for detector testing and alignment practically in every Nuclear Physics or Particle Physics experiment.Since most of these applications are sensitive to the angular and momentum distribution of cosmic muons, an accurate modelling of these distributions is a key feature for any generation tool conceived to simulate the cosmic muon flux. This can make the generator quite time-consuming, which is a strong limit when one needs to reach high statistics or to study large structures.
A new Monte Carlo generator for cosmic-ray muons, named Efficient COsmic MUon Generator (EcoMug for short), especially designed to be fast ($\gtrsim 10^5$ muons generated per second on a standard machine) without losing accuracy, is presented here. It is written as a header-only C{}\texttt{++}11 library, ready to be integrated into whatever C{}\texttt{++} code, in particular C{}\texttt{++} code based on Geant4 simulation tool. By default, EcoMug relies on a simple and effective parametrisation of the experimental data of cosmic ray differential flux at sea level, taken from the literature, but the library is written in such a way that every user can easily replace it with his own user-defined parametrisation.
Unlike other tools, EcoMug is able to generate muons from different kind of surfaces (plane, cylinder and half-sphere), while keeping the correct angular and momentum distribution of generated tracks inside a fiducial volume. This allows to optimise the generation surface according to the system under study, and leads to a further improvement of the overall simulation efficiency.
In this contribution we will present the main features of EcoMug, starting from its mathematical foundation, and eventually showing some interesting applications.
References
D. Pagano, G. Bonomi, A. Donzella, A. Zenoni, G. Zumerle and N. Zurlo \
EcoMug: An Efficient COsmic MUon Generator for cosmic-ray muon applications \
Nucl.Instrum.Meth. A 1014 (2021) 165732Speaker: Nicola Zurlo (Università degli Studi di Brescia & INFN Sezione di Pavia (IT)) -
25
DarkSUSY 6: beyond supersymmetric dark matter
I will present an overview of the widely used DarkSUSY package, with a focus on recent
developments. DarkSUSY is a highly modular and flexible library of numerical routines
to accurately compute a variety of astrophysical signals from dark matter, both in
supersymmetric and other particle physic models. This includes direct detection
rates in low-background counting experiments and indirect detection through antiprotons,
antideuterons, gamma-rays and positrons from the Galactic halo, or high-energy
neutrinos from the center of the Earth or the Sun. High-precision tools are
furthermore provided for the computation of the relic density in the Universe today,
including situations where the dark matter particles reside in a secluded dark
sector or when chemical and kinetic decoupling are intertwined. The most recent
major update, DarkSUSY 6.3, adds the possibility of computing the abundance of
feebly interacting dark matter particles through the freeze-in mechanism.Speaker: Torsten Bringmann
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20
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Tutorials and demos
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26
Tutorial for BlackHawk In-Person: Amphi Dirac (Online: main zoom room)
In-Person: Amphi Dirac
Online: main zoom room
Speaker: Jérémy Auffinger (Université Claude Bernard Lyon 1) -
27
Tutorial for CLASS In-Person: Amphi Dirac (Online: secondary zoom room)
In-Person: Amphi Dirac
Online: secondary zoom room
Speaker: Nils Schöneberg -
28
Tutorial for DarkSUSY In-Person: Amphi Dirac (Online: main zoom room)
In-Person: Amphi Dirac
Online: main zoom room
Speaker: Torsten Bringmann (University of Oslo (NO))
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26
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ColliderConvener: Robert Valentin Harlander (Rheinisch Westfaelische Tech. Hoch. (DE))
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29
Review on NNLO matching and parton showersSpeaker: Marius Wiesemann (Max Planck Society (DE))
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30
Review on LHC Recasting ToolsSpeaker: Sabine Kraml (LPSC Grenoble)
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31
Recasting long-lived particle searches at the LHC with CheckMATE 2
In this talk, we will give a brief overview of CheckMATE 2 and discuss recent developments. In particular, we present the implementation of four types of long-lived particle searches, viz. displaced leptons, disappearing track, displaced vertex with either muons or with missing transverse energy, and heavy charged tracks. These four categories cover the signatures of a large range
of physics models. We illustrate their potential for exclusion and discuss their mutual overlaps in mass-lifetime space for two simple phenomenological models involving either a $U(1)$-charged or a coloured scalar.Speaker: Zeren Simon Wang (National Tsing Hua University) -
32
Probing long-lived particles with SModelS v2
The new developments in SModelS, an automated tool enabling the fast interpretation of simplified model results from the LHC, make it possible to include a wide range of constraints for long-lived particles and treat them at the same footing as the constraints from prompt searches. We present these new features of SModelS v2.x and the new experimental analyses included in its database. To illustrate how they constrain in particular scenarios with long-lived particles, we show results for scalar or fermionic dark matter in the scotogenic model. Finally, we also report on our SModelS/pyhf interface, allowing the usage of full likelihoods as published by ATLAS.
Speaker: Gael Alguero -
10:40
Break
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33
Rivet and ConturSpeaker: Louie Dartmoor Corpe (CERN)
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34
Collider Phenomenology & LHC Recasting with MadAnalysis 5
In this contribution, we report about the latest developments in MadAnalysis 5 relevant for recasting studies. The recasting interface has been extended to accommodate signal region combinations through full and simplified likelihoods which allow users to calculate more accurate global exclusion limits for new physics. Additionally, we will briefly introduce the new recasting capabilities of MadAnalysis 5 for long-lived particles and currently existing analyses. For this task SFS module within MadAnalysis has been enhanced by a particle propagation module that distorts particle trajectories along a helicoidal path. In addition to recasting, this allows users to design analyses for exotic particles and exploit their unconventional trajectories, which may remain undisturbed under the "fast-particle" assumption.
Speaker: Jack Araz (IPPP - Durham University) -
35
Automated Collider Event Selection, Plotting, & Machine Learning with AEACuS, RHADAManTHUS, & MInOS
A trio of automated collider event analysis tools are described and demonstrated. AEACuS interfaces with the standard MadGraph/MadEvent, Pythia, and Delphes simulation chain, via the Root file output. An extensive algorithm library facilitates the computation of standard collider event variables and the transformation of object groups (including jet clustering and substructure analysis). Arbitrary user-defined variables and external function calls are also supported. An efficient mechanism is provided for sorting events into channels with distinct features. RHADAManTHUS generates publication-quality one- and two-dimensional histograms from event statistics computed by AEACuS, calling MatPlotLib on the back end. Large batches of simulation (representing either distinct final states and/or oversampling of a common phase space) are merged internally, and per-event weights are handled consistently throughout. Arbitrary bin-wise functional transformations are readily specified, e.g. for visualizing signal-to-background significance as a function of cut threshold. MInOS implements machine learning on computed event statistics with XGBoost. Ensemble training against distinct background components may be combined to generate composite classifications with enhanced discrimination, and trained models may be stored or converted into standalone executable code for reapplication. ROC curves, as well as score distribution, feature importance, and significance plots are generated on the fly. Each of these tools is controlled via instructions supplied in a reusable card file, employing a simple, compact, and powerful meta-language syntax.
Speaker: Prof. Joel Walker (Sam Houston State University) -
36
Implementation and benchmarking of a columnar analysis framework for searches of the Higgs boson decays into two muons
The analysis framework developed for searches of the Higgs boson decaying into two muons with CMS detector is presented. The framework showcases the tools for columnar analysis in HEP (coffea package) as well as an efficient job distribution with state of the art scheduling tools (Dask, Apache Spark). The performance of the framework and parallelization of job processing has been studied using a massively parallel Analysis Facility at Purdue University.
Speaker: Dmitry Kondratyev (Purdue University (US))
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29
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Tutorials and demos
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37
Tutorial for Contur In-Person: Amphi Dirac (Online: secondary zoom room)
In-Person: Amphi Dirac
Online: secondary zoom room
Speaker: Louie Dartmoor Corpe (CERN)To prepare for the tutorial:
The tutorial will be run via Docker, so please install Docker on your local machine:
https://docs.docker.com/get-docker/
Then, once you've got the Docker desktop up and running, in advance of the tutorial you will benefit from pulling the CONTUR docker image as follows.
```
docker pull hepstore/contur-herwig:2.1.0-py3
```
and also download the Zip file attached to the agenda.
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38
Tutorial for AEACuS, RHADAManTHUS, & MInOS In-Person: Amphi Dirac (Online: main zoom room)
In-Person: Amphi Dirac
Online: main zoom room
Speaker: Joel Walker (Sam Houston State University)
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37
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General toolsConvener: Tomas Gonzalo (RWTH Aachen)
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39
Review on Statistical Tools and SamplersSpeaker: Will Handley (University of Cambridge)
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40
Nested sampling for frequentist computation: fast estimation of small p-values
We propose (2105.13923) a novel method for computing $p$-values based on nested sampling (NS). The computational cost of NS scales as $\log^2{1/p}$, which compares favorably to the $1/p$ scaling for Monte Carlo (MC) simulations. For significances greater than about $4\sigma$ in both a toy problem and a simplified resonance search, we show that NS requires orders of magnitude fewer simulations than ordinary MC estimates. This is particularly relevant for high-energy physics, which adopts a $5\sigma$ gold standard for discovery.
Speaker: Andrew Fowlie (Nanjing Normal University) - 41
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42
Review on EFT ToolsSpeaker: Ilaria Brivio (University of Heidelberg)
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10:40
Break
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43
GUM and GAMBITSpeaker: Anders Kvellestad (University of Oslo)
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44
scikinC: a tool for deploying machine learning as a binaries
Machine Learning plays a major role in computational phyics providing a mechanism to approximate arbitrarily complex functions with, for example, Artificial Neural Networks and Boosted Decision Trees.
Unfortunately, the integration of machine learning models trained with python frameworks in production code, often developed in C, C++ or FORTRAN, is notoriously a complicated task.
In this contribution we will present scikinC, a transpiler for scikit-learn and keras models into plain C, intended to be compiled into shared objects and dynamically linked to other applications.
Applications to the parametrization of the LHCb detector will be also presented.Speaker: Lucio Anderlini (Universita e INFN, Firenze (IT)) -
45
FlexibleDecay: An automated calculator of scalar decay widths
We present FlexibleDecay, a tool to calculate decays of scalars in an arbitrary BSM model. The tool aims for high precision particularly in the case of Higgs boson decays. In the case of scalar and pseudoscalar Higgs boson decays the known higher order SM QED, QCD and EW effects are taken into account where possible. The program works in a modified MSbar scheme that exhibits a decoupling property with respect to heavy BSM physics, with BSM parameters themselves treated in the MSbar/DRbar-scheme allowing for an easy connection to high scale tests for, e.g., perturbativity and vacuum stability, and the many observable calculations readily available in MSbar/DRbar programs. Pure BSM effects are taken into account at the leading order, including all one-loop contributions to loop-induced processes. The program is implemented as an extension to FlexibleSUSY, which determines the mass spectrum for arbitrary BSM models, and does not require any extra configuration from the user.
Speaker: Wojciech Kotlarski (TU - Dresden) -
46
NPointFunctions: a calculator of amplitudes and observables in FlexibleSUSY
We present NPointFunctions, a package to calculate any desired one-loop amplitudes for an arbitrary BSM model. It aims to be customizable, modular and extensible with additional process- or amplitude- dependent contributions. The program relies on the SARAH-generated output used with FeynArts/FormCalc packages, embedded in an appropriate way. The resulting tool is an extension to FlexibleSUSY, a generator of spectrum generator programs. Currently, several LFV processes were already implemented, which, in addition to some modifications to the basic FlexibleSUSY workflow, will be discussed.
Speaker: Uladzimir Khasianevich (TU Dresden)
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39
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Tutorials and demos
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47
Tutorial for scikinC In-Person: Amphi Dirac (Online: main zoom room)
In-Person: Amphi Dirac
Online: main zoom room
Speaker: Lucio Anderlini (Universita e INFN, Firenze (IT))
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47
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