arXiv subjects

Gerardo Ganis

Publications and source records attributed to Gerardo Ganis.

At least 19 recordsLinked to original sources

arXiv2026

LEP Data@EDM4hep: mitigating data loss risks by increasing data FAIRness, with a view on FCC-ee

The LEP data represents the most precise and highest centre-of-mass energy sample of $e^+e^-$ collision data collected to date. Numerous scientific articles have been published since the conclusion of the experiments, underscoring the ongoing relevance of this dataset and the need to secure its long-term availability according to FAIR data preservation principles. These data could also play a crucial new role in the context of the evaluation of the physics potential of FCC-ee, due to the overlapping centre-of-mass energies, offering a valuable benchmark for detector performance and physics analyses. To fulfill this role, the data should be made available in EDM4hep, the standardized event data format currently developed in the context of the common HEP software ecosystem Key4hep. Migrating to EDM4hep would not only beneficial to future studies but also significantly mitigate the risk of data loss, increase accessibility and interoperability, hence facilitate long-term data preservation. A proof of concept workflow to perform the migration has been developed and successfully applied to ALEPH data.

hep-ex↗

arXiv2026

Modern jet flavour tagging in hadronic Z decays with archived ALEPH data

We present a reanalysis of archived data from the ALEPH experiment at LEP in the $\mathrm{Z \to q\bar{q}}$ final state. We apply modern jet flavour tagging techniques to improve the separation between the different hadronic decay channels of the Z boson, achieving up to one order of magnitude improvement in misidentification rate for b- and c-quark jets compared to the legacy algorithms used for the most recent ALEPH results, for the same identification efficiency. We also present the first implementation of strange quark jet tagging with LEP data, which allows for the selection of a $\mathrm{Z \to s\bar{s}}$ enriched event sample. These improvements in the flavour tagging performance are achieved by leveraging the lifetime, particle identification, and secondary vertex information, as well as modern classifiers based on a deep learning approach. We also demonstrate the calibration of the tagger in data using a tag-and-probe method, obtaining good data to simulation agreement for all quark flavours. These results pave the way for improved measurements of electroweak precision observables with LEP archived data, and can serve as a guidance for the development of detectors and algorithms for future electron-positron colliders.

hep-ex↗

arXiv2025

Data Preservation in High Energy Physics

Data preservation significantly increases the scientific output of high-energy physics experiments during and after data acquisition. For new and ongoing experiments, the careful consideration of long-term data preservation in the experimental design contributes to improving computational efficiency and strengthening the scientific activity in HEP through Open Science methodologies. This contribution is based on 15 years of experience of the DPHEP collaboration in the field of data preservation and focuses on aspects relevant for the strategic programming of particle physics in Europe: the preparation of future programs using data sets preserved from previous similar experiments (e.g. HERA for EIC), and the use of LHC data long after the end of the data taking. The lessons learned from past collider experiments and recent developments open the way to a number of recommendations for the full exploitation of the investments made in large HEP experiments.

hep-ex↗

arXiv2024

Focus topics for the ECFA study on Higgs / Top / EW factories

In order to stimulate new engagement and trigger some concrete studies in areas where further work would be beneficial towards fully understanding the physics potential of an $e^+e^-$ Higgs / Top / Electroweak factory, we propose to define a set of focus topics. The general reasoning and the proposed topics are described in this document.

hep-ph↗

arXiv2023

The Key4hep software stack: Beyond Future Higgs factories

The Key4hep project aims to provide a turnkey software solution for the full experiment lifecycle, based on established community tools. Several future collider communities (CEPC, CLIC, EIC, FCC, and ILC) have joined to develop and adapt their workflows to use the common data model EDM4hep and common framework. Besides sharing of existing experiment workflows, one focus of the Key4hep project is the development and integration of new experiment independent software libraries. Ongoing collaborations with projects such as ACTS, CLUE, PandoraPFA and the OpenDataDector show the potential of Key4hep as an experiment-independent testbed and development platform. In this talk, we present the challenges of an experiment-independent framework along with the lessons learned from discussions of interested communities (such as LUXE) and recent adopters of Key4hep in order to discuss how Key4hep could be of interest to the wider HEP community while staying true to its goal of supporting future collider designs studies.

hep-ex↗

arXiv2023

Key4hep: Progress Report on Integrations

Detector studies for future experiments rely on advanced software tools to estimate performance and optimize their design and technology choices. The Key4hep project provides a flexible turnkey solution for the full experiment life-cycle based on established community tools such as ROOT, Geant4, DD4hep, Gaudi, podio and spack. Members of the CEPC, CLIC, EIC, FCC, and ILC communities have joined to develop this framework and have merged, or are in the progress of merging, their respective software environments into the Key4hep stack. These proceedings will give an overview over the recent progress in the Key4hep project: covering the developments towards adaptation of state-of-the-art tools for simulation (DD4hep, Gaussino), track and calorimeter reconstruction (ACTS, CLUE), particle flow (PandoraPFA), analysis via RDataFrame, and visualization with Phoenix, as well as tools for testing and validation.

hep-ex↗

arXiv2023

Of Frames and schema evolution -- The newest features of podio

The podio event data model (EDM) toolkit provides an easy way to generate a performant implementation of an EDM from a high level description in yaml format. We present the most recent developments in podio, most importantly the inclusion of a schema evolution mechanism for generated EDMs as well as the "Frame", a thread safe, generalized event data container. For the former we discuss some of the technical aspects in relation with supporting different I/O backends and leveraging potentially existing schema evolution mechanisms provided by them. Regarding the Frame we introduce the basic concept and highlight some of the functionality as well as important aspects of its implementation. The usage of podio for generating different EDMs for future collider projects (most importantly EDM4hep, the common EDM for the Key4hep project) has inspired new features. We present some of those smaller new features and end with a brief overview on current developments towards a first stable version as well as an outlook on future developments beyond that.

hep-ex↗

arXiv2023

Towards podio v1.0 -- A first stable release of the EDM toolkit

A performant and easy-to-use event data model (EDM) is a key component of any HEP software stack. The podio EDM toolkit provides a user friendly way of generating such a performant implementation in C++ from a high level description in yaml format. Finalizing a few important developments, we are in the final stretches for release v1.0 of podio, a stable release with backward compatibility for datafiles written with podio from then on. We present an overview of the podio basics, and go into slighty more technical detail on the most important topics and developments. These include: schema evolution for generated EDMs, multithreading with podio generated EDMs, the implementation of them as well as the basics of I/O. Using EDM4hep, the common and shared EDM of the Key4hep project, we highlight a few of the smaller features in action as well as some lessons learned during the development of EDM4hep and podio. Finally, we show how podio has been integrated into the Gaudi based event processing framework that is used by Key4hep, before we conclude with a brief outlook on potential developments after v1.0.

hep-ex↗

arXiv2021

Offline Computing resources for FCC-ee and related challenges

The international Future Circular Collider (FCC) study aims at designing pp, e$^+$e$^-$, e$^\pm$p colliders to be built in a new 100 km tunnel in the Geneva region. The electroweak, Higgs and top factory (FCC-ee) is designed to provide collisions at a centre of mass energy range between 90 (Z-pole) and 365 GeV ($\mathrm{t\bar{t}}$) and unprecedented integrated luminosities, producing huge amounts of data which will pose significant challenges to data processing. In this essay we discuss the needs in terms of storage and CPU for the diverse phases of the project, and the possible solutions mostly based on the models developed for HL-LHC.

hep-ex↗

arXiv2021

Review and outlook of accelerator-related codes and their interplay with the experiments software

Powerful flexible computer codes are essential for the design and optimisation of accelerator and experiments. We briefly review what already exists and what is needed in terms of accelerator codes. For the FCC-ee it will be important to include the effects of beamstrahlung and beam-beam interaction as well as machine imperfections and sources of beam induced backgrounds relevant for the experiments and consider the possibility of beam-polarisation. The experiment software Key4hep, which aims to provide a common software stack for future experiments, is described and the possibility of extending this concept to machine codes is discussed. We analyse how to interface and connect the accelerator and experiment codes in an efficient and flexible way for optimisation of the FCC-ee interaction region design, and discuss the possibility of using shared data formats as an interface.

hep-ex↗

arXiv2021

Key4hep, a framework for future HEP experiments and its use in FCC

The road map to the FCC Feasibility Study Report, for submission to the next Update of the European Strategy for Particle Physics, will require detailed simulation and advanced reconstruction algorithms to explore and maximise the physics reach of proposed detector solutions. The optimisation process will require maximal flexibility in changing detector geometries, materials and sensitive areas, and efficient tools to quantify the overall performance. To synergise such developments the CEPC, CLIC, FCC, ILC and SCT communities have engaged in the commissioning of a `Turnkey Software Stack' (Key4hep), which would provide all the necessary ingredients, from simulation to analysis, for future experiments. This approach is based on the positive experience of the linear collider projects ILC and CLIC, which have developed and used a common software stack (iLCSoft) over the last decade. Key4hep aims to cover most, if not all, future linear and circular machines colliding leptons (electrons, muons), and hadrons. The common software ecosystem will facilitate writing specific components for experiments ensuring coherency and maximising the re-use of established solutions. Project-specific software frameworks will require adaptation to fully profit from the common software base. In this essay we present the status and plans for re-framing the FCC software framework, FCCSW, around Key4hep and discuss the challenges associated with the transition.

hep-ex↗

arXiv2019

FCC-ee: Your Questions Answered

This document answers in simple terms many FAQs about FCC-ee, including comparisons with other colliders. It complements the FCC-ee CDR and the FCC Physics CDR by addressing many questions from non-experts and clarifying issues raised during the European Strategy symposium in Granada, with a view to informing discussions in the period between now and the final endorsement by the CERN Council in 2020 of the European Strategy Group recommendations. This document will be regularly updated as more questions appear or new information becomes available.

hep-ph↗

arXiv2018

A Roadmap for HEP Software and Computing R&D for the 2020s

Particle physics has an ambitious and broad experimental programme for the coming decades. This programme requires large investments in detector hardware, either to build new facilities and experiments, or to upgrade existing ones. Similarly, it requires commensurate investment in the R&D of software to acquire, manage, process, and analyse the shear amounts of data to be recorded. In planning for the HL-LHC in particular, it is critical that all of the collaborating stakeholders agree on the software goals and priorities, and that the efforts complement each other. In this spirit, this white paper describes the R&D activities required to prepare for this software upgrade.

physics.comp-ph↗

arXiv2016

Status Report of the DPHEP Collaboration: A Global Effort for Sustainable Data Preservation in High Energy Physics

Data from High Energy Physics (HEP) experiments are collected with significant financial and human effort and are mostly unique. An inter-experimental study group on HEP data preservation and long-term analysis was convened as a panel of the International Committee for Future Accelerators (ICFA). The group was formed by large collider-based experiments and investigated the technical and organizational aspects of HEP data preservation. An intermediate report was released in November 2009 addressing the general issues of data preservation in HEP and an extended blueprint paper was published in 2012. In July 2014 the DPHEP collaboration was formed as a result of the signature of the Collaboration Agreement by seven large funding agencies (others have since joined or are in the process of acquisition) and in June 2015 the first DPHEP Collaboration Workshop and Collaboration Board meeting took place. This status report of the DPHEP collaboration details the progress during the period from 2013 to 2015 inclusive.

hep-ex↗

arXiv2015

ROOT - A C++ Framework for Petabyte Data Storage, Statistical Analysis and Visualization

ROOT is an object-oriented C++ framework conceived in the high-energy physics (HEP) community, designed for storing and analyzing petabytes of data in an efficient way. Any instance of a C++ class can be stored into a ROOT file in a machine-independent compressed binary format. In ROOT the TTree object container is optimized for statistical data analysis over very large data sets by using vertical data storage techniques. These containers can span a large number of files on local disks, the web, or a number of different shared file systems. In order to analyze this data, the user can chose out of a wide set of mathematical and statistical functions, including linear algebra classes, numerical algorithms such as integration and minimization, and various methods for performing regression analysis (fitting). In particular, ROOT offers packages for complex data modeling and fitting, as well as multivariate classification based on machine learning techniques. A central piece in these analysis tools are the histogram classes which provide binning of one- and multi-dimensional data. Results can be saved in high-quality graphical formats like Postscript and PDF or in bitmap formats like JPG or GIF. The result can also be stored into ROOT macros that allow a full recreation and rework of the graphics. Users typically create their analysis macros step by step, making use of the interactive C++ interpreter CINT, while running over small data samples. Once the development is finished, they can run these macros at full compiled speed over large data sets, using on-the-fly compilation, or by creating a stand-alone batch program. Finally, if processing farms are available, the user can reduce the execution time of intrinsically parallel tasks - e.g. data mining in HEP - by using PROOF, which will take care of optimally distributing the work over the available resources in a transparent way.

physics.data-an↗

arXiv2014

The Need for a Versioned Data Analysis Software Environment

Scientific results in high-energy physics and in many other fields often rely on complex software stacks. In order to support reproducibility and scrutiny of the results, it is good practice to use open source software and to cite software packages and versions. With ever-growing complexity of scientific software on one side and with IT life-cycles of only a few years on the other side, however, it turns out that despite source code availability the setup and the validation of a minimal usable analysis environment can easily become prohibitively expensive. We argue that there is a substantial gap between merely having access to versioned source code and the ability to create a data analysis runtime environment. In order to preserve all the different variants of the data analysis runtime environment, we developed a snapshotting file system optimized for software distribution. We report on our experience in preserving the analysis environment for high-energy physics such as the software landscape used to discover the Higgs boson at the Large Hadron Collider.

cs.SE↗

arXiv2014

PROOF as a Service on the Cloud: a Virtual Analysis Facility based on the CernVM ecosystem

PROOF, the Parallel ROOT Facility, is a ROOT-based framework which enables interactive parallelism for event-based tasks on a cluster of computing nodes. Although PROOF can be used simply from within a ROOT session with no additional requirements, deploying and configuring a PROOF cluster used to be not as straightforward. Recently great efforts have been spent to make the provisioning of generic PROOF analysis facilities with zero configuration, with the added advantages of positively affecting both stability and scalability, making the deployment operations feasible even for the end user. Since a growing amount of large-scale computing resources are nowadays made available by Cloud providers in a virtualized form, we have developed the Virtual PROOF-based Analysis Facility: a cluster appliance combining the solid CernVM ecosystem and PoD (PROOF on Demand), ready to be deployed on the Cloud and leveraging some peculiar Cloud features such as elasticity. We will show how this approach is effective both for sysadmins, who will have little or no configuration to do to run it on their Clouds, and for the end users, who are ultimately in full control of their PROOF cluster and can even easily restart it by themselves in the unfortunate event of a major failure. We will also show how elasticity leads to a more optimal and uniform usage of Cloud resources.

cs.DC↗

arXiv2003

New results from an extensive aging test on bakelite Resistive Plate Chambers

We present recent results of an extensive aging test, performed at the CERN Gamma Irradiation Facility on two single--gap RPC prototypes, developed for the LHCb Muon System. With a method based on a model describing the behaviour of an RPC under high particle flux conditions, we have periodically measured the electrode resistance R of the two RPC prototypes over three years: we observe a large spontaneous increase of R with time, from the initial value of about 2 MOhm to more than 250 MOhm. A corresponding degradation of the RPC rate capabilities, from more than 3 kHz/cm2 to less than 0.15 kHz/cm2 is also found.

physics.ins-det↗