1,000 research outputs found
LHC Higgs boson mass combination
No full textA measurement of the Higgs boson mass is presented based on the combined data samples of the ATLAS and CMS experiments at the CERN LHC in the and decay channels. The results are obtained from a simultaneous fit to the reconstructed invariant mass peaks in the two channels and for the two experiments. The measured masses from the individual channels and the two experiments are found to be consistent among themselves. The combined measured mass of the Higgs boson is
Unfolding algorithms and tests using RooUnfold
No full textThe RooUnfold package provides a common framework to evaluate and use different unfolding algorithms, side-by-side. It currently provides implementations or interfaces for the Iterative Bayes, Singular Value Decomposition, and TUnfold methods, as well as bin-by-bin and matrix inversion reference methods. Common tools provide covariance matrix evaluation and multi-dimensional unfolding. A test suite allows comparisons of the performance of the algorithms under different truth and measurement models. Here I outline the package, the unfolding methods, and some experience of their use.The RooUnfold package provides a common framework to evaluate and use different unfolding algorithms, side-by-side. It currently provides implementations or interfaces for the Iterative Bayes, Singular Value Decomposition, and TUnfold methods, as well as bin-by-bin and matrix inversion reference methods. Common tools provide covariance matrix evaluation and multi-dimensional unfolding. A test suite allows comparisons of the performance of the algorithms under different truth and measurement models. Here I outline the package, the unfolding methods, and some experience of their use.The RooUnfold package provides a common framework to evaluate and usedifferent unfolding algorithms, side-by-side. It currently provides implemen-tations or interfaces for the Iterative Bayes, SVD, and TUnfold methods, aswell as bin-by-bin and matrix inversion reference methods. Common toolsprovide covariance matrix evaluation and multi-dimensional unfolding. A testsuite allows comparisons of the performance of the algorithms under differ-ent truth and measurement models. Here I outline the package, the unfoldingmethods, and some experience of their use
A study of J/#psi# production at the LEP e"+e"- collider And the implementation of the DELPHI slow controls system
No full textThis thesis describes two separate areas of work conducted for the DELPHI detector at LEP. The first concerns the Slow Controls of the DELPHI detector, which enable a single operator to oversee the proper functioning of the apparatus and to diagnose faults as they occur. The hardware and software of this system, as well as their interface to the experiment and the operator, are described. Some conclusions are drawn from seven years' design work and the initial six years' operation of DELPHI. Secondly, a study is made of the production, at e"+e"- collision centre of mass energies close to the Z"0 resonance, of J/#psi# mesons, decaying to #mu#"+#mu#"-. J/#psi# mesons produced via a B-hadron are used to measure the mean B lifetime, #tau#_B (1.53 #+-# 0.11 (stat.) #+-# 0.06 (syst.)) ps. A measurement is also made of the fraction of J/#psi#s produced promptly at the e"+e"- collision point, N(Z"0 #-># prompt J/#psi#X) / N(Z"0 #-># J/#psi#X) = (9.6 #+-# 3.2 (stat.) #+-# 1.2 (syst.))%. This method is largely model-independent. (author)SIGLEAvailable from British Library Document Supply Centre- DSC:DN056663 / BLDSC - British Library Document Supply CentreGBUnited Kingdo
Measurements of the Higgs boson inclusive and differential fiducial cross-sections in the diphoton decay channel with collisions at 13TeV with the ATLAS detector
No full textA measurement of inclusive and differential fiducial cross-sections for the production of the Higgs boson decaying into two photons is performed using 139 fb-1 of proton–proton collision data recorded at 13 TeV by the ATLAS experiment at the Large Hadron Collider. The inclusive cross-section times branching ratio, in a fiducial region closely matching the experimental selection, is measured to be 67 6 fb, which is in agreement with the state-of-the-art Standard Model prediction of 64 +_4 fb. Extrapolating this result to the full phase space and correcting for the branching ratio, the total cross-section for Higgs boson production is estimated to be 58 +- 6 pb. In addition, the cross-sections in four fiducial regions sensitive to various Higgs boson production modes and differential cross-sections as a function of either one or two of several observables are measured. All the measurements are found to be in agreement with the Standard Model predictions. The measured transverse momentum distribution of the Higgs boson is used as an indirect probe of the Yukawa coupling of the Higgs boson to the bottom and charm quarks. In addition, five differential cross-section measurements are used to constrain anomalous Higgs boson couplings to vector bosons in the Standard Model effective field theory framework.Fil: The ATLAS Collaboration. The ATLAS Collaboration; ArgentinaFil: Dova, Maria Teresa. Atlas Experiment, Cern; Suiza. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; ArgentinaFil: Aad, Georges. Centre National de la Recherche Scientifique; FranciaFil: Abbott, Braden. Oklahoma State University; Estados UnidosFil: Abed Abud, Adam. Cern - European Organization For Nuclear Research. The Cern Council; SuizaFil: Abeling, Kira. Universität Göttingen; AlemaniaFil: Abidi, Syed Haider. Brookhaven National Laboratory; Estados UnidosFil: Aboulhorma, Asmaa. Universite Mohammed V. Rabat; Otros paises de ÁfricaFil: Abramowicz, Halina. Universitat Tel Aviv; IsraelFil: Abreu, Henso. Technion - Israel Institute of Technology; IsraelFil: Abulaiti, Yiming. University of New York; Estados UnidosFil: Achkar, Baida. Universität Göttingen; AlemaniaFil: Adam, Lennart. Johannes Gutenberg Universitat Mainz; AlemaniaFil: Adamczyk, Leszek. AGH University of Science and Technology; PoloniaFil: Adamek, Lukas. University of Toronto; CanadáFil: Adelman, Jahred. Northeastern Illinois University (northeastern Illinois);Fil: Adye, Tim. Rutherford Appleton Laboratory; Reino UnidoFil: Afik, Yoav. Cern - European Organization For Nuclear Research. The Cern Council; SuizaFil: Agapopoulou, Christina. Universite Paris-saclay (universite Paris-saclay);Fil: Agaras, Merve Nazlim. Institut de Fisica D Altes Energies (ifae);Fil: Agarwala, Jinky. Istituto Nazionale di Fisica Nucleare; ItaliaFil: Aggarwal, Anamika. Radboud Universiteit Nijmegen; Países BajosFil: Aguilar Saavedra, Juan Antonio. Universidad de Granada; EspañaFil: Ahmed, Waleed Syed. McGill University. Montreal Neurological Institute and Hospital; CanadáFil: Aizenberg, Iakov. Weizmann Institute of Science; IsraelFil: Akatsuka, Shunichi. Kyoto University; JapónFil: Akbiyik, Melike. Johannes Gutenberg Universitat Mainz; AlemaniaFil: Akesson, Torsten. Lund University; SueciaFil: Akimov, Andrey. Russian Academy of Sciences; RusiaFil: Al Khoury, Konie. Columbia University; Estados UnidosFil: Alberghi, Gian Luigi. Istituto Nazionale di Fisica Nucleare; Itali
XRootD and Object Store: A new paradigm
No full textThe XRootD software framework is essential for data access at WLCG sites. The WLCG community is exploring and expanding XRootD functionality. This presents a particular challenge at the RAL Tier-1 as the Echo storage service is a Ceph based Erasure Coded object store. External access to Echo uses gateway machines which run GridFTP and caching servers. Local jobs access Echo via caches on every worker node, but it is clear there are inefficiencies in the system. Remote jobs also access data via XRootD on Echo. For CMS jobs this is via the AAA service. ATLAS, who are consolidating their storage at fewer sites, are increasingly accessing job input data remotely. This paper describes the continuing work to optimise both local and remote data access by testing different caching methods
Author Correction: A detailed map of Higgs boson interactions by the ATLAS experiment ten years after the discovery
No full textIn the version of this article initially published, the ATLAS Collaboration
author names, affiliations and acknowledgements were omitted and
have now been included in the HTML and PDF versions of the article
Search for heavy stable and long-lived particles in e(+)e(-) collisions at root s=189 GeV
No full textA search for stable and long-lived heavy charged particles was performed using the data taken by the DELPHI experiment at an energy of 189 GeV. The Cherenkov light detected in the Ring Imaging Cherenkov Detector and the ionisation loss measured in the Tim</p
XRootD and Object Store: A new paradigm
No full textThe XRootD software framework is essential for data access at WLCG sites. The WLCG community is exploring and expanding XRootD functionality. This presents a particular challenge at the RAL Tier-1 as the Echo storage service is a Ceph based Erasure Coded object store. External access to Echo uses gateway machines which run GridFTP and caching servers. Local jobs access Echo via caches on every worker node, but it is clear there are inefficiencies in the system. Remote jobs also access data via XRootD on Echo. For CMS jobs this is via the AAA service. ATLAS, who are consolidating their storage at fewer sites, are increasingly accessing job input data remotely. This paper describes the continuing work to optimise both local and remote data access by testing different caching methods
- …
