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Status Report of the DPHEP Study Group: Towards a Global Effort for Sustainable Data Preservation in High Energy Physics

Akopov, Z.; Amerio, Silvia; Asner, David; Avetisyan, Eduard; Barring, Olof; Beacham, James; Bellis, Matthew; Bernardi, Gregorio; Bethke, Siegfried; Boehnlein, Amber; Brooks, Travis; Browder, Thomas; Brun, Rene; Cartaro, Concetta; Cattaneo, Marco; Chen, Ga
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
95.45%
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 organisational aspects of HEP data preservation. An intermediate report was released in November 2009 addressing the general issues of data preservation in HEP. This paper includes and extends the intermediate report. It provides an analysis of the research case for data preservation and a detailed description of the various projects at experiment, laboratory and international levels. In addition, the paper provides a concrete proposal for an international organisation in charge of the data management and policies in high-energy physics.

Heisenberg's Uncertainty Relation and Bell Inequalities in High Energy Physics

Di Domenico, A.; Gabriel, A.; Hiesmayr, B. C.; Hipp, F.; Huber, M.; Krizek, G.; Mühlbacher, K.; Radic, S.; Spengler, Ch.; Theussl, L.
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
95.46%
An effective formalism is developed to handle decaying two-state systems. Herewith, observables of such systems can be described by a single operator in the Heisenberg picture. This allows for using the usual framework in quantum information theory and, hence, to enlighten the quantum feature of such systems compared to non-decaying systems. We apply it to systems in high energy physics, i.e. to oscillating meson-antimeson systems. In particular, we discuss the entropic Heisenberg uncertainty relation for observables measured at different times at accelerator facilities including the effect of CP violation, i.e. the imbalance of matter and antimatter. An operator-form of Bell inequalities for systems in high energy physics is presented, i.e. a Bell-witness operator, which allows for simple analysis of unstable systems.; Comment: 17 pages

Nonextensive statistical mechanics - Applications to nuclear and high energy physics

Tsallis, C.; Borges, Ernesto P.
Tipo: Artigo de Revista Científica
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95.44%
A variety of phenomena in nuclear and high energy physics seemingly do not satisfy the basic hypothesis for possible stationary states to be of the type covered by Boltzmann-Gibbs (BG) statistical mechanics. More specifically, the system appears to relax, along time, on macroscopic states which violate the ergodic assumption. Some of these phenomena appear to follow, instead, the prescriptions of nonextensive statistical mechanics. In the same manner that the BG formalism is based on the entropy $S_{BG}=-k \sum_i p_i \ln p_i$, the nonextensive one is based on the form $S_q=k(1-\sum_ip_i^q)/(q-1)$ (with $S_1=S_{BG}$). Typically, the systems following the rules derived from the former exhibit an {\it exponential} relaxation with time toward a stationary state characterized by an {\it exponential} dependence on the energy ({\it thermal equilibrium}), whereas those following the rules derived from the latter are characterized by (asymptotic) {\it power-laws} (both the typical time dependences, and the energy distribution at the stationary state). A brief review of this theory is given here, as well as of some of its applications, such as electron-positron annihilation producing hadronic jets, collisions involving heavy nuclei, the solar neutrino problem...

Data Preservation in High Energy Physics

South, David M.
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
95.47%
Data from high-energy physics (HEP) experiments are collected with significant financial and human effort and are in many cases unique. At the same time, HEP has no coherent strategy for data preservation and re-use, and many important and complex data sets are simply lost. In a period of a few years, several important and unique experimental programs will come to an end, including those at HERA, the b-factories and at the Tevatron. An inter-experimental study group on HEP data preservation and long-term analysis (DPHEP) was formed and a series of workshops were held to investigate this issue in a systematic way. The physics case for data preservation and the preservation models established by the group are presented, as well as a description of the transverse global projects and strategies already in place.; Comment: Proceedings of plenary talk given at the 18th International Conference on Computing in High Energy and Nuclear Physics (CHEP 2010). 10 pages, 9 figures

Data Preservation and Long Term Analysis in High Energy Physics

South, David M.
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
95.51%
Several important and unique experimental high-energy physics programmes at a variety of facilities are coming to an end, including those at HERA, the B-factories and the Tevatron. The wealth of physics data from these experiments is the result of a significant financial and human effort, and yet until recently no coherent strategy existed for data preservation and re-use. To address this issue, an inter-experimental study group on data preservation and long-term analysis in high-energy physics was convened at the end of 2008, publishing an interim report in 2009. The membership of the study group has since expanded, including the addition of the LHC experiments, and a full status report has now been released. This report greatly expands on the ideas contained in the original publication and provides a more solid set of recommendations, not only concerning data preservation and its implementation in high-energy physics, but also the future direction and organisational model of the study group. The main messages of the status report were presented for the first time at the 2012 International Conference on Computing in High Energy and Nuclear Physics and are summarised in these proceedings.; Comment: Proceedings of plenary talk given at the 2012 International Conference on Computing in High Energy and Nuclear Physics (CHEP 2012). 8 pages...

Emerging Computing Technologies in High Energy Physics

Farbin, Amir
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
95.44%
While in the early 90s High Energy Physics (HEP) lead the computing industry by establishing the HTTP protocol and the first web-servers, the long time-scale for planning and building modern HEP experiments has resulted in a generally slow adoption of emerging computing technologies which rapidly become commonplace in business and other scientific fields. I will overview some of the fundamental computing problems in HEP computing and then present the current state and future potential of employing new computing technologies in addressing these problems.; Comment: To be published in the proceedings of DPF-2009, Detroit, MI, July 2009, eConf C090726

High-energy physics and cosmological perturbations: observing new physics at large scales

Chialva, Diego
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
95.47%
Correlators of primordial perturbations could provide us with the signatures of physics at earlier times/higher momentum scales than inflation. The key-mechanisms are the interference and cumulation in time related to the interplay of negative- and positive-frequency components of fields and energy density generated by the high-momentum scale physics. Here, we discuss which signatures are universal for such scenarios, and which ones instead would distinguish the specific cases (for example modified initial states for inflationary perturbations or modified dispersion relations). We also discuss the scale dependence of the correlators in presence of these signatures, especially for some scenarios, and how this could be interesting for observations.; Comment: 7 pages. Prepared for the proceedings of the European Physical Society Conference on High Energy Physics EPS-HEP2013, 18-24 July 2013, Stockholm, Sweden

FPGA based High Speed Data Acquisition System for High Energy Physics Application

Mandal, Swagata; Sau, Suman; Chakrabarti, Amlan; Chattopadhyay, Subhasis
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
95.46%
In high energy physics experiments (HEP), high speed and fault resilient data communication is needed between detectors/sensors and the host PC. Transient faults can occur in the communication hardware due to various external effects like presence of charged particles, noise in the environment or radiation effects in HEP experiments and that leads to single/multiple bit error. In order to keep the communication system functional in such a radiation environment where direct intervention of human is not possible, a high speed data acquisition (DAQ) architecture is necessary which supports error recovery. This design presents an efficient implementation of field programmable gate array (FPGA) based high speed DAQ system with optical communication link supported by multi-bit error correcting model. The design has been implemented on Xilinx Kintex-7 board and is tested for board to board communication as well as for PC communication using PCI (Peripheral Component Interconnect express). Data communication speed up to 4.8 Gbps has been achieved in board to board and board to PC communication and estimation of resource utilization and critical path delay are also measured.

Computing trends using graphic processor in high energy physics

Niculescu, Mihai; Zgura, Sorin-Ion
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
95.47%
One of the main challenges in Heavy Energy Physics is to make fast analysis of high amount of experimental and simulated data. At LHC-CERN one p-p event is approximate 1 Mb in size. The time taken to analyze the data and obtain fast results depends on high computational power. The main advantage of using GPU(Graphic Processor Unit) programming over traditional CPU one is that graphical cards bring a lot of computing power at a very low price. Today a huge number of application(scientific, financial etc) began to be ported or developed for GPU, including Monte Carlo tools or data analysis tools for High Energy Physics. In this paper, we'll present current status and trends in HEP using GPU.

Development of CMOS pixel sensors for tracking and vertexing in high energy physics experiments

Senyukov, Serhiy; Baudot, Jerome; Besson, Auguste; Claus, Giles; Cousin, Loic; Dulinski, Wojciech; Goffe, Mathieu; Hippolyte, Boris; Maria, Robert; Molnar, Levente; Castro, Xitzel Sanchez; Winter, Marc
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
95.44%
CMOS pixel sensors (CPS) represent a novel technological approach to building charged particle detectors. CMOS processes allow to integrate a sensing volume and readout electronics in a single silicon die allowing to build sensors with a small pixel pitch ($\sim 20 \mu m$) and low material budget ($\sim 0.2-0.3\% X_0$) per layer. These characteristics make CPS an attractive option for vertexing and tracking systems of high energy physics experiments. Moreover, thanks to the mass production industrial CMOS processes used for the manufacturing of CPS the fabrication construction cost can be significantly reduced in comparison to more standard semiconductor technologies. However, the attainable performance level of the CPS in terms of radiation hardness and readout speed is mostly determined by the fabrication parameters of the CMOS processes available on the market rather than by the CPS intrinsic potential. The permanent evolution of commercial CMOS processes towards smaller feature sizes and high resistivity epitaxial layers leads to the better radiation hardness and allows the implementation of accelerated readout circuits. The TowerJazz $0.18 \mu m$ CMOS process being one of the most relevant examples recently became of interest for several future detector projects. The most imminent of these project is an upgrade of the Inner Tracking System (ITS) of the ALICE detector at LHC. It will be followed by the Micro-Vertex Detector (MVD) of the CBM experiment at FAIR. Other experiments like ILD consider CPS as one of the viable options for flavour tagging and tracking sub-systems.

De Geronimo, G.; Christian, D.; Bebek, C.; Garcia-Sciveres, M.; Von der Lippe, H.; Haller, G.; Grillo, A. A.; Newcomer, M.
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
95.47%
This whitepaper summarizes the status, plans, and challenges in the area of integrated circuit design in the United States for future High Energy Physics (HEP) experiments. It has been submitted to CPAD (Coordinating Panel for Advanced Detectors) and the HEP Community Summer Study 2013(Snowmass on the Mississippi) held in Minnesota July 29 to August 6, 2013. A workshop titled: US Workshop on IC Design for High Energy Physics, HEPIC2013 was held May 30 to June 1, 2013 at Lawrence Berkeley National Laboratory (LBNL). A draft of the whitepaper was distributed to the attendees before the workshop, the content was discussed at the meeting, and this document is the resulting final product. The scope of the whitepaper includes the following topics: Needs for IC technologies to enable future experiments in the three HEP frontiers Energy, Cosmic and Intensity Frontiers; Challenges in the different technology and circuit design areas and the related R&D needs; Motivation for using different fabrication technologies; Outlook of future technologies including 2.5D and 3D; Survey of ICs used in current experiments and ICs targeted for approved or proposed experiments; IC design at US institutes and recommendations for collaboration in the future.

How good are your fits? Unbinned multivariate goodness-of-fit tests in high energy physics

Williams, Mike
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
95.46%
Multivariate analyses play an important role in high energy physics. Such analyses often involve performing an unbinned maximum likelihood fit of a probability density function (p.d.f.) to the data. This paper explores a variety of unbinned methods for determining the goodness of fit of the p.d.f. to the data. The application and performance of each method is discussed in the context of a real-life high energy physics analysis (a Dalitz-plot analysis). Several of the methods presented in this paper can also be used for the non-parametric determination of whether two samples originate from the same parent p.d.f. This can be used, e.g., to determine the quality of a detector Monte Carlo simulation without the need for a parametric expression of the efficiency.; Comment: 32 pages, 12 figures

Advanced Analysis Methods in High Energy Physics

Bhat, Pushpalatha C.
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
95.45%
During the coming decade, high energy physics experiments at the Fermilab Tevatron and around the globe will use very sophisticated equipment to record unprecedented amounts of data in the hope of making major discoveries that may unravel some of Nature's deepest mysteries. The discovery of the Higgs boson and signals of new physics may be around the corner. The use of advanced analysis techniques will be crucial in achieving these goals. I will discuss some of the novel methods of analysis that could prove to be particularly valuable for finding evidence of any new physics, for improving precision measurements and for exploring parameter spaces of theoretical models.; Comment: 9 pages, 5 figures, To be published in the Proceedings of the VII International Workshop on Advanced Computing and Analysis Techniques in Physics Research, Fermilab, Oct. 16-20, 2000 (American Institute of Physics, NY, 2001) edited by P.C. Bhat and M. Kasemann

Signatures of very high energy physics in the squeezed limit of the bispectrum (violation of Maldacena's condition)

Chialva, Diego
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
95.47%
We investigate the signatures in the squeezed limit of the primordial scalar bispectrum due to modifications of the standard theory at high energy. In particular, we consider the cases of modified dispersion relations and/or modified initial quantum state (both in the Boundary Effective Field Theory and in the New Physics Hyper-Surface formulations). Using the in-in formalism we study in details the squeezed limit of the contributions to the bispectrum from all possible cubic couplings in the effective theory of single-field inflation. We find general features such as enhancements and/or non-local shape of the non-Gaussianities, which are relevant, for example, for measurements of the halo bias and which distinguish these scenarios from the standard one (with Bunch-Davies vacuum as initial state and standard kinetic terms). We find that the signatures change according to the magnitude of the scale of new physics, and therefore several pieces of information regarding high energy physics could be obtained in case of detection of these signals, especially bounds on the scales of new physics.; Comment: 37 pages plus bibliography, version matching the one accepted for publication by JCAP. Increased pedagogical comments, improved presentation and text...

Data Preservation and Long Term Analysis in High Energy Physics

South, David M.
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
95.49%
High energy physics data is a long term investment and contains the potential for physics results beyond the lifetime of a collaboration. Many existing experiments are concluding their physics programs, and looking at ways to preserve their data heritage. Preservation of high-energy physics data and data analysis structures is a challenge, and past experience has shown it can be difficult if adequate planning and resources are not provided. A study group has been formed to provide guidelines for such data preservation efforts in the future. Key areas to be investigated were identified at a workshop at DESY in January 2009, to be followed by a workshop at SLAC in May 2009. More information can be found at http://dphep.org; Comment: To appear in the proceedings of 44th Rencontres de Moriond on QCD and High Energy Interactions, La Thuile, Valle d'Aosta, Italy, 14-21 Mar 2009. 4 pages, 2 figures + 1 photo, 1 style file

Evolutionary Computation in High Energy Physics

Teodorescu, Liliana
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
95.48%
Evolutionary Computation is a branch of computer science with which, traditionally, High Energy Physics has fewer connections. Its methods were investigated in this field, mainly for data analysis tasks. These methods and studies are, however, less known in the high energy physics community and this motivated us to prepare this lecture. The lecture presents a general overview of the main types of algorithms based on Evolutionary Computation, as well as a review of their applications in High Energy Physics.; Comment: Lecture presented at 2006 Inverted CERN School of Computing; to be published in the school proceedings (CERN Yellow Report)

A pedagogical introduction to quantum integrability, with a view towards theoretical high-energy physics

Lamers, J.
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
95.47%
These are lecture notes of an introduction to quantum integrability given at the Tenth Modave Summer School in Mathematical Physics, 2014, aimed at PhD candidates and junior researchers in theoretical physics. We introduce spin chains and discuss the coordinate Bethe ansatz (CBA) for a representative example: the Heisenberg XXZ model. The focus lies on the structure of the CBA and on its main results, deferring a detailed treatment of the CBA for the general $M$-particle sector of the XXZ model to an appendix. Subsequently the transfer-matrix method is discussed for the six-vertex model, uncovering a relation between that model and the XXZ spin chain. Equipped with this background the quantum inverse-scattering method (QISM) and algebraic Bethe ansatz (ABA) are treated. We emphasize the use of graphical notation for algebraic quantities as well as computations. Finally we turn to quantum integrability in the context of theoretical high-energy physics. We discuss factorized scattering in two-dimensional QFT, and conclude with a qualitative introduction to one current research topic relating quantum integrability to theoretical high-energy physics: the Bethe/gauge correspondence.; Comment: 74 pages, 10 figures, 3 tables; v2: minor corrections

Data Preservation in High Energy Physics

Kogler, Roman; South, David M.; Steder, Michael
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
95.48%
Data from high-energy physics experiments are collected with significant financial and human effort and are mostly unique. However, until recently no coherent strategy existed for data preservation and re-use, and many important and complex data sets have simply been lost. While the current focus is on the LHC at CERN, in the current period several important and unique experimental programs at other facilities are coming to an end, including those at HERA, b-factories and the Tevatron. To address this issue, an inter-experimental study group on HEP data preservation and long-term analysis (DPHEP) was convened at the end of 2008. The group now aims to publish a full and detailed review of the present status of data preservation in high energy physics. This contribution summarises the results of the DPHEP study group, describing the challenges of data preservation in high energy physics and the group's first conclusions and recommendations. The physics motivation for data preservation, generic computing and preservation models, technological expectations and governance aspects at local and international levels are examined.; Comment: 8 pages, 6 figures, proceedings of ACAT 2011 poster

Automated Reconstruction of Particle Cascades in High Energy Physics Experiments

Actis, O.; Erdmann, M.; Henrichs, A.; Hinzmann, A.; Kirsch, M.; Müller, G.; Steggemann, J.
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
95.45%
We present a procedure for reconstructing particle cascades from event data measured in a high energy physics experiment. For evaluating the hypothesis of a specific physics process causing the observed data, all possible reconstruction versions of the scattering process are constructed from the final state objects. We describe the procedure as well as examples of physics processes of different complexity studied at hadron-hadron colliders. We estimate the performance by 20 microseconds per reconstructed decay vertex, and 0.6 kByte per reconstructed particle in the decay trees.; Comment: 8 pages, 2 figures. Submitted to Computational Science & Discovery

South, David M.