Online data quality monitoring system at BESⅢ

The online Data Quality Monitoring (DQM) tool plays an important role in the data recording process of HEP experiments. The BESⅢ DQM collects data from the online data flow, reconstructs them with offline reconstruction software and automatically analyzes the reconstructed data with user-defined algorithms. The DQM software is a scalable distributed system. The monitored results are gathered and displayed in various formats, which provides the shifter with current run information that can be used to identify problems quickly. This paper gives an overview of the DQM system at BESⅢ.     

Onsite data processing and monitoring for the Daya Bay experiment

The Daya Bay Reactor Neutrino Experiment started running on September 23, 2011. The offline computing environment, consisting of 11 servers at Daya Bay, was built to process onsite data. With the current computing ability, onsite data processing is running smoothly. The Performance Quality Monitoring system (PQM) has been developed to monitor the detector performance and data quality. Its main feature is the ability to efficiently process multiple data streams from the three experimental halls. The PQM processes raw data files from the Daya Bay data acquisition system, generates and publishes histograms via a graphical web interface by executing the user-defined algorithm modules, and saves the histograms for permanent storage. The fact that the whole process takes only around 40 minutes makes it valuable for the shift crew to monitor the running status of all the sub-detectors and the data quality.     

Application of SNi PER framework to BESⅢ physics analysis

A fast physics analysis framework has been developed based on SNi PER to process the increasingly large data sample collected by BESⅢ.In this framework,a reconstructed event data model with Smart Ref is designed to improve the speed of Input/Output operations,and necessary physics analysis tools are migrated from BOSS to SNi PER.A real physics analysis e~+e~-→π~+π~-J/ψ is used to test the new framework,and achieves a factor of10.3 improvement in Input/Output speed compared to BOSS.Further tests show that the improvement is mainly attributed to the new reconstructed event data model and the lazy-loading functionality provided by Smart Ref.     

Strange quarkonium states at BESⅢ

We present physics opportunities and topics with the s states(strangeonia)that can be studied with the BES detector operating at the BEPC collider.Though the φ and η/ states have long been established experimentally,only a handful of strangeonia are well known,in contrast to the rich ccharmoium system.An overview of the s states and their experimental status is presented in this paper.The BES experiment has collected the world’s largest samples of J/ψ,ψ(2S),ψ(3770),and direct e+e-annihilations at energies below the J/ψand above 3.8 Ge V,and will continue to accumulate high quality,large integrated luminosity in theτ-charm energy region.These data,combined with the excellent performance of the BESⅢ detector,will offer unprecedented opportunities to explore the s system.In this paper we describe the experimental techniques to explore strangeonia with the BESⅢ detector.     

The BEPCⅡ Data Production and BESⅢ offline Analysis Software System

The BES detector has operated for about 12 years,and the BES offline data analysis environment also has been developed and upgraded along with developments of the BES hardware and software.The BESⅢ software system will operate for many years.Thus they should meet developments of the new technology in software,It should be highly flexible,Powerful,stable and easy for maintenance.And following points should be taken into account:1) To benefit the collaboration and make better exchanges with the international HEP experiments this system shoule be set up by adopting or referring the newest technology in the software from advanced experiments in the world.2).It should support hundreds of the existing BES software packages and serve for both old experts who familiar with BESII software and computing environment and new members who is going to benefit from the new system.3).The most BESII existing packages will be modified or re-designed according to the hardware changes.     

Experience with the COMPASS Conditions Data Base

The COMPASS experiment at CERN is starting data taking in summer 2001,The COMPASS off-line framework(CORAL)will use the CERN Conditions Data Base(CDB)to handle time dependent quantities like calibration constants and data from the slow control system.We describe the use of the CDB within CORAL and the fullscale performance tests on the COMPASS Computing Farm(CCF),The CDB has been interfaced to the SCADA PVSS slow control system.To continuously transfer all the data to the CDB and make them available to the users,We describe this interface,a feasibility study performed using mock data and we predict the expected performance.     

Monitoring the BaBar Data Acquisition System

The BaBar data acquisition system(DAQ)transports data from the detector front end eletronics to short term disk storage.A monitoring application(VMON)has been developed to monitor the one hundred and ninety computers in the dataflow system.Performance information for each CPU is collected and multicast across the existing data transport network.The packets are currently collected by a single UNIX workstation and archived.A ROOT based GUI provides control and displays the DAQ performance in real time.The same GUI is reused to recover archived VMON data,VMON has been deployed and constantly monitors the BaBar dataflow system.It has been used for diagnostics and provides input to models projecting future performance.The application has no measurable impact on data taking ,responds instantaneously on the human timescale to requests for information display,and uses only 3% of a 300MHz Sun Ultra5 CPU.     

Future Physics Programme of BESⅢ

There has recently been a dramatic renewal of interest in hadron spectroscopy and charm physics. This renaissance has been driven in part by the discovery of a plethora of charmonium-like XYZ states at BESⅢ and B factories, and the observation of an intriguing proton-antiproton threshold enhancement and the possibly related X(1835) meson state at BESⅢ, as well as the threshold measurements of charm mesons and charm baryons. We present a detailed survey of the important topics in tau-charm physics and hadron physics that can be further explored at BESⅢ during the remaining operation period of BEPCⅡ. This survey will help in the optimization of the data-taking plan over the coming years, and provides physics motivation for the possible upgrade of BEPCⅡ to higher luminosity.     

Some topics on charmonium decays at BESⅢ experiment

The construction of BESⅢ detector has been finished and the data taking is under plan. Some physics topics on charmonium decays at BESⅢ experiment are discussed in this paper. The measurement of properties of η_c and η_c at BESⅢ is discussed and the expected precision of the measurement is estimated based on BOSS. Also the χ_cJ decay and the measurement of hyperon decay parameters are mentioned.     

Study of low momentum track reconstruction for the BESⅢ main drift chamber

In order to overcome the difficulty brought by the circling charged tracks with transverse momentum less than 120 MeV in the BESⅢ Main Drift Chamber （MDC）, a specialized method called TCurlFinder was developed. This tracking method focuses on the charged track reconstruction under 120 MeV and possesses a special mechanism to reject background noise hits. The performance of the package has been carefully checked and tuned by both Monte Carlo data and real data. The study shows that this tracking method could obviously enhance the reconstruction efficiency in the low transverse momentum region, providing physics analysis with more and reliable data.     

Studies of dE/dx measurements with the BESⅢ

The Beijing Spectrometer Ⅲ（BESⅢ）is a general-purpose detector used for the study of τ-charm physics at the Beijing Electron-Positron Collider Ⅱ（BEPC Ⅱ）.This paper presents our studies of the dE/dx measurement in the drift chamber of BESⅢ,which is important for the identification of charged particles.Corrections applied to the dE/dx measurement in data reconstruction are discussed.After our current dE/dx calibration,a resolution of about 6% has been obtained for minimum ionization particles,and a 3σ K/πseparation is obtained for momenta up to 760 MeV/c.These results meet the design goals of the BESⅢ drift chamber.     

Building an Advanced Computing Environment with SAN Support

The current computing environment of our Computing Center in IHEP uses a SAS (server Attached Storage)architecture,attaching all the storage devices directly to the machines.This kind of storage strategy can‘t meet the requirement of our BEPC II/BESⅢ project properly.Thus we design and implement a SAN-based computing environment,which consists of several computing farms,a three-level storage pool,a set of storage management software and a web-based data management system.The feature of ours system includes cross-platform data sharing,fast data access,high scalability,convenient storage management and data management.     

The KLOE Online Calibration System

Based on all the features of the KLOE online software,the online calibration system performs current calibration quality checking in real time and starts automatically new calibration procedures when needed.Acalibration manager process controls the system,implementing the interface to the online system,receiving information from the run control and translating its state transitions to a separate state machine.It acts as a “ calibration run controller“and performs failure recovery when requested by a set of process checkers.The core of the system is a multi-threaded OO histogram server that receives histogramming commands by remote processes and operates on local ROOT histograms.A client library and C,fortran and C application interface libraries allow the user to connect and define his own histogram or read histograms owned by others using an bool-like interface.Several calibration processes running in parallel in a destributed,multiplatform environment can fill the same histograms,allowing fast external information check.A monitor thread allow remote browsing for visual inspection,Pre-filtered data are read in nonprivileged spy mode from the data acquisition system via the Kloe Integrated Dataflow,privileged spy mode from the data acquisiton system via the Kole Integrated Dataflow.The main characteristics of the system are presented.     

Recent results on hadron spectroscopy from BES

The BES-Ⅲ Detector is a very versatile multipurpose device located at the Institute of High Energy Physics(IHEP) in Beijing,China.Concerning the physics program it ties stringently up to the past BES and BES-Ⅱ experiments.Since start of the data taking in the middle of 2008 the accumulated dataset of 200·106 J/ψ events and 100·106 ψ events already exceeds the world data on these resonances.In addition to studies of the charmonium systems the data offers great opportunity for investigations in the light hadron sector.In detail it will be reported about the confirmation of the enhancement in p invariant mass in radiative J/ψ decays,the search for decays Y(2175) → K0 K0,observation of a charged κ± in K±π0 and observation of a new excited baryon N(2065) decaying to pπ0 and charged conjugate.The first result is based on data taken by BES-Ⅱ and BES-Ⅲ,the latter three on data collected by BES-Ⅱ only.     

Extreme ultraviolet and soft x-ray spectral lines in Rb ⅩⅩⅨ

An extensive theoretical set of atomic data for Rb XXIX in a wide range with L-shell electron excitations to the M-shell has been reported. We have computed energy levels for the lowest 113 fine structure levels of Rb XXIX. The fully relativistic multiconfigurational Dirac–Fock method(MCDF) within the framework of Dirac–Coulomb Hamiltonian taking quantum electrodynamics(QED) and Breit corrections into account has been adopted for calculations. Radiative data are reported for electric dipole(E1), magnetic dipole(M1), electric quadrupole(E2), and magnetic quadrupole(M2)transitions from the ground level, although calculations have been performed for a much larger number of levels. To assess the accuracy of results, we performed analogous calculations using flexible atomic code(FAC). Comparisons are made with existing available results and a good agreement has been achieved. Most of the wavelengths calculated lie in the soft x-ray(SXR) region. Lifetimes for all 113 levels have also been provided for the first time. Additionally, we have provided the spectra for allowed transitions from n = 2 to n = 3 within the x-ray region and also compared our SXR photon wavelengths with experimentally recognized wavelengths. We hope that our results will be beneficial in fusion plasma research and astrophysical applications.     

Go4：Multithreaded Inter—Task Communication with ROOT—writing non—blocking GUIs

The future GSI Online-Offline-Object-Oriented analysis framework Go4 based on ROOT[CERN,R.Brun et al] provides a mechanism to monitor and control an analuysis at any time.This is achieved by running the GUI and the analysis in different tasks.To control these tasks by one non-lbocking GUI,the Go4TaskHandler package was developed.It offers an asynchronous inter task communication via independent channels for commands,data,and status information,Each channel is processed by a dedicated thread and has a buffer queue as interface to the working thread.The threads are controlled by the Go4ThreadMAanager package,based on the ROOT TThread package,In parallel to the GUI actions,the analysis tasks can display objects like histograms in the GUI.A test GUI was implemented using the Qt widget library(Trolltech Inc.).A Qt to ROOT interface has been developed.The Go4 packages may be utilized for any ROOT application that requires to control independent data processing or monitoring tasks from a non-blocking GUI.     

Object Oriented Reconstruction and Particle Identification in the ATLAS Calorimeter

The reconstruction and subsequent particle identification is a challenge in a complex and a high luminosity environment such as those expected in the ATLAS detector at the LHC.The ATLAS software has chosen the object oriented paradigm and has recently migrated much of its software components developed earlier using procedural programming languages.The new software,which emphasizes on the separation between algorthms and data objects,has been successfully integrated in the broader ATLAS framework.We will present a status report of the reconstruction software summarizing the experiences gained in the migration of several software components.We will examine some of the components of the calorimeter software design,which include simulation of real-time detector effects and online environment,and strategies deployed for identification of particles.     

Operation and Optimization of a Linux PC farm for Physics Analysis in the ZEUS Experiment

The ZEUS experiment has migrated its reconstruction and analysis farms to a PC-based environment.More than one year of experience has been acquired with successful operation of an analysis farm designed for several hundred users.Specially designed software has been used to proveide fast and reliable access to large amounts of data (30 TB in total),After the ongoing upgrade of the HERA luminosity,higher requirements will arise in terms of data storage capacity and throughput rate,The necessity of a bigger disk cache has led to consideration of solutions based on commodity technology,PC-based file servers are being tested as a cost-effective storage system,In this article we present the hardware and software solutions deplogyed and discuss their performance.scalability and maintenance issues.     

The ALICE Data Challenges

Since 1998,the ALICE experiment and the CERN/IT division have jointly executed several large-scale high throughput distributed computing exercises:the ALICE data challenges.The goals of these regular exercises are to test hardware and software components of the data acqusition and computing systems in realistic conditions and to execute an early integration of the overall ALICE computing infrastructure.This paper reports on the third ALICE Data Challenge (ADC III) that has been performed at CERN from January to March 2001.The data used during the ADC Ⅲ are simulated physics raw data of the ALICE TPC,produced with the ALICE simulation program AliRoot.The data acquisition was based on the ALICE online framework called the ALICE Data Acquisition Test Environment (DATE) system.The data after event building,were then formatted with the ROOT I/O package and a data catalogue based on MySQl was established.The Mass Storage System used during ADC III is CASTOR.Different software tools have been used to monitor the performances,DATE has demonstrated performances of more than 500 MByte/s.An aggregate data throughput of 85 MByte/s was sutained in CASTOR over several days.The total collected data amounts to 100 TBytes in 100.00 files.     

Study of BESⅢ MUC offline software with cosmic-ray data

Cosmic-ray data of 90 M events have been collected and used for calibration,alignment as well as detector tuning. A special tracking algorithm for the BESⅢ muon counter is developed and verified with Monte-Carlo simulation and then further confirmed with the cosmic-ray data. The obtained strip resolutions are in good agreement with the design values. A new alignment approach for the BESⅢ muon counter is confirmed with the cosmic-ray data and proposed to be used in future analysis of experimental data.