高能物理与核物理最新文献

{"title":"Gravitational Instability of a Nonrotating Galaxy","authors":"A. Chao","doi":"10.1103/PHYSREVSTAB.12.104201","DOIUrl":"https://doi.org/10.1103/PHYSREVSTAB.12.104201","url":null,"abstract":"Gravitational instability of the distribution of stars in a galaxy is a well-known phenomenon in astrophysics. This work is a preliminary attempt to analyze this phenomenon using the standard tools developed in accelerator physics. By applying this analysis, it is found that a stable nonrotating galaxy would become unstable if its size exceeds a certain limit that depends on its mass density.","PeriodicalId":66916,"journal":{"name":"高能物理与核物理","volume":"2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2005-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81682276","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"ALICE Multi-site Data Transfer Tests on a Wide Area Network","authors":"S. Bagnasco, D. Mura, E. Fragiacomo, M. Masera, F. Carminati, F. Minafra, G. Re, J. Svec, R. Barbera, M. Sitta, G. Donvito, P. Cerello, R. Turrisi, A. Fritz, D. Bari","doi":"10.5170/CERN-2005-002.1269","DOIUrl":"https://doi.org/10.5170/CERN-2005-002.1269","url":null,"abstract":"","PeriodicalId":66916,"journal":{"name":"高能物理与核物理","volume":"17 1","pages":"1269-1278"},"PeriodicalIF":0.0,"publicationDate":"2005-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74636258","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Volume-based Representation of the Magnetic Field","authors":"N. Amapane, V. Andreev, V. Drollinger, V. Karimäki, V. Klyukhin, T. Todorov","doi":"10.5170/CERN-2005-002.310","DOIUrl":"https://doi.org/10.5170/CERN-2005-002.310","url":null,"abstract":"The access to the magnetic field has a large impact on both CPU performance and accuracy of simulation, reconstruction and analysis software. An approach to the magnetic field access based on a volume geometry is described. The volumes are constructed in such a way that their boundaries correspond to field discontinuities, which are due to changes in magnetic permeability of the materials. The field in each volume is continuous. The value of the field at a given point of a volume is obtained by interpolation from a regular grid of values resulting from a TOSCA calculation or, when it is available, from a parameterization. To allow global access to the magnetic field, a volume finding algorithm that exploits explicitly the layout and the symmetries of the detector is used. The main clients of the magnetic field, which are the simulation (GEANT) and the propagation of track parameters and errors in the reconstruction, can be made aware of the magnetic field volumes by connecting the per-volume magnetic field providers to the corresponding volume in the respective geometries. In this way the global volume search is by-passed and the access to the field is sped up significantly.","PeriodicalId":66916,"journal":{"name":"高能物理与核物理","volume":"41 1","pages":"310-312"},"PeriodicalIF":0.0,"publicationDate":"2005-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90512278","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Isospin Effect of Momentum Dependent Interaction in Heavy Ion Collisions","authors":"Liu Jian","doi":"10.7498/aps.54.3082","DOIUrl":"https://doi.org/10.7498/aps.54.3082","url":null,"abstract":"We take the isospin degree of freedom in the momentum dependent interaction to obtain an isospin and momentum dependent interaction with a form practically usable in isospin dependent quantum molecular dynamics model. We investigate the isospin effect of momentum dependent interaction on the observable in the intermediate energy heavy ion collisions. It is found that momentum dependent interaction with and without isospin dependence, lead to significant different predictions on the nuclear stopping (momentum dissipation) and isospin fractionation ratio. In particular the momentum dependent interaction with the isospin degree of freedom induces reductions for the dependence of nuclear stopping on the two-body collisions and the dependence of isospin fractionation ratio on the symmetry potential. However it does not change obviously the features for the nuclear stopping and isospin fractionation ratio as the good probe of in-medium nucleon-nucleon cross section and symmetry potential. The isospin dependence of momentum dependent interaction is thus important for studying accurately the equation of state of isospin asymmetry nuclear matter.","PeriodicalId":66916,"journal":{"name":"高能物理与核物理","volume":"29 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2005-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78147404","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Software Agents in Data and Workflow Management","authors":"T. Barrass, Y. Wu, I. Semeniouk, D. Bonacorsi, D. Newbold, L. Tuura, T. Wildish, C. Charlot, Nicola De Filippis, S. Metson, I. Fisk, J. Hernández, C. Grandi, A. Afaq, J. Rehn, O. Maroney, K. Rabbertz, W. Jank, P. Garcia-Abia, M. Ernst, A. Fanfani","doi":"10.5170/CERN-2005-002.838","DOIUrl":"https://doi.org/10.5170/CERN-2005-002.838","url":null,"abstract":"CMS currently uses a number of tools to transfer data which, taken together, form the basis of a heterogeneous datagrid. The range of tools used, and the directed, rather than optimized nature of CMS recent large scale data challenge required the creation of a simple infrastructure that allowed a range of tools to operate in a complementary way. The system created comprises a hierarchy of simple processes (named ‘agents’) that propagate files through a number of transfer states. File locations and some application metadata were stored in POOL file catalogues, with LCG LRC or MySQL back-ends. Agents were assigned limited responsibilities, and were restricted to communicating state in a well-defined, indirect fashion through a central transfer management database. In this way, the task of distributing data was easily divided between different groups for implementation. The prototype system was developed rapidly, and achieved the required sustained transfer rate of ~10 MBps, with O(10) files distributed to 6 sites from CERN. Experience with the system during the data challenge raised issues with underlying technology (MSS write/read, stability of the LRC, maintenance of file catalogues, synchronization of filespaces), all of which have been successfully identified and handled. The development of this prototype infrastructure allows us to plan the evolution of backbone CMS data distribution from a simple hierarchy to a more autonomous, scalable model drawing on emerging agent and grid technology. DATA DISTRIBUTION FOR CMS The Compact Muon Solenoid (CMS) experiment at the LHC will produce Petabytes of data a year [1]. This data is then to be distributed to multiple sites which form a hierarchical structure based on available resources: the detector is associated with a Tier 0 site; Tier 1 sites are typically large national computing centres; and Tier 2 sites are Institutes with a more restricted availability of resources and/or services. A core set of Tier 1 sites with large tape, disk and network resources will receive raw and reconstructed data to safeguard against data loss at CERN. Smaller sites, associated with certain analysis groups or Universities, will also subscribe to certain parts of the data. Sites at all levels will be involved in producing Monte Carlo data for comparison with detector data. At the Tier 0 the raw experiment data undergoes a process called reconstruction in which it is restructured to represent physics objects. This data will be grouped hierarchically by stream and dataset based on physics content, then further subdivided by finer granularity metadata. There are therefore three main use cases for distribution in CMS. The first can be described as a push with high priority, in which raw data is replicated to tape at Tier 1s. The second is a subscription pull, where a site subscribes to all data in a given set and data is transferred as it is produced. This use case corresponds to a site registering an interest in the data ","PeriodicalId":66916,"journal":{"name":"高能物理与核物理","volume":"86 1","pages":"838-841"},"PeriodicalIF":0.0,"publicationDate":"2004-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79158697","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"PION-NUCLEUS DOUBLE CHARGE-EXCHANGE","authors":"Hq Jiang, B. Zou","doi":"10.1142/1042","DOIUrl":"https://doi.org/10.1142/1042","url":null,"abstract":"Present status in theoretical and experimental studies for pion double charge exchange is reviewed in this paper. Various possible mechanisms for pion double charge exchange are discussed and some open problems are addressed.","PeriodicalId":66916,"journal":{"name":"高能物理与核物理","volume":"304 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"1992-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86764494","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A NEW CO-BOUNDARY OPERATOR AND ITS APPLICATIONS","authors":"K. Chou, Yue-Liang Wu, Yan-bo Xie","doi":"10.1142/9789814280389_0115","DOIUrl":"https://doi.org/10.1142/9789814280389_0115","url":null,"abstract":"In this note new co-boundary operators are defined in the product form. Theassociative composition law of spatial translation group field is discussed using thesenew operators. The quantization condition of monopoles in SU(2) and SU(3) gaugetheories follows easily from the new formalism.","PeriodicalId":66916,"journal":{"name":"高能物理与核物理","volume":"49 1","pages":"1023-1027"},"PeriodicalIF":0.0,"publicationDate":"1986-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77526387","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"EFFECTIVE ACTION AND CHIRAL ANOMALIES IN ANY EVEN DIMENSIONAL SPACE","authors":"K. Chou, X. Song","doi":"10.1142/9789814280389_0113","DOIUrl":"https://doi.org/10.1142/9789814280389_0113","url":null,"abstract":"General expression for gauge covariant anomalous current is obtained from the difference of left handed and right handed Abelian anomaly in 2n+2 dimensions by the method of Weil homomorphism. The general form of symmetric and asymmetric anomalies, gauge invariant Wess-Zumino effective action and anomaly free condition in 2n dimensions are summarized in one closed formula, showing the deep connections among all these topological properties of gauge fields and pseudascalar Goldstone fields in 2n and 2n+e dimensions.","PeriodicalId":66916,"journal":{"name":"高能物理与核物理","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"1985-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87259484","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"SYMMETRICAL ANOMALY, UNSYMMETRICAL ANOMALY AND EFFECTIVE LAGRANGIAN","authors":"K. Chou, Han-Ying Guo, Ke Wu, Xing-chang Song","doi":"10.1142/9789814280389_0112","DOIUrl":"https://doi.org/10.1142/9789814280389_0112","url":null,"abstract":"Both the symmetrical anomaly and the unsymmetrical anomaly are derived from an effective Lagrangian recently constructed on the basis of Chern-Simons topological invariants.","PeriodicalId":66916,"journal":{"name":"高能物理与核物理","volume":"33 1","pages":"1004-1008"},"PeriodicalIF":0.0,"publicationDate":"1984-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83109282","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"SOME DISCUSSIONS ON THE SU(3)×U(1) ELECTRO-WEAK UNIFIED MODEL OF LEPTONS AND QUARKS","authors":"G. Zhou, K. Chou, C. Gao","doi":"10.1142/9789814280389_0110","DOIUrl":"https://doi.org/10.1142/9789814280389_0110","url":null,"abstract":"In this paper we discussed the following problems in the SU(3)×U(1) unified model proposed earlier: (ⅰ) Two possible choices of the Higgs fields and their comparison with the Weinberg-Salam model; (ⅱ) The form of the Higgs self potential and the realization of the spontaneous symmetry breaking; (ⅲ) The relation between the mass spectrum and the generalized Cabibbo mixing angles in a model with several generations of fermions.","PeriodicalId":66916,"journal":{"name":"高能物理与核物理","volume":"118 1","pages":"991-998"},"PeriodicalIF":0.0,"publicationDate":"1981-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74435735","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}