467 research outputs found
Low missing mass, single- and double diffraction dissociation at the LHC
Low missing mass, single- and double diffraction dissociation is calculated
for the LHC energies from a dual-Regge model, dominated by a Pomeron Regge pole
exchange. The model reproduces the rich resonance structure in the low missing
mass Mx region. The diffractionly excited states lie on the nucleon trajectory,
appended by the isolated Roper resonance. Detailed predictions for the squared
momentum transfer and missing mass dependence of the differential and
integrated single- and double diffraction dissociation in the kinematical range
of present and future LHC measurements are given. The model predicts a possible
turn-down of the cross section towards, t -> 0 in a region probably accessible
in future experiments in the nearly forward direction.
The present work is a continuation and extension (e.g. with double
diffraction) of a previous work using the dual Regge approach
Observables of QCD Diffraction
A new combinatorial vector space measurement model is introduced for soft QCD diffraction. The model independent mathematical construction resolves experimental complications; the theoretical framework of the approach includes the Good-Walker view of diffraction, Regge phenomenology together with AGK cutting rules and random fluctuations.Peer reviewe
Central Diffraction at ALICE
10 pages, 8 figuresThe ALICE experiment is shown to be well suited for studies of exclusive final states from central diffractive reactions. The gluon-rich environment ofthe central system allows detailed QCD studies and searches for exotic mesonstates, such as glueballs, hybrids and new charmonium-like states. It wouldalso provide a good testing ground for detailed studies of heavy quarkonia. Dueto its central barrel performance, ALICE can accurately measure the low-masscentral systems with good purity. The efficiency of the Forward MultiplicityDetector (FMD) and the Forward Shower Counter (FSC) system for detectingrapidity gaps is shown to be adequate for the proposed studies. With thisdetector arrangement, valuable new data can be obtained by tagging centraldiffractive processes.Peer reviewe
Multivariate Techniques for Identifying Diffractive Interactions at the LHC
31 pages, 14 figures, 11 tablesClose to one half of the LHC events are expected to be due to elastic or inelastic diffractive scattering. Still, predictions based on extrapolations of experimental data at lower energies differ by large factors in estimating the relative rate of diffractive event categories at the LHC energies. By identifying diffractive events, detailed studies on proton structure can be carried out. The combined forward physics objects: rapidity gaps, forward multiplicity and transverse energy flows can be used to efficiently classify proton-proton collisions. Data samples recorded by the forward detectors, with a simple extension, will allow first estimates of the single diffractive (SD), double diffractive (DD), central diffractive (CD), and non-diffractive (ND) cross sections. The approach, which uses the measurement of inelastic activity in forward and central detector systems, is complementary to the detection and measurement of leading beam-like protons. In this investigation, three different multivariate analysis approaches are assessed in classifying forward physics processes at the LHC. It is shown that with gene expression programming, neural networks and support vector machines, diffraction can be efficiently identified within a large sample of simulated proton-proton scattering events. The event characteristics are visualized by using the self-organizing map algorithm.Peer reviewe
Turning the LHC Ring into a New Physics Search Machine
The LHC Collider Ring is proposed to be turned into an ultimate automatic search engine for new physics in four consecutive phases: (1) Searches for heavy particles produced in Central Exclusive Process (CEP): pp -> p + X + p based on the existing Beam Loss Monitoring (BLM) system of the LHC; (2) Feasibility study of using the LHC Ring as a gravitation wave antenna; (3) Extensions to the current BLM system to facilitate precise registration of the selected CEP proton exit points from the LHC beam vacuum chamber; (4) Integration of the BLM based event tagging system together with the trigger/data acquisition systems of the LHC experiments to facilitate an on-line automatic search machine for the physics of tomorrow.Peer reviewe
The International Large Detector: Letter of Intent
163 pages, 91 figuresThe International Large Detector (ILD) is a concept for a detector at the International Linear Collider, ILC. The ILC will collide electrons and positrons at energies of initially 500 GeV, upgradeable to 1 TeV. The ILC has an ambitious physics program, which will extend and complement that of the Large Hadron Collider (LHC). A hallmark of physics at the ILC is precision. The clean initial state and the comparatively benign environment of a lepton collider are ideally suited to high precision measurements. To take full advantage of the physics potential of ILC places great demands on the detector performance. The design of ILD is driven by these requirements. Excellent calorimetry and tracking are combined to obtain the best possible overall event reconstruction, including the capability to reconstruct individual particles within jets for particle ow calorimetry. This requires excellent spatial resolution for all detector systems. A highly granular calorimeter system is combined with a central tracker which stresses redundancy and efficiency. In addition, efficient reconstruction of secondary vertices and excellent momentum resolution for charged particles are essential for an ILC detector. The interaction region of the ILC is designed to host two detectors, which can be moved into the beam position with a push-pull scheme. The mechanical design of ILD and the overall integration of subdetectors takes these operational conditions into account
SiD Letter of Intent
Letter of Intent for SiD detector concept presented to ILC IDAGLetter of intent describing SiD (Silicon Detector) for consideration by the International Linear Collider IDAG panel. This detector concept is founded on the use of silicon detectors for vertexing, tracking, and electromagnetic calorimetry. The detector has been cost-optimized as a general-purpose detector for a 500 GeV electron-positron linear collider
Study on the foam fractionation in the recovery of total saikosaponins and heavy metal ions
泡沫分离技术是一种利用表面吸附原理进行分离的新型分离技术,在废水处理、医药工业、食品、电镀、化工等领域均有广泛的应用前景。本文针对泡沫分离法在中药领域中柴胡总皂苷的分离及废水处理领域中重金属离子Zn2+和Ni2+的去除分别进行了研究。重点考察了气速、pH值、溶质初始浓度、表面活性剂种类、表面活性剂浓度、载液量和分离时间等因素对分离效果的影响。主要结论如下: (1)在泡沫分离柴胡总皂苷的实验中,首先对比了用水和乙醇做溶剂所得料液的分离效果,确定乙醇为最佳提取溶剂;其次采用对二甲氨基苯甲醛-磷酸显色法测量柴胡总皂苷的浓度,并用分光光度计进行全波长扫描,确定柴胡皂苷a的最大显色波长为536nm;最...Foam fractionation, an ecological and economical method belonging to the adsorptive bubble separation techniques, exhibits wider application in wastewater treatment, pharmaceutical industry, galvanization, chemical industry and food industry. This paper studied the technology of foam separation for separating saikosaponins from Bupleuri Chinese DC and removing mental ions (Zn2+ and Ni2+) in aqueou...学位:工学硕士院系专业:化学化工学院_化学工艺学号:2062010115149
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