Review of the trigger systems of the ATLAS and CMS detectors at the LHC

The characteristics and principles of multilevel trigger systems of the ATLAS and CMS detectors are considered. Calorimeter algorithms for particle identification are described. The parameters of the trigger chambers used for muon track identification are presented. Methods for designing custom processors based on custom integrated circuits and programmable arrays are described. The parameters of the trigger systems of the ATLAS and CMS detectors are compared.     

Results of searches for extra spatial dimensions in the CMS experiment at the LHC

An overview of basic results of the CMS experiment that concern searches for signals from extra spatial dimensions in the course of the first run of the Large Hadron Collider (LHC) at the c.m. proton–proton collision energies of 00000 and 8 TeV is given.     

Searches for extra dimensions in the CMS experiment at the Large Hadron Collider (LHC)

Predictions of multidimensonal theories are analyzed, and the possibility of detecting signals from extra spatial dimensions in the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC) is studied.     

Search for Heavy Neutral Gauge Bosons in the Dilepton Channel in the CMS Experiment at the LHC

Physics of Atomic Nuclei - Results of searching for narrow heavy resonances on the basis of their decays into a pair of leptons in the CMS experiment at the LHC are reported. The 2016–2018...     

Search for New Heavy Higgs Bosons in the ATLAS and CMS Experiments at the LHC (Brief Review)

JETP Letters - The discovery of the Higgs boson by the ATLAS and CMS collaborations in 2012 was an important milestone in the modern elementary particle physics, which finally confirm the Standard...     

Searches for physics beyond the standard model in proton-proton interactions at \sqrt s = 7 TeV in the CMS experiment at the LHC

The results obtained in the CMS experiment at the LHC from searches for various physics phenomena beyond the Standard Model in proton-proton interactions at the c.m. energy of 7 TeV are presented. The respective analysis is based on data measured in the CMS experiment over the period spanning 2010 and 2011.     

A novel evaluation method for thin films mechanical characterizations using cutting system

In this study, we suggest a nano-cutting system to determine the shear strength of the thin films using fracture mechanics analysis of the diamond blade. Based on Merchant's cutting model, we analyze the thin films cutting process with regard to shear angle and resistant forces as initiation of the yield in the chip to establish a direct correlation between the cutting forces and the shear strength. Validating the proposed method was conducted using homogenous polycarbonate disk showing similar shear strengths between different cutting directions. Next, we examined a thin copper electroplated film used in traces of printed circuit board. A thin copper film was examined and found the intrinsic shear strength (307.5 MPa) and adhesion force (44 N/m) between the film and substrate. The result was comparable with tensile strength values reported in the literatures. Finally, we used SEM to visually verify the feasibility of nano-cutting technique to determine thin film properties.     

Searches for signals from microscopic black holes in processes of proton collisions at \sqrt s = 7 TeV in the CMS experiment at the LHC

If the fundamental scale of multidimensional gravity is about one or several TeV units, microscopic black holes or objects referred to as string balls may be produced at the LHC. The most recent results obtained by the CMS Collaboration at the LHC from searches for such signals at the c.m. protoninteraction energy of 7 TeV and for an integrated luminosity of 4.7 fb^?1. Lower limits on the masses of objects of strongly acting gravity were set in the parameter region accessible to tests at the present time. Prospects for further research in this field are discussed.     

Significance calculation and a new analysis method in searching for new physics at the LHC

The LHC experiments have great potential in discovering many possible new particles up to the TeV scale. The significance calculation of an observation of a physics signal with known location and shape is no longer valid when either the location or the shape of the signal is unknown. We find the current LHC significance calculation of new physics is over-estimated and strongly depends on the specifics of the method and the situation it applies to. We describe general procedures for significance calculation and comparing different search schemes. A new method uses maximum likelihood fits with floating parameters and scans the parameter space for the best fit to the entire sample. We find that the new method is significantly more sensitive than current method and is insensitive to the exact location of the new physics signal we search.     

Performance evaluation of BPM system in SSRF using PCA method

The beam position monitor (BPM) system is of most importance in a light source. The capability of the BPM depends on the resolution of the system. The traditional standard deviation on the raw data method merely gives the upper limit of the resolution. Principal component analysis (PCA) had been introduced in the accelerator physics and it could be used to get rid of the actual signals. Beam related information was extracted before the evaluation of the BPM performance. A series of studies had been made in the Shanghai Synchrotron Radiation Facility (SSRF) and PCA was proved to be an effective and robust method in the performance evaluations of our BPM system.     

A data analysis method for isochronous mass spectrometry using two time-of-flight detectors at CSRe

The concept of isochronous mass spectrometry(IMS) applying two time-of-flight(TOF) detectors originated many years ago at GSI. However, the corresponding method for data analysis has never been discussed in detail. Recently, two TOF detectors have been installed at CSRe and the new working mode of the ring is under test. In this paper, a data analysis method for this mode is introduced and tested with a series of simulations. The results show that the new IMS method can significantly improve mass resolving power via the additional velocity information of stored ions. This improvement is especially important for nuclides with Lorentz factor γ-value far away from the transition point γt of the storage ring CSRe.     

基于OPNET的远程测试系统性能评估方法研究

针对通信网络对远程测试应用的支持性能评估问题,探讨了运用网络仿真对远程测试通信网进行仿真研究的具体流程。在一般进行网络仿真研究的工作流程基础之上,围绕远程测试应用要求的服务质量,给出了分析远程测试网络的性能指标,并重点介绍了利用OPNET建立远程测试通信网络模型及其业务流模型的方法。最后运用该方法对远程测试系统性能指标进行仿真和获取,验证了该仿真方法的有效性和可行性。     

A new FPGA-based trigger/DAQ system for the MTV experiment at TRIUMF

A new FPGA based data acquisition (DAQ) and trigger combined system is developed for the MTV experiment (Mott Polarimetry for T-Violation Experiment). The MTV experiment measures backward Mott scattering events by detecting the incident and scattered tracks using a drift chamber. For the backward scattering probability is as small as less than 0.1%, efficient triggering system is required to select the desired events. An intelligent Level-2 trigger system reading hitting pattern together with its digital readout system are built in a custom FPGA system. In this paper, design overview and results from performance tests are described.     

Robust method for dielectric tensor evaluation from spectrophotometric data

This paper deals with the mathematical modeling of the interaction between the electromagnetic waves of the optical range and multilayer optical structures, the application of which is highly popular today. A robust method for calculating the optical properties of a single layer is described using the measured or required parameters. References to the scientific works reported in this area are presented.     

QCD analysis of CMS W+ charm measurements at LHC with s~(1/2)=7 TeV and implications for strange PDF

We calculate cross-sections and cross-section ratios of a charm quark production in association with a W gauge boson at next-to-leading order QCD using MadGraph and CTIONNLO,CT14 NNLO,and MSTW2008 NNLO PDFs.We compare the results with measurements from the CMS detector at the LHC at a center-of-mass energy of 7 TeV.Moreover,we calculate absolute and normalized differential cross-sections as well as differential cross-section ratios as a function of the lepton pseudorapidity from the W boson decay.The correlation between the CT14 NNLO PDFs and Predictions for W+charm data are studied as well.Furthermore,by employing the error PDF updating method proposed by the CTEQ-TEA group,we update CT14 NNLO PDFs,and analyze the impact of CMS 7 TeV W+charm production data to the original CT14 NNLO PDFs.By comparison of the g(x,Q),s(x,Q),u(x,Q),d(x,Q),u(x,Q),and d(x,Q) PDFs at Q=1.3 GeV and Q=100 GeV for the CT14 NNLO and CT14 NNLO+Wc,we see that the error band of the s(x,Q) PDF is reduced in the region x 0.4,and the error band of g(x,Q) PDF is also slightly reduced at region 0.01 x 0.1.     

Design and performance analysis of various one dimensional codes using different data formats for OCDMA system

In this paper, the design, implementation and performance analysis of various one dimensional codes in an OCDMA system for different data formats is presented. A number of different codes are used with optical CDMA to improve its error performance. Here, three such codes, optical orthogonal codes (OOC), Walsh Hadamard codes and zero cross-correlation (ZCC) codes have been compared using different data formats, NRZ raised cosine, NRZ rectangular, RZ raised cosine and RZ rectangular. It is found that NRZ raised cosine has the best system performance for all the codes used. After that, the three codes have been compared in terms of the BER, eye diagrams and received optical power using NRZ raised cosine modulation format. It is analyzed that ZCC codes have zero cross-correlation property. The simulation results revealed that ZCC codes can provide a better BER compared to the OOC and Walsh Hadamard codes and it is most suitable to be employed in the OCDMA systems.