17524844
Measuring the hadronic cross-section at KLOE using the radiative return
We present a study of the reaction e+e−→π+π−γ at theφ peak with the KLOE detector at the φ–factory DAΦNE. This reaction allows us to obtain the cross section for e+e−→π+π− from theee center-of-mass energy W = mφ = 1019 MeV down to threshold, i.e.2mπ < Mππ < mφ. This is called radiative return. The status of the analysis and preliminary results on the invariant mass spectrum of the two-pion-state are presented.
17251648
Measurement of the DAΦNE luminosity with the KLOE detector using large angle Bhabha scattering
We describe the method of measuring the integrated luminosity of the e+e- collider DAΦNE, the Frascati φ-factory. The measurement is done with the KLOE detector selecting large angle Bhabha scattering events and normalizing them to the effective cross section. The e+e-→e+e-(γ) cross section is calculated using different event generators which account for the $\mathcal{O}(\alpha)$ radiative initial and final state corrections, and the φ resonance contribution. The accuracy of the measurement is 0.6%, where 0.3% comes from systematic errors related to the event counting and 0.5% from theoretical evaluations of the cross section.
126297547
Experimental study of hadron inclusive production in J / psi energy region
117751922
Substructural dependence of the multiparticle production in relativistic heavy-ion interactions
122689361
Search for New Phenomena with the Monojet and Missing Transverse Momentum Signature Using the ATLAS Detector in $\sqrt{s}=7$ TeV Proton-Proton Collisions
A search for new phenomena in events featuring a high energy jet and large missing transverse momentum in proton-proton collisions at root s = 7 TeV is presented using a dataset corresponding to an integrated luminosity of 33 pb(-1) recorded with the ATLAS detector at the Large Hadron Collider. The number of observed events is consistent with the Standard Model prediction. This result is interpreted in terms of limits on a model of Large Extra Dimensions. (C) 2011 CERN. Published by Elsevier B.V. All rights reserved.
125260045
Evidence of sigma particle in J / psi ---> omega pi pi
123281398
Transfer matrix of linear solenoid fringe superimposed magnet
The general transfer matrix of the superimposed solenoid magnet linear fringe field is given in this paper. It is an exact analytic matrix. The symplectic condition for the arbitrary shape solenoid will be discussed also.
122103110
Experimental studies on the photoelectron instability in the Beijing Electron Positron Collider
A vertical coupled-bunch instability was observed for a positron beam at the Beijing Electron Positron Collider (BEPC). The experimental results show that the instability has similar characteristics as that observed in the Photon Factory of KEK several years ago. The instability at BEPC can be explained by the effect of an electron cloud which is produced in the beam chamber by synchrotron light hitting the wall.
56018915
Bunch lengthening study in BEPC
The bunch lengthening in the Beijing Electron-Positron Collider (BEPC) is investigated systematically with streak camera and the method of beam spectrum analysis. Many available results are obtained from the measurement and the corresponding scaling law is summarized in the light of the existing theoretical explanation. Due to its importance for BEPC upgrades, the related parameters and effects of bunch lengthening are studied in details.
55996561
Experiment to measure the electron cloud at BEPC
Many experiments on photoelectron instability (PEI) have been carried out at the Beijing Electron Positron Collider (BEPC) in IHEP, China, in collaboration with KEK. Simulations on the PEI with a physical model give qualitative agreements with the observations at both BEPC and KEK-B. Based on the detectors at Advanced Photon Source (APS), ANL, a specially-constructed detector was installed at the BEPC. It is hoped to obtain realistic values for the photoelectron (PE) and secondary electron yields as well as the energy spectrum of the electron cloud through the direct measurements of the properties of the PE cloud for both stable and unstable beams. In this paper, the experimental results at the BEPC are presented after the description of the instrumentation, and some discussions are followed afterwards.
53403255
THE BUNCH LENGTH MEASUREMENT OF BEPC WITH A STREAK CAMERA
A dual-axis streak camera Hamamatsu model C5680-11, has been installed on Beijing Electron-Positron Collider (BEPC) to measure the bunch length and the bunch lengthening in the storage ring. The results of the measurement are more accurate and reliable than that measured with other instruments, and play important roles in the future upgrade of BEPC. In this paper we describe the synchrotron light extracting optics setup, the operating principle, features, the basic system configuration of the streak camera. Some typical results of the measurement in recent years are presented. The measurement errors including systematic and random are also analyzed.