118952634
Linear and nonlinear aspects of relativistic heavy ion interactions from EMU01 results
The recent status of the EMU01 experiment where nuclear emulsions are used as both target/detector material for horizontally exposed stacks and as detector for vertically exposed chamber plates is discussed. An investigation of the behaviour in the number of produced particles per participating nucleon reveal weak nonlinear effects for the most central collisions. Intermittency index can be obtained from the density distributions for S+Au and S+Ag interactions which corresponds to fractal dimensions somewhat smaller than unity.
118728331
KLOE measurement of the $\sigma(\pi^+ \pi^- (\gamma))$ cross section and the pi+ pi- contribution to the muon anomaly
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
209856078
Measurement of the Matrix Element for the Decay $\eta^{\prime} \to \eta \pi^+\pi^-$
117751922
Substructural dependence of the multiparticle production in relativistic heavy-ion interactions
3128292
Lattice design of Beijing Light Source
In this paper, the preliminary design of the magnet lattice of the Beijing Light Source (BLS) is described. The Beijing Light Source is a new generation light source with the energy of 2.2 GeV-2.5 GeV. By choosing the FBA (five bend achromat) and TBA (triplet bend achromat) structure very low horizontal emittance is reached using superconducting dipole magnets. Having made some harmonic corrections, an acceptable dynamic aperture is obtained though further improvement is being done to enlarge the horizontal aperture.
10335512
Antilambda production in Au+Au collisions at 11.7A GeV/c.
We present results for antilambda and antiproton production in Au+Au collisions at 11.7 A GeV/c including spectra and extracted invariant yields for both species in central and peripheral collisions in the rapidity range 1.0<y<1.4. The antilambda yield increases from dN(Lambda;)/dy = 1.2(+0.7+0.2)(-0.6-0.2)x10(-3) in peripheral collisions to 19(+4+3)(-5-2)x10(-3) in central collisions. The direct antiproton yield is deduced from the measured total antiproton spectra to extract the ratio of antilambda-to-direct-antiproton production. The Lambda/p ratio near midrapidity increases from 0.26(+0.19+0.5)(-0.15-0.4) in peripheral collisions to 3.6(+4.7+2.7)(-1.8-1.1) in central collisions, a value larger than current theoretical estimates.
55843797
LATTICE DESIGN FOR THE BEPCII STORAGE RING
BEPCII, the upgrading project of the BEPC, has been being designed with a luminosity of 10 33 cm -2 s -1 at the J/ψ energy. It still keeps the potential to provide beams as a synchrotron radiation (SR) facility. The storage rings for collision contain a positron and an electron ring and the ring for dedicated SR uses the outer parts of the two rings. To fit all the conditions either on beam or on space limit, lattices are carefully designed for both high energy physics and SR experiments with sufficient dynamic apertures and high efficiencies for injection. The features of the lattices are also discussed in the paper. 1 DESIGN REQUIREMENTS BEPCII is an upgrade project of the Beijing ElectronPositron Collider (BEPC), in which a new inner ring will be installed inside the old one. It will provide colliding beams with the center-of-mass energy from 1.0GeV×2 to 2.0GeV×2 and also the dedicated synchrotron radiation beam with 2.5 GeV. For the colliding beams the luminosity is optimized at 1.89 GeV with 1×10 33 cm -2 s -1 . For the dedicated synchrotron radiation beam, the current is 250 mA with an emittance as low as possible. There have been several beam-lines in the BEPC for the synchrotron radiation experiments, so the current bending magnets and insertion devices in the southern region have to be fixed at their present positions. In order to increase the average luminosity, the “topoff” injection scheme up to 1.89 GeV is adopted. This requires that the injection and collision optics must be the same. The main parameters are shown in Tables 1 and 2.
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.
208884192
BEAM INSTABILITY STUDIES IN THE BEPC
The Beijing Electron Positron Collider (BEPC) has been operated since 1987 for the experiment of high energy physics and synchrotron radiation application. About 25mA of a single bunch per beam for colliding is obtained at the energy of 1.55GeV, and over 120mA multi-bunch electron beam is reached at the energy of 2.2GeV in routine operation. Many current dependent phenomena have been observed and analysed during operation and machine studies for years. The bunch lengthening effect, the beam photoelectron instability, the dust effect and the beam ion instability are intensively studied in recent years.