118124145
BEPCII/BESIII Upgrade and the Prospective Physics
The Status of BEPCII/BESIII upgrade is described, BEPCII is designed to reach a luminosity of $10^{33}/cm^{-2}s^{-1}$ at c. m. energy of 3.89GeV, and BESIII detector is fully rebuilt. The project is on track and is progressing well. The machine and detector are expected to commission together at the late half of 2007, and start to take some engineer run end of 2007 or beginning of 2008.
39938475
Experimental Study of Long Coupled Helix Resonator
Experimental tests of a coupled normal temperature low a helix resonator with six-half-wavelength are described. The frequency shift and dynamic instability of the resonator are studied experimentally. The mechanical vibration caused by ponderomotive effect has been controlled. This resonator can run stably at a RF power of 50 KW , frequency of 27 MHz, duty factor of 1/6, and the maximum voltage gain is more than 1.1 MV. Some measures have been taken to increase the stability of the helix. The resonator tested is a model for heavy ion booster following a small van de graff accelerator.
121624088
GENERAL REVIEW OF BES PHYSICS, ACHIEVEMENT AND FUTURE
A general review of BES physics results are given. New results from BES on J/ψ, ψ(2S) and ψ(3770) decays are presented. Enhancement of the mass spectrum at the threshold is observed in the decay of J/ψ to . Analyzes of sigma and kappa signals are reported in J/ψ to ωπ+π- and J/ψ to respectively. Results of new ψ(2S) decay channels are reported and compared with 12% rule. Some results from ψ(3770) scanning and D decays are reported. The status of BEPCII/BESIII project is briefly reported.
178557411
THE STATUS OF BESIII PROJECT
123211493
Exploring the feasibility of a separated function RFQ with mini-vane structure
The accelerating field in the conventional RFQ is originated by the surface modulation of the quadruple electrodes. However, the axial accelerating field generated in this way is quite limited. To enhance the energy gain as well as the focusing power, a post-RFQ accelerating structure called separated function RFQ (SFRFQ) was proposed (Progr. Nat. Sci. 12(1) (2002) 23), and its feasibility has been explored (Chin. Phys. 51(6) (2002)). The RF accelerating field in the SFRFQ structure mainly occurs at gaps between periodical cells, while the electrical quadruple field inside the cells provides the transverse focusing. It turns out that the overall performance can be improved considerably, comparing with that of conventional RFQ. The preliminary results of calculation and model measurements are presented and discussed in the paper.
179453560
NEW BES AND CLEO RESULTS
123608448
Experience of BESIII data production with local cluster and distributed computing model
The BES III detector is a new spectrometer which works on the upgraded high-luminosity collider, BEPCII. The BES III experiment studies physics in the tau-charm energy region from 2 GeV to 4.6 GeV . From 2009 to 2011, BEPCII has produced 106M ψ(2S) events, 225M J/ψ events, 2.8 fb−1 ψ(3770) data, and 500 pb−1 data at 4.01 GeV. All the data samples were processed successfully and many important physics results have been achieved based on these samples. Doing data production correctly and efficiently with limited CPU and storage resources is a big challenge. This paper will describe the implementation of the experiment-specific data production for BESIII in detail, including data calibration with event-level parallel computing model, data reconstruction, inclusive Monte Carlo generation, random trigger background mixing and multi-stream data skimming. Now, with the data sample increasing rapidly, there is a growing demand to move from solely using a local cluster to a more distributed computing model. A distributed computing environment is being set up and expected to go into production use in 2012. The experience of BESIII data production, both with a local cluster and with a distributed computing model, is presented here.
14733840
Monte Carlo Simulations of Type Ia Supernova Observations in Supernova Surveys
We have performed Monte Carlo simulations of Type Ia supernova (SN Ia) surveys to quantify their efficiency in discovering peculiar overluminous and underluminous SNe Ia. We determined how the type of survey (magnitude-limited, distance-limited, or a hybrid) and its characteristics (observation frequency and detection limit) affect the discovery of peculiar SNe Ia. We find that there are strong biases against the discovery of peculiar SNe Ia introduced by at least four observational effects: the Malmquist bias, the age of the SN Ia at the time of its discovery, the shape of its light curve, and its degree of extinction. Surveys with low observation frequency (less than once per 10 days) tend to discover SNe Ia that are too old for observers to easily recognize their peculiarity. Subluminous SNe Ia are underrepresented in magnitude-limited surveys because they can only be found within a small volume and they remain above the detection limit for less time. Conversely, overluminous SNe Ia are more easily found in magnitude-limited surveys, although their likely association with dusty regions reduces the volume in which they can be discovered. The unbiased rate of peculiar SNe Ia can be recovered only in distance-limited surveys with high observation frequencies and with detection limits that are fainter than the peak magnitude of a subluminous SN Ia in the farthest potential host.
119213503
Radiation field simulation of C-ADS Injector II
The injector of C-ADS (Chinese Accelerator Driven Sub-critical System) project is a high current, fully super-conducting proton accelerator. Meanwhile, a BLM system is indispensable to this facility, especially in low energy segments. This paper presents some basic simulations for 10MeV proton by Monte Carlo program FLUKA, as well as the distributions on different secondary particles in three aspects: angular, energy spectrum and current. These results are beneficial to selecting the detector type and its location and determining its dynamic range matching different requirements for both fast and slow beam loss. Further, the major impact of the background is analyzed, such as superconducting cavity X radiation and radiation caused by material activation, in this paper as well. This work is meaningful in BLM system research.
6352305
ABJM with Flavors and FQHE
We add fundamental matters to the = 6 Chern-Simons theory (ABJM theory), and show that D6-branes wrapped over AdS4 × S3/2 in type IIA superstring theory on AdS4 × 3 give its dual description with = 3 supersymmetry. We confirm this by the arguments based on R-symmetry, supersymmetry, and brane configuration of ABJM theory. We also analyze the fluctuations of the D6-brane and compute the conformal dimensions of dual operators. In the presence of fractional branes, the ABJM theory can model the fractional quantum Hall effect (FQHE), with RR-fields regarded as the external electric-magnetic field. We show that an addition of the flavor D6-brane describes a class of fractional quantum Hall plateau transitions.
14326353
Evidence for Extremely High Dust Polarization Efficiency in NGC 3184
Recent studies have found the Type II-plateau supernova (SN) 1999gi to be highly polarized (pmax = 5.8%, where pmax is the highest degree of polarization measured in the optical bandpass) and minimally reddened [E(B-V) = 0.21 ± 0.09 mag]. From multiple lines of evidence, including the convincing fit of a "Serkowski" interstellar polarization (ISP) curve to the continuum polarization shape, we conclude that the bulk of the observed polarization is likely due to dust along the line of sight and is not intrinsic to SN 1999gi. We present new spectropolarimetric observations of four distant Galactic stars close to the line of sight to SN 1999gi (two are within 002) and find that all are null to within 0.2%, effectively eliminating Galactic dust as the cause of the high polarization. The high ISP coupled with the low reddening implies an extraordinarily high polarization efficiency for the dust along this line of sight in NGC 3184: ISP/E(B-V) = 31% mag -1. This is inconsistent with the empirical Galactic limit [ISP/E(B-V) < 9% mag-1] and represents the highest polarization efficiency yet confirmed for a single sight line in either the Milky Way or an external galaxy.