118561275
Test of the prototype of electron detector for LHAASO project using cosmic rays
LHAASO project is to be built in south-west China, which use an array of 5137 election detectors for the measurement of the incident electrons arriving at the detector plane. For the quality control of the big quantity of electron detectors, a cosmic ray hodoscope with two-dimensional spacial sensitivity and good time resolution has been developed. The ?rst prototype of electron detector is tested with the hodoscope and the performance of the detector is validated to be consistent with the design.
119599949
Backward Compton scattering and QED with noncommutative plane in the strong uniform magnetic field
In the strong uniform magnetic field, the noncommutative plane (NCP) caused by the,lowest Landau level (LLL) effect, and QED with NCP (QED-NCP) are studied. Being similar to the condensed matter theory of quantum Hall effect, an effective filling factor f (B) is introduced to characterize the possibility that the electrons stay on the LLL. The analytic and numerical results of the differential cross section for the process of backward Compton scattering in accelerator with unpolarized or polarized initial photons are calculated. The existing data of BL38B2 in Spring-8 have been analyzed roughly and compared with the numerical predictions primitively. We propose a precise measurement of the differential cross sections of backward Compton scattering in a strong perpendicular magnetic field, which may reveal the effects of NCP.
208866876
The high transverse momentum non-photonic electron measurements in Au + Au collisions at sNN = 200 GeV at RHIC
We present preliminary results of Non-Photonic Electron (NPE) production, NPE-hadron azimuthal correlation as well as NPE elliptic flow studies at midrapidity using a data set with high statistics and low photon conversion background from Au + Au collisions at sNN = 200 GeV collected at RHIC in Run 2010.
12322167
Asymptotic limits and sum rules for gauge field propagators
Abstract For gauge field propagators, the asumptotic behavior is obtained in all directions of the complex k2-plane, and for general, linear, covariant gauges. Asymptotically free theories are considered. Except for coefficients, the functional form of the leading asymptotic terms is gauge-independent. Exponents are determined exactly by one-loop expressions. Sum rules are derived, which generalize the superconvergence relations obtained in the landau gauge.
110532551
Status of high current R&D Energy Recovery LINAC at Brookhaven National Laboratory
An ampere class 20 MeV superconducting Energy Recovery Linac (ERL) is under construction at Brookhaven National Laboratory (BNL) for testing of concepts relevant for high-energy coherent electron cooling and electron-ion colliders. One of the goals is to demonstrate an electron beam with high charge per bunch ({approx} 5 nC) and low normalized emittance ({approx} 5 mm-mrad) at an energy of 20 MeV. Flexible lattice of ERL loop provides a test-bed for investigating issues of transverse and longitudinal instabilities, and diagnostics for intense CW e-beam. The superconducting 703 MHz RF photoinjector is considered as an electron source for such a facility. We will start with a straight pass (gun - 5 cell cavity - beam stop) test for the SRF Gun performance studies. Later, we will install and test a novel injection line concept for emittance preservation in a lower energy merger. In this paper we present the status and our plans for construction and commissioning of this facility.
122503839
Properties of an Accelerating Gauss-Bonnet Vacuum in Five Dimensions
The causal structure of a five-dimensional C-metric like vacuum solution of Gauss-Bonnet gravity is analyzed in detail, the Gauss-Bonnet parameter make it more complex than that of a C-metric like solution of Einstein gravity. The acceleration of the observer fixed at a spatial position is calculated, the effect of the Gauss-Bonnet parameter comes in, but the acceleration of the origin is not affected by the parameter. The geodesics of the test particles in the spacetime are investigated, it is found that objects accelerate to go to the horizon in the accelerating spacetime.
14783506
System-size dependence of transverse momentum correlations at √s NN=62.4 and 200 GeV at the BNL Relativistic Heavy Ion Collider
We present a study of the average transverse momentum ($p_t$) fluctuations and $p_t$ correlations for charged particles produced in Cu+Cu collisions at midrapidity for $\sqrt{s_{NN}} =$ 62.4 and 200 GeV. These results are compared with those published for Au+Au collisions at the same energies, to explore the system size dependence. In addition to the collision energy and system size dependence, the $p_t$ correlation results have been studied as functions of the collision centralities, the ranges in $p_t$, the pseudorapidity $\eta$, and the azimuthal angle $\phi$. The square root of the measured $p_t$ correlations when scaled by mean $p_t$ is found to be independent of both colliding beam energy and system size studied. Transport-based model calculations are found to have a better quantitative agreement with the measurements compared to models which incorporate only jetlike correlations.