120748606
Current status of RENO
We report the current status of Reactor Experiment for Neutrino Oscillation(RENO), which is located on the site of Yonggwang nuclear power plant in the southwestern part of Korea. Two identical detectors are being constructed at 290m and 1380m from the reactor cores, and mockup detector is built to study many technical questions of liquid scintillator and main detectors.
120829108
NaI (Tl) Calorimeter Calibration and Simulation for Coulomb Sum Rule Experiment in Hall-A at Jefferson Lab
A precision measurment of inclusive electron scattering cross sections is carried out at Jefferson Lab in the quasi-elastic region for 4He, 12C, 56Fe and 208Pb targets. The longitudinal (RL) and transverse (RT) response functions of the nucleon need to be extracted precisely in the momentum transfer range 0.55 GeV/c ≤ |q| ≤ 1.0 GeV/c. To achieve the above goal, a NaI (Tl) calorimeter is used to distinguish good electrons from background, including pions and low energy electrons rescattered from the walls of the spectrometer magnets. Due to a large set of kinematics and changes in HV settings, a number of calibrations are performed for the NaI (Tl) detector. Corrections for a few blocks of NaI (Tl) with bad or no signal are applied. The resolution of the NaI (Tl) detector after calibration reached at E = 1 GeV. The performance of the NaI (Tl) detector is compared with a simulation. The good calibration and background analysis for the NaI(Tl) detector are very important for the reduction of the systematic error of cross sections and the separation of RL and RT.
121196804
CERN beam test of silicon-tungsten calorimeter test module
PIN diode silicon sensors with low leakage current were developed as 4×4 pixel arrays from 5 inch wafers. A test module of silicon-tungsten calorimeter was designed, built using the sensors, and tested with high energy beam of electron, muon, and hadrons for the study of its application at the future linear collider. The construction of the test module and the results of the beam test are discussed.
121615298
Measurement of the refractive index of the LAB-based liquid scintillator and acrylic at RENO
In this paper, we describe the first measurement of the refractive index of the linear alkyl benzene (LAB)-based liquid scintillator and acrylic used at the Reactor Experiment for Neutrino Oscillation (RENO). The refractive index of a material is an important optical property and the prism spectrometer is the most common device for measuring the refractive index. Using the minimum deviation technique, which requires an exact measurement of the apex angle, we determined the refractive indices at six different wavelengths and then fitted them. We also compared the refractive index of the LAB-based liquid scintillator with the refractive indices of other liquid scintillator solvents commonly used in reactor neutrino experiments.
119303854
Time and Amplitude of Afterpulse Measured with a Large Size Photomultiplier Tube
Abstract We have studied the afterpulse of a hemispherical photomultiplier tube for an upcoming reactor neutrino experiment. The timing, the amplitude, and the rate of the afterpulse for a 10 in. photomultiplier tube were measured with a 400 MHz FADC up to 16 μ s time window after the initial signal generated by an LED light pulse. The time and amplitude correlation of the afterpulse shows several distinctive groups. We describe the dependencies of the afterpulse on the applied high voltage and the amplitude of the main light pulse. The present data could shed light upon the general mechanism of the afterpulse.
15518582
Pentaquarks in SU(3) quark model
Based on the flavor SU(3) symmetry, we classify all the possible pentaquark baryons made of four quarks and one antiquark. In particular, we present possible multiplets of pentaquarks, their interactions with mesons, and the mass relations within a multiplet. We also study the pentaquark decays in the generalized OZI rule.
119171103
Model-independent aspects of the reaction $\bar{K} + N \to K + \Xi$
Various model-independent aspects of the $\bar{K} N \to K \Xi$ reaction are investigated, starting from the determination of the most general structure of the reaction amplitude for $\Xi$ baryons with $J^P=\frac12^\pm$ and $\frac32^\pm$ and the observables that allow a complete determination of these amplitudes. Polarization observables are constructed in terms of spin-density matrix elements. Reflection symmetry about the reaction plane is exploited, in particular, to determine the parity of the produced $\Xi$ in a model-independent way. In addition, extending the work of Biagi $\mathrm{\textit{et al. } [Z. Phys.\ C \textbf{34}, 175 (1987)]}$, a way is presented of determining simultaneously the spin and parity of the ground state of $\Xi$ baryon as well as those of the excited $\Xi$ states.
118535105
Production cross section of neutron-rich isotopes with radioactive and stable beams
The production cross section of neutron-rich isotopes of Ca, Zn, Te, Xe, and Pt are predicted in the diffusive multinucleon transfer reactions with stable and radioactive beams. With these isotopes one can treat the neutron shell evolution beyond $N=28$, 50, 82, and 126. Because of the small cross sections, the production of nuclei near the neutron drip line requires the optimal choice of reaction partners and bombarding energies.