118548008
A New Multi-wavelength Solar Telescope: Optical and Near-infrared Solar Eruption Tracer (ONSET)
A new multi-wavelength solar telescope, the Optical and Near-infrared Solar Eruption Tracer (ONSET) of Nanjing University, has been constructed. It was fabricated at the Nanjing Institute of Astronomical Optics & Technology, and the operation is jointly administered with Yunnan Astronomical Observatory. ONSET is able to observe the Sun in three wavelength windows: He I 10830 angstrom, H alpha and white-light at 3600 angstrom and 4250 , which are selected in order to simultaneously record the dynamics of the corona, chromosphere and photosphere respectively. Full-disk or partial-disk solar images with a field of 10' at three wavelengths can be obtained nearly simultaneously. It is designed to trace solar eruptions with high spatial and temporal resolutions. This telescope was installed at a new solar observing site near Fuxian Lake in Yunnan Province, southwest China. The site is located at E102N24, with an altitude of 1722 m. The seeing is stable and has high quality. We give a brief description of the scientific objectives and the basic structure of ONSET. Some preliminary results are also presented.
118189735
Studies of neutron-rich nuclei with the CLARA-PRISMA setup and description of the heavy-ion detector DANTE
A polymeric antioxidant which comprises a monomeric unit having a formula (I): (I) wherein R1 is methyl or ethyl; and a monomeric unit having a formula (II): (II) which imparts an excellent resistance against heat- or light-aging to a synthetic fiber and a resin.
119301447
Calibration of pulse transit time through a cable for EAS experiments
In ground-based extensive air shower experiments, the direction and energy are reconstructed by measuring the relative arrival time of secondary particles, and the energy they deposit. The measurement precision of the arrival time is crucial for determination of the angular resolution. For this purpose, we need to obtain a precise relative time offset for each detector, and to apply the calibration process. The time offset is associated with the photomultiplier tube, cable, relevant electronic circuits, etc. In view of the transit time through long cables being heavily dependent on the ambient temperature, a real-time calibration method for the cable transit time is investigated in this paper. Even with a poor-resolution time-to-digital converter, this method can achieve high precision. This has been successfully demonstrated with the Front-End-Electronic board used in the Daya Bay neutrino experiment.
118454051
Investigation of excited states in $^{18}$Ne via resonant elastic scattering of $^{17}$F+p and its astrophysical implication in the stellar reaction of $^{14}$O($\alpha$,$p$)$^{17}$F
Properties of proton resonances in $^{18}$Ne have been investigated efficiently by utilizing a technique of proton resonant elastic scattering with a $^{17}$F radioactive ion (RI) beam and a thick proton target. A 4.22~MeV/nucleon $^{17}$F RI beam was produced via a projectile-fragmentation reaction, and subsequently separated by a Radioactive Ion Beam Line in Lanzhou ({\tt RIBLL}). Energy spectra of the recoiled protons were measured by two sets of $\Delta$E-E silicon telescope at center-of-mass scattering angles of $\theta_{c.m.}$$\approx$175${^\circ}$$\pm$5${^\circ}$, $\theta_{c.m.}$$\approx$152${^\circ}$$\pm$8${^\circ}$, respectively. Several proton resonances in $^{18}$Ne were observed, and their resonant parameters have been determined by an $R$-matrix analysis of the differential cross sections in combination with the previous results. The resonant parameters are related to the reaction-rate calculation of the stellar $^{14}$O($\alpha$,$p$)$^{17}$F reaction, which was thought to be the breakout reaction from the hot CNO cycles into the $rp$-process in x-ray bursters. Here, $J^\pi$=(3$^-$, 2$^-$) are tentatively assigned to the 6.15-MeV state which was thought the key 1$^-$ state previously. In addition, a doublet structure at 7.05 MeV are tentatively identified, and its contribution to the resonant reaction rate of $^{14}$O($\alpha$,$p$)$^{17}$F could be enhanced by at least factors of about 4$\sim$6 in comparison with the previous estimation involving only a singlet. The present calculated resonant rates are much larger than those previous values, and it may imply that this breakout reaction could play a crucial role under x-ray bursters conditions.
122356247
Automatic analysis of the emulsion chamber using the image scanner applied to the Tibet hybrid experiment
A new method of emulsion chamber analysis by using an image scanner is developed in order to process a large number of X-ray films used in the Tibet hybrid experiment which is carried out to observe primary proton spectrum in the PeV region. The experimental procedure in this method consists of multiple steps of processing the image of the X-ray films, i.e. the detection of cascade showers induced by high-energy γ-rays, the noise reduction, the spatial reconstruction of γ-families and their energy determination. The quality of the results obtained by the new method is compared with that obtained by the current manual method or Monte Carlo simulations. It is shown that sufficiently high quality of the emulsion chamber analysis is realized by the automatic method both in energy and geometrical resolution.
108549890
A fast Time‐of‐Flight detector also used as a tracker
We present a possible scheme for a fast Time‐of‐Flight detector which could also serve as part of the charged particle tracking system. The detector consists of scintillating fibers read out by newly developed microchannel plate photomultipliers. The performance of the detector in the experimental environment of the τ/charm factory was investigated by a detailed Monte Carlo simulation. The time and space resolutions of the detector are expected to be about 92 ps and 140 μm, respectively.
18650091
Search for Ambient Neutralino Dark Matter at Accelerator
We investigate the possibility of using accelarator beam particles to collide with the ambient neutralino dark matter particles in cosmic rays as a way to search for the cold dark matter. We study in detail its inelastic and elastic scattering with the projectile particles at electron-positron colliders and discuss the possible experimental signals and the relevent background.
119076801
An inflation model with large variations in the spectral index
Recent fits of cosmological parameters by a Wilkinson Microwave Anisotropy Probe (WMAP) measurement favor a primordial scalar spectrum with a varying index. This result, if it stands, could severely constrain inflation model building. Most extant slow-roll inflation models allow for only a tiny amount of scale variations in the spectrum. We propose in this paper an extra-dimensional inflation model which is natural theoretically and can generate the required variations of the spectral index as implied by the WMAP for suitable choices of parameters.
118959658
Natural inflation, Planck scale physics and oscillating primordial spectrum
In the "natural inflation" model, the inflaton potential is periodic. We show that Planck scale physics may induce corrections to the inflaton potential, which is also periodic with a greater frequency. Such high frequency corrections produce oscillating features in the primordial fluctuation power spectrum, which are not entirely excluded by the current observations and may be detectable in high precision data of cosmic microwave background (CMB) anisotropy and large scale structure (LSS) observations.
14998446
The FCNC top-squark decay as a probe of squark mixing
In supersymmetry (SUSY) the flavor mixing between top-squark (stop) and charm-squark (scharm) induces the flavor-changing neutral-current (FCNC) stop decay t̃1 → cχ̃1. Searching for this decay serves as a probe of soft SUSY breaking parameters. Focusing on the stop pair production followed by the FCNC decay of one stop and the charge-current decay of the other stop, we investigate the potential of detecting this FCNC stop decay at the Fermilab Tevatron, the CERN Large Hadron Collider (LHC) and the next-generation ee linear collider (LC). We find that this decay may not be accessible at the Tevatron, but could be observable at the LHC and the LC with high sensitivity for some part of parameter space. 14.80.Ly, 11.30.Hv Typeset using REVTEX
119293229
The neutrino mass hierarchy at reactor experiments now that θ13 is large
A bstractNow that θ13 is known to be large, a medium baseline reactor experiment can observe the fine structure of the electron antineutrino survival probability curve, approximately periodic oscillations in L/E with period $ 4\pi /\left| {\varDelta M_{31}^2} \right| $. The periodicity with respect to L/E is broken by 2-3 oscillations which, in the case of the normal (inverted) hierarchy, shift the first 16 oscillations nearly 1% higher (lower) and move the next 16 lower (higher). The energy of each peak determines a particular combination of the mass differences, for example $ {\cos^2}\left( {{\theta_{12 }}} \right)\left| {\varDelta M_{31}^2} \right|+{\sin^2}\left( {{\theta_{12 }}} \right)\left| {\varDelta M_{32}^2} \right| $ for all peaks visible at baselines under 40 km. Comparing these combinations with each other or with NOνA results one can in principle determine the mass hierarchy. Alternately, as the Fourier transforms of the 1-3 and 2-3 oscillation probabilities are out of phase by the 1-2 oscillation probability, near the maximum of the 1-2 oscillation the complex phase of the total survival probability can be used to determine the hierarchy. Two interference effects make this task difficult. First, kilometer distances between the reactors reduce the amplitudes of peaks below about 4 MeV. Second, even reactors 100 or more kilometers away significantly obscure the 1-2 oscillation maximum, which also complicates a measurement of the solar mixing angle with a single detector.