39223572
Observation of a spin-flip M1 transition in 7(lambda)Li.
Using a large-acceptance germanium detector array (Hyperball), we have observed a spin-flip M1 gamma transition between the ground-state spin doublet of (7)(Lambda)Li (3/2(+)-->1/2(+)). The observed energy of 691.7+/-0.6(stat)+/-1.0(syst) keV provides crucial information on the strength of the spin-spin interaction between a Lambda and a nucleon. This is the first observation of well-identified hypernuclear gamma transitions using germanium detectors.
122783059
Radio frequency picosecond phototube
Abstract We propose a photon detector for recording low-level and ultra-fast optical signals, based on radio frequency (RF) analysis of low-energy photoelectrons (PEs). By using currently developed 500 MHz RF deflector, it is possible to scan circularly and detect single PEs, amplified in multi-channel plates (MCPs). The operation of the tube is investigated by means of thermionic electron source. It is demonstrated that the signals generated in the MCP can be processed event by event; by using available nanosecond electronics and that time resolution better than 20 ps can be achieved. Timing characteristics of the Cherenkov detector with RF phototube in a ‘head-on’ geometry is investigated by means of Monte Carlo simulation.
123162199
RF Cherenkov picosecond timing technique for high energy physics applications
Abstract The Cherenkov time-of-propagation (TOP) detector and Cherenkov time-of-flight (TOF) detector in a “head-on” geometry based on the recently proposed time measuring technique with radio frequency (RF) phototube are considered. Results of the Monte Carlo simulations are presented.
6839874
The structure of Pariacoto virus reveals a dodecahedral cage of duplex RNA
The 3.0 Å resolution crystal structure of Pariacoto virus (PaV) reveals extensive interactions between portions of the viral RNA genome and the icosahedral capsid. Under the protein shell of the T = 3 quasi equivalent capsid lies a dodecahedral cage composed of RNA duplex that accounts for ∼35% of the single-stranded RNA genome. The highly basic N-terminal regions (residues 7–54) of the subunits, forming pentamers (A subunits) are clearly visible in the density map and make numerous interactions with the RNA cage. The C-terminal segments (residues 394–401) of the A subunits lie in channels near the quasi three-fold axes. Electron cryo-microscopy and image reconstruction of PaV particles clearly show the dodecahedral RNA cage.
125394021
gamma-ray spectroscopy of (Lambda)Be-9
123272214
New (e,e′K+) hypernuclear spectroscopy with a high resolution kaon spectrometer
Abstract A new ( e , e ′ K + ) hypernuclear spectroscopy is proposed at Jefferson Lab. With a newly designed high resolution kaon spectrometer (HKS) and a new experimental configuration to reduce background electrons associated with bremsstrahlung, it is expected to realize much higher yield and hypernuclear mass resolution than those of the first successful experiment at Jefferson Lab Hall-C, which demonstrated the feasibility of hypernuclear electroproduction for Λ hypernuclear spectroscopy.
118805500
Study on the mixing among the $0^{++}$ mesons around $1\sim 2$ $\mathrm{GeV}$ with the QCD sum rules
We calculate the correlation functions of $0^{++}$ $q\bar q$, $s\bar s$ and glueball in the QCD sum rules and obtain the mass matrix where non-diagonal terms are determined by the cross correlations among the three states. Diagonalizing the mass matrix and identifying the eigenstates as the physical $0^{++}$ scalar mesons, we can determine the mixing. Concretely, our calculations determine the fractions of $q\bar q$, $s\bar s$ and glueball in the physical states $f_0(1370)$, $f_0(1500)$ and $f_0(1710)$, the results are consistent with that gained by the phenomenological research.
119236104
Fermion correction to the mass of the scalar glueball in QCD sum rule
Contributions of fermions to the mass of the scalar glueball $0^{++}$ are calculated at two-loop level in the framework of QCD sum rules. It obviously changes the coefficients in the operator product expansion (OPE) and shifts the mass of glueball.