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.
119255652
Bucking coil implementation on PMT for active canceling of magnetic field
Aerogel and water Cerenkov detectors were employed to tag kaons for a lambda hypernuclear spectroscopic experiment which used the (e,e'K{sup +}) reaction in experimental Hall C at Jefferson Lab (JLab E05-115). Fringe fields from the kaon spectrometer magnet yielded ~5 Gauss at the photomultiplier tubes (PMT) for these detectors which could not be easily shielded. As this field results in a lowered kaon detection efficiency, we implemented a bucking coil on each photomultiplier tubes to actively cancel this magnetic field, thus maximizing kaon detection efficiency.
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.
122072860
Delayed Pion Spectroscopy of Hypernuclei
New possibilities of hypernuclear studies at modern electron accelerators based on recently developed radio frequency photomultiplier tubes are discussed.
125558237
Hypernuclear spectrometer system (HNSS) at CEBAF
The hypernuclear spectrometer system at CEBAF and experimental setup are discussed. The SOS (short orbit spectrometer) built for Hall C at CEBAF and an existing high resolution Enge split‐pole spectrometer will form a hypernuclear spectrometer system with energy resolution on the order of 1 MeV and relative low cost. It will be used to perform the first phase experiments which will provide valuable and important information on rates and performance of the coincidence measurements. This information will guide us for future hypernuclear physics studies. This would enable us to start the first phase hypernuclear experiments as early as in 1995.
119227533
Molecular states with hidden charm and strange in QCD Sum Rules
This work uses the QCD Sum Rules to study the masses of the and molecular states with quantum numbers . Interpolating currents with definite C-parity are employed, and the contributions up to dimension eight in the Operator Product Expansion (OPE) are taken into account. The results indicate that two hidden strange charmonium-like states may exist in the energy ranges of and , respectively. The hidden strange charmonium-like states predicted in this work may be accessible in future experiments, e.g., BESIII, BelleII and SuperB. Possible decay modes, which may be useful in further research, are predicted.
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.
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.