729 research outputs found
Thermal Conductivity of the Quasi One-Dimensional Spin System Sr_2_V_3_O_9_
We have measured the thermal conductivity along the [101] direction,
kappa_[101]_, along the [10-1] direction, kappa_[10-1]_, and along the b-axis,
kappa_b_, of the quasi one-dimensional S=1/2 spin system Sr_2_V_3_O_9_ in
magnetic fields up to 14 T, in order to find the thermal conductivity due to
spinons and to clarify whether the spin-chains run along the [101] or [10-1]
direction. It has been found that both kappa_[101]_, kappa_[10-1]_ and kappa_b_
show one peak around 10 K in zero field and that the magnitude of kappa_[10-1]_
is larger than those of kappa_[101]_ and kappa_b_. By the application of
magnetic field along the heat current, the peak of kappa_[10-1]_ is markedly
suppressed, while the peaks of kappa_[101]_ and kappa_b_ little change. These
results indicate that there is a large contribution of spinons to kappa_[10-1]_
and suggest that the spin-chains run along the [10-1] direction.Comment: 3 pages, 4 figure
Total reaction cross section on a deuteron target and the eclipse effect of the constituent neutron and proton
Background: Eclipse effect of the neutron and proton in a deuteron target is
essential to correctly describe high-energy deuteron scattering. The
nucleus-deuteron scattering needs information not only on the nucleus-proton
but also the nucleus-neutron interaction, for which no direct measurement of
the nucleus-neutron cross sections is available for unstable nuclei.
Purpose: We systematically evaluated the total reaction cross sections by a
deuteron target to explore the feasibility of extracting the nucleus-neutron
interaction from measurable cross sections.
Methods: High-energy nucleus-deuteron collision is described by the Glauber
model, in which the proton and neutron configuration of the deuteron is
explicitly taken into account.
Results: Our calculation reproduces available experimental total reaction
cross section data on the nucleus-deuteron scattering. The possibility of
extracting the nucleus-neutron total reaction cross section from
nucleus-deuteron and nucleus-proton total reaction cross sections is explored.
The total reaction cross sections of a nucleus by proton, neutron, and deuteron
targets can be expressed, to good accuracy, in terms of the nuclear matter
radius and neutron skin thickness. Incident-energy dependence of the total
reaction cross sections is examined.
Conclusions: The total reaction cross section on a deuteron target includes
information on both the nucleus-neutron and nucleus-proton profile functions.
Measuring the cross sections by deuteron and proton targets is a promising tool
to extract the nuclear size properties.Comment: 9 pages, 5 figures, to appear in Phys. Rev.
Existence of Dynamical Scaling in the Temporal Signal of Time Projection Chamber
The temporal signals from a large gas detector may show dynamical scaling due
to many correlated space points created by the charged particles while passing
through the tracking medium. This has been demonstrated through simulation
using realistic parameters of a Time Projection Chamber (TPC) being fabricated
to be used in ALICE collider experiment at CERN. An interesting aspect of this
dynamical behavior is the existence of an universal scaling which does not
depend on the multiplicity of the collision. This aspect can be utilised
further to study physics at the device level and also for the online monitoring
of certain physical observables including electronics noise which are a few
crucial parameters for the optimal TPC performance.Comment: 5 pages, 6 figure
Measurement of the tensor analyzing power T20 in the dd->^3Hen and dd->^3Hp at intermediate energies and at zero degree
The data on the tensor analyzing power T20 in the dd->^3Hen and dd-> ^3Hp
reactions at 140, 200 and 270 MeV of the deuteron kinetic energy and at zero
degree obtained at RIKEN Accelerator Research Facility are presented. The
observed positive sign of T20 clearly demonstrates the sensitivity to the D/S
wave ratios in the ^3He and ^3H in the energy domain of the measurements. The
T20 data for the ^3He-n and ^3H-p channels are in agreement within experimental
accuracy.Comment: 9 pages, 3 figures, submitted in Phys.Lett.
De novo Sequencing of Novel Mycoviruses From Fusarium sambucinum: An Attempt on Direct RNA Sequencing of Viral dsRNAs
An increasing number of viruses are continuously being found in a wide range of organisms, including fungi. Recent studies have revealed a wide viral diversity in microbes and a potential importance of these viruses in the natural environment. Although virus exploration has been accelerated by short-read, high-throughput sequencing (HTS), and viral de novo sequencing is still challenging because of several biological/molecular features such as micro-diversity and secondary structure of RNA genomes. This study conducted de novo sequencing of multiple double-stranded (ds) RNA (dsRNA) elements that were obtained from fungal viruses infecting two Fusarium sambucinum strains, FA1837 and FA2242, using conventional HTS and long-read direct RNA sequencing (DRS). De novo assembly of the read data from both technologies generated near-entire genomic sequence of the viruses, and the sequence homology search and phylogenetic analysis suggested that these represented novel species of the Hypoviridae, Totiviridae, and Mitoviridae families. However, the DRS-based consensus sequences contained numerous indel errors that differed from the HTS consensus sequences, and these errors hampered accurate open reading frame (ORF) prediction. Although with its present performance, the use of DRS is premature to determine viral genome sequences, the DRS-mediated sequencing shows great potential as a user-friendly platform for a one-shot, whole-genome sequencing of RNA viruses due to its long-reading ability and relative structure-tolerant nature
Shallow and diffuse spin-orbit potential for proton elastic scattering from neutron-rich helium isotopes at 71 MeV/nucleon
Vector analyzing powers for proton elastic scattering from 8He at 71
MeV/nucleon have been measured using a solid polarized proton target operated
in a low magnetic field of 0.1 T. The spin-orbit potential obtained from a
phenomenological optical model analysis is found to be significantly shallower
and more diffuse than the global systematics of stable nuclei, which is an
indication that the spin-orbit potential is modified for scattering involving
neutron-rich nuclei. A close similarity between the matter radius and the
root-mean-square radius of the spin-orbit potential is also identified.Comment: 6 pages, 4 figures, accepted for publication in Physical Review C
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