694 research outputs found
The effective interaction hyperspherical harmonics method for non-local potentials
A different formulation of the effective interaction hyperspherical harmonics
(EIHH) method, suitable for non-local potentials, is presented. The EIHH method
for local interactions is first shortly reviewed to point out the problems of
an extension to non-local potentials. A viable solution is proposed and, as an
application, results on the ground-state properties of 4- and 6-nucleon systems
are presented. One finds a substantial acceleration in the convergence rate of
the hyperspherical harmonics series. Perspectives for an application to
scattering cross sections, via the Lorentz transform method are discussed.Comment: 6 pages, 1 figure, to be published in the Proceedings of the
International Nuclear Physics Conference, Vancouver, 201
Ab initio calculation of the 4He(e,e'd)d reaction
The two-body knock-out reaction 4He(e,e'd)d is calculated at various momentum
transfers. The full four-nucleon dynamics is taken into account microscopically
both in the initial and the final states. As NN interaction the central
MT-I/III potential is used. The calculation shows a strong reduction of the
coincidence cross section due to the final state interaction. Nonetheless the
theoretical results exhibit a considerable overestimation of the experimental
cross section at lower momentum transfer. Comparisons with other, less
complete, calculations suggest that consideration of a more realistic ground
state might not be sufficient for a good agreement with experiment, rather a
more realistic final state interaction could play an essential role.Comment: 14 pages, 5 figure
Multiscale entanglement in ring polymers under spherical confinement
The interplay of geometrical and topological entanglement in semiflexible
knotted polymer rings confined inside a spherical cavity is investigated using
advanced numerical methods. By using stringent and robust algorithms for
locating knots, we characterize how the knot length lk depends on the ring
contour length, Lc and the radius of the confining sphere, Rc . In the no- and
strong- confinement cases we observe weak knot localization and complete knot
delocalization, respectively. We show that the complex interplay of lk, Lc and
Rc that seamlessly bridges these two limits can be encompassed by a simple
scaling argument based on deflection theory. The same argument is used to
rationalize the multiscale character of the entanglement that emerges with
increasing confinement.Comment: 9 pages 9 figure
自記式「健康チェック票THI」による健康に及ぼす喫煙の影響評価-地方都市と大都市の学生間の比較-
キャンパスが群馬県内(Iキャンパス)、東京都内(Tキャンパス)および愛知県内(Nキャンパス)にあるA私立大学の学生347人(男子121人、女子226人)を対象に、喫煙が健康に及ぼす影響について、自記式「健康チェック票THI」によって評価した。対象学生の喫煙率は全国平均と比較して、Iキャンパスの男子学生がやや高かったことを除くと、ほぼ同程度であった。健康状態は1.2万人の標準グループから得られた尺度得点の分布をもとに、パーセンタイル値で評価した。喫煙者の健康状態は非喫煙者と比較して、身体面およびメンタル面の両方において劣る傾向がみられ、特に、女子学生の方が男子学生より顕著であった。さらに、Iキャンパスの学生より、TキャンパスやNキャンパスの学生の方が、メンタル面の症状レベルが高い傾向が認められた。これらの結果は、喫煙が身体面の健康状態に悪影響を及ぼすことを確認するとともに、その影響は地方都市より大都会で学ぶ学生に強く出やすい可能性を示している
Pulling adsorbed polymers from surfaces with the AFM: stick versus slip, peeling versus gliding
We consider the response of an adsorbed polymer that is pulled by an AFM
within a simple geometric framework. We separately consider the cases of i)
fixed polymer-surface contact point, ii) sticky case where the polymer is
peeled off from the substrate, and iii) slippery case where the polymer glides
over the surface. The resultant behavior depends on the value of the surface
friction coefficient and the adsorption strength. Our resultant force profiles
in principle allow to extract both from non-equilibrium force-spectroscopic
data.Comment: 6 pages, 3 figures; accepted for publication in Europhys. Lett.,
http://www.edpsciences.org/journal/index.cfm?edpsname=ep
Test of J-matrix inverse scattering potentials on electromagnetic reactions of few-nucleon systems
The J-matrix inverse scattering nucleon-nucleon potentials (JISP), describing
both two-nucleon data and bound and resonant states of light nuclei to high
accuracy, are tested on the total photoabsorption cross sections of Deuteron,
Triton, 3He and 4He. The calculations in the three- and four-body systems are
carried out via the Lorentz integral transform method and the hyperspherical
harmonics (HH) technique. To this end the HH formalism has been adapted to
accommodate non-local potentials. The cross sections calculated with the JISP
are compared to those obtained with more traditional realistic interactions,
which include two- and three-nucleon forces. While the results of the two kinds
of potential models do not differ significantly at lower energies, beyond the
resonance peak they show fairly large discrepancies, which increase with the
nuclear mass. We argue that these discrepancies may be due to a probably
incorrect long range behavior of the JISP, since the one pion exchange is not
manifestly implemented there.Comment: 18 pages, 4 figures, 1 tabl
The HeH Reaction with Full Final--State Interaction
An {\it ab initio} calculation of the HeH longitudinal
response is presented. The use of the integral transform method with a Lorentz
kernel has allowed to take into account the full four--body final state
interaction (FSI). The semirealistic nucleon-nucleon potential MTI--III and the
Coulomb force are the only ingredients of the calculation. The reliability of
the direct knock--out hypothesis is discussed both in parallel and in non
parallel kinematics. In the former case it is found that lower missing momenta
and higher momentum transfers are preferable to minimize effects beyond the
plane wave impulse approximation (PWIA). Also for non parallel kinematics the
role of antisymmetrization and final state interaction become very important
with increasing missing momentum, raising doubts about the possibility of
extracting momentum distributions and spectroscopic factors. The comparison
with experimental results in parallel kinematics, where the Rosenbluth
separation has been possible, is discussed.Comment: 17 pages, 5 figure
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