We have collected the first physics data of an experimental search for the simplest kaonic nuclear bound state, “K− pp”, by the 3He(K− n) reaction at J-PARC. We confirmed that our spectrometer system ...works as designed and observed clear peak structure composed of the quasi-elastic K−“n” → K−n and the charge-exchange K−“p” → ¯̅K0n reactions in the forward neutron spectrum.
It has been numerically found that the setup of Newton's cradle can exhibit a rigid-body like behavior, that is, the target cluster starts to move collectively without emitting the outermost particle ...if the purely repulsive interaction between the neighbouring particles is very "soft" KS, Phys. Rev. Lett. 104, 124302 (2010). We show theoretically that such an interaction leads to an evanescent mode within the cluster, which delivers the momentum within the cluster without any propagating oscillation.
We previously reported in a retrospective study that CEA-based RT-PCR was useful for predicting the prognosis of patients with node-negative colorectal cancer. RT-PCR is well established for ...laboratory use, but many issues remain to be resolved prior to its clinical application. In addition to the false positive rate of RT-PCR, we addressed several issues, including the timing of lymph node sampling, stability of RNA after surgery, and reproducibility of results. After appropriate modification, including development of a tissue sampling kit, a multi-institutional clinical study was commenced prospectively from November 2001, and 100 patients were enrolled for examination of micrometastasis. RNA was stable in lymph nodes for up to 3 h after surgical resection. This range of sampling time was acceptable to the surgeons. RNA was well preserved in RNA later at -20 degrees C for 3 weeks. Dilutions of MKN45 and LoVo cells served as positive controls for conventional PCR since these controls were found to be highly stable and ensured reproducibility. Moreover, simultaneous use of quantitative PCR (Light Cycler) ensured double confirmation of the results. Our clinical study showed that the quality of RNA was excellent or good in most samples (98 of 100; 98%). Twenty-four of 98 (24.5%) cases were judged to be micrometastasis-positive. In conclusion, the current translational research study established a clinically feasible RT-PCR system for micrometastasis. Our system could potentially be useful as a clinical tool.
History memorized on glass transition Miyamoto, Yoshihisa; Yamao, Hiromi; Sekimoto, Ken
Slow Dynamics in Complex Systems,
04/2004, Letnik:
708
Journal Article
Recenzirano
The memory effect is studied in the glass to rubber transition of polyisoprene rubber with the strain as a controlling parameter. A phenomenological model is proposed taking the history of the ...temperature and the strain into account, by which the experimental results are interpreted. It is shown both experimentally and theoretically that the glassy state memorizes the time-course of strain upon glassification, not as a single parameter but as the history itself.
A double-hyperfragment event has been found in a hybrid-emulsion experiment. It is identified uniquely as the sequential decay of ( 6)(LambdaLambda)He emitted from a Xi(-) hyperon nuclear capture at ...rest. The mass of ( 6)(LambdaLambda)He and the Lambda-Lambda interaction energy DeltaB(LambdaLambda) have been measured for the first time devoid of the ambiguities due to the possibilities of excited states. The value of DeltaB(LambdaLambda) is 1.01+/-0.20(+0.18)(-0.11) MeV. This demonstrates that the Lambda-Lambda interaction is weakly attractive.
In the J-PARC E15 experiment, a K− pp search was performed via the 3He(K−, n) reaction at 1.0 GeV/c. A forward-going neutron is detected by a neutron counter with 15 m flight length, and decay ...particles from K− pp are simultaneously measured by a cylindrical detector system that surrounds a liquid 3He target system. In March and May, 2013, we carried out the first physics data-taking with 5×109 incident kaons on the 3He target, and we have obtained a preliminary exclusive analysis result of 3He(K−, Λp)n reaction.
In spite of the recent crucial progresses in the studies of nonmesonic weak decay (NMWD) of Λ hypernuclei, its consistent understanding is yet to be achieved. In the experimental progresses, the long ...standing Γn/Γp problem has finally been solved recently. And for the first time, two-nucleon induced NMWD channel has been identified experimentally and its decay width, 0.27±0.13, measured but only with a 2σ confidence level. On the other hand, the decay asymmetry remains to be understood yet and the accurate measurement of the decay width of each channel is much awaited for the consistent understanding of NMWD. In E18 of J-PARC, we are going to measure Γi of NMWD including Γ2N with 10 % statistical uncertainties. Main concerns in E18 experiment such as the handling of the high beam intensity, the neutron background contamination in the neutron coincidence yields and the control of the trigger rates with the beam intensity as high as 107π+/spill are discussed and it is shown that they can be handled properly.
We developed a trigger system for the measurement of proton-induced rare hadronic reactions around the beam kinetic energy
T
p
=
400
MeV
based on highly segmented trigger scintillation detectors and ...programmable logic modules. The trigger system was designed to enhance events with the negative-pion production by the difference of the curvatures of the particle tracks in a magnetic field. Since the production cross-section of the negative-pion by the proton-induced reactions was smaller by about 3 orders of magnitude than the total cross-section around the beam energy, we expected large reduction of the trigger rate by the negative-pion selection. The construction of the trigger system was not trivial due to a large detector acceptance that was inevitable to measure the rare reactions. The performance of the trigger system was evaluated by using
T
p
=
430
MeV
proton beams. An excellent reduction, more than 2 orders of magnitude reduction, of the background events was achieved.
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