http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Shiu, S. H.,Kohri, H.,Chang, W. C.,Ahn, D. S.,Ahn, J. K.,Chen, J. Y.,Daté,, S.,Ejiri, H.,Fujimura, H.,Fujiwara, M.,Fukui, S.,Gohn, W.,Hicks, K.,Hotta, T.,Hwang, S. H.,Imai, K.,Ishikawa, T.,Joo, American Physical Society 2018 Physical Review C Vol.97 No.1
<P>We report the measurement of the gamma p -> K+Lambda and gamma p -> K+Sigma(0) reactions at SPring-8. The differential cross sections and photon-beam asymmetries are measured at forward K+ production angles using linearly polarized tagged-photon beams in the range of E-gamma = 1.5-3.0 GeV. With increasing photon energy, the cross sections for both gamma p -> K+Lambda and gamma p -> K+Sigma(0) reactions decrease slowly. Distinct narrow structures in the production cross section have not been found at E gamma = 1.5-3.0 GeV. The forward peaking in the angular distributions of cross sections, a characteristic feature of t-channel exchange, is observed for the production of Lambda in the whole observed energy range. A lack of similar feature for Sigma(0) production reflects a less dominant role of t-channel contribution in this channel. The photon-beam asymmetries remain positive for both reactions, suggesting the dominance of K* exchange in the t channel. These asymmetries increase gradually with the photon energy, and have a maximum value of +0.6 for both reactions. Comparison with theoretical predictions based on the Regge trajectory in the t channel and the contributions of nucleon resonances indicates the major role of t-channel contributions as well as non-negligible effects of nucleon resonances in accounting for the reaction mechanism of hyperon photoproduction in this photon energy regime.</P>
Measurement of time-dependent CP asymmetries in B0→KS0ηγ decays
Nakano, H.,Ishikawa, A.,Sumisawa, K.,Yamamoto, H.,Adachi, I.,Aihara, H.,Al Said, S.,Asner, D. M.,Aulchenko, V.,Aushev, T.,Ayad, R.,Babu, V.,Badhrees, I.,Bansal, V.,Behera, P.,Beleñ,o, C.,Bhuyan, American Physical Society 2018 Physical Review D Vol.97 No.9
<P>We report a measurement of time-dependent CP violation parameters in B-0 -> K-S(0)eta gamma decays. The study is based on a data sample, containing 772 x 10(6)B(B)over-bar pairs, that was collected at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. We obtain the CP violation parameters of S = -1.32 +/- 0.77(stat) +/- 0.36(syst) and A = -0.48 +/- 0.41(stat) f 0.07(syst) for the invariant mass of the K-S(0)eta system up to 2.1 GeV/c(2).</P>
Search for strange tribaryons in the He4(K<i>stop</i>−,n<sup>π±</sup>) reaction
Yim, H.,Bhang, H.,Chiba, J.,Choi, Seonho,Fukuda, Y.,Hanaki, T.,Hayano, R.S.,Iio, M.,Ishikawa, T.,Ishimoto, S.,Ishiwatari, T.,Itahashi, K.,Iwai, M.,Iwasaki, M.,Kienle, P.,Kim, J.H.,Matsuda, Y.,Ohnishi, Elsevier 2010 Physics letters: B Vol.688 No.1
<P><B>Abstract</B></P><P>We have recently reported on an indication of the strange tribaryon state, S<SUP>+</SUP>, with a mass M∼3140 MeV/<SUP>c2</SUP> and width Γ<23 MeV/<SUP>c2</SUP>, in the neutron time-of-flight (TOF) spectrum of the He4(K<I>stop</I>−,n<SUP>π±</SUP>) reaction of the KEK-PS E471 experiment in a search for the deeply bound narrow <SUP>K−</SUP>ppn (total isospin T=0) state. In an attempt to confirm the state and search for other possible T=0, 1 tribaryonic states, we have re-measured the neutron energy spectrum of the same reaction in the KEK-PS E549 experiment with an upgraded setup for which the TOF resolution was improved 1.5 times and the statistics was increased 6 times. However, in the neutron spectra, we find such a smooth distribution that we conclude the state is either not so strong to stick out of the inclusive background or too broad to be identified as a distinct peak. We estimated the upper limits of the formation probability of the possible tribaryonic state for three widths, 0, 20, and 40 MeV/<SUP>c2</SUP>. The obtained upper limit (95% CL) for a state as narrow as 20 MeV/<SUP>c2</SUP> is at most 1% per stopped kaon over the wide mass range of 3000–3200 MeV/<I>c</I><SUP>2</SUP>, while it reaches to 4∼5% at around 3140 MeV/<I>c</I><SUP>2</SUP> for Γ⩾40 MeV/<SUP>c2</SUP>, implying the possible existence of unknown processes including tribaryonic formation.</P>
SEARCH FOR STRANGE TRIBARYON STATES IN THE 4He(STOPPED K-, p) REACTION
SATO, M.,BHANG, H.,CHIBA, J.,CHOI, SEONHO,FUKUDA, Y.,HANAKI, T.,HAYANO, R. S.,IIO, M.,ISHIKAWA, T.,ISHIMOTO, S.,ISHIWATARI, T.,ITAHASHI, K.,IWAI, M.,IWASAKI, M.,KIENLE, P.,KIM, J. H.,MATSUDA, Y.,OHNIS World Scientific 2009 International Journal of Modern Physics A Vol.24 No.2
<P> We have measured a proton energy from the stopped K<SUP>-</SUP> reaction on <SUP>4</SUP> He to search for strange tribaryon states at KEK 12 GeV PS. No statistically significant signal was observed in the missing mass spectrum obtained by the inclusive <SUP>4</SUP> He ( stopped K<SUP>-</SUP>, p) measurement. Upper limits of the formation branching ratio at the 95 % C.L. were derived for neutral tribaryon states with strangeness -1 to be (0.4 ~ 6) × 10<SUP>-4</SUP>, (0.2 ~ 6) × 10<SUP>-3</SUP> and (0.06 ~ 5) × 10<SUP>-2</SUP>/(stopped K<SUP>-</SUP>) for assumed natural widths of 0, 20 and 40 MeV /c<SUP>2</SUP>, respectively. </P>
Precision measurement of the 3d->2p x-ray energy in kaonic <sup>4</sup>He
Okada, S.,Beer, G.,Bhang, H.,Cargnelli, M.,Chiba, J.,Choi, S.,Curceanu, C.,Fukuda, Y.,Hanaki, T.,Hayano, R.S.,Iio, M.,Ishikawa, T.,Ishimoto, S.,Ishiwatari, T.,Itahashi, K.,Iwai, M.,Iwasaki, M.,Juhasz, North-Holland Pub. Co 2007 Physics letters: B Vol.653 No.5
We have measured the Balmer-series x-rays of kaonic <SUP>4</SUP>He atoms using novel large-area silicon drift x-ray detectors in order to study the low-energy K@?-nucleus strong interaction. The energy of the 3d->2p transition was determined to be 6467+/-3(stat)+/-2(syst) eV. The resulting strong-interaction energy-level shift is in agreement with theoretical calculations, thus eliminating a long-standing discrepancy between theory and experiment.
THE INFLUENCE OF AFFECTED LAYER OF EDM ON THE WEAR CHARACTERISTICS OF CEMENTED TUNGSTEN CARBIDE
K. ISHIKAWA,A. IWABUCHI,T. SHIMIZU 한국트라이볼로지학회 2002 한국트라이볼로지학회 학술대회 Vol.2002 No.10
This paper describes the wear characteristics of WC-Co cemented carbides machined with Wire-cut or Die-sinking EDM. We prepared the specimens with different grades of grinding to remove the affected layer after the EDM. These specimens were experimented by block-an-cylinder type tribometer. The result indicated that although the hardness of the affected layer was lower than that of the bulk, wear resistance was increased. In order to investigate the cause of the increase in wear resistance of the affected layer, the layer was observed and analyzed by SEM and ESCA. We also discussed the mean free path of Co phase.