検索対象:     
報告書番号:
※ 半角英数字
 年 ~ 
 年
検索結果: 5 件中 1件目~5件目を表示
  • 1

発表形式

Initialising ...

選択項目を絞り込む

掲載資料名

Initialising ...

発表会議名

Initialising ...

筆頭著者名

Initialising ...

キーワード

Initialising ...

使用言語

Initialising ...

発行年

Initialising ...

開催年

Initialising ...

選択した検索結果をダウンロード

論文

$$beta$$ decay of $$^{75}$$Ni and the systematics of the low-lying level structure of neutron-rich odd-$$A$$ Cu isotopes

Bello Garrote, F. L.*; Sahin, E.*; 角田 佑介*; 大塚 孝治*; G$"o$rgen, A.*; Orlandi, R.; 他61名*

Physical Review C, 102(3), p.034314_1 - 034314_13, 2020/09

 被引用回数:1 パーセンタイル:35.83(Physics, Nuclear)

Detailed spectroscopy of neutron-rich odd-$$A$$ Cu isotopes is of great importance for studying the shell evolution in the region of $$^{78}$$Ni. Excited states in $$^{75}$$Cu were populated in the $$beta$$ decay of $$^{75}$$Ni isotopes, which were produced by the in-flight fission at RIBF, RIKEN. The $$^{75}$$Ni isotopes were separated, identified, and implanted in a highly segmented Si detector array for the detection of the $$beta$$-decay electrons, while the delayed $$gamma$$ rays were detected by an array of HPGe cluster detectors. A level scheme of $$^{75}$$Cu was built up to $$sim$$4 MeV, from which the location of the two previously known low-lying isomeric states was clarified. The level structure below 2 MeV was interpreted based on the results of the shell-model calculations and the systematics of odd-$$A$$ Cu isotopes, revealing the evolution of single-particle states in this region.

論文

First measurements of absolute branching fractions of the $$Xi_c^0$$ baryon at Belle

Li, Y. B.*; 谷田 聖; Belle Collaboration*; 他161名*

Physical Review Letters, 122(8), p.082001_1 - 082001_7, 2019/03

AA2019-0537.pdf:0.88MB

 被引用回数:23 パーセンタイル:92.73(Physics, Multidisciplinary)

We present the first measurements of absolute branching fractions of $$Xi_c^0$$ decays into $$Xi^- pi^+$$, $$Lambda K^- pi^+$$, and $$p K^- K^- pi^+$$ final states. The measurements are made using a data set comprising $$(772pm 11)times 10^{6}$$ $$Bbar{B}$$ pairs collected at the $$Upsilon(4S)$$ resonance with the Belle detector at the KEKB $$e^+e^-$$ collider. We first measure the absolute branching fraction for $$B^- to bar{Lambda}_c^- Xi_c^0$$ using a missing-mass technique, the result is $${cal B}(B^- to bar{Lambda}_c^- Xi_c^0) = [9.51 pm 2.10(rm stat.) pm 0.88(rm syst.)] times 10^{-4}$$. We subsequently measure the product branching fractions $${cal B}(B^- to bar{Lambda}_c^- Xi_c^0){cal B}(Xi_c^0 to Xi^- pi^+)$$, $${cal B}(B^- to bar{Lambda}_c^- Xi_c^0) {cal B}(Xi_c^0 to Lambda K^- pi^+)$$, and $${cal B}(B^- to bar{Lambda}_c^- Xi_c^0) {cal B}(Xi_c^0 to p K^- K^- pi^+)$$ with improved precision. Dividing these product branching fractions by the result for $$B^- to bar{Lambda}_c^- Xi_c^0$$ yields the following branching fractions: $${cal B}(Xi_c^0 to Xi^- pi^+)= [1.80 pm 0.50(rm stat.) pm 0.14(rm syst.)]%$$, $${cal B}(Xi_c^0 to Lambda K^- pi^+)=[1.17 pm 0.37(rm stat.) pm 0.09(rm syst.)]%$$, and $${cal B}(Xi_c^0 to p K^- K^- pi^+)=[0.58 pm 0.23(rm stat.) pm 0.05(rm syst.)]%$$. Our result for $${cal B}(Xi_c^0 to Xi^- pi^+)$$ can be combined with $$Xi_c^0$$ branching fractions measured relative to $$Xi_c^0 to Xi^- pi^+$$ to yield other absolute $$Xi_c^0$$ branching fractions.

論文

Is seniority a partial dynamic symmetry in the first $$nu$$$$g_{9/2}$$ shell?

Morales, A. I.*; Orlandi, R.; 他61名*

Physics Letters B, 781, p.706 - 712, 2018/06

 被引用回数:12 パーセンタイル:83.89(Astronomy & Astrophysics)

By studying the $$beta$$ decay of the radioactive nuclei $$^{72}$$Co and $$^{74}$$Co produced at RIBF, RIKEN, the low-lying excited states in $$^{72,74}$$Ni were studied for the first time up to spin 8$$^+$$. These states originate from the valence neutrons occupying the $$g_{9/2}$$ orbit, and permit to investigate the seniority quantum number. The data reveal that the seniority isomerism of the 8$$^+$$ state disappears, and this phenomenon is explained by comparison with shell model calculations and the influence of spherical doubly-magic $$^{78}$$Ni.

論文

Invariant-mass and fractional-energy dependence of inclusive production of dihadrons in $$e^+e^-$$ annihilation at $$sqrt{s}=$$ 10.58 GeV

Seidl, R.*; 谷田 聖; Belle Collaboration*; 他161名*

Physical Review D, 96(3), p.032005_1 - 032005_21, 2017/08

 被引用回数:9 パーセンタイル:50.63(Astronomy & Astrophysics)

The inclusive cross sections for dihadrons of charged pions and kaons ($$e^+e^- to hhX$$) in electron-positron annihilation are reported. They are obtained as a function of the total fractional energy and invariant mass for any di-hadron combination in the same hemisphere as defined by the thrust event-shape variable and its axis. Since same-hemisphere dihadrons can be assumed to originate predominantly from the same initial parton, di-hadron fragmentation functions are probed. These di-hadron fragmentation functions are needed as an unpolarized baseline in order to quantitatively understand related spin-dependent measurements in other processes and to apply them to the extraction of quark transversity distribution functions in the nucleon. The di-hadron cross sections are obtained from a 655 fb$$^{-1}$$ data sample collected at or near the $$Upsilon(4S)$$ resonance with the Belle detector at the KEKB asymmetric-energy $$e^+e^-$$ collider.

論文

Measurement of the relative yields of $$psi(2S)$$ to $$psi(1S)$$ mesons produced at forward and backward rapidity in $$p+p$$, $$p+$$Al, $$p+$$Au, and $$^3$$He+Au collisions at $$sqrt{s_{NN}}=200$$ GeV

Adare, A.*; 長谷川 勝一; 今井 憲一; 佐甲 博之; 佐藤 進; 谷田 聖; PHENIX Collaboration*; 他361名*

Physical Review C, 95(3), p.034904_1 - 034904_10, 2017/03

AA2017-0047.pdf:0.58MB

 被引用回数:13 パーセンタイル:81.31(Physics, Nuclear)

The PHENIX Collaboration has measured the ratio of the yields of $$psi(2S)$$ to $$psi(1S)$$ mesons produced in $$p+p$$, $$p+$$Al, $$p+$$Au, and $$^3$$He+Au collisions at $$sqrt{s_{NN}}=200$$ GeV over the forward and backward rapidity intervals $$1.2 < |y| < 2.2$$. We find that the ratio in $$p+p$$ collisions is consistent with measurements at other collision energies. In collisions with nuclei, we find that in the forward ($$p$$-going or $$^3$$He-going) direction, the relative yield of $$psi(2S)$$ mesons to $$psi(1S)$$ mesons is consistent with the value measured in $$p+p$$ collisions. However, in the backward (nucleus-going) direction, the $$psi(2S)$$ meson is preferentially suppressed by a factor of $$sim 2$$. This suppression is attributed in some models to the breakup of the weakly bound $$psi(2S)$$ meson through final-state interactions with comoving particles, which have a higher density in the nucleus-going direction. These breakup effects may compete with color screening in a deconfined quark-gluon plasma to produce sequential suppression of excited quarkonia states.

5 件中 1件目~5件目を表示
  • 1