| Item type |
学位論文 / Thesis or Dissertation(1) |
| 公開日 |
2010-02-22 |
| タイトル |
|
|
タイトル |
Study of Σ-Nucleus Potential by the (π-,k+)reaction |
| タイトル |
|
|
タイトル |
Study of Σ-Nucleus Potential by the (π-,k+)reaction |
|
言語 |
en |
| 言語 |
|
|
言語 |
eng |
| 資源タイプ |
|
|
資源タイプ識別子 |
http://purl.org/coar/resource_type/c_46ec |
|
資源タイプ |
thesis |
| 著者名 |
SAHA, Pranab Kumar
|
| フリガナ |
サハ, プラナブ クマー
|
| 著者 |
SAHA, Pranab Kumar
|
| 学位授与機関 |
|
|
|
学位授与機関名 |
総合研究大学院大学 |
| 学位名 |
|
|
学位名 |
博士（理学） |
| 学位記番号 |
|
|
内容記述タイプ |
Other |
|
内容記述 |
総研大甲第545号 |
| 研究科 |
|
|
値 |
数物科学研究科 |
| 専攻 |
|
|
値 |
12 加速器科学専攻 |
| 学位授与年月日 |
|
|
学位授与年月日 |
2001-09-28 |
| 学位授与年度 |
|
|
値 |
2001 |
| 要旨 |
|
|
内容記述タイプ |
Other |
|
内容記述 |
In order to study the Σ-nucleus potential, we carried out an experiment at the K6 beam line of the 12-GeV proton synchrotron in High Energy Accelerator Research Organization(KEK) using the superconducting kaon spectrometer(SKS) system. In the present experiment, for the first time we measured inclusive (π -,K+) spectra on CH2, Si, Ni, In and Bi targets with reasonable statistics covering a wider excitation energy region. We extracted the information on the Σ- nucleus optical potential from the analysis of the spectral shape. The CH2 target was used to calibrate the excitation energy scale(horizontal axis) from the elementary process, p(π -,K+)Σ-. The C spectrum was also able to be extracted from the CH2 target. The SKS, which has a wider momentum acceptance and good energy resolution was helpful to obtain a good statistics data keeping a good energy resolution. The calibration of the energy scale was done successfully with a precision of ±0.1 MeV. The angular distribution of the elementary cross section was found to be consistent with the previous bubble chamber data. All the inclusive spectra were found to be very identical in shape from the Σ- binding energy threshold to around 90 MeV excited regions. The mass number dependence of the cross section was obtained from the ratio of the cross section. Compared to the eikonal approximation, present experimental data showed a rather weak mass number dependence. A Monte Carlo simulation was done for the quasi-free Si spectrum where no final state interaction of Σ- to the residual nucleus was considered. The simulated spectrum could not reproduce the observed spectral shape. The strength of the observed spectrum was found to be much suppressed, particularly, near the binding energy threshold. We compared the observed Si spectral shape to the theoretical spectra calculated by using two types of phenomenological potential in the framework of DWIA. One is based on the one boson exchange potential(OBEP) describing the two-body YN interaction, which represents an attractive Σ-nucleus potential, and the other one is obtained from the Σ--atomic X-ray data, which represents a repulsive Σ-nucleus potential. None of the potential could reproduce the observed spectral shape. In particular, the peak position of the observed spectrum was found to be much shifted towards the higher excitation energy from both of the calculated spectra. Energy dependence of the elementary cross section was found to be very sensitive to the spectral shape. Taking into account this effect, another DWIA calculation was done for Si. The spectral shape was found to be significantly changed from that of the previous calculation by using the same Σ-uncleus potential in both calculation, but still different from the observed one. Then a detail analysis was done to reproduce the observed spectral shape using Woods-Saxon type potentials. A strong repulsive potential of which depth of the real part(VΣ) > 90 MeV with a moderately absorptive imaginary part(WΣ) was favorable in reproducing the observed spectral shape. |
| 所蔵 |
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|
値 |
有 |
要旨・審査要旨 / Abstract, Screening Result (214.4 kB)
