2005 Fiscal Year Final Research Report Summary
Study of CP violation on top-quark
| Project/Area Number |
15540278
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Particle/Nuclear/Cosmic ray/Astro physics
|
|---|
| Research Institution | Okayama University |
|---|
Principal Investigator |
TANAKA Reizaburo Okayama University, Graduate School of Natural Science and Technology, Associate professor (90325077)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
SUMINO Yukinari Tohoku University, Graduate School of Science, Assistant professor (80260412)
NAKANO Itsuo Okayama University, Graduate School of Natural Science and Technology, professor (90133024)
|
|---|
| Project Period (FY) |
2003 – 2005
|
| Keywords | CP violation / anomalous coupling / baryogenesis / top-quark / helicity / hadron collider / Tevatron / LHC |
|---|
| Research Abstract |
The aim of this research is the study of CP violation and anomalous coupling on top-quark decay at CDF experiment. That will lead to the beyond the Standard Model and some knowledge about the baryogenesis of universe. The study on the mechanism of the top-quark production and decay is especially important since the CDF Run-II is expected to produce a lot of top-quark pair creation.
We have developed a method applicable to top-quark semi-leptonic decay although the reconstruction of top-quark spin at hadron collider is not simple. That is called a sine-helicity method, which reconstructs the effective-spin of the top-quark. This method projects lepton direction to the top-quark helicity at top-quark rest system. We have confirmed that the angular distribution of top-quark decay is reproduced that from the polarized top-quark.
We have suggested to apply this new top-quark effective-spin for the study of anomalous coupling at top-quark decay vertex. This method is more sensitive to the anomalous coupling than the familiar beam line base and off-diagonal base definition of top-quark spin axis. We have also studied a method using angular correlation between W-boson and a charged particle. We used a likely-method to analyze lepton+four jets events.
We have also studied the sensitivity of Tevatron and LHC experiments. And we have gotten the conclusion that this mehod will be promising.
|
