物理セミナー 日時: 2002-11-26 16:00 - 17:00 場所: ４号館 345号室 会議名: 物理セミナー： Searches for Baryon Instability Other than Proton Decay 連絡先: takeshi.komatsubarakek.jp 講演者: Yuri Kamyshkov  (Tennessee) 講演言語: 英語 アブストラクト: Experimental observation of nucleon instability is one of the missing key components required for the explanation of baryon asymmetry of the universe. Proton decays with the modes and rates predicted by the original (B-L)-conserving schemes of Grand Unification are not observed experimentally. There are reasons to believe that (B-L) might not be conserved in nature, thus leading to the nucleon decay into lepton+(X) and to phenomena such as Majorana masses of neutrinos, neutrinoless double-beta decays, and most spectacularly to the transitions of neutron to anti-neutron. The energy scale where these processes can occur is far beyond the reach of contemporary colliders. This scale itself is not a strict prediction of theory (for example, it can be as low as ~100 TeV) and therefore it needs to be explored by experiments. Physics motivation and experimental approaches in searching for (B-L)-violating transition will be discussed, in particular: mode-independent limit for nucleon decay, searches for neutron disappearance in KamLAND, and new experimental possibilities in searching for neutron-antineutron transitions with cold and ultra-cold neutrons. [index]