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Re: Exam and consultation

New postPosted: Mon 10 Jan 2011 19:49
by Larisa_MEPhI
Are there any explanations for the fact that there are no stable nuclei with A=5 in the early Universe?

Re: Exam and consultation

New postPosted: Mon 10 Jan 2011 19:58
by Maxim Khlopov
It reflects experimental fact of nuclear physics: there is no stable nucleus with A=5.
Therefore there is a gap that strongly suppresses formation of nuclei with A>5 in Big Bang Nuceleosynthesis.
Regards
M.Yu.Khlopov

Re: Exam and consultation

New postPosted: Mon 10 Jan 2011 21:22
by Ilya Rozhnov
Бариогенезис выходит за рамки стандартной модели, я правильно понимаю?
Можно вернуть равновесие частиц и античастиц, произведя над материей какие-то обратные действия? Можно ли это сделать (и вообще говорить об этом) локально? Если равновесие удастся вернуть, то после этого оно нарушится в ту же сторону (частиц), или не обязательно?

Re: Exam and consultation

New postPosted: Mon 10 Jan 2011 22:12
by Maxim Khlopov
Dear Ilya,
Yes, baryosynthesis needs physics beyond the Standard model.
In particular, you need processes with baryon and lepton charge nonconservation.
Therefore you need local restoration of these kind of processes.
In very hot stars electron-positron plasma may be in equilibrium, but it is not sufficient to restore equilibrium for processes with lepton charge violation.
In principle, if the equilibrium is restored, all the excess of particles over antiparticles is washed out, but the successive behaviour and generation of excess is determined by the mechanism of baryosynthesis and may lead to different result.
Regards
M.Yu.Khlopov

Re: Exam and consultation

New postPosted: Tue 3 May 2011 14:54
by Ilya Rozhnov
По поводу экзамена: если вам удобно, то я бы назначил на 12 завтра.

Re: Exam and consultation

New postPosted: Tue 3 May 2011 17:45
by Maxim Khlopov
Dear Ilya,
For me it would be fine 12.00 Moscow time tomorrow.
I'd like to recommend you to come earlier, take the ticket and prepare to be ready to answer that time.
We'll need some time for you to put the main points of your answer on the whiteboard
See you tomorrow
Regards
M.Yu.Khlopov

Re: Exam and consultation

New postPosted: Tue 3 May 2011 18:07
by Ilya Rozhnov
Хорошо, я постараюсь прийти пораньше.

Re: Exam and consultation

New postPosted: Tue 3 May 2011 18:13
by Maxim Khlopov
After consultation with K.M.Belotsky we decided that it would be better if you come to him at 12 and be ready to answer at 13.00.
Belotsky will confirm you.
Regards
M.Yu.Khlopov