Chronology Current Month Current Thread Current Date
[Year List] [Month List (current year)] [Date Index] [Thread Index] [Thread Prev] [Thread Next] [Date Prev] [Date Next]

Re: [Phys-l] BEC

Thank you very much. So I conclude that we can add up electrons and protons and neutrons together, to find out their bosonic or fermionic behaviour.

A Rusli 17 May 2006

Terry Scott wrote:

We have an active Ultra Cold Atom group in our department, so I went
and asked one of our theorists for an answer to this question. Here is
his response:


"Alkali metals (such as Rb, Na, Li and also Cs) have an odd number of
electrons (hence are group 1 elements). If their mass number is also
odd, then their nucleus must also contain an odd total number of
nucleons, and so the total number of fermions in the atom is even
(i.e. odd number of fermionic electrons + odd number of fermionic
nucleons = even total number of fermions). By addition of angular
momentum the composite atom must have integer spin, and is hence a
boson.

For example. Li-7 is a boson, whereas Li-6 is a Fermion. Similarly,
K-40 is a fermion whereas K-39 is a boson."


Terry Scott
Department of Physics
University of Otago
Dunedin
New Zealand






AR> Dear friends, 16 May 2006

AR> I would like to ask on the recent discoveries of Bose-Einstein AR> Condensates : It is reported that Rb-85, Rb-87, NA-23, Li-7, are bosons, AR> while to my understanding they contain odd numbers of protons and/or AR> neutrons, which should cause them to be fermions instead.

AR> Could anybody give some explanation? Thank you.

AR> A Rusli
AR> Physics Department
AR> Parahyangan Catholic University
AR> Bandung, Indonesia

AR> _______________________________________________
AR> Forum for Physics Educators
AR> Phys-l@carnot.physics.buffalo.edu
AR> https://carnot.physics.buffalo.edu/mailman/listinfo/phys-l

_______________________________________________
Forum for Physics Educators
Phys-l@carnot.physics.buffalo.edu
https://carnot.physics.buffalo.edu/mailman/listinfo/phys-l

.