Bob_for_short said:
...Could you name several names of senior, experienced theoretical particle physicists who are highly respected, please?
...
My nomination (adding to people already mentioned by others) would be Lance Dixon at SLAC-Stanford.
http://www.slac.stanford.edu/slac/faculty/hepfaculty/dixon.html
http://www.slac.stanford.edu/~lance/
I have several reservations about adding this name to your list. One is that I'm the wrong person to ask, since not being an insider myself, I can't claim to know who is highly respected in particle physics.
Another problem is that, although we can tell you names of "senior, experienced theoretical particle physicists who are highly respected", these will not necessarily be suitable people for you to write to for the purpose you have in mind!
You say you are trying for a position in the USA. I think maybe you should get a rec from at least one mainstream USA particle theorist. Also senior is good, but not too senior. A very old famous guy may have already in his life received too many dubious-appeal letters or have already helped too many near-desperate struggling colleagues. So very old might work but is risky.
So I say Lance for 3 reasons.
Lance is absolutely mainstream
Lance is USA
Lance is still fairly young (although already known and respected.)
Michael Peskin, also at SLAC-Stanford, is of course well-known too, and of about the right generation. I have the impression that he has an odd (maybe even congenial to you) sense of humor.
Here is his homepage:
http://www.slac.stanford.edu/~mpeskin/
It has this beautiful quote from a Classical Chinese story:
`Whereever you go', said the Patriarch, `I'm convinced you'll come to no good. So remember, when you get into trouble, I absolutely forbid you to say that you are my disciple. If you give a hint of any such thing I shall flay you alive, break all your bones, and banish your soul to the Place of Ninefold Darkness, where it will remain for ten thousand aeons.' `I certainly won't venture to say a word about you,' promised Monkey. `I'll say I found it all out for myself.'
--from A Journey to the West, by Cheng-En Wu, tr. by Arthur Waley