RE: muon transfer to Oxygen

["Le, Anh Thu" <atle@phys.ksu.edu>]

Dear Dr. Kammel,

In our paper we emphasized on the importance of the screening 
effect on the resonances. The resonance could enhance the rate 
drastically. However, only the screening at small distance(say, 
R<0.5au) is important, in general. Therefore we don't think that 
there's any need for taking into account the molecular structure. 

Thomas-Fermi screening is probably not sophisticated enough to 
accurately predict the rate. In our paper we just wanted to 
illustrate the effect. More realistic screening based on more 
advanced theories (DFT for example) is desirable, if needed. On 
the other hand, for certain systems, the effect of screening on 
transition rate is very weak (Nitrogen is an example). 

With best regards,
A.T.

************************************************************************
***** 
Anh-Thu Le                                        
Research Assistant Professor                Phone:(785) 532-1635 
Department of Physics                       Fax: (785) 532- 6806 
Kansas State University                     Email:atle@phys.ksu.edu    
Manhattan, KS 66506
http://www.phys.ksu.edu/personal/atle 
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*********** 



> -----Original Message-----
> From: Peter Kammel [mailto:kammel@npl.uiuc.edu] 
> Sent: Thursday, October 12, 2006 5:00 PM
> To: Lin, Chii-Dong; Le, Anh Thu
> Subject: muon transfer to Oxygen
> 
> 
> Dear Chii-Dong, dear Anh-Thu,
> 
> We are measuring the muon capture rate on the proton,
> see http://www.npl.uiuc.edu/exp/mucapture/
> and just preparing our first physics result on this
> fundamental quantity.
> 
> An important correction to our measured rate comes from
> trace impurities (~E-8) of H2O in our ultraclean hydrogen 
> target. Thus I read you paper about muon transfer with great 
> interest. Within the next few months, we expect to have a new 
> results on the N and O transfer rate from 
> mu+p atoms.
> 
> You emphasize the significant effect of electronic screening
> on the transfer cross section using a Thomas-Fermi model.
> The existing experiment has been performed with O2 molecules
> in H2 and our new experiment will be for H2O molecules in
> H2.
> 
> Could you comment on or calculate the effect of the 
> electronic molecular structure on the shielding and thus the 
> transfer cross section?
> 
> With my best regards
> 
> 
> Peter
> 
> 
> 
> Peter Kammel  /  pkammel@uiuc.edu
> Department of Physics, Loomis Laboratory
> University of Illinois at Urbana-Champaign
> 1110 West Green Street, Urbana, IL 61801
> Tel (217) 333-5424 / Fax (217) 333-1215
> 
>