Dear Graziano, I confirm that the present relative uncertainty of the 
fine-structure constant is 0.37 parts per billion (ppb), as written in 
the Introduction (see Ref.[1]).

The present experimental uncertainty of a_e=(g_e-2)/2, the anomalous 
magnetic moment of the electron, is 0.24 ppb (see same Ref.[1]). Note 
that 0.28 ppt is the present relative uncertainty of g_e/2.

My affiliation is: INFN, Sezione di Padova, I-35131 Padova, Italy

All the best, Massimo


Graziano Venanzoni wrote:
> 
> Dear Massimo,
> thanks very much for your detailed corrections. We will discuss them 
> with Guido and Henryk and let you know (in the case we will have some 
> problems).
> A presto,
> G.
> 
> On Thu, 12 Nov 2009, Massimo Passera wrote:
> 
>> Dear Graziano, Guido and Henryk,
>>
>> I am sending you part of my comments and suggestions on the draft, 
>> starting from the two-page "Introduction".
>>
>> As, for these first two pages, Graziano also inspired himself from 
>> some of the parts I wrote for our common paper on e+e- physics in 
>> Frascati, I dare suggest here a non-negligible number of modifications 
>> and improvements. Here they are:
>>
>> 1,L,1,6  (page 1, left, paragraph 1, line 6)
>>
>> between the measurements --> between the precise measurements
>>
>> 1,L,1,11
>>
>> and there are strong theoretical arguments hinting at the presence of 
>> physics beyond the SM.    -->
>>
>> and there are clear phenomenological facts (dark matter, 
>> matter-antimatter asymmetry in the universe) as well as strong 
>> theoretical arguments hinting at the presence of physics beyond the SM.
>>
>> 1,L,2,4
>>
>> "is the fine-structure constant alpha which depends logarithmically on 
>> the energy scale. It has been determined at zero momentum transfer 
>> with an impressive accuracy of 0.37 parts per billion (ppb) [1] from 
>> the mea-
>> surement of the anomalous electron magnetic moment [1], relying on the 
>> validity of perturbative QED."        -->
>>
>> "is the fine-structure constant alpha, determined from the anomalous 
>> magnetic moment of the electron with an impressive relative precision 
>> of 0.37 parts per billion (ppb) [1] relying on the validity of 
>> perturbative QED [2]."
>>
>> Then add [2], the reference to Kinoshita, in the bibliography:
>>
>> G.~Gabrielse, D.~Hanneke, T.~Kinoshita, M.~Nio and B.C.~Odom,
>>  %``New Determination of the Fine Structure Constant from the Electron
>>  %  g Value and QED,''
>>  Phys.\ Rev.\ Lett.\  {\bf 97}, 030802 (2006);
>>                       {\bf 99}, 039902 (2007) (E)
>>
>> 1,R,1,3
>>
>> There are several points here. Also, some definitions are missing. I 
>> propose to replace the piece starting from "At the M_Z scale the..." 
>> and ending with "prediction of the Higgs mass." with the PDF file in 
>> attachment. This would uniform the notation and introduce the missing 
>> definitions. Also, given the importance of Delta_alpha in the context 
>> of this report, I added a few introductory lines explaining its 
>> relevance for the SM phenomenology. I hope you'll like them. Please 
>> see the attachment change.pdf (also in latex: change.tex).
>>
>>
>> 2,L, Eq.(3)
>>
>> a_mu^had --> a_mu^HLO
>>
>> 2,L,2,3
>>
>> uses the result in --> uses the hadronic light-by-light result of
>>
>> 2,L,2,10
>>
>> a_mu --> a_mu^SM
>>
>> 2,L,2,13
>>
>> proposed experiments of the measurement of a_mu -->
>> proposed muon g-2 experiments
>>
>> 2,R,1,2
>>
>> accuray --> accuracy
>>
>> 2,R,7,2&5
>>
>> a_mu^had --> a_mu^HLO
>>
>> 2,R, 4 lines from bottom
>>
>> perspectives --> prospects
>>
>>
>> -----------------------------------------------------------------
>>
>> I actually have some more comments on other parts of the draft. I'll 
>> send them to you by tomorrow night, in case you still want to consider 
>> them.
>>
>> Thanks for all your work!
>>
>> All the best, Massimo
>>