[Triumf-seminars] TRIUMF Journal Club Seminar today at 12:00

postmaster@admin.triumf.ca postmaster@admin.triumf.ca
Mon, 8 May 2006 05:00:04 -0700


---------------------- multipart/mixed attachment
Date/Time: Mon 2006-05-08 at 12:00

Location:  MainOffice Boardroom

Speaker:   Ian Allison (TRIUMF)

Title:     Indication of a Cosmological Variation of the Proton-Electron Mass Ratio Based on Laboratory Measurement and Reanalysis of H2 Spectra

Abstract: author: E. Reinhold et al.

http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PRLTAO000096000015151101000001&idtype=cvips&gifs=yes

Based on highly accurate laboratory measurements of Lyman bands of H2 and an updated representation of the structure of the ground X 1Sigma_g^+ and excited B 1Sigma_u^+ and C 1Piu states, a new set of sensitivity coefficients Ki is derived for all lines in the H2 spectrum, representing the dependence of their transition wavelengths on a possible variation of the proton-electron mass ratio µ=mp/me. Included are local perturbation effects between B and C levels and adiabatic corrections. The new wavelengths and Ki factors are used to compare with a recent set of highly accurate H2 spectral lines observed in the Q 0347-383 and Q 0405-443 quasars, yielding a fractional change in the mass ratio of Deltaµ/µ=(2.4±0.6)×10-5 for a weighted fit and Deltaµ/µ=(2.0±0.6)×10-5 for an unweighted fit. This result indicates, at a 3.5sigma confidence level, that µ could have decreased in the past 12 Gyr.

Check out more on Journal Club here:
http://trshare.triumf.ca/~theoryweb/ttgjclub.html

Please bring your lunch, news, rumors and new Journal Club topics.

______________________________

Subscription information available at http://admin.triumf.ca/netdata/seminars/list


---------------------- multipart/mixed attachment--