Cold molecule spectroscopy for constraining the evolution of the fine structure constant.
نویسندگان
چکیده
We report precise measurements of ground-state, Lambda-doublet microwave transitions in the hydroxyl radical molecule (OH). Utilizing slow, cold molecules produced by a Stark decelerator we have improved over the precision of the previous best measurement 25-fold for the F'=2-->F=2 transition, yielding (1 667 358 996 +/- 4)Hz, and by tenfold for the F'=1-->F=1 transition, yielding (1 665 401 803 +/-12)Hz. Comparing these laboratory frequencies to those from OH megamasers in interstellar space will allow a sensitivity of 1 ppm for Delta(alpha/alpha) over approximately 10(10) yr.
منابع مشابه
Ultra-Fine Grained Dual-Phase Steels
This paper provides an overview on obtaining low-carbon ultra-fine grained dual-phase steels through rapid intercritical annealing of cold-rolled sheet as improved materials for automotive applications. A laboratory processing route was designed that involves cold-rolling of a tempered martensite structure followed by a second tempering step to produce a fine grained aggregate of ferrite and ca...
متن کاملMethods for constraining fine structure constant evolution with OH microwave transitions.
We investigate the constraints that OH microwave transitions in megamasers and molecular absorbers at cosmological distances may place on the evolution of the fine structure constant alpha=e(2)/ variant Planck's over 2pi c. The centimeter OH transitions are a combination of hyperfine splitting and lambda doubling that can constrain the cosmic evolution of alpha from a single species, avoiding s...
متن کاملThe Effect of Hydrophobicity and Hydrophilicity of Gold Nanoparticle on Proteins Structure and Function
The surface parameter of nanoparticles such as hydrophobicity and a hydrophilicity on protein structure and function is very important. In this study, conformational changes of glucose oxidase (GOx) in the mercaptopurine: GNPs and 11-mercaptoundecanoic acid: GNPs as a hydrophobic and a hydrophilic GNPs surface was investigated by various spectroscopic techniques, including: UV-Vis absorption, f...
متن کاملThe Effect of Hydrophobicity and Hydrophilicity of Gold Nanoparticle on Proteins Structure and Function
The surface parameter of nanoparticles such as hydrophobicity and a hydrophilicity on protein structure and function is very important. In this study, conformational changes of glucose oxidase (GOx) in the mercaptopurine: GNPs and 11-mercaptoundecanoic acid: GNPs as a hydrophobic and a hydrophilic GNPs surface was investigated by various spectroscopic techniques, including: UV-Vis absorption, f...
متن کاملIn situ activation of a Ni catalyst with Mo ion for hydrogen evolution reaction in alkaline solution
In this study Ni catalyst have been activated during hydrogen evolution reaction (HER) by adding Mo ions into the alkaline electrolyte. After dissolving different amounts of ammonium molybdate in the 1M NaOH as electrolyte, Ni catalyst was used as cathode for HER. Afterwards a comparison between hydrogen overpotential measured in Ni catalyst with and without in situ activation has been made; th...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Physical review letters
دوره 96 14 شماره
صفحات -
تاریخ انتشار 2006