A new search for the variation of fundamental constants using the rovibrational levels and isotope effects of the magnesium fluoride molecule  

作　　者：Di Wu Jin Wei Taojing Dong Chenyu Zu Yong Xia Jianping Yin 吴迪;魏晋;董涛晶;祖晨宇;夏勇;印建平

机构地区：[1]State Key Laboratory of Precision Spectroscopy,School of Physics and Electronic Science,East China Normal University,Shanghai 200241,China [2]Collaborative Innovation Center of Extreme Optics,Shanxi University,Taiyuan 030006,China [3]NYU-ECNU Institute of Physics at NYU Shanghai,Shanghai 200062,China

出　　处：《Chinese Physics B》2025年第2期215-221,共7页中国物理B(英文版)

基　　金：Project supported by the National Natural Science Foundation of China (Grant Nos. 12174115,11834003,and 91836103)。

摘　　要：The recently demonstrated methods for cooling and trapping diatomic molecules offer new possibilities for precision searches in fundamental physical theories.Here,we propose to study the variations of the fine-structure constant(α=e^(2)/(hc)) and the proton-to-electron mass ratio(μ=m_(p)/m_(e)) with time by taking advantage of the nearly degenerate rovibrational levels in the electronic states of the magnesium fluoride(MgF) molecule.Specifically,due to the cancellation between the fine-structure splitting and the rovibrational intervals in the different MgF natural isotopes,a degeneracy occurs for A^(2)П_(3/2)(v'=0,J'=18.5,-) and A^(2)П_(1/2)(v "=0,J" =20.5,-).We find that using the nearly degenerate energy level of such states can be 104 times more sensitive than using a pure rotational transition to measure the variations of α and μ.To quantify the small gap between A^(2)П_(3/2)(v'=0,J'=18.5,-) and A^(2)П_(1/2)(v "=0,J" =20.5,-),special transitions of choice are feasible:X^(2)Σ_(1/2)~+(v=0,J=19.5,+) to A^(2)П_(3/2)(v'=0,J'=18.5,-) and X^(2)Σ_(1/2)~+(v=0.J=19.5,+)to A^(2)П_(1/2)(v "=0,J" =20.5,-).In addition,we estimate the frequency uncertainties caused by the narrow linewidth,Zeeman shift,Stark shift,Doppler broadening and blackbody radiation.

关 键 词：cold molecule proton-to-electron mass ratio precision measurement 

分 类 号：O56[理学—原子与分子物理]