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We identify the molecular ion NH^+ as a potential candidate for probing variations in the fine structure constant alpha and electron-to-proton mass ratio mu. NH^+ has an anomalously low-lying excited Sigma state, being only a few hundred…

原子物理 · 物理学 2012-09-07 K. Beloy , M. G. Kozlov , A. Borschevsky , A. W. Hauser , V. V. Flambaum , P. Schwerdtfeger

Spectra of molecular hydrogen (H$_2$) are employed to search for a possible proton-to-electron mass ratio ($\mu$) dependence on gravity. The Lyman transitions of H$_2$, observed with the Hubble Space Telescope towards white dwarf stars that…

广义相对论与量子宇宙学 · 物理学 2014-10-02 Julija Bagdonaite , Edcel J. Salumbides , Simon P. Preval , Martin A. Barstow , John D. Barrow , Michael T. Murphy , Wim Ubachs

Accurate measurements of different transition frequencies between atomic levels of the electronic and hyperfine structure over time are used to investigate temporal variations of the fine structure constant $\alpha$ and the…

原子物理 · 物理学 2014-12-01 N. Huntemann , B. Lipphardt , Chr. Tamm , V. Gerginov , S. Weyers , E. Peik

We report new upper limits on any possible long-term time variation of the ratio of the electron to proton masses, $(m_e/m_p)$, the fine-structure constant, ($\alpha$), and the quantity $\alpha^2 g_p(m_e/m_p)$, where $g_p$ is the proton…

天体物理学 · 物理学 2011-07-18 Lennox L. Cowie , Antoinette Songaila

Carbon monoxide (CO) absorption in the sub-damped Lyman-$\alpha$ absorber at redshift $z_{abs} \simeq 2.69$, toward the background quasar SDSS J123714.60+064759.5 (J1237+0647), was investigated for the first time in order to search for a…

宇宙学与河外天体物理 · 物理学 2016-08-17 M. Daprà , M. L. Niu , E. J. Salumbides , M. T. Murphy , W. Ubachs

Many physical theories beyond the Standard Model predict time variations of basic physics parameters. Direct measurement of the time variations of these parameters is very difficult or impossible to achieve. By contrast, measurements of…

宇宙学与河外天体物理 · 物理学 2017-03-29 Rodger I. Thompson

Molecular hydrogen transitions in quasar spectra can be used to constrain variation in the proton-to-electron mass ratio, $\mu\equiv m_p/m_e$, at high redshifts ($z\gtrsim 2$). We present here an analysis of a new spectrum of the quasar…

宇宙学与河外天体物理 · 物理学 2015-05-28 Julian A. King , Michael T. Murphy , Wim Ubachs , John K. Webb

The observed time delays between photons with different circular polarizations from an astrophysical object provide a new, interesting way of testing the Einstein Equivalence Principle (EEP). In this paper, we constrain the EEP by…

高能天体物理现象 · 物理学 2020-09-30 Shuang-Xi Yi , Yuan-Chuan Zou , Jun-Jie Wei , Qi-Qi Zhou

Absorption spectroscopy toward high-redshift quasars provides strong constraints on the putative variation of fundamental constants of physics on cosmological time scales. The submillimeter ground-state transitions of methylidyne (CH) and…

宇宙学与河外天体物理 · 物理学 2026-02-25 S. Muller , A. Beelen , M. Guelin , J. H. Black , F. Combes , H. L. Bethlem , M. Gerin , C. Henkel , K. M. Menten , M. T. Murphy , W. Ubachs , N. Wozny

The fractionation of nitrogen (N) in star-forming regions is a poorly understood process. To put more stringent observational constraints on the N-fractionation, we have observed with the IRAM-30m telescope a large sample of 66 cores in…

太阳与恒星天体物理 · 物理学 2018-05-02 L. Colzi , F. Fontani , V. M. Rivilla , A. Sánchez-Monge , L. Testi , M. T. Beltrán , P. Caselli

Astrophysical tests of the stability of fundamental couplings are becoming an increasingly important probe of new physics. Motivated by the recent availability of new and stronger constraints we update previous works testing the consistency…

宇宙学与河外天体物理 · 物理学 2017-01-31 C. J. A. P. Martins , A. M. M. Pinho

A clock comparison experiment, analyzing the ratio of spin precession frequencies of stored ultracold neutrons and $^{199}$Hg atoms is reported. %57 No daily variation of this ratio could be found, from which is set an upper limit on the…

The Radio Ammonia Mid-Plane Survey (RAMPS) is a molecular line survey that aims to map a portion of the Galactic midplane in the first quadrant of the Galaxy (l = 10 deg - 40 deg, |b| < 0.4 deg) using the Green Bank Telescope. We present…

A precision measurement by AMS of the antiproton-to-proton flux ratio in primary cosmic rays in the absolute rigidity range from 1 to 450 GV is presented based on $3.49\times10^5$ antiproton events and $2.42\times10^9$ proton events. Above…

高能天体物理现象 · 物理学 2017-02-01 Francesco Nozzoli

The anomalous magnetic moment of the muon is one of the most precisely measured quantities in physics. Its experimental value exhibits a $4.2 \, \sigma$ discrepancy $\delta a_\mu=(251 \pm 59) \times 10^{-11}$ with its theoretical value…

综合物理 · 物理学 2021-04-20 Laurent Nottale

Recently, methanol was identified as a sensitive target system to probe variations of the proton-to-electron mass ratio $\mu$ [Jansen \emph{et al.} Phys. Rev. Lett. \textbf{106}, 100801 (2011)]. The high sensitivity of methanol originates…

化学物理 · 物理学 2012-03-07 Paul Jansen , Isabelle Kleiner , Li-Hong Xu , Wim Ubachs , Hendrick L. Bethlem

We compare three different models of rotating neutron star spacetimes: the Hartle-Thorne (HT) slow-rotation approximation at second order in rotation, the exact analytic vacuum solution of Manko et al. and a numerical solution of the full…

广义相对论与量子宇宙学 · 物理学 2011-05-23 Emanuele Berti , Frances White , Asimina Maniopoulou , Marco Bruni

All evidence so far suggests that the absolute spatial orientation of an experiment never affects its outcome. This is reflected in the Standard Model of physics by requiring all particles and fields to be invariant under Lorentz…

We obtain constraints on the variation of the fundamental constants from the full shape of the redshift-space correlation function of a sample of luminous galaxies drawn from the Data Release 9 of the Baryonic Oscillations Spectroscopic…

We used a continuously rotating torsion balance instrument to measure the acceleration difference of beryllium and titanium test bodies towards sources at a variety of distances. Our result Delta a=(0.6+/-3.1)x10^-15 m/s^2 improves limits…

广义相对论与量子宇宙学 · 物理学 2008-11-26 S. Schlamminger , K. -Y. Choi , T. A. Wagner , J. H. Gundlach , E. G. Adelberger