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Pang R, Yin J, Wang Y, Lin Q, Wang Z, Xu L, Hou S, Wang H, Yin J, Yang T. Theoretical Investigation of Spectroscopic Properties of the Alkaline-Earth-Metal Monohydrides toward Laser Cooling and Magneto-Optical Trapping. ACS OMEGA 2023; 8:19391-19401. [PMID: 37305276 PMCID: PMC10249082 DOI: 10.1021/acsomega.3c00352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Accepted: 04/10/2023] [Indexed: 06/13/2023]
Abstract
Alkaline-earth-metal monohydrides MH (M = Be, Mg, Ca, Sr, Ba) have long been regarded as promising candidates toward laser cooling and trapping; however, their rich internal level structures that are amenable to magneto-optical trapping have not been completely explored. Here, we first systematically evaluated Franck-Condon factors of these alkaline-earth-metal monohydrides in the A2Π1/2 ← X2Σ+ transition, exploiting three respective methods (the Morse potential, the closed-form approximation, and the Rydberg-Klein-Rees method). The effective Hamiltonian matrix was introduced for MgH, CaH, SrH, and BaH individually in order to figure out their molecular hyperfine structures of X2Σ+, the transition wavelengths in the vacuum, and hyperfine branching ratios of A2Π1/2(J' = 1/2,+) ← X2Σ+(N = 1,-), followed by possible sideband modulation proposals to address all hyperfine manifolds. Lastly, the Zeeman energy level structures and associated magnetic g factors of the ground state X2Σ+(N = 1,-) were also presented. Our theoretical results here not only shed more light on the molecular spectroscopy of alkaline-earth-metal monohydrides toward laser cooling and magneto-optical trapping but also can contribute to research in molecular collisions involving few-atom molecular systems, spectral analysis in astrophysics and astrochemistry, and even precision measurement of fundamental constants such as the quest for nonzero detection of electron's electric dipole moment.
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Affiliation(s)
- Renjun Pang
- State
Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, P. R. China
| | - Junhao Yin
- State
Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, P. R. China
| | - Yueyang Wang
- State
Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, P. R. China
| | - Qinning Lin
- State
Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, P. R. China
| | - Zesen Wang
- State
Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, P. R. China
| | - Liang Xu
- Shanghai
Key Laboratory of Modern Optical Systems, University of Shanghai for Science and Technology, Shanghai 200093, P. R. China
| | - Shunyong Hou
- State
Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, P. R. China
| | - Hailing Wang
- State
Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, P. R. China
| | - Jianping Yin
- State
Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, P. R. China
| | - Tao Yang
- State
Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, P. R. China
- Collaborative
Innovation Center of Extreme Optics, Shanxi
University, Taiyuan, Shanxi 030006, P.
R. China
- Xinjiang
Astronomical Observatory, Chinese Academy
of Sciences, 150 Science
1-Street, Urumqi, Xinjiang 830011, P. R. China
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Le T. Stringent limit on space-time variation of fine-structure constant using high-resolution of quasar spectra. Heliyon 2020; 6:e05011. [PMID: 32995647 PMCID: PMC7511822 DOI: 10.1016/j.heliyon.2020.e05011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 06/19/2020] [Accepted: 09/17/2020] [Indexed: 11/13/2022] Open
Abstract
We have obtained a new limit on the space-time variation of the fine-structure constant(α=e24πε0ℏc)using the observations of Mg II line in quasar J110325-264515 spectra with redshiftzabs=1.8389. The obtained parameter isΔα/α=(−0.155±0.728)×10−6. It was derived from the comparison between the quasar J110325-264515 spectra and the laboratory sample spectra. The obtained result appears as a new highly sensitive probe of the cosmological variability of the fine-structure constant. From the relative spectra of the Mg II, we found the most stringent constraint up today onΔα/αcomparing to the previously published results.
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New Limit on Space-Time Variations in the Proton-to-Electron Mass Ratio from Analysis of Quasar J110325-264515 Spectra. Symmetry (Basel) 2020. [DOI: 10.3390/sym12030344] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Astrophysical tests of current values for dimensionless constants known on Earth, such as the fine-structure constant, α , and proton-to-electron mass ratio, μ = m p / m e , are communicated using data from high-resolution quasar spectra in different regions or epochs of the universe. The symmetry wavelengths of [Fe II] lines from redshifted quasar spectra of J110325-264515 and their corresponding values in the laboratory were combined to find a new limit on space-time variations in the proton-to-electron mass ratio, ∆ μ / μ = ( 0.096 ± 0.182 ) × 10 − 7 . The results show how the indicated astrophysical observations can further improve the accuracy and space-time variations of physics constants.
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Syme AM, Mousley A, Cunningham M, McKemmish LK. Diatomic Rovibronic Transitions as Potential Probes for Proton-to-Electron Mass Ratio Across Cosmological Time. Aust J Chem 2020. [DOI: 10.1071/ch19448] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Astrophysical molecular spectroscopy is an important method of searching for new physics through probing the variation of the proton-to-electron mass ratio, μ, with existing constraints limiting variation to a fractional change of less than 10−17per year. To improve on this constraint and therefore provide better guidance to theories of new physics, new molecular probes will be useful. These probes must have spectral transitions that are observable astrophysically and have different sensitivities to variation in the proton-to-electron mass ratio. Here, we concisely detail how the set of potential molecular probes and promising sensitive transitions is constrained based on how the frequency and intensity of these transitions align with available telescopes. Our detailed investigation focuses on rovibronic transitions in astrophysical diatomic molecules, using the spectroscopic models of 11 diatomics to identify sensitive transitions and probe how they generally arise in real complex molecules with many electronic states and fine structure. While none of the 11 diatomics investigated have sensitive transitions likely to be astrophysically observable, we have found that at high temperatures (1000K) five of these diatomics have a significant number of low intensity sensitive transitions arising from an accidental near-degeneracy between vibrational levels in the ground and excited electronic states. This insight enables screening of all astrophysical diatomics as potential probes of proton-to-electron mass variation, with CN, CP, SiN and SiC being the most promising candidates for further investigation for sensitivity in rovibronic transitions.
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5
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Updated Constraints on the Variations of the Fine-Structure Constant from an Analysis of White-Dwarf Spectra. Symmetry (Basel) 2019. [DOI: 10.3390/sym11070936] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
I used observed spectra from the white-dwarf star G191-B2B to constrain the spatial and temporal variation of the fine-structure constant,[...]
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6
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An Updated Constraint on Variations of the Fine-Structure Constant Using Wavelengths of Fe II Absorption Line Multiplets. Symmetry (Basel) 2018. [DOI: 10.3390/sym10120722] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
A new stringent limit relating to the variation of the fine-structure constant (α= e2/4πε0ℏc) has been extracted from Ritz wavelengths of 27 quasi_stellar object (QSO) absorption spectra lines of Fe II. The calculation was combined with laboratory wavelengths and QSO spectra to obtain the result ∆α/α=(0.027±0.832)×10-6. This result suggests how dedicated astrophysical estimations can improve these limits in the future and can also constrain space_time variations.
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Martins CJAP. The status of varying constants: a review of the physics, searches and implications. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2017; 80:126902. [PMID: 28805650 DOI: 10.1088/1361-6633/aa860e] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The observational evidence for the recent acceleration of the universe demonstrates that canonical theories of cosmology and particle physics are incomplete-if not incorrect-and that new physics is out there, waiting to be discovered. A key task for the next generation of laboratory and astrophysical facilities is to search for, identify and ultimately characterize this new physics. Here we highlight recent developments in tests of the stability of nature's fundamental couplings, which provide a direct handle on new physics: a detection of variations will be revolutionary, but even improved null results provide competitive constraints on a range of cosmological and particle physics paradigms. A joint analysis of all currently available data shows a preference for variations of α and μ at about the two-sigma level, but inconsistencies between different sub-sets (likely due to hidden systematics) suggest that these statistical preferences need to be taken with caution. On the other hand, these measurements strongly constrain Weak Equivalence Principle violations. Plans and forecasts for forthcoming studies with facilities such as ALMA, ESPRESSO and the ELT, which should clarify these issues, are also discussed, and synergies with other probes are briefly highlighted. The goal is to show how a new generation of precision consistency tests of the standard paradigm will soon become possible.
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Affiliation(s)
- C J A P Martins
- Centro de Astrofísica da Universidade do Porto, Rua das Estrelas, 4150-762 Porto, Portugal. Instituto de Astrofísica e Ciências do Espaço, CAUP, Rua das Estrelas, 4150-762 Porto, Portugal
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CONSTRAINT ON A COSMOLOGICAL VARIATION IN THE PROTON-TO-ELECTRON MASS RATIO FROM ELECTRONIC CO ABSORPTION. ACTA ACUST UNITED AC 2016. [DOI: 10.3847/0004-637x/826/2/192] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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9
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Leite A, Martins C. Current and future constraints on Bekenstein-type models for varying couplings. Int J Clin Exp Med 2016. [DOI: 10.1103/physrevd.94.023503] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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10
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Electronic structure calculation of the KYb molecule with dipole moments, polarizabilities, and ro-vibrational studies. COMPUT THEOR CHEM 2016. [DOI: 10.1016/j.comptc.2015.12.022] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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11
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Bagdonaite J, Ubachs W, Murphy MT, Whitmore JB. Constraint on a varying proton-electron mass ratio 1.5 billion years after the big bang. PHYSICAL REVIEW LETTERS 2015; 114:071301. [PMID: 25763949 DOI: 10.1103/physrevlett.114.071301] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Indexed: 06/04/2023]
Abstract
A molecular hydrogen absorber at a lookback time of 12.4 billion years, corresponding to 10% of the age of the Universe today, is analyzed to put a constraint on a varying proton-electron mass ratio, μ. A high resolution spectrum of the J1443+2724 quasar, which was observed with the Very Large Telescope, is used to create an accurate model of 89 Lyman and Werner band transitions whose relative frequencies are sensitive to μ, yielding a limit on the relative deviation from the current laboratory value of Δμ/μ=(-9.5 ± 5.4(stat)± 5.3(syst))×10(-6).
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Affiliation(s)
- J Bagdonaite
- Department of Physics and Astronomy, and LaserLaB, VU University, De Boelelaan 1081, 1081 HV Amsterdam, Netherlands
| | - W Ubachs
- Department of Physics and Astronomy, and LaserLaB, VU University, De Boelelaan 1081, 1081 HV Amsterdam, Netherlands
| | - M T Murphy
- Centre for Astrophysics and Supercomputing, Swinburne University of Technology, Melbourne, Victoria 3122, Australia
| | - J B Whitmore
- Centre for Astrophysics and Supercomputing, Swinburne University of Technology, Melbourne, Victoria 3122, Australia
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12
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Špirko V. Highly Sensitive Ammonia Probes of a Variable Proton-to-Electron Mass Ratio. J Phys Chem Lett 2014; 5:919-923. [PMID: 26274089 DOI: 10.1021/jz500163j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The mass sensitivity of the vibration-rotation-inversion energy levels of ammonia is probed using the nonrigid inverter theory. It is shown that the sensitivity exhibits non-negligible centrifugal distortion dependence, which is currently disregarded. The centrifugal distortion effects are especially important in the case of the Δk = ±3 "forbidden" transitions involving accidentally coinciding ro-inversional states |a,J,K = 3⟩ and |s,J,K = 0⟩ of the ν2 vibrational state of (14)NH3. The energy differences of these states exhibit very anomalous mass sensitivities (see Jansen etal. J. Chem. Phys. 2014 , 140 , 010901 ), thus appearing as new highly sensitive probes of the cosmological variability of the proton-to-electron mass ratio.
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Affiliation(s)
- Vladimír Špirko
- Academy of Sciences of the Czech Republic, Institute of Organic Chemistry and Biochemistry, Flemingovo nám. 2, 166 10 Prague 6, Czech Republic
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13
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Jansen P, Bethlem HL, Ubachs W. Perspective: Tipping the scales: Search for drifting constants from molecular spectra. J Chem Phys 2014; 140:010901. [DOI: 10.1063/1.4853735] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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14
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Bagdonaite J, Daprà M, Jansen P, Bethlem HL, Ubachs W, Muller S, Henkel C, Menten KM. Robust constraint on a drifting proton-to-electron mass ratio at z=0.89 from methanol observation at three radio telescopes. PHYSICAL REVIEW LETTERS 2013; 111:231101. [PMID: 24476248 DOI: 10.1103/physrevlett.111.231101] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Indexed: 06/03/2023]
Abstract
A limit on a possible cosmological variation of the proton-to-electron mass ratio μ is derived from methanol (CH3OH) absorption lines in the benchmark PKS1830-211 lensing galaxy at redshift z=0.89 observed with the Effelsberg 100-m radio telescope, the Institute de Radio Astronomie Millimétrique 30-m telescope, and the Atacama Large Millimeter/submillimeter Array. Ten different absorption lines of CH3OH covering a wide range of sensitivity coefficients K(μ) are used to derive a purely statistical 1σ constraint of Δμ/μ=(1.5±1.5)×10(-7) for a lookback time of 7.5 billion years. Systematic effects of chemical segregation, excitation temperature, frequency dependence, and time variability of the background source are quantified. A multidimensional linear regression analysis leads to a robust constraint of Δμ/μ=(-1.0±0.8(stat)±1.0(sys))×10(-7).
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Affiliation(s)
- J Bagdonaite
- Department of Physics and Astronomy, VU University Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, Netherlands
| | - M Daprà
- Department of Physics and Astronomy, VU University Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, Netherlands
| | - P Jansen
- Department of Physics and Astronomy, VU University Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, Netherlands
| | - H L Bethlem
- Department of Physics and Astronomy, VU University Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, Netherlands
| | - W Ubachs
- Department of Physics and Astronomy, VU University Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, Netherlands
| | - S Muller
- Onsala Space Observatory, Chalmers University of Technology, SE 439-92 Onsala, Sweden
| | - C Henkel
- Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, 53121 Bonn, Germany and Astronony Department, King Abdulaziz University, Post Office Box 80203, Jeddah 21589, Saudi Arabia
| | - K M Menten
- Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, 53121 Bonn, Germany
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15
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Bagdonaite J, Jansen P, Henkel C, Bethlem HL, Menten KM, Ubachs W. A stringent limit on a drifting proton-to-electron mass ratio from alcohol in the early universe. Science 2013; 339:46-8. [PMID: 23239626 DOI: 10.1126/science.1224898] [Citation(s) in RCA: 100] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The standard model of physics is built on the fundamental constants of nature, but it does not provide an explanation for their values, nor require their constancy over space and time. Here we set a limit on a possible cosmological variation of the proton-to-electron mass ratio μ by comparing transitions in methanol observed in the early universe with those measured in the laboratory. From radio-astronomical observations of PKS1830-211, we deduced a constraint of Δμ/μ = (0.0 ± 1.0) × 10(-7) at redshift z = 0.89, corresponding to a look-back time of 7 billion years. This is consistent with a null result.
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Affiliation(s)
- Julija Bagdonaite
- Department of Physics and Astronomy, VU University Amsterdam, Amsterdam, Netherlands
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Abe M, Moriwaki Y, Hada M, Kajita M. Ab initio study on potential energy curves of electronic ground and excited states of 40CaH+ molecule. Chem Phys Lett 2012. [DOI: 10.1016/j.cplett.2011.11.048] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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17
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Ellingsen S, Voronkov M, Breen S. Practical limitations on astrophysical observations of methanol to investigate variations in the proton-to-electron mass ratio. PHYSICAL REVIEW LETTERS 2011; 107:270801. [PMID: 22243297 DOI: 10.1103/physrevlett.107.270801] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2011] [Indexed: 05/31/2023]
Abstract
The possibility of using astrophysical observations of rotational transitions in the methanol molecule to measure, or constrain temporal and spatial variations in the proton-to-electron mass ratio (μ) has recently been investigated by several groups. Here we outline some of the practical considerations of making such observations, including both the instrumental and astrophysical limitations which exist at present. This leads us to conclude that such observations are unlikely to be able to improve evidence either for, or against the presence of variations in the proton-to-electron mass ratio by more than an order of magnitude beyond current limits.
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Affiliation(s)
- Simon Ellingsen
- School of Mathematics and Physics, University of Tasmania, TAS 7001, Australia.
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van Weerdenburg F, Murphy MT, Malec AL, Kaper L, Ubachs W. First constraint on cosmological variation of the proton-to-electron mass ratio from two independent telescopes. PHYSICAL REVIEW LETTERS 2011; 106:180802. [PMID: 21635080 DOI: 10.1103/physrevlett.106.180802] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2011] [Indexed: 05/30/2023]
Abstract
A high signal-to-noise spectrum covering the largest number of hydrogen lines (90 H(2) lines and 6 HD lines) in a high-redshift object was analyzed from an observation along the sight line to the bright quasar source J2123-005 with the Ultraviolet and Visual Echelle Spectrograph on the European Southern Observatory Very Large Telescope (Paranal, Chile). This delivers a constraint on a possible variation of the proton-to-electron mass ratio of Δμ/μ=(8.5 ± 3.6(stat) ± 2.2(syst))×10(-6) at redshift z(abs) = 2.059, which agrees well with a recently published result on the same system observed at the Keck telescope yielding Δμ/μ=(5.6 ± 5.5(stat) ± 2.9(syst))×10(-6). Both analyses used the same robust absorption line fitting procedures with detailed consideration of systematic errors.
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Affiliation(s)
- F van Weerdenburg
- Institute for Lasers, Life and Biophotonics, VU University Amsterdam, The Netherlands
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Uzan JP. Varying Constants, Gravitation and Cosmology. LIVING REVIEWS IN RELATIVITY 2011; 14:2. [PMID: 28179829 PMCID: PMC5256069 DOI: 10.12942/lrr-2011-2] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 03/23/2011] [Indexed: 05/27/2023]
Abstract
Fundamental constants are a cornerstone of our physical laws. Any constant varying in space and/or time would reflect the existence of an almost massless field that couples to matter. This will induce a violation of the universality of free fall. Thus, it is of utmost importance for our understanding of gravity and of the domain of validity of general relativity to test for their constancy. We detail the relations between the constants, the tests of the local position invariance and of the universality of free fall. We then review the main experimental and observational constraints that have been obtained from atomic clocks, the Oklo phenomenon, solar system observations, meteorite dating, quasar absorption spectra, stellar physics, pulsar timing, the cosmic microwave background and big bang nucleosynthesis. At each step we describe the basics of each system, its dependence with respect to the constants, the known systematic effects and the most recent constraints that have been obtained. We then describe the main theoretical frameworks in which the low-energy constants may actually be varying and we focus on the unification mechanisms and the relations between the variation of different constants. To finish, we discuss the more speculative possibility of understanding their numerical values and the apparent fine-tuning that they confront us with.
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Affiliation(s)
- Jean-Philippe Uzan
- Institut d’Astrophysique de Paris, UMR-7095 du CNRS, Université Pierre et Marie Curie, 98 bis bd Arago, 75014 Paris, France
- Department of Mathematics and Applied Mathematics, Cape Town University, Rondebosch, 7701 South Africa
- National Institute for Theoretical Physics (NITheP), Stellenbosch, 7600 South Africa
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Jansen P, Xu LH, Kleiner I, Ubachs W, Bethlem HL. Methanol as a sensitive probe for spatial and temporal variations of the proton-to-electron mass ratio. PHYSICAL REVIEW LETTERS 2011; 106:100801. [PMID: 21469780 DOI: 10.1103/physrevlett.106.100801] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2010] [Indexed: 05/30/2023]
Abstract
The 6.7 and 12.2 GHz masers, corresponding to the 5(1) → 6(0)A+ and 2(0) → 3(-1)E transitions in methanol (CH3OH), respectively, are among the brightest radio objects in the sky. We present calculations for the sensitivity of these and other transitions in the ground state of methanol to a variation of the proton-to-electron mass ratio. We show that the sensitivity is greatly enhanced due to a cancellation of energies associated with the hindered internal rotation and the overall rotation of the molecule. We find sensitivities of K(μ) = -42 and K(μ) = -33, for the 5(1) → 6(0)A+ and 2(0) → 3(-1)E transitions, respectively. The sensitivities of other transitions in the different isotopologues of methanol range from -88 to 330. This makes methanol a sensitive probe for spatial and temporal variations of the proton-to-electron mass ratio.
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Affiliation(s)
- Paul Jansen
- Institute for Lasers, Life and Biophotonics, VU University Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
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22
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Bowler MW, Cliff MJ, Waltho JP, Blackburn GM. Why did Nature select phosphate for its dominant roles in biology? NEW J CHEM 2010. [DOI: 10.1039/b9nj00718k] [Citation(s) in RCA: 122] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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King JA, Webb JK, Murphy MT, Carswell RF. Stringent null constraint on cosmological evolution of the proton-to-electron mass ratio. PHYSICAL REVIEW LETTERS 2008; 101:251304. [PMID: 19113692 DOI: 10.1103/physrevlett.101.251304] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2008] [Indexed: 05/27/2023]
Abstract
We present a strong constraint on variation of the proton-to-electron mass ratio mu over cosmological time scales using molecular hydrogen transitions in optical quasar spectra. Using high quality spectra of quasars Q0405-443, Q0347-383, and Q0528-250, variation in micro relative to the present day value is limited to Deltamicro/micro=(2.6+/-3.0)x10;{-6}. We reduce systematic errors compared to previous works by substantially improving the spectral wavelength calibration method and by fitting absorption profiles to the forest of hydrogen Lyman alpha transitions surrounding each H2 transition. Our results are consistent with no variation, and inconsistent with a previous approximately 4sigma detection of mu variation involving Q0405-443 and Q0347-383. If the results of this work and those suggesting that alpha may be varying are both correct, then this would tend to disfavor certain grand unification models.
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Affiliation(s)
- Julian A King
- School of Physics, University of New South Wales, Sydney, NSW 2052, Australia
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