English
Related papers

Related papers: Sensitivity to alpha-variation in ultracold atomic…

200 papers

The fine structure constant, $\alpha$, sets the strength of the electromagnetic force. The Standard Model of particle physics provides no explanation for its value, which could potentially vary. The wavelengths of stellar absorption lines…

Solar and Stellar Astrophysics · Physics 2022-11-30 Michael T. Murphy , Daniel A. Berke , Fan Liu , Chris Flynn , Christian Lehmann , Vladimir A. Dzuba , Victor V. Flambaum

We analyse the scattering rate of an impurity atom in a Fermi sea as a function of momentum and temperature in the BCS-BEC crossover. The cross section is calculated using a microscopic multichannel theory for the Feshbach resonance…

Quantum Gases · Physics 2015-10-19 Rasmus Søgaard Christensen , Georg M. Bruun

We discover several magnetic Feshbach resonances in collisions of ultracold K(39) atoms, by studying atom losses and molecule formation. Accurate determination of the magnetic-field resonance locations allows us to optimize a quantum…

Atomic Physics · Physics 2009-11-13 C. D'Errico , M. Zaccanti , M. Fattori , G. Roati , M. Inguscio , G. Modugno , A. Simoni

The fine-structure constant, $\alpha$, controls the strength of the electromagnetic interaction. There are extensions of the standard model in which $\alpha$ is dynamical on cosmological length and time-scales. The physics of the cosmic…

Cosmology and Nongalactic Astrophysics · Physics 2019-02-27 Tristan L. Smith , Daniel Grin , David Robinson , Davy Qi

Review of recent works devoted to the variation of the fundamental constants is presented including atomic clocks, quasar absorption spectra, and Oklo natural nuclear reactor data. Assuming linear variation with time we can compare…

Atomic Physics · Physics 2008-11-26 V. V. Flambaum

Alpha-alpha scattering is discussed in terms of a chiral two pion exchange potential which turns out to be attractive and singular at the origin, hence demanding renormalization. When 8Be is treated as a resonance state a model independent…

Nuclear Theory · Physics 2008-11-26 E. Ruiz Arriola

$\Lambda$-doublet spectra of light diatomic radicals have high sensitivity to the possible variations of the fine structure constant alpha and electron-to-proton mass ratio beta. For molecules OH and CH sensitivity is further enhanced…

Cosmology and Nongalactic Astrophysics · Physics 2009-09-01 M. G. Kozlov

We report the experimental determination of the scattering parameters for a p-wave Feshbach resonance in a single component Fermi gas of 6Li atoms in the lowest spin state. The time scale of the cross-dimensional relaxation reflects the…

Atomic Physics · Physics 2016-09-30 Takuya Nakasuji , Jun Yoshida , Takashi Mukaiyama

We report a robust constrain on the possible variation of fine-structure constant, alpha = e^2/(hbar*c), obtained using O III 4959,5007, nebular emission lines from QSOs. We find Delta-alpha/alpha=-(2.1 +/- 1.6) x 10^(-5) based on a well…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 H. Rahmani , N. Maheshwari , R. Srianand

Verification of theoretical predictions of an oscillating behavior of the fine-structure constant, alpha, with cosmic time requires high precision measurements at individual redshifts, while in earlier studies the mean Delta alpha/alpha…

Astrophysics · Physics 2009-11-11 S. A. Levshakov , M. Centurion , P. Molaro , S. D'Odorico , D. Reimers , R. Quast , M. Pollmann

We use the relativistic Hartree-Fock method, many-body perturbation theory and configuration-interaction method to calculate the dependence of atomic transition frequencies on the fine structure constant, alpha. The results of these…

Atomic Physics · Physics 2008-11-26 J. C. Berengut , V. A. Dzuba , V. V. Flambaum , M. V. Marchenko

We explore the potential variation of two fundamental constants, the fine-structure constant $\alpha$ and the proton-to-electron mass ratio $\mu$, within the framework of modified gravity theories and finite-temperature effects. Utilising…

Solar and Stellar Astrophysics · Physics 2025-09-17 Akhil Uniyal , Surajit Kalita , Yosuke Mizuno , Sayan Chakrabarti , Yan Lu

An accurate knowledge of the scattering length is fundamental in ultracold quantum gas experiments and essential for the characterisation of the system as well as for a meaningful comparison to theoretical models. Here, we perform a careful…

Recently it was pointed out that transition frequencies in certain diatomic molecules have an enhanced sensitivity to variations in the fine-structure constant $\alpha$ and the proton-to-electron mass ratio $m_p/m_e$ due to a near…

Atomic Physics · Physics 2010-08-31 K. Beloy , A. Borschevsky , P. Schwerdtfeger , V. V. Flambaum

A high-precision relativistic calculations of Cd-like Nd$^{12+}$, Sm$^{14+}$ and Sn-like Pr$^{9+}$, Nd$^{10+}$ atomic properties is carried out using an approach that combines configuration interaction and a linearized coupled-cluster…

Atomic Physics · Physics 2015-06-22 M. S. Safronova , V. A. Dzuba , V. V. Flambaum , U. I. Safronova , S. G. Porsev , M. G. Kozlov

A magnetic field dependent Feshbach resonance has been observed in the elastic scattering collision rate between atoms in the F = 2, M = -2 state of 85 Rb. Changing the magnetic field by several Gauss caused the collision rate to vary by a…

Magnetic Feshbach resonances are an invaluable tool for controlling ultracold atoms and molecules. They can be used to tune atomic interactions and have been used extensively to explore few- and many-body phenomena. They can also be used…

The ultracold mixture of \Na and \Rb atoms has become an important system for investigating physics in Bose-Bose atomic mixtures and for forming ultracold ground-state polar molecules. In this work, we provide an improved characterization…

Quantum Gases · Physics 2022-02-23 Zhichao Guo , Fan Jia , Bing Zhu , Lintao Li , Jeremy M. Hutson , Dajun Wang

The $\alpha$-optical potential is one of the key input parameters used to measure the reaction rate of the ($\gamma,\alpha$)-process using the Hauser-Feshbach(HF) statistical model and the principle of detailed balance. $\alpha$-elastic…

‹ Prev 1 3 4 5 6 7 10 Next ›