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The stability of the linear chain structure of three $\alpha$ clusters for $^{12}$C against the bending and fission is investigated in the cranking covariant density functional theory, in which the equation of motion is solved on a 3D…

Nuclear Theory · Physics 2020-07-22 Z. X. Ren , S. Q. Zhang , P. W. Zhao , N. Itagaki , J. A. Maruhn , J. Meng

In extensions of general relativity and in theories aiming at unifying gravity with the forces of the Standard Model, the value of the "fundamental constants" is often determined by the vacuum expectation value of new fields, which may thus…

General Relativity and Quantum Cosmology · Physics 2014-03-19 Cosimo Bambi

Theories unifying gravity with other interactions suggest spatial and temporal variation of fundamental ``constants'' in the Universe. A change in the fine structure constant, alpha, could be detected via shifts in the frequencies of atomic…

Data recorded by the JADE experiment at the PETRA e^+e^- collider were used to measure distributions of new event shape observables. The distributions were compared with resummed QCD calulations (O(alpha_s^2)+NLLA), and the strong coupling…

High Energy Physics - Experiment · Physics 2009-10-30 P. A. Movilla Fernandez

We use the strong nebular lines of O III, 5007 A and 4959 A, to set a robust upper limit on the time dependence of the fine structure constant. We find |alpha^{-1} d alpha(t)/dt | < 2*10^{-13} yr, corresponding to Delta alpha/alpha(0) =…

Astrophysics · Physics 2009-09-29 John N. Bahcall , Charles L. Steinhardt , David Schlegel

It was hypothesized in the literature that some physical parameters may be time-evolving and the astrophysical data can serve as a probe. Recently, James Webb Space Telescope (JWST) have released its early observations. In this work, we…

Cosmology and Nongalactic Astrophysics · Physics 2024-11-15 Ze-Fan Wang , Lei Lei , Lei Feng , Yi-Zhong Fan

We introduce a methodology to test models with spatial variations of the fine-structure constant $\alpha$, based on the calculation of the angular power spectrum of these measurements. This methodology enables comparisons of observations…

Cosmology and Nongalactic Astrophysics · Physics 2017-04-24 A. M. M. Pinho , M. Martinelli , C. J. A. P. Martins

Since 1995, LEP has steadily increased the center of mass energy of the colliding beams, from the M_Z resonance to 133, 161 and 172 GeV. New measurements of the strong coupling constant, alpha_s, at these energies have been performed by the…

High Energy Physics - Experiment · Physics 2008-02-03 S. Marti i Garcia

The relative effects of variation of the fine structure constant alpha=e^2/hc and dimensionless strong interaction parameter m_q/Lambda_{QCD} are enhanced 5-6 orders of magnitude in very narrow ultraviolet transition between the ground and…

Atomic Physics · Physics 2011-11-23 V. V. Flambaum

Our calculations have shown that the 5f_5/2-7s_1/2 23131 cm^{-1} transition from the ground state in the ion Th^{3+} is very sensitive to the temporal variation of the fine structure constant alpha (q=-75300 cm^{-1}). The line is very…

Atomic Physics · Physics 2010-04-29 V. V. Flambaum , S. G. Porsev

We present a determination of the strong coupling constant using ATLAS inclusive jet cross section data at sqrt{s} = 7TeV, with their full information on the bin-to-bin correlations. Several procedures for combining the statistical…

High Energy Physics - Phenomenology · Physics 2015-06-11 Bogdan Malaescu

As is well known, measurements of the Sunyaev-Zeldovich effect can be combined with observations of the X-ray surface brightness of galaxy clusters to estimate the angular diameter distance to these structures. In this paper, we show that…

Cosmology and Nongalactic Astrophysics · Physics 2021-11-01 R. F. L. Holanda , V. C. Busti , L. R. Colaço , J. S. Alcaniz , S. J. Landau

The two-parametric Mittag-Leffler function (MLF), $E_{\alpha,\beta}$, is fundamental to the study and simulation of fractional differential and integral equations. However, these functions are computationally expensive and their numerical…

Numerical Analysis · Mathematics 2019-12-24 Ibrahim O. Sarumi , Khaled M. Furati , Abdul Q. M. Khaliq

An exploratory study for a new determination of the strong coupling constant alpha_s(MZ) from existing world data on the proton structure function F2p in the Q**2-range from ~ 5 to ~ 120 (GeV/c)**2 is presented. The main features of our…

High Energy Physics - Phenomenology · Physics 2015-06-25 S. Simula , M. Osipenko

We forecast the ability of future CMB and galaxy lensing surveys to constrain variations of the fine structure constant. We found that lensing data, as those expected from satellite experiments as Euclid could improve the constraint from…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Matteo Martinelli , Eloisa Menegoni , Alessandro Melchiorri

Astrophysical tests of the stability of fundamental couplings, such as the fine-structure constant $\alpha$, are becoming an increasingly powerful probe of new physics. Here we discuss how these measurements, combined with local atomic…

Cosmology and Nongalactic Astrophysics · Physics 2015-09-09 C. J. A. P. Martins , A. M. M. Pinho , R. F. C. Alves , M. Pino , C. I. S. A. Rocha , M. von Wietersheim

In this paper we discuss effective strong coupling constants. Those are well behaved in the low-Q^2 domain, contrarily to alpha_s from pQCD. We present an extraction of an effective strong coupling constant from Jefferson Lab polarized data…

High Energy Physics - Phenomenology · Physics 2009-08-24 A. Deur

An update is described of a model independent method to determine the hadronic contribution to the QED running coupling at the Z-boson mass scale, $\Delta\alpha_{\text{HAD}}(M_{Z}^{2})$. The major source of uncertainty is from the…

High Energy Physics - Phenomenology · Physics 2022-03-29 Cesareo A. Dominguez , Luis A. Hernández

We perform an extraction of alpha_s based on sum rules involving isovector hadronic tau decay data. The particular sum rules employed are constructed specifically to suppress contributions associated with poorly known higher dimension…

High Energy Physics - Phenomenology · Physics 2009-06-07 K. Maltman , T. Yavin

We report a measurement of the strong coupling constant, $\alpha_s(M_Z)$, extracted from inclusive jet production in $p\bar{p}$ collisions at $\sqrt{s}=$1800 GeV. The QCD prediction for the evolution of $\alpha_s$ with jet transverse energy…

High Energy Physics - Experiment · Physics 2010-05-12 T. Affolder
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