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Related papers: The strong coupling, unification, and recent data

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We calculate ~$\sin^2\theta(M_Z)$ ~in the MSSM in terms of ~ $\alpha_{EM}$, ~$G_F$, ~$m_t$, ~$\tan\beta$ ~and SUSY mass parameters with the same accuracy as the present calculations of ~$\sin^2\theta(M_Z)$ ~in the SM. We compare the results…

High Energy Physics - Phenomenology · Physics 2009-10-28 P. H. Chankowski , Z. Płuciennik , S. Pokorski

We demonstrate the feasibility of determining the strong coupling constant, $\alpha_s$, from the inclusive semileptonic decay width of $B$ mesons. We express the semileptonic $B$ decay width as a function of $\alpha_s(5\mathrm{\,GeV})$, the…

High Energy Physics - Phenomenology · Physics 2025-10-07 Yuzhi Che , Long Chen , Jinfei Wu , Xinchou Lou , Xiang Chen , Xin Guan , Yan-Qing Ma , Manqi Ruan

The initial data on the production and decay of the Higgs boson reported significant deviations from the Standard Model (SM) expectations, prompting much speculation about its couplings to the other particles. Although the latest data has…

High Energy Physics - Phenomenology · Physics 2013-11-20 Debajyoti Choudhury , Rashidul Islam , Anirban Kundu

In minimal theories with extra spatial dimensions at scales mu_0 much lower than the conventional GUT scale, unification can give too-large predictions for alpha_3(M_Z) given alpha_1(M_Z) and alpha_2(M_Z) as empirical input. We…

High Energy Physics - Phenomenology · Physics 2009-10-31 Paul H. Frampton , Andrija Rasin

The strong coupling constant $\alpha_s(\mu)$ is extracted from the fits to charmonium spectrum and fine structure splittings. The relativistic kinematics is taken into account and relativistic corrections are shown to increase the matrix…

High Energy Physics - Phenomenology · Physics 2009-10-31 A. M. Badalian , V. L. Morgunov

The complete calculation of the 2-loop electroweak corrections to the renormalization of the electric charge in the Standard Model allows to discuss in detail the value of the MSbar effective coupling $\hat e(m_Z)$. We discuss the…

High Energy Physics - Phenomenology · Physics 2009-11-10 Alessandro Vicini

From a fit to the experimental data on the $b\bar{b}$ fine structure, the two-loop coupling constant is extracted. For the 1P state the fitted value is $\alpha_s(\mu_1) = 0.33 \pm 0.01(exp)\pm 0.02 (th)$ at the scale $\mu_1 = 1.8 \pm 0.1$…

High Energy Physics - Phenomenology · Physics 2009-10-31 A. M. Badalian , B. L. G. Bakker

We present a new determination of the strong coupling constant alpha_s through the scaling violations in the fragmentation functions for charged pions, charged kaons, and protons. In our fit we include the latest e+e- annihilation data from…

High Energy Physics - Phenomenology · Physics 2009-10-31 B. A. Kniehl , G. Kramer , B. Pötter

A program including all radiative corrections to the MSSM at the same level as the radiative corrections to the SM has been developed and used to perform global fits to all electroweak data from LEP, SLC and the Tevatron and the radiative…

High Energy Physics - Phenomenology · Physics 2016-09-06 W. de Boer , A. Dabelstein , W. Hollik , W. Moesle , U. Schwickerath

This paper presents a summary of the current status of determinations of the strong coupling constant alpha_s. A detailed description of the definition, scale dependence and inherent theoretical ambiguities is given. The various physical…

High Energy Physics - Phenomenology · Physics 2009-10-31 Ian Hinchliffe , Aneesh V. Manohar

To obtain the value of electromagnetic coupling constant at $q^2=m^2_Z$, $\bar{\alpha}$, which plays a key role in electroweak physics one has to integrate the cross-section of $e^+e^-$-annihilation into hadrons divided by $(s-m^2_Z)$ over…

High Energy Physics - Phenomenology · Physics 2007-05-23 R. B. Nevzorov , A. V. Novikov , M. I. Vysotsky

We review the determination of the QED coupling at the Z pole, which is a crucial parameter for electroweak theory. We include recent e+e- -> hadron data from Novosibirsk and Beijing to re-evaluate alpha (M_Z^2). We find 1/alpha (M_Z^2) =…

High Energy Physics - Phenomenology · Physics 2008-11-26 A. D. Martin , J. Outhwaite , M. G. Ryskin

In this paper we fix our attention, on hadron structure, and show that also the strong interaction strength alpha_S, ordinarily called the "(perturbative) coupling--constant square}", can be evaluated within our theory, and found to…

General Physics · Physics 2011-04-15 Erasmo Recami , Tonin-Zanchin , Antonino Del Popolo , Mario Gambera

The Standard Model does not provide a very good fit to the most recent precision electroweak data from LEP, due primarily to the observed branching ratios for $Z$ decay to $b\bar b$ and $c\bar c$. The possibility that an extension of the…

High Energy Physics - Phenomenology · Physics 2007-05-23 Howard E. Haber

In this talk we present a determination of the strong coupling constant $\alpha_\text{s}$ and its energy-scale dependence based on a next-to-next-to-leading order (NNLO) QCD analysis of dijet production. Using the invariant mass of the…

High Energy Physics - Phenomenology · Physics 2025-07-03 João Pires

We argue that supersymmetric grand unification of gauge couplings is not incompatible with small $\alpha_s$, even without large GUT-scale corrections, if one relaxes a usual universal gaugino mass assumption. A commonly assumed relation…

High Energy Physics - Phenomenology · Physics 2009-10-28 L. Roszkowski , M. Shifman

The current status of measurements of the strong coupling constant from different reactions is reviewed. Including new results presented at the 1996 ICHEP conference, a global average alpha_s(Mz) = 0.118 +- 0.003 is obtained.

High Energy Physics - Experiment · Physics 2007-05-23 Michael Schmelling

The status of coupling constant unification -- assuming the validity of the standard model or of its minimal supersymmetric extension at high energies -- and of relations between various Yukawa couplings (assuming the supersymmetri…

High Energy Physics - Phenomenology · Physics 2007-05-23 Nir Polonsky

I will discuss the current status of the determination of $\alpha(m_Z)$ and $\alpha_s(m_Z)$.

High Energy Physics - Phenomenology · Physics 2009-10-28 Tatsu Takeuchi

We reanalyze deep inelastic scattering data of BCDMS Collaboration by including proper cuts of ranges with large systematic errors. We perform also the fits of high statistic deep inelastic scattering data of BCDMS, SLAC, NM and BFP…

High Energy Physics - Phenomenology · Physics 2007-05-23 V. G. Krivokhijine , A. V. Kotikov
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