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Related papers: Once more on extra quark-lepton generations and pr…

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If there is an extra U(1) gauge symmetry broken at low energies, then it may be possible from the charges of the known quarks and leptons under this U(1) to make inferences about how much gauge unification occurs at high scales and about…

High Energy Physics - Phenomenology · Physics 2011-05-12 S. M. Barr , Almas Khan

We present an overview of the present status and prospects for progress in electroweak measurements at future collider experiments leading to precision tests of the Standard Model of Electroweak Interactions. Special attention is paid to…

High Energy Physics - Phenomenology · Physics 2016-09-06 U. Baur , M. Demarteau

The existence of extra chiral generations with all fermions heavier than $m_Z$ is strongly disfavored by the precision electroweak data. However the data still allow a few extra generations if the neutral leptons have masses close to 50…

High Energy Physics - Phenomenology · Physics 2007-05-23 V. Novikov

The existence of the fourth quark-lepton generation is not excluded by the electroweak precision data. However, the recent results on the 126 GeV higgs boson production and decay do not allow an extra generation at least as far as the…

High Energy Physics - Phenomenology · Physics 2013-12-19 M. I. Vysotsky

The upper bounds that the LHC measurements searching for heavy resonances beyond the Standard model set on the resonance production cross sections are not universal. They depend on various characteristics of the resonance under…

High Energy Physics - Phenomenology · Physics 2021-12-03 Mikulas Gintner , Josef Juran

Electroweak Precision Measurements are stringent tests of the Standard Model and sensitive probes to New Physics. Accurate studies of the Z-boson couplings to the first-generation quarks could reveal potential discrepancies between the…

High Energy Physics - Phenomenology · Physics 2024-06-07 Krzysztof Mękała , Daniel Jeans , Junping Tian , Jürgen Reuter , Aleksander Filip Żarnecki

The $W$ boson mass is one of the most important electroweak precision observables for testing the Standard Model or its extensions. The very recent measured $W$ boson mass at CDF shows about $7\sigma$ deviations from the SM prediction,…

High Energy Physics - Phenomenology · Physics 2022-09-14 Chih-Ting Lu , Lei Wu , Yongcheng Wu , Bin Zhu

This note presents constraints on Standard Model parameters using published and preliminary precision electroweak results measured at the electron-positron colliders LEP and SLC. The results are compared with precise electroweak…

We report a selection of the most recent CDF and D0 results on top quark and W and Z boson properties, based on Tevatron Run 2 data. The large datasets of W and Z bosons allow a very precise measurement of the W mass and detailed studies of…

High Energy Physics - Experiment · Physics 2019-08-14 Sandra Leone

The upper bounds that the LHC measurements searching for heavy resonances beyond the Standard model set on the resonance production cross sections are not universal. They depend on various characteristics of the resonance under…

High Energy Physics - Phenomenology · Physics 2020-02-25 Mikuláš Gintner , Josef Juráň

The existence of extra chiral generations with all fermions heavier than $M_Z$ is strongly disfavored by the precision electroweak data. The exclusion of one additional generation of heavy fermions in SUSY extension of Standard Model is…

High Energy Physics - Phenomenology · Physics 2007-05-23 V. A. Ilyin , M. Maltoni , V. A. Novikov , L. B. Okun , A. N. Rozanov , M. I. Vysotsky

Instead of anchoring the seesaw mechanism with the conventional heavy right-handed neutrino singlet, a small Majorana neutrino mass may be obtained just as well with the addition of a heavy triplet of leptons per family to the minimal…

High Energy Physics - Phenomenology · Physics 2009-11-07 Ernest Ma

This note presents constraints on Standard Model parameters using published and preliminary precision electroweak results measured at the electron-positron colliders LEP and SLC. The results are compared with precise electroweak…

We present an update of the Standard Model fit to electroweak precision data. We include newest experimental results on the top quark mass, the W mass and width, and the Higgs boson mass bounds from LEP, Tevatron and the LHC. We also…

High Energy Physics - Phenomenology · Physics 2022-07-25 M. Baak , M. Goebel , J. Haller , A. Hoecker , D. Kennedy , K. Moenig , M. Schott , J. Stelzer

We analyze various models with an extra U(1) gauge symmetry in addition to the Standard Model (SM) gauge group at low energies, and impose limits on the mass of the neutral Z' boson, M_Z', predicted in all such models, and on the Z-Z'…

High Energy Physics - Phenomenology · Physics 2010-01-15 Jens Erler , Paul Langacker , Shoaib Munir , Eduardo Rojas

I review constraints on the Standard Model (SM) Higgs boson from high energy electroweak (EW) precision data. The same data set also strongly limits various mixing effects of hypothetical extra neutral gauge bosons (Z') with the ordinary Z.…

High Energy Physics - Phenomenology · Physics 2009-07-07 Jens Erler

The precise measurement of physics observables and the test of their consistency within the standard model (SM) are an invaluable approach, complemented by direct searches for new particles, to determine the existence of physics beyond the…

The possibility of additional quarks and leptons beyond the three generations already established is discussed. The make-up of this Report is (I) Introduction: the motivations for believing that the present litany of elementary fermions is…

High Energy Physics - Phenomenology · Physics 2009-07-09 Paul H. Frampton , P. Q. Hung , Marc Sher

We consider the extension of the standard model with an arbitrary number of U(1) gauge fields coupled to baryon-minus-lepton number and/or hypercharge. Under the assumption that A^b_FB from the LEP1 experiment is an unlucky fluctuation, we…

High Energy Physics - Phenomenology · Physics 2011-03-23 A. Ferroglia , A. Lorca , J. J. van der Bij

An updated fit to the precision electroweak data and to the direct measurement of the top quark mass $m_t$ provides significant constraints on $m_t$ and on the Higgs boson mass $M_H$: $m_t/\text{GeV}=172\pm 6$ and…

High Energy Physics - Phenomenology · Physics 2008-11-26 John Ellis , G. L. Fogli , E. Lisi