scholarly journals A PARITY INVARIANT SU(3)c ⊗ SU(3)L ⊗ U(1) MODEL

1995 ◽  
Vol 10 (02) ◽  
pp. 159-164 ◽  
Author(s):  
R. FOOT
Keyword(s):  
Standard Model ◽  
New Physics ◽  
The Novel ◽  
Gauge Model ◽  
Gauge Bosons ◽  
Parity Symmetry ◽  
The Standard Model ◽  
Low Energies

We examine a SU (3)c ⊗ SU (3)L ⊗ U (1) gauge model which has a parity symmetric Lagrangian. The parity symmetry has the novel feature that it interchanges the gluons with the SU (3)L gauge bosons (which contain the ordinary SU (2)L weak gauge bosons). We show that the model reduces to the standard model at low energies and also predict new physics in the form of exotic fermions.

SEARCHES FOR NEW PHYSICS AT HIGH ENERGY COLLIDERS

2005 ◽  
Vol 20 (22) ◽  
pp. 5164-5173 ◽  
Author(s):  
BEATE HEINEMANN
Keyword(s):  
Standard Model ◽  
Extra Dimensions ◽  
High Energy ◽  
New Physics ◽  
Standard Model Background ◽  
Beyond The Standard Model ◽  
Gauge Bosons ◽  
Model Background ◽  
The Standard Model

Recent searches for physics beyond the Standard Model at high energy colliders are presented. The main focus is on searches for supersymmetry, extra dimensions and new gauge bosons. In all search analyses the data are found to agree well with the Standard Model background expectation and no evidence for contributions from physics beyond the Standard Model is found. The data are thus used to place limits on new physics scenarios.

scholarly journals ANOMALOUS HIGGS COUPLINGS

1999 ◽  
Vol 14 (20) ◽  
pp. 3121-3156 ◽  
Author(s):  
M. C. GONZALEZ-GARCIA
Keyword(s):  
Higgs Boson ◽  
Standard Model ◽  
Higgs Doublet ◽  
New Physics ◽  
Boson Production ◽  
Gauge Bosons ◽  
Effective Interactions ◽  
Decay Modes ◽  
Effective Lagrangian ◽  
The Standard Model

We review the effects of new effective interactions on Higgs-boson phenomenology. New physics in the electroweak bosonic sector is expected to induce additional interactions between the Higgs doublet field and the electroweak gauge bosons, leading to anomalous Higgs couplings as well as anomalous gauge-boson self-interactions. Using a linearly realized SU (2)L× U (1)Y invariant effective Lagrangian to describe the bosonic sector of the Standard Model, we review the effects of the new effective interactions on the Higgs-boson production rates and decay modes. We summarize the results from searches for the new Higgs signatures induced by the anomalous interactions in order to constrain the scale of new physics, in particular at CERN LEP and Fermilab Tevatron colliders.

scholarly journals The CKM unitarity problem: a trace of new physics at the TeV scale?

2020 ◽  
Vol 80 (2) ◽  
Author(s):  
Benedetta Belfatto ◽  
Revaz Beradze ◽  
Zurab Berezhiani
Keyword(s):  
Standard Model ◽  
Decay Constant ◽  
New Physics ◽  
Muon Decay ◽  
Beyond The Standard Model ◽  
Neutron Lifetime ◽  
Gauge Bosons ◽  
Family Symmetry ◽  
Ckm Matrix ◽  
The Standard Model

Abstract After the recent high precision determinations of $$V_{us}$$Vus and $$V_{ud}$$Vud, the first row of the CKM matrix shows more than $$4\sigma $$4σ deviation from unitarity. Two possible scenarios beyond the Standard Model can be investigated in order to fill the gap. If a 4th non-sequential quark $$b'$$b′ (a vector-like weak isosinglet) participates in the mixing, with $$\vert V_{ub'} \vert \sim 0.04$$|Vub′|∼0.04, then its mass should be no more than 6 TeV or so. A different solution can come from the introduction of the gauge horizontal family symmetry $$SU(3)_\ell $$SU(3)ℓ acting between the lepton families and spontaneously broken at the scale of about 6 TeV. Since the gauge bosons of this symmetry contribute to muon decay in interference with Standard Model, the Fermi constant is slightly smaller than the muon decay constant so that unitarity is recovered. Also the neutron lifetime problem, that is about $$4\sigma $$4σ discrepancy between the neutron lifetimes measured in beam and trap experiments, is discussed in the light of the these determinations of the CKM matrix elements.

MEASUREMENTS OF THE PROPERTIES OF THE Z BOSON, THE STANDARD MODEL AND BEYOND

1991 ◽  
Vol 06 (02) ◽  
pp. 199-216
Author(s):  
THOMAS G. RIZZO
Keyword(s):  
Standard Model ◽  
Z Boson ◽  
New Physics ◽  
Beyond The Standard Model ◽  
Gauge Bosons ◽  
The Standard Model

Recent measurements of the properties of the Z boson at the SLC and LEP colliders are compared with the radiatively corrected predictions of the standard model as well as several classes of models containing additional gauge bosons. The possible evidence for new physics beyond the standard model is discussed.

scholarly journals ALTERNATIVE IMPLEMENTATION OF THE HIGGS BOSON

2011 ◽  
Vol 26 (07) ◽  
pp. 461-467
Author(s):  
ROBERT FOOT ◽  
ARCHIL KOBAKHIDZE
Keyword(s):  
Higgs Boson ◽  
Standard Model ◽  
Gauge Invariance ◽  
Degrees Of Freedom ◽  
Energy Scale ◽  
Tree Level ◽  
Radiative Corrections ◽  
Gauge Bosons ◽  
The Standard Model ◽  
Low Energies

We discuss an alternative implementation of the Higgs boson within the Standard Model which is possible if the renormalizability condition is relaxed. Namely, at energy scale Λ the Higgs boson interacts at tree-level only with matter fermions, while the full gauge invariance is still maintained. The interactions with the electroweak gauge bosons are induced at low energies through the radiative corrections. In this scenario the Higgs boson can be arbitrarily heavy, interacting with the Standard Model fields arbitrarily weakly. No violation of unitarity in the scattering of longitudinal electroweak bosons occurs, since they become unphysical degrees of freedom at energies Λ ~ TeV.

SINGLE PRODUCTION OF THE GAUGE BOSONS VIA eγ COLLISION AT THE HIGH ENERGY e+e- LINEAR COLLIDERS

2012 ◽  
Vol 27 (21) ◽  
pp. 1250119
Author(s):  
CHONG-XING YUE ◽  
JIE-NIAN DAI ◽  
JIAO ZHANG ◽  
JING GUO
Keyword(s):  
Standard Model ◽  
Linear Collider ◽  
High Energy ◽  
New Physics ◽  
Gauge Bosons ◽  
The Standard Model ◽  
Linear Colliders ◽  
The Future ◽  
Single Production

The eγ collider is better suited to study single production of the gauge bosons. In this paper, we first consider the contributions of the three-site Higgsless (3SHL) model and the left–right twin Higgs (LRTH) model to the standard model (SM) processes eγ→eZ and eγ→νeW, and then study single production of the new neutral and charged gauge bosons predicted by these two models via eγ collision in the future high energy e+e- linear collider experiments. We find that the correction effects of 3SHL model on the processes eγ→eZ and eγ→νeW might be detected in the future, while this is not the case for the LRTH model. The process eγ→eZ' can give rise to different signatures in the 3SHL and LRTH models and thus can be used to distinguish these two kinds of new physics models at the high energy e+e- linear colliders.

scholarly journals A SIMPLE SOLUTION FOR THE FLAVOR QUESTION

1996 ◽  
Vol 11 (32n33) ◽  
pp. 2639-2647 ◽  
Author(s):  
FELICE PISANO
Keyword(s):  
Standard Model ◽  
Gauge Group ◽  
Degrees Of Freedom ◽  
New Physics ◽  
Simple Solution ◽  
Next Generation ◽  
The Standard Model ◽  
Low Energies

We consider a simple way of solving the flavor question by embedding the three-family standard model in a semisimple gauge group extending minimally the weak isospin factor. Quantum chiral anomalies between families of fermions cancel with a matching of the number of families and the number of color degrees of freedom. Our demonstration shows how the theory leads to determination of families structure when the standard model is the input at low energies. The new physics is limited to start below a few TeVs within the reach of the next generation colliders.

scholarly journals Standard Model prediction of the Bc lifetime

2021 ◽  
Vol 2021 (7) ◽  
Author(s):  
Jason Aebischer ◽  
Benjamín Grinstein
Keyword(s):  
Standard Model ◽  
Model Prediction ◽  
Strange Quark ◽  
Standard Model Prediction ◽  
New Physics ◽  
Operator Product ◽  
Special Focus ◽  
Third Order ◽  
Clear Cut ◽  
The Standard Model

Abstract Applying an operator product expansion approach we update the Standard Model prediction of the Bc lifetime from over 20 years ago. The non-perturbative velocity expansion is carried out up to third order in the relative velocity of the heavy quarks. The scheme dependence is studied using three different mass schemes for the $$ \overline{b} $$ b ¯ and c quarks, resulting in three different values consistent with each other and with experiment. Special focus has been laid on renormalon cancellation in the computation. Uncertainties resulting from scale dependence, neglecting the strange quark mass, non-perturbative matrix elements and parametric uncertainties are discussed in detail. The resulting uncertainties are still rather large compared to the experimental ones, and therefore do not allow for clear-cut conclusions concerning New Physics effects in the Bc decay.

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