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 STRATEGY TOWARDS MIRROR-FERMION SIGNATURES

2000 ◽  
Vol 15 (02) ◽  
pp. 265-282 ◽  
Author(s):  
GEORGE TRIANTAPHYLLOU
Keyword(s):  
Standard Model ◽  
Gauge Group ◽  
New Physics ◽  
Higgs Mechanism ◽  
Viable Alternative ◽  
Electroweak Scale ◽  
Fermion Model ◽  
The Standard Model

The existence of mirror fermions interacting strongly under a new gauge group and having masses near the electroweak scale has been recently proposed as a viable alternative to the standard-model Higgs mechanism. The main purpose of this work is to investigate which specific experimental signals are needed to clearly differentiate the mirror-fermion model from other new-physics models. In particular, the case is made for a future large lepton collider with c.o.m. energies of roughly 4 TeV or higher.

scholarly journals THEORY OF CP VIOLATION IN THE B-MESON SYSTEM

2002 ◽  
Vol 17 (22) ◽  
pp. 2936-2950 ◽  
Author(s):  
MATTHIAS NEUBERT
Keyword(s):  
Cp Violation ◽  
Standard Model ◽  
B Meson ◽  
New Physics ◽  
B Decays ◽  
The Standard Model ◽  
Recent Developments ◽  
Meson System

Recent developments in the theory of CP violation in the B-meson system are reviewed, with focus on the determination of sin 2β from B → J/ψ K decays, its implications for tests of the Standard Model and searches for New Physics, and the determination of γ and α from charmless hadronic B decays.

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.

scholarly journals Developments in Rare Kaon Decay Physics

2000 ◽  
Vol 50 (1) ◽  
pp. 249-297 ◽  
Author(s):  
A.R. Barker ◽  
S.H. Kettell
Keyword(s):  
Standard Model ◽  
New Physics ◽  
High Mass ◽  
Current Status ◽  
Model Parameters ◽  
Beyond The Standard Model ◽  
Kaon Decay ◽  
Kaon Decays ◽  
The Standard Model

▪ Abstract  We review the current status of the field of rare kaon decays. The study of rare kaon decays has played a key role in the development of the standard model, and the field continues to have significant impact. The two areas of greatest import are the search for physics beyond the standard model and the determination of fundamental standard-model parameters. Due to the exquisite sensitivity of rare kaon decay experiments, searches for new physics can probe very high mass scales. Studies of the K → π ν[Formula: see text] modes in particular, where the first event has recently been seen, will permit tests of the standard-model picture of quark mixing and CP violation.

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.

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.

scholarly journals Disentangling QCD and new physics in D → πℓ+ℓ−

2021 ◽  
Vol 2021 (4) ◽  
Author(s):  
Aoife Bharucha ◽  
Diogo Boito ◽  
Cédric Méaux
Keyword(s):  
Standard Model ◽  
Branching Ratio ◽  
Branching Ratios ◽  
New Physics ◽  
Operator Product ◽  
Beyond The Standard Model ◽  
Spectral Functions ◽  
The Standard Model ◽  
Model Independent ◽  
Weak Annihilation

Abstract In this paper we consider the decay D+ → π+ℓ+ℓ−, addressing in particular the resonance contributions as well as the relatively large contributions from the weak annihilation diagrams. For the weak annihilation diagrams we include known results from QCD factorisation at low q2 and at high q2, adapting the existing calculation for B decays in the Operator Product Expansion. The hadronic resonance contributions are obtained through a dispersion relation, modelling the spectral functions as towers of Regge-like resonances in each channel, as suggested by Shifman, imposing the partonic behaviour in the deep Euclidean. The parameters of the model are extracted using e+e− → (hadrons) and τ → (hadrons) + ντ data as well as the branching ratios for the resonant decays D+ → π+R(R → ℓ+ℓ−), with R = ρ, ω, and ϕ. We perform a thorough error analysis, and present our results for the Standard Model differential branching ratio as a function of q2. Focusing then on the observables FH and AFB, we consider the sensitivity of this channel to effects of physics beyond the Standard Model, both in a model independent way and for the case of leptoquarks.

scholarly journals Indirect $$ \mathcal{CP} $$ probes of the Higgs-top-quark interaction: current LHC constraints and future opportunities

2020 ◽  
Vol 2020 (11) ◽  
Author(s):  
Henning Bahl ◽  
Philip Bechtle ◽  
Sven Heinemeyer ◽  
Judith Katzy ◽  
Tobias Klingl ◽  
...  
Keyword(s):  
Higgs Boson ◽  
Standard Model ◽  
Top Quark ◽  
Decay Channel ◽  
New Physics ◽  
Current Data ◽  
Quark Interaction ◽  
The Standard Model ◽  
Vector Bosons ◽  
Selection Of

Abstract The $$ \mathcal{CP} $$ CP structure of the Higgs boson in its coupling to the particles of the Standard Model is amongst the most important Higgs boson properties which have not yet been constrained with high precision. In this study, all relevant inclusive and differential Higgs boson measurements from the ATLAS and CMS experiments are used to constrain the $$ \mathcal{CP} $$ CP -nature of the top-Yukawa interaction. The model dependence of the constraints is studied by successively allowing for new physics contributions to the couplings of the Higgs boson to massive vector bosons, to photons, and to gluons. In the most general case, we find that the current data still permits a significant $$ \mathcal{CP} $$ CP -odd component in the top-Yukawa coupling. Furthermore, we explore the prospects to further constrain the $$ \mathcal{CP} $$ CP properties of this coupling with future LHC data by determining tH production rates independently from possible accompanying variations of the $$ t\overline{t}H $$ t t ¯ H rate. This is achieved via a careful selection of discriminating observables. At the HL-LHC, we find that evidence for tH production at the Standard Model rate can be achieved in the Higgs to diphoton decay channel alone.

scholarly journals Standard model from a supergravity model with a naturally small cosmological constant

2021 ◽  
Vol 2021 (5) ◽  
Author(s):  
Shing Yan Li ◽  
Yu-Cheng Qiu ◽  
S.-H. Henry Tye
Keyword(s):  
String Theory ◽  
Standard Model ◽  
Cosmological Constant ◽  
Supersymmetry Breaking ◽  
Supersymmetric Standard Model ◽  
Degrees Of Freedom ◽  
Interaction Terms ◽  
Supersymmetric Version ◽  
The Standard Model ◽  
Linear Version

Abstract Guided by the naturalness criterion for an exponentially small cosmological constant, we present a string theory motivated 4-dimensional $$ \mathcal{N} $$ N = 1 non-linear supergravity model (or its linear version with a nilpotent superfield) with spontaneous supersymmetry breaking. The model encompasses the minimal supersymmetric standard model, the racetrack Kähler uplift, and the KKLT anti-D3-branes, and use the nilpotent superfield to project out the undesirable interaction terms as well as the unwanted degrees of freedom to end up with the standard model (not the supersymmetric version) of strong and electroweak interactions.

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