Composite Models Of Quarks Research Articles

The SU(8) GUT with composite quarks and leptons

We consider the L-R symmetric composite model for quarks and leptons where constituent preons possessing some local SU(N)MF metaflavor symmetry are bound by the chiral SO(n)L×SO(n)R gauge metacolor forces. The strengthening of the 't Hooft's anomaly matching condition, when the massless fermion composites are required to complete a single representation of the SU(N)MF rather than some set of its representations, allows to fix the number of basic metaflavors N. Particularly, just eight left-handed and eight right-handed preons and their composites preserving the global chiral symmetry SU(8)L×SU(8)R are turned out to underlie the physical world at small distances that uniquely identifies the local metaflavor symmetry SU(8)MF as its effective unified symmetry. We next show that the spontaneous L-R symmetry violation caused by the simultaneously emerged composite scalars reduces this initially vectorlike SU(8)MF theory down to the conventional SU(5) GUT with an extra local family symmetry SU(3)F and three standard families of quarks and leptons. Though the tiny confinement scale for universal preons composing both quarks and leptons makes it impossible to directly confirm their composite nature, simultaneous emergence of several extra SU(5)×SU(3)F multiplets of heavy composite fermions may help with a model verification. Generally, they may be located at scales from O(100) TeV up to the Planck mass scale depending on an interplay between the compositeness scale and scale of the family symmetry SU(3)F. Some of them through a natural see-saw mechanism provide the physical neutrino masses which, in contrast to conventional picture, appear to follow an inverted family hierarchy. Others mix with ordinary quark-lepton families in a way that there may arise a marked violation of unitarity in the CKM matrix for leptons.

Composite Pseudoclassical Models of Quarks

Composite models of quarks are proposed, analogous to composite models of leptons. A model-based explanation of the appearance of generations of fundamental particles in the Standard Model is given. New empirical formulas are proposed for the quark masses, modifying Barut’s well-known formula.

A New Quantum Number Triangular Array That Defines the Internal Organization of Valence Quarks, the Hadron Quark Model, and the CKM Matrix

Purpose: The Harmonic Neutron Hypothesis, HNH, has demonstrated that many of the fundamental physical constants, including the quarks, are associated with partial harmonic fractional exponents, , of a fundamental frequency, vF. The model has shown that the properties of the quarks are based on a progression of prime number composites. They also fall on three separate power law lines related to integer factors of the Y-intercept, , of a fundamental electromagnetic line which is scaled by the Rydberg constant, R and Planck’s constant. The quark lines are scaled by the quantum number factors {1, 2, 3}, and their Y-intercepts are referred to as nbem. The goal is to present a new proto-quark model in a six-quark inverted triangular array that defines the global organization of the valence quarks, which determines the hadronic quantum numbers, the standard hadron quark model, and the Cabibbo-Kobayashi-Maskawa (CKM) matrix. Methods: The charm, bottom, top quarks are associated with power law line Y-intercept, nbem equal to 1; the strange and down quarks with nbem equal to 2; and the up quark with nbem equal to 3. An inverted equilateral triangular array with three rows arranged from upper row (triangle base) to bottom row (triangle vertex), is associated respectively with nbem numbers 1, 2, and 3. The novelty of our perspective thus defines a new global valence quark organization which supersedes the Standard hadron composite quark model. The quarks are ordered via relative mass, partial fractions, and nbem quantum number. The top row of our inverted triangle includes the c, b, and t quarks from left to right; the middle row depicts the d and s quarks; and the bottom row, the up quark. Results: Our array depicts a quantum generator of the global organization of the valence quarks defining the composite quark model. The vertices of the triangular array are the up quarks, the midpoints are the down quarks. All weak transitions are from a corner to a midpoint or vice versa. The standard 3 by 3 CKM matrix is generated from the new quark triangle with each up type quark (u, c, and t) transforming to each down type (d, s, and b), with their experimental flavor transition magnitudes given. Conclusion: A new quark quantum number, nbem, is an important discovery that generates a new proto-valence quark triangle that secondarily generates the composite quark model and the CKM matrix.

A Statistical Model of Spacetime, Black Holes and Matter

I propose first a simple model for quantum black holes based on a harmonic oscillator representing the black hole horizon covered by Planck length sized squares carrying soft hair. Secondly, I redefine the partition function sum over horizon squares by a sum over black hole stretched horizon constituents which are black holes themselves. From this partition function Hawking radiation and Bekenstein-Hawking entropy law have been predicted. Based on this model I propose that the structures of black holes and spacetime atoms are the same. Requiring consistent quantization for both spacetime and matter, black hole structure is considered for matter particles using a composite model for quarks and leptons.

Standard Model Matter Emerging from Spacetime Preons

I consider a statistical mechanical model for black holes as atoms of spacetime with the partition function sum taken over area eigenvalues as given by loop quantum gravity. I propose a unified structure for matter and spacetime by applying the area eigenvalues to a black hole composite model for quarks and leptons. Gravitational baryon number’s non-conservation mechanism is predicted. Argument is given for unified field theory based on gravitational and electromagnetic interactions only. The standard model of non-Abelian gauge interactions is briefly discussed.

In-medium decay widths of hidden and open charm vector mesons in a field theoretic model for composite hadrons

We calculate the decay widths of the charmonium states, J/ψ, ψ(3686) and ψ(3770), to [Formula: see text] pairs, as well as the decay width of D* → Dπ, in isospin asymmetric strange hadronic matter, using a field theoretical model for composite hadrons with quark constituents. For this purpose, we use the quark–antiquark pair creation term of the free Dirac Hamiltonian written in terms of the constituent quark field operators, and use explicit charmonium, D, [Formula: see text], D* and π states to evaluate the matrix elements for the charmonium as well as D* decay amplitudes. The medium modifications of the partial decay widths of charmonium to [Formula: see text] pair, arising from the mass modifications of the [Formula: see text] and the charmonium states calculated in a chiral effective model, are also included. The results of the present investigations are then compared with the decay widths computed earlier, in a model using light quark pair creation in 3P0 state. As in 3P0 model, the decay amplitude in the present model is multiplied with a strength parameter for the light quark pair creation, which is fitted from the observed vacuum decay width. The effects of the isospin asymmetry, the strangeness fraction of the hadronic matter on the masses of the charmonium states and [Formula: see text] mesons and hence on the decay widths, have also been studied. The isospin asymmetry effect is observed to be dominant for high densities, leading to appreciable difference in the decay channels of the charmonium to D+ D- and [Formula: see text] pairs. The decay width of D* → Dπ in the hadronic matter has also been calculated within the composite quark model in the present work, accounting for the medium modifications of the D and D* masses. The density modifications of the charmonium states and D(D*) mesons, which are observed to be appreciable at high densities, will be of relevance in the compressed baryonic matter (CBM) experiments at the future facility of FAIR, GSI, where charmed hadrons will be produced by annihilation of antiprotons on nuclei. The interactions of the charmonium states and D(D*) with the nuclear medium could lead to the possibility of the formation of exotic bound states of the nuclei with the (excited) charmonium states as well as with D(D*) mesons.

A composite model of quarks and bosons

A composite model of quarks and bosons is proposed in which a spin 1/2 isospin doublet ψ is the basic building block of quarks and bosons in the standard model. The ψ has two components v and w with charges [Formula: see text] and Q = 0, respectively, that combine to form the three generations of colored quark flavors. A strong force described by a triplet of massless gluons binds the constituents called geminis. The confining constituent non-Abelian SU(2)C field theory is called constituent dynamics with a confining energy scale Λ CD . The constituent dynamics condensate [Formula: see text] spontaneously breaks the electroweak symmetry SU(2)L×U(1)Y→U(1) EM and a triplet of Nambu–Goldstone bosons make the gauge bosons W± and Z0 massive, while retaining a massless photon. A global custodial SU(2)L×SU(2)R symmetry guarantees that the symmetry breaking in the weak interaction sector agrees with electroweak data. The non-Abelian SU(2)C color dynamics satisfies asymptotic freedom, which resolves the gauge and Higgs mass hierarchy problems and makes the model ultraviolet complete. The composite constituent dynamics model can realize a SU(3)C×SU(2)L×U(1)Y electroweak and strong interaction model that satisfies the naturalness principle. The three generations of colorless quarks α and β with charges Q = +1e and Q = 0, respectively, which are predicted to exist in the composite model can form bound states which can be identified with the spectrum of exotic mesons.

Search for heavy resonances, and resonant diboson production with the ATLAS detector

Heavy resonances decaying into a pair of fundamental particles such as jj , l+ l− , γγ , and lV , are among the most common features to search for phenomena beyond the standard model (SM). Electroweak boson pair production, such as WW or ZZ with subsequent decays to lV l′ V′ and lljj respectively, is a powerful test of the spontaneously broken gauge symmetry of the SM and can be also used to search for phenomena beyond the SM. There is a wide spectrum of theoretical models predicting these kinds of resonant signatures. This note covers several searches for these new phenomena conducted within ATLAS in 2011 and 2012 for the LHC 7 and 8 TeV center of mass energies respectively. No significant deviations from the SM have been observed and therefore, limits are set on the characteristic parameters of several new physics models. These benchmark models include new heavy Z ′ /W ′ gauge bosons, chiral excitation of the SM weak gauge bosons, Z * /W * Randal-Sundrum and ADD gravitons, Composite models for quarks, e.g. q * with substructure scale Λ , Quantum black holes, TeV−1 Kaluza-Klein excitation of γ/Z and more.

New search for processes violating the Pauli exclusion principle in sodium and in iodine

In this paper a new search for non-Paulian nuclear processes, i.e. processes normally forbidden by the Pauli Exclusion Principle (PEP), is presented. It has been carried out at the Gran Sasso National Laboratory of the INFN by means of the highly radiopure DAMA/LIBRA set-up (sensitive mass of about 250 kg highly radiopure NaI(Tl)). In particular, a new improved upper limit for the spontaneous non-Paulian emission rate of protons with energy E p ≥ 10 MeV in 23Na and 127I has been obtained: 1.63 × 10−33 s−1 (90% C.L.). The corresponding limit on the relative strength (δ 2) for the searched non-Paulian transition is δ 2≲(3–4)×10−55 (90% C.L.). Moreover, PEP-violating electron transitions in iodine atoms have also been investigated. Lifetimes shorter than 4.7×1030 s are excluded at 90% C.L.; this allows us to derive the limit δ 2 e <1.28×10−47 (90% C.L.). This latter limit can also be related to a possible finite size of the electron in composite models of quarks and leptons providing superficial violation of the PEP; the obtained upper limit on the electron size is r 0<5.7×10−18 cm (energy scale of E≳3.5 TeV).

Supersymmetric composite models on intersecting D-branes

We construct supersymmetric composite models of quarks and leptons from type IIA T 6 / ( Z 2 × Z 2 ) orientifold with intersecting D6-branes. In case of T 6 = T 2 × T 2 × T 2 with no tilted T 2 , a composite model of supersymmetric SU ( 5 ) grand unified theory with four generations is constructed. In case of that one T 2 is tilted, a composite model with SU ( 3 ) c × SU ( 2 ) L × U ( 1 ) Y gauge symmetry with three generations of left-handed quarks and leptons is constructed. These models are not realistic, but contain relatively fewer additional exotic particles and U ( 1 ) gauge symmetries due to the introduction of the compositeness of quarks and leptons. The masses of some exotic particles are naturally generated through the Yukawa interactions among “preons”.

A Composite Model of Quarks with the 'Effective Supersymmetry'

We present a composite model of quarks with `effective supersymmetry'. The model is based on the gauge group $(SU(2)_S \times SU(2)_M) \times (SU(2)_U \times SU(2)_C \times SU(2)_T) \times SU(5)_{SM}$, where $SU(5)_{SM}$ is the standard model gauge group. In the dynamical supersymmetry breaking sector based on the gauge group $SU(2)_S \times SU(2)_M$, supersymmetry is dynamically broken. The preon sector is constructed by the model proposed by Nelson and Strassler. The fermion mass hierarchy among the up-type quarks originates from the $SU(2)_U \times SU(2)_C \times SU(2)_T$ gauge dynamics. The supersymmetry breaking is mediated to the minimal supersymmetric standard model sector by the `preon' superfields which compose the quarks in the first two generations. To obtain an experimentally acceptable mass spectrum, the scalar quarks in the first two generations need masses of order 10 TeV, while the other superpartners need masses less than 1 TeV. Therefore, the mass spectrum in our model is one example of the `effective supersymmetry' model proposed by Cohen, Kaplan and Nelson.

A supersymmetric composite model of quarks and leptons

We present a class of supersymmetric models with complete generations of composite quarks and leptons using recent non-perturbative results for the low energy dynamics of supersymmetric QCD. In these models, the quarks arise as composite “mesons” and the leptons emerge as composite “baryons”. The quark and lepton flavor symmetries are linked at the preon level. Baryon number violation is automatically suppressed by accidental symmetries. We give some speculations on how this model might be made realistic.

Bounds on the Mass of Excited Fermions

According to the present limits, it is possible that the mass of the excited fermions (M*), which arise in composite models of quarks and leptons, could lay in the range: mW&lt;M*≪Λ, where Λ denotes the scale of compositeness. For this scenario, the effective Lagrangian approach should be applied to study systematically the effects of these new fermions. Using this approach, we discuss the validity of the limits on M* obtained at FNAL from the direct search. We also derive indirect bounds on M*, which are independent of Λ, from high precision measurements, using three models (sequential, mirror and homodoublet).

SUPERFICIAL NON-UNITARITY OF THE QUARK-MIXING MATRIX AS A POSSIBLE EVIDENCE FOR THE SUBSTRUCTURE OF QUARKS

Superficial non-unitarity of the quark-mixing matrix, which has been predicted to be momentum transfer dependent due to the possible substructure of quarks, is discussed in composite models of quarks and leptons. A precise measurement of the momentum transfer dependence of the branching ratios for inclusive hadronic decays of τ→vτ+ hadrons and for inclusive semi-leptonic decays of K, D, B and [Formula: see text] hadrons is proposed as one of the best experimental searches for a possible evidence of the substructure of quarks.

HOW TO SOLVE THE CKM QUARK MIXING MATRIX

It was pointed out that given the us element of the CKM quark mixing matrix, all the other elements can be successfully explained or predicted by using the five relations derived in a composite model of quarks (and leptons).

Excitation and Decay of Correlated Atomic States

Doubly excited states of atoms and ions in which two electrons are excited from the ground configuration display strong radial and angular electron correlations. They are prototypical examples of quantum-mechanical systems with strong coupling. Two distinguishing characteristics of these states are: (i) their organization into successive families, with only weak coupling between families, and (ii) a hierarchical nature of this coupling, with states from one family decaying primarily to those in the next lower family. A view of the pair of electrons as a single entity, with the electron-electron repulsion between them divided into an adiabatic and a nonadiabatic piece, accounts for many of the dominant features. The stronger, adiabatic part determines the family structure and the weaker, nonadiabatic part the excitation and decay between successive families. Similar considerations extend to three-electron atomic states, which group into five different classes. They are suggestive of composite models for quarks in elementary particle physics, which exhibit analogous groupings into families with a hierarchical arrangement of masses and electroweak decays.

Tests of a composite model of quarks and leptons.

Recent studies of radiative corrections to electroweak processes restrict the particle content of dynamical-symmetry-breaking schemes. The minimal anomaly-free model with one doublet of Dirac fermions $F\ensuremath{\equiv}(U,D)$ having charges $Q=\ifmmode\pm\else\textpm\fi{}\frac{1}{2}$ is consistent with such restrictions. These fermions may be regarded as the constituents of a strongly interacting Higgs sector, so that the longitudinal $W$ and $Z$ and higher-spin excitations (including vector mesons, called ${\ensuremath{\rho}}_{T}$, with isospin $I=1$, and ${\ensuremath{\omega}}_{T}$, with $I=0$) are all composites of $F'\mathrm{s}$. It is then natural to ask if these fermions can be the sole carriers of weak SU(2), so that quarks and leptons would also have to be composed of them. Some tests of this hypothesis in hadronic and ${e}^{+}{e}^{\ensuremath{-}}$ collisions are suggested.

Superficial violation of the Pauli principle due to the possible substructure of electrons.

Superficial violation of the Pauli principle due to the possible substructure of electrons is discussed in composite models of quarks and leptons. The ratio of the Pauli forbidden atomic transition to the allowed one is estimated to be of order 10{sup {minus}50}--10{sup {minus}44} for heavy atoms if the size of the electron is of order 10{sup {minus}17} cm.

Excited-quark and -lepton production at hadron colliders.

The existence of excited states is a natural consequence of composite models for quarks and leptons. Production rates and signatures are discussed for hadron colliders presently operating (CERN Super $p\overline{p}$ Synchrotron and Fermilab Tevatron) or under study (CERN Large Hadron Collider and Superconducting Super Collider). Contact interactions may be an important source for excited fermions and could influence the signatures of such particles significantly. Excited quarks could be discovered with masses up to about ⅓-\textonehalf{} of the total collider energy while excited leptons could be accessible up to ⅕-⅓ of the available energy. Large lepton yields are expected if quarks and leptons share common subconstituents.

Phenomenological Kähler sigma models (I)

The mathematical formalism of supersymmetric sigma models is developed to the point where they can describe realistic composite models of quarks and leptons. The sigma models of interest are the effective lagrangians of confining supersymmetric gauge theories. The dynamics of the massless bound states in the gauge theory is reflected in the geometry of the target manifold of the sigma model, which is required to be a non-compact, non-homogeneous Kähler manifold. More precisely, it is the deformation of a complex coset space G /K̃ such that the isometry group is just G. Special topics discussed include the construction of the most general potential, weak gauging of isometries, four-Fermi interactions and the target manifold curvature, and soft chiral and supersymmetry breaking.