Related papers: Non-Anomalous Discrete R-symmetry Decrees Three Ge…
New regularities found in the pseudoscalar meson octet are reported. They invite to reconsider models where elementary fermions and composite QCD open strings can be grouped in common supermultiplets. It is proven that, with fermions having…
In the Standard Model, some combination of the baryon $\bf B$ and lepton $\bf L$ number symmetry is free of mixed anomalies with strong and electroweak $su(3) \times su(2) \times u(1)_{\tilde Y}$ gauge forces. However, it can still suffer…
The recent discovery by SuperKamiokande of evidence for neutrino masses requires the addition of at least seven new parameters to the Standard Model. We discuss the general theoretical schemes which require their inclusion, and point out…
We present supersymmetric, tadpole-free d=4,N=1 orientifold vacua with a three family chiral fermion spectrum that is identical to that of the Standard Model. Starting with all simple current orientifolds of all Gepner models we perform a…
We present a simple $U(1)_{B_3-3L_\mu}$ gauge Standard Model extension that can easily account for the anomalies in $R(K)$ and $R(K^*)$ reported by LHCb. The model is economical in its setup and particle content. Among the Standard Model…
It is noted that a set of facts points to the relevance in four dimensions of conventional supersymmetric unification based on minimally a string-unified G(224)-symmetry, or maximally SO(10). These include: (i) the observed family-…
We consider large classes of chiral extensions of the Standard Model, including new quark generations that do not involve additional neutrinos as well as lepton generations without quarks. An analysis of renormalization flows of Yukawa and…
I discuss supersymmetric extensions of the Standard Model containing an extra U(1)' gauge symmetry which provide a solution to the mu-problem and at the same time protect the proton from decaying via dimension 4 operators. Moreover, all…
We propose a renormalisable model based on $A_4$ family symmetry with an $SU(5)$ grand unified theory (GUT) which leads to the minimal supersymmetric standard model (MSSM) with a two right-handed neutrino seesaw mechanism. Discrete…
We consider a scenario where a supersymmetric model has multiple dark matter particles. Adding a U(1)' gauge symmetry is a well-motivated extension of the Minimal Supersymmetric Standard Model (MSSM). It can cure the problems of the MSSM…
We study the properties of vectorlike fermions that have the same gauge charges as the Standard Model lepton doublets, but opposite lepton number. These antileptons undergo decays mediated by heavier scalar leptoquarks, while the symmetries…
We introduce a non-Abelian discrete $\Delta_{27}$ family symmetry into the recently proposed classes of Exceptional Supersymmetric Standard Model ($E_6$SSM) based on a broken $E_6$ Grand Unified Theory (GUT) in order to solve the flavour…
Recently a promising mechanism for supersymmetry breaking that utilizes both an anomalous U(1) gauge symmetry and an effective mass term m ~ 1TeV of certain relevant fields has been proposed. In this paper we examine whether such a…
A moderate extension of the minimal supersymmetric standard model which includes a U(1)_(B-L) gauge group (B and L being the baryon and lepton number) and a Peccei-Quinn symmetry, U(1)_PQ, is presented. The hybrid inflationary scenario is…
Following the newly formulated notion of form invariance of the neutrino mass matrix, a complete model of leptons is constructed. It is based on a specific unitary 3 X 3 matrix U in family space, such that U^2 is the simple discrete…
N=1, D=4 Superstring possessing $SO(6)\otimes SO(5)$ symmetry action and with the same gauge symmetry obtained from zero mass spectrum of vector meson as well, is constructed from the bosonic string in twenty six dimensions. Without…
Under the assumptions that $SU(3)_c\times U(1)_Y \times G^{\prime}$ with $G^{\prime}$ simple is a local symmetry group at high energies, that color is parity-conserving, and the Y-charges are irreducible, we show that anomaly constraints…
The supersymmetric sector of minimal supersymmetric standard model (MSSM) possesses a U(1) R-symmetry which contains Z_2 matter parity. Non-zero neutrino masses, consistent with a 'redefined' R-symmetry, are possible through the see-saw…
We point out that in extended supersymmetric models such as supersymmetric left-right models, it is possible to have leptoquarks that explain the HERA high $Q^2$ anomaly without giving up R-parity conservation. The leptoquarks belong to…
We give a detailed description of the model construction procedures about our new approach to the family structure of the standard model. SM-like chiral fermion spectra, largely "derivable" from the gauge anomaly constraints, are formulated…