Related papers: Proton Stability, Gauge Coupling Unification and a…
The ATLAS and CMS collaborations recently recorded possible di-photon excess at 750 GeV and a less significant di-boson excess around 1.9 TeV. Such excesses may be produced in heterotic-string derived Z' models, where the di-photon excess…
General $U(1)$ extension of the Standard Model (SM) is a well motivated beyond the Standard Model(BSM) scenario where three generations of right handed neutrinos (RHNs) are introduced to cancel gauge and mixed gauge-gravity anomalies. After…
We study a class of non-exotic minimal $U(1) '$ extensions of the Standard Model, which includes all scenarios that are anomaly-free with the ordinary fermion content augmented by one Right-Handed neutrino per generation, wherein the new…
So far the most sophisticated experiments have shown no trace of new physics at the TeV scale. Consequently, new models with unexplored parameter regions are necessary to explain current results, re-examine the existing data, and propose…
The stability of dark matter is naturally explained if there is an additional U(1) symmetry which is spontaneously broken to a discrete symmetry at a high-energy scale. Such a framework is realized in the context of the SO(10) grand…
We propose a seesaw model with a hidden gauge symmetry $SU(2)_H \times U(1)_X$ where two types of standard model singlet fermions in realizing a seesaw mechanism are organized into $SU(2)_H$ doublet. Then we formulate scalar and gauge…
We begin the study of a class of string-motivated effective supergravity theories in light of current data from the CERN Large Hadron Collider (LHC). The case of heterotic string theory, in which the dilaton is stabilized via…
We discuss the phenomenology and cosmology of a Standard-like Model inspired by string theory, in which the gauge fields are localized on D-branes wrapping certain compact cycles on an underlying geometry, whose intersection can give rise…
We study linked loops of string in the presence of bosonic condensates and fermionic zero modes on the strings. We find that the strings necessarily carry a current if the bosons have an Aharanov-Bohm interaction with the string. The…
An algorithm to systematically and efficiently generate free fermionic heterotic string models was recently introduced. This algorithm has been adopted by the Free Fermionic Model Construction (FFMC) program at Baylor University. As its…
We present a model based on the gauge group SU(2)$_L\times$SU(2)$_R\times$SU(4)$_C$ with gauge couplings that are found to be unified at a scale $M_G$ near the string unification scale. The model breaks to the minimal supersymmetric…
An extension of the adjoint SU(5) model with a flavour symmetry based on the Z_4 group is investigated. The Z_4 symmetry is introduced with the aim of leading the up- and down-quark mass matrices to the Nearest-Neighbour-Interaction form.…
We explore the possibility of string theories in only four spacetime dimensions without any additional compactified dimensions. We show that, provided the theory is defined in curved spacetime that has a cosmological interpration, it is…
We study gauge theories where quasi-hidden sectors are added to the MSSM for the sake of string consistency conditions which would otherwise not be satisfied. We focus on quiver gauge theories motivated by weakly coupled type II orientifold…
Measurements of the ZZ production cross sections in proton-proton collisions at center-of-mass energies of 7 and 8 TeV are presented. Candidate events for the leptonic decay mode ZZ to 2 l 2 nu, where l denotes an electron or a muon, are…
I study the phenomenology of heavy neutral bosons Z', predicted in GUT-inspired U(1)' models, at the Large Hadron Collider. In particular, I investigate possible signatures due to Z' decays into superymmetric particles, such as chargino,…
Within supersymmetric SU(5) GUT we suggest mechanisms for suppression of baryon number violating dimension five and six operators. The mechanism is based on the idea of split multiplets (i.e. quarks and leptons are not coming from a single…
To assist in the search for phenomenologically realistic models in the string landscape, we must develop tools for investigating all gauge charges, including U(1) charges, in string models. We introduce the process for constructing…
I discuss gauge coupling unification in a class of superstring standard--like models, which are derived in the free fermionic formulation. Recent calculations indicate that the superstring unification scale is at $O(10^{18}GeV)$ while the…
We report the most general expression for the chiral charges of a $Z'$ gauge boson coming from an $E_6$ unification model, as a function of the electroweak parameters and the charges of the $U(1)$ factors in the chain of subgroups. These…