Search results for "UniFi"
showing 10 items of 302 documents
Spiral Inflation with Coleman-Weinberg Potential
2015
We apply the idea of spiral inflation to Coleman-Weinberg potential, and show that inflation matching well observations is allowed for a symmetry-breaking scale ranging from an intermediate scale to GUT scale even if the quartic coupling $\lambda$ is of $\mathcal{O}(0.1)$. The tensor-to-scalar ratio can be of $\mathcal{O}(0.01)$ in case of GUT scale symmetry-breaking.
Analysis of enhancedβeffects in minimal flavor violation GUT scenarios
2006
Long-range forces between macroscopic objects are mediated by light particles that interact with the electrons or nucleons, and include spin-dependent static components as well as spin- and velocity-dependent components. We parametrize the long-range potential between two fermions assuming rotational invariance, and find 16 different components. Applying this result to electrically neutral objects, we show that the macroscopic potential depends on 72 measurable parameters. We then derive the potential induced by the exchange of a new gauge boson or spinless particle, and compare the limits set by measurements of macroscopic forces to the astrophysical limits on the couplings of these partic…
Search for pair production of second generation scalar leptoquarks
2008
We report on a search for the pair production of second generation scalar leptoquarks (LQ) in ppbar collisions at the center of mass energy sqrt(s)=1.96 TeV using a data set corresponding to an integrated luminosity of 1.0 fb-1 collected with the D0 experiment at the Fermilab Tevatron Collider. Topologies arising from the LQLQbar->muqnuq and LQLQbar->muqmuq decay modes are investigated. No excess of data over the standard model prediction is observed and upper limits on the leptoquark pair production cross section are derived at the 95% C.L. as a function of the leptoquark mass and the branching fraction beta for the decay LQ->muq. These are interpreted as lower limits on the lepto…
Supersymmetric type-III seesaw mechanism: Lepton flavor violating decays and dark matter
2011
We study a supersymmetric version of the seesaw mechanism type III. The model consists of the minimal supersymmetric extension of the standard model particle content plus three copies of $\mathbf{24}$ superfields. The fermionic part of the $SU(2)$ triplet contained in the $\mathbf{24}$ is responsible for the type-III seesaw, which is used to explain the observed neutrino masses and mixings. Complete copies of $\mathbf{24}$ are introduced to maintain gauge coupling unification. These additional states change the beta functions of the gauge couplings above the seesaw scale. Using minimal Supergravity boundary conditions, we calculate the resulting supersymmetric mass spectra at the electrowea…
331 models and grand unification: From minimal SU(5) to minimal SU(6)
2016
We consider the possibility of grand unification of the $\mathrm{ SU(3)_c \otimes SU(3)_L \otimes U(1)_X}$ model in an SU(6) gauge unification group. Two possibilities arise. Unlike other conventional grand unified theories, in SU(6) one can embed the $\mathrm{ SU(3)_c \otimes SU(3)_L \otimes U(1)_X}$ model as a subgroup such that different multiplets appear with different multiplicities. Such a scenario may emerge from the flux breaking of the unified group in an E(6) F-theory GUT. This provides new ways of achieving gauge coupling unification in $\mathrm{ SU(3)_c \otimes SU(3)_L \otimes U(1)_X}$ models while providing the radiative origin of neutrino masses. Alternatively, a sequential va…
Dark matter in minimal supergravity with type-II seesaw mechanism
2009
We calculate the relic density of the lightest neutralino in a supersymmetric seesaw type-II (``triplet seesaw'') model with minimal supergravity boundary conditions at the grand unified theory (GUT) scale. The presence of a triplet below the GUT scale, required to explain measured neutrino data in this setup, leads to a characteristic deformation of the sparticle spectrum with respect to the pure minimal supergravity (mSUGRA) expectations, affecting the calculated relic dark matter (DM) density. We discuss how the DM allowed regions in the $({m}_{0},{M}_{1/2})$ plane change as a function of the (type-II) seesaw scale. We also compare the constraints imposed on the models parameter space fo…
General flavor blind minimal supersymmetric standard model andCPviolation
2001
We study the implications on flavor changing neutral current and $\mathrm{CP}$ violating processes in the context of supersymmetric theories without a new flavor structure (flavor blind supersymmetry). The low-energy parameters are determined by the running of the soft breaking terms from the grand unified scale with supersymmetric (SUSY) phases consistent with the electric dipole moment constraints. We find that the $\mathrm{CP}$ asymmetry in $\stackrel{\ensuremath{\rightarrow}}{b}s\ensuremath{\gamma}$ can reach large values potentially measurable at B factories, especially in the low $BR(\stackrel{\ensuremath{\rightarrow}}{b}s\ensuremath{\gamma})$ region, while the contributions to electr…
SO(10) grand unification model for degenerate neutrino masses
1994
This version corrects the first one in eq.3.4 and table 1 where there was a bar missing in the 126 representation. All other equations and results are unchanged and correct. However, the criticism we had made in the earlier version to the work of Caldwell and Mohapatra was not correct and has been removed from the "note added" where it appeared. Moreover one new reference has been added to ref.13.
Naturality, unification and dark matter
2010
We consider a model where electroweak symmetry breaking is driven by technicolor dynamics with minimal particle content required for walking coupling and saturation of global anomalies. Furthermore, the model features three additional Weyl fermions singlet under technicolor interactions, two of which provide for a one-loop unification of the standard model gauge couplings. Among these extra matter fields exists a possible candidate for weakly interacting dark matter. We evaluate the relic densities and find that they are sufficient to explain the cosmological observations and avoid the experimental limits from earth-based searches. Hence, we establish a nonsupersymmetric framework where hie…
Status and implications of neutrino masses: a brief panorama
2015
15 pages.- 10 figures