We study a number of models, based on a non-Abelian discrete group, that successfully reproduce the simple and predictive Yukawa textures usually associated with U͑2͒ theories of flavor. These models allow for solutions to the solar and atmospheric neutrino problems that do not require altering successful predictions for the charged fermions or introducing sterile neutrinos. Although Yukawa matrices are hierarchical in the models we consider, the mixing between second-and third-generation neutrinos is naturally large. We first present a quantitative analysis of a minimal model proposed in earlier work, consisting of a global fit to fermion masses and mixing angles, including the most important renormalization group effects. We then propose two new variant models: The first reproduces all important features of the SU(5)ϫU(2) unified theory with neither SU͑5͒ nor U͑2͒. The second demonstrates that discrete subgroups of SU͑2͒ can be used in constructing viable supersymmetric theories of flavor without scalar universality even though SU͑2͒ by itself cannot.
We present a model of fermion masses based on a minimal, non-Abelian discrete symmetry that reproduces the Yukawa matrices usually associated with U(2) theories of flavor. Mass and mixing angle relations that follow from the simple form of the quark and charged lepton Yukawa textures are therefore common to both theories. We show that the differing representation structure of our horizontal symmetry allows for new solutions to the solar and atmospheric neutrino problems that do not involve modification of the original charged fermion Yukawa textures, or the introduction of sterile neutrinos.
The preponderance of matter over antimatter in the early universe, the dynamics of the supernovae that produced the heavy elements necessary for life, and whether protons eventually decay—these mysteries at the forefront of particle physics and astrophysics are key to understanding the early evolution of our universe, its current state, and its eventual fate. The Deep Underground Neutrino Experiment (DUNE) is an international world-class experiment dedicated to addressing these questions as it searches for leptonic charge-parity symmetry violation, stands ready to capture supernova neutrino bursts, and seeks to observe nucleon decay as a signature of a grand unified theory underlying the standard model. The DUNE far detector technical design report (TDR) describes the DUNE physics program and the technical designs of the single- and dual-phase DUNE liquid argon TPC far detector modules. This TDR is intended to justify the technical choices for the far detector that flow down from the high-level physics goals through requirements at all levels of the Project. Volume I contains an executive summary that introduces the DUNE science program, the far detector and the strategy for its modular designs, and the organization and management of the Project. The remainder of Volume I provides more detail on the science program that drives the choice of detector technologies and on the technologies themselves. It also introduces the designs for the DUNE near detector and the DUNE computing model, for which DUNE is planning design reports. Volume II of this TDR describes DUNE's physics program in detail. Volume III describes the technical coordination required for the far detector design, construction, installation, and integration, and its organizational structure. Volume IV describes the single-phase far detector technology. A planned Volume V will describe the dual-phase technology.
The preponderance of matter over antimatter in the early universe, the dynamics of the supernovae that produced the heavy elements necessary for life, and whether protons eventually decay—these mysteries at the forefront of particle physics and astrophysics are key to understanding the early evolution of our universe, its current state, and its eventual fate. DUNE is an international world-class experiment dedicated to addressing these questions as it searches for leptonic charge-parity symmetry violation, stands ready to capture supernova neutrino bursts, and seeks to observe nucleon decay as a signature of a grand unified theory underlying the standard model. Central to achieving DUNE's physics program is a far detector that combines the many tens-of-kiloton fiducial mass necessary for rare event searches with sub-centimeter spatial resolution in its ability to image those events, allowing identification of the physics signatures among the numerous backgrounds. In the single-phase liquid argon time-projection chamber (LArTPC) technology, ionization charges drift horizontally in the liquid argon under the influence of an electric field towards a vertical anode, where they are read out with fine granularity. A photon detection system supplements the TPC, directly enhancing physics capabilities for all three DUNE physics drivers and opening up prospects for further physics explorations. The DUNE far detector technical design report (TDR) describes the DUNE physics program and the technical designs of the single- and dual-phase DUNE liquid argon TPC far detector modules. Volume IV presents an overview of the basic operating principles of a single-phase LArTPC, followed by a description of the DUNE implementation. Each of the subsystems is described in detail, connecting the high-level design requirements and decisions to the overriding physics goals of DUNE.
We apply the Linear Delta Expansion (LDE) to the Lindstedt-Poincaré ("distorted time") method to find improved approximate solutions to nonlinear problems. We find that our method works very well for a wide range of parameters in the case of the anharmonic oscillator (Duffing equation) and of the non-linear pendulum. The approximate solutions found with this method are better behaved and converge more rapidly to the exact ones than in the simple Lindstedt-Poincaré method. * Electronic address: paolo@ucol.mx † Electronic address: fefo@cgic.ucol.mx
We consider the phenomenology of a naturally leptophobic Z-prime boson in the 1 to 10 GeV mass range. The Z-prime's couplings to leptons arise only via a radiativelygenerated kinetic mixing with the Z and photon, and hence are suppressed. We map out the allowed regions of the mass-coupling plane and show that such a Z-prime that couples to quarks with electromagnetic strength is not excluded by the current data. We then discuss possible signatures at bottom and charm factories.
The work contained herein constitutes a report of the "Beyond the Standard Model" working group for the Workshop "Physics at TeV Colliders", Les Houches, France, 26 May-6 June, 2003. The research presented is original, and was performed specifically for the workshop. Tools for calculations in the minimal supersymmetric standard model are presented, including a comparison of the dark matter relic density predicted by public codes. Reconstruction of supersymmetric particle masses at the LHC and a future linear collider facility is examined. Less orthodox supersymmetric signals such as non-pointing photons and Rparity violating signals are studied. Features of extra dimensional models are examined next, including measurement strategies for radions and Higgs', as well as the virtual effects of Kaluza Klein modes of gluons. An LHC search strategy for a heavy top found in many little Higgs model is presented and finally, there is an update on LHC Z ′ studies. XIV Radion Mixing Effects In The Two-Higgs-DoubletModel 74 XV Search For The Radion Decay φ → hh With γγ+bb, τ τ +bb And bb+bb Final States In CMS 80 XVI The Invisible Higgs Decay Width In The ADD Model At The LHC 86 XVII Determining the extra-dimensional location of the Higgs boson 92 XVIII The sensitivity of the LHC for TeV scale dimensions in dijet production 95 XIX Little Higgs Model: LHC Potential 99 XX Z ′ studies at the LHC: an update 104 5 Part I Abstract An accord specifying a unique set of conventions for supersymmetric extensions of the Standard Model together with generic file structures for (1) supersymmetric model specifications and input parameters, (2) electroweak scale supersymmetric mass and coupling spectra, and (3) decay tables is defined, to provide a universal interface between spectrum calculation programs, decay packages, and high energy physics event generators. AbstractWe present and describe an internet resource which allows the user to compare different calculations of MSSM spectra. After providing (currently mSUGRA) SUSY breaking input parameters, the spectra predicted by the publicly available programs ISASUGRA, SOFTSUSY, SPHENO and SUSPECT are output by the resource. The variance and range of results is also produced. AbstractWe compare the relic density of neutralino dark matter within the minimal supergravity model (mSUGRA) using four different public codes for supersymetric spectra evaluation.Abstract SFITTER is a new tool to determine supersymmetric model parameters from collider measurements. It allows to perform a grid search for the minimal χ 2 and/or a fit of a given model. Currently, the model parameters in the general MSSM or in a gravity mediated SUSY breaking model can be tested using a given set of mass, branching ratio and cross section measurements. AbstractWe present the Fortran code SDECAY, a program which calculates the decay widths and branching ratios of all supersymmetric particles in the Minimal Supersymmetric Standard Model, including higher order effects. The usual two-body decays of sfermions and gauginos as ...
We present a model where Majorana neutrino mass terms are forbidden by the flavor symmetry group ∆(27). Neutrinos are Dirac fermions and their masses arise in the same way as those of the charged fermions, due to very small Yukawa couplings. The model fits current neutrino oscillation data and correlates the octant of the atmospheric angle θ 23 with the magnitude of the lightest neutrino mass, with maximal mixing excluded for any neutrino mass hierarchy.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.