4,347 research outputs found

    Lifting a Realistic SO(10) Grand Unified Model to Five Dimensions

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    It has been shown recently that the problem of rapid proton decay induced by dimension five operators arising from the exchange of colored Higgsinos can be simply avoided in grand unified models where a fifth spatial dimension is compactified on an orbifold. Here we demonstrate that this idea can be used to solve the Higgsino-mediated proton decay problem in any realistic SO(10) model by lifting that model to five dimensions. A particular SO(10) model that has been proposed to explain the pattern of quark and lepton masses and mixings is used as an example. The idea is to break the SO(10) down to the Pati-Salam symmetry by the orbifold boundary conditions. The entire four-dimensional SO(10) model is placed on the physical SO(10) brane except for the gauge fields, the 45 and a single 10 of Higgs fields, which are placed in the five-dimensional bulk. The structure of the Higgs superpotential can be somewhat simplified in doing so, while the Yukawa superpotential and mass matrices derived from it remain essentially unaltered.Comment: 17 pages, version to be published in Phys. Rev. D with expanded discussion of the suppression of dim-5 proton decay operator

    Mathematical and computational studies of equilibrium capillary free surfaces

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    The results of several independent studies are presented. The general question is considered of whether a wetting liquid always rises higher in a small capillary tube than in a larger one, when both are dipped vertically into an infinite reservoir. An analytical investigation is initiated to determine the qualitative behavior of the family of solutions of the equilibrium capillary free-surface equation that correspond to rotationally symmetric pendent liquid drops and the relationship of these solutions to the singular solution, which corresponds to an infinite spike of liquid extending downward to infinity. The block successive overrelaxation-Newton method and the generalized conjugate gradient method are investigated for solving the capillary equation on a uniform square mesh in a square domain, including the case for which the solution is unbounded at the corners. Capillary surfaces are calculated on the ellipse, on a circle with reentrant notches, and on other irregularly shaped domains using JASON, a general purpose program for solving nonlinear elliptic equations on a nonuniform quadrilaterial mesh. Analytical estimates for the nonexistence of solutions of the equilibrium capillary free-surface equation on the ellipse in zero gravity are evaluated

    Does the effect of driving distance on PGA/LPGA tour earnings differ across genders?

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    Since the early 21st century, the game of golf has seen a shift in importance of touch and finesse towards power and distance. Though many studies have observed the effects of individual golf statistics on earnings, none have examined if these effects fluctuate between genders. The purpose of my study is to show male and female professional golfers the effects of hitting the ball far and if their practice time might be better off spent practicing other areas of the game. By using player statistics from the 2015 PGA and LPGA cross sectional data set, this paper will examine if the effects that driving distance has on tournament earnings differentiates between men and women. Other econometric studies have found that there is an incentive effect for players to maximize effort in the final round, as well as to focus on their abilities from 100 yards and in to increase tour earnings. Those knowledgeable in golf should expect longer hitters to have an advantage over the field and therefor make more money. My study found that the impact of driving distance on tour earnings is different for men and women. Men who drive the ball further than average see a significant increase in tour earnings. Surprisingly, women who hit the ball further than average see a significant decrease in tour earnings. In addition, I found that the number of wins a player has to be the most significant for both men and women

    Radioisotopes Produced by Neutron Irradiation of Food

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    The use of neutrons for cargo interrogation has the potential to drastically improve threat detection. Previous research has focussed on the production of 24Na, based on the isotopes produced in pharmaceuticals and medical devices. For both the total acitivity and the ingestion dose we show that a variety of isotopes contribute and that 24Na is only dominant under certain conditions. The composition of the foods has a strong influence on the resulting activity and ingestion dose suggesting that the pharmaceuticals and medical devices considered initially are not a viable analogue for foodstuffs. There is an energy dependence to the isotopes produced due to the cross-sections of different reactions varying with neutron energy. We show that this results in different isotopes dominating the ingestion dose at different energies, which has not been considered in previous literature

    Resonant leptogenesis in a predictive SO(10) grand unified model

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    An SO(10) grand unified model considered previously by the authors featuring lopsided down quark and charged lepton mass matrices is successfully predictive and requires that the lightest two right-handed Majorana neutrinons be nearly degenerate in order to obtain the LMA solar neutrino solution. Here we use this model to test its predictions for baryogenesis through resonant-enhanced leptogenesis. With the conventional type I seesaw mechanism, the best predictions for baryogenesis appear to fall a factor of three short of the observed value. However, with a proposed type III seesaw mechanism leading to three pairs of massive pseudo-Dirac neutrinos, resonant leptogenesis is decoupled from the neutrino mass and mixing issues with successful baryogenesis easily obtained.Comment: 22 pages including 1 figure; published version with reference adde

    Lepton Flavor Violation in Supersymmetric SO(10) Grand Unified Models

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    The study for lepton flavor violation combined with the neutrino oscillation may provide more information about the lepton flavor structure of the grand unified theory. In this paper, we study two lepton flavor violation processes, τ→μγ\tau\to \mu\gamma and Z→τμZ\to \tau\mu, in the context of supersymmetric SO(10) grand unified models. We find the two processes are both of phenomenological interest. In particular the latter may be important in some supersymmetric parameter space where the former is suppressed. Thus, Z-dacay may offer another chance for looking for lepton flavor violation.Comment: 26 pages, 10 figure

    University Admissions Leaders Rethink Recruitment Strategies in the Wake of COVID-19

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    In the wake of COVID-19, university admissions leaders were challenged to rethink recruitment strategies and practices. This qualitative research inquiry explored how admissions leaders changed student recruitment strategies in response to the inability to connect with prospective students in-person. The study collected data from six university admissions leaders in the Midwest region of the United States. Systems theory and the concept of organizational adaptation supported this investigation. Findings of the study reveal challenges admissions offices faced in response to the pandemic, identify new recruitment strategies developed by admissions leaders, and information what strategies may comprise the future of recruitment. Three themes emerged from the study: (1) enhancement of web presence, (2) expansion of virtual experiences, and (3) continuation of online and in-person recruitment strategies as the new standard

    Bound-State Model of Weak and Strong Interactions

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    The pion-nucleon coupling constant is calculated from first principles by use of the N/D matrix method. Three models are introduced which contain pions, nucleons, and weakly interacting intermediate bosons of the scalar, pseudoscalar, and vector variety. The basic interactions are taken to be parity and isotopic spin conserving. Certain physical assumptions in the nature of boundary conditions and the known fact that the weak coupling is very weak, together with use of the Born approximation for N, enable us to obtain an eigenvalue equation which expresses the pion-nucleon coupling constant in terms of the three masses in the problem. The correct value for gπ^2 can be obtained for an intermediate vector meson of mass comparable to the nucleon mass with essentially no cutoff employed; on the other hand, the experimental value is also obtained with a spin-zero boson and a relatively small cutoff energy
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