Higher-dimensional operators in SUSY SO(10) GUT models

SO(10) GUT models with only small Higgs fields use higher-dimensional operators to generate realistic fermion mass matrices. In particular, a Higgs field in the spinor representation, 16^d_H, acquires a weak scale vev. We include the weak vev of the corresponding field \bar{16}^u_H and investigate the effect on two successful models, one by Albright and Barr (AB) and another by Babu, Pati and Wilczek (BPW). We find that the BPW model is a particular case within a class of models with identical fermion masses and mixings. In contrast, we expect corrections to the parameters of AB-type models.Comment: 3 page

The roles, needs, and challenges of Arkansas women in agriculture

Participants of the 2005-2007 Arkansas Women in Agriculture conferences were surveyed for this study to identify recent changes in their roles on and off the farm, the factors important to their success, and the problems they face in their businesses. Respondents were broken into two groups—Farm (women owner-operators of farms, ranches, or agribusinesses) and Non-farm (women working in supporting agricultural industries)—for comparisons and responses were also analyzed across years. Farm women most often reported problems keeping good employees each year, while Non-farm women often reported having problems with being respected as a female business person. For Farm women, the factor most often cited as important to success in their business was being able to pass the business on to family; for Non-farm women it was being able to apply their talents and skills. These results suggest that different types of agricultural women hold different attitudes about business and face different challenges. Results across years suggest that successes and problems may change over time. This marks some of the first research on the roles, challenges, and attitudes of Arkansas’ women in agriculture. Based on the results of this research, educational efforts are underway across the state to assist Arkansas’ women in agriculture. However, given the small sample of women surveyed, further research is still needed to fully understand the roles, challenges, and attitudes of Arkansas’ women in agriculture

Construction of a Minimal Higgs SO(10) SUSY GUT Model

A full account is given of the procedure used by the authors to construct an SO(10) supersymmetric grand unified model of the fermion mass matrices. Various features of the model which gives remarkably accurate results for the quark and lepton masses and mixings were presented earlier in separate publications. The construction of the matrices is first discussed in the framework of effective operators, from which one naturally obtains the maximal \nu_\mu - \nu_\tau mixing, while the small angle or maximal mixing solutions for the solar neutrinos depend upon the nature of the Majorana matrix. A set of Higgs and fermion superfields is then introduced from which the Higgs and Yukawa superpotentials uniquely give the structure of the mass matrices previously obtained. The right-handed Majorana matrix arises from one Higgs field coupling to several pairs of superheavy conjugate neutrino singlets. For the simple version considered, 10 input parameters accurately yield the 20 masses and mixings of the quarks and leptons, and the 3 masses of the right-handed neutrinos.Comment: 37 pages including 4 figures, corrected a misprint in Table I and several misprints in Fig.

Predicting quark and lepton masses and mixings

A model is presented that fits the quark and lepton masses and mixings wherein five dimensionless parameters and a phase account for fifteen dimensionless observables. Among these are the Wolfenstein parameters $\rho$ and $\eta$, the $\nu_e-\nu_{\mu}$ and $\nu_e-\nu_{\tau}$ mixing angles which are predicted to be small and comparable while the $\nu_{\mu}-\nu_{\tau}$ mixing angle is predicted to be large. The model is based on supersymmetric SO(10) with the form of the mass matrices motivated by simplicity at the level of grand unification.Comment: 15 pages, LaTe

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

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

Health Information Services Available for People Living With HIV/AIDS: Perspectives of Library and Information Professionals

There is an urgent need for availability of life-saving health information services as well as adequate marketing, advertising, and dissemination strategies to people living with HIV/AIDS (PLWHAs), and to the broader public at large, especially in the context of a recent UNAIDS estimation that the number of people living with HIV in the United States, at the end of 2003, exceeded one million for the first time. This study explores the HIV/AIDS health information services that are available within the local community of Knoxville, Tennessee, and presents focus group perspectives of nine library and information professionals about awareness and use of these services by PLWHAs. The study forms part of a larger plan to apply a community informatics (CI) approach to examine the provision of health information services for PLWHAs in terms of how PLWHAs and other stakeholders including health care service providers, academic community at the University of Tennessee, community leaders and activists, and faith-based organizations, use and apply information and communication technologies (ICTs) to empower and enable PLWHAs to meet their information needs, goals, and aspirations. Here we report findings from the project’s first phase of documenting perspectives of library and information professionals about existing HIV/AIDS information services, users of these services, barriers and challenges to effective use, and the role of health information professionals in the context of developing ideal information support services for PLWHAs

SO(10) and Large nu_mu - nu_tau Mixing

A general approach to understanding the large mixing seen in atmospheric neutrinos is explained, as well as a highly predictive SO(10) model which implements this approach. It is also seen how bimaximal mixing naturally arises in this scheme. (Talk presented at NNN99, SUNY Stony Brook, Sept. 22-26, 1999)Comment: 10 pages, LaTe

Explicit SO(10) Supersymmetric Grand Unified Model

A complete set of Higgs and matter superfields is introduced with well-defined SO(10) properties and U(1) \times Z_2 \times Z_2 family charges from which the Higgs and Yukawa superpotentials are constructed. The Higgs fields solve the doublet-triplet splitting problem, while the structures of the four Dirac fermion mass matrices obtained involve just six effective Yukawa operators. The right-handed Majorana matrix, M_R, arises from one Higgs field coupling to several pairs of superheavy conjugate neutrino singlets. In terms of 10 input parameters to the mass matrices, the model accurately yields the 20 masses and mixings of the lightest quarks and leptons, as well as the masses of the 3 heavy right-handed neutrinos. The bimaximal atmospheric and solar neutrino vacuum solutions are favored in this simplest version with a moderate hierarchy in M_R. The large mixing angle MSW solution is obtainable, on the other hand, with a considerably larger hierarchy in M_R which is also necessary to obtain baryogenesis through the leptogenesis mechanism.Comment: 11 pages including 4 figures, contribution to NEUTRINO 2000 and talk presented at SUSY2

Explicit SO(10) Supersymmetric Grand Unified Model for the Higgs and Yukawa Sectors

A complete set of fermion and Higgs superfields is introduced with well-defined SO(10) properties and U(1) x Z_2 x Z_2 family charges from which the Higgs and Yukawa superpotentials are constructed. The structures derived for the four Dirac fermion and right-handed Majorana neutrino mass matrices coincide with those previously obtained from an effective operator approach. Ten mass matrix input parameters accurately yield the twenty masses and mixings of the quarks and leptons with the bimaximal atmospheric and solar neutrino vacuum solutions favored in this simplest version.Comment: Published version appearing in PRL in which small modifications to original submission and a paragraph concerning proton decay appea