On Neutrino Masses and Mixings from Extra Dimensions

In the framework of a Kaluza-Klein type theory with the Standard Model fields localized on a 4-dimensional section while gravity propagates in a full $4+\delta$-dimensional space-time, we examine a mechanism of naturally small neutrino mass generation through couplings of Standard Model singlet fermion(s) living also in the full space-time. A numerical studies is carried out on the charged current universality constraint from the ratio of pion decay partial widths. The bounds obtained on the fundamental mass scale could be stringent.Comment: 16 pages latex, no figure; small modifications in discussions; version to appear in Phys.Lett.

A Simple Phenomenological Parametrization of Supersymmetry without R-Parity

We present a parametrization of the supersymmetric standard model without R-parity that permits efficient phenomenological analyses of the full model without a priori assumptions. Under the parametrization, which is characterized by a single vacuum expectation value for the scalar components of the Y=-1/2 superfields, the expressions for tree-level mass matrices are quite simple. They do not involve the trilinear R-parity violating couplings; however, the bilinear {\mu}_i terms do enter and cannot be set to zero without additional assumptions. We set up a framework for doing phenomenology and show some illustrative results for fermion mass matrices and related bounds on parameters. We find in particular that large values of tan(beta) can suppress R-parity violating effects, substantially weakening experimental constraints.Comment: LaTeX file plus postscript figure files, 17 pages; minor typographical changes, to appear in Physics Letters

Could the τ\tau be substantially different from ee and μ\mu in the supersymmetric standard model?

R-parity stands as an ad hoc assumption in the most popular version of the supersymmetric standard model. More than fifteen years' studies of R-parity violations have been restricted to various limiting scenarios. We illustrate how the single-VEV parametrization provides a workable framework to analyze the phenomenology of the complete theory of supersymmetry without R-parity. In our comprehensive study of various aspects of the resulting leptonic phenomenology at tree-level, we find that the physical $\tau$ lepton could actually bear substantial gaugino and higgsino components, making it very different from the $e$ and the $\mu$.Comment: 7 pages in postscript. Talk given by O.K. at Tau98, to be published in the proceedings; reprint number adde

The Generic Supersymmetric Standard Model as the Complete Theory of Supersymmetry without R-parity

The generic supersymmetric standard model is a model built from a supersymmetrized standard model field spectrum the gauge symmetries only. The popular minimal supersymmetric standard model differs from the generic version in having R-parity imposed by hand. We review an efficient formulation of the model in which all the admissible R-parity violating terms are incorporated without bias. The model gives many new interesting R-parity violating phenomenological features only started to be studied recently. Some of our recent results will be discussed, including newly identified 1-loop contributions to neutrino masses and electric dipole moments of neutron and electron. This is related to the largely overlooked R-parity violating contributions to squark and slepton mixings, which we also present in detail.Comment: 10 pages latex using espcrc2.sty (included) with a latex table and 3 eps- figure files incoporated, typos in a couple of expressions fixe

Solution to the strong CP problem with gauge-mediated supersymmetry breaking

We demonstrate that a certain class of low scale supersymmetric ``Nelson-Barr'' type models can solve the strong and supersymmetric CP problems while at the same time generating sufficient weak CP violation in the $K^{0}-\bar{K}^{0}$ system. In order to prevent one-loop corrections to $\bar{\theta}$ which violate bounds coming from the neutron electric dipole moment (EDM), one needs a scheme for the soft supersymmetry breaking parameters which can naturally give sufficient squark degeneracies and proportionality of trilinear soft supersymmetry-breaking parameters to Yukawa couplings. We show that a gauge-mediated supersymmetry breaking sector can provide the needed degeneracy and proportionality, though that proves to be a problem for generic Nelson-Barr models. The workable model we consider here has the Nelson-Barr mass texture enforced by a gauge symmetry; one also expects a new U(1) gauge superfield with mass in the TeV range. The resulting model is predictive. We predict a measureable neutron EDM and the existence of extra vector-like quark superfields which can be discovered at the LHC. Because the $3\times 3$ Cabbibo-Kobayashi-Maskawa matrix is approximately real, the model also predicts a flat unitarity triangle and the absence of substantial CP violation in the $B$ system at future $B$ factories. We discuss the general issues pertaining to the construction of such a workable model and how they lead to the successful strategy. A detailed renormalization group study is then used to establish the feasibility of the model considered

Flavor Changing Higgs Decays in Supersymmetry with Minimal Flavor Violation

We study the flavor changing neutral current decays of the MSSM Higgs bosons into strange and bottom quarks. We focus on a scenario of minimum flavor violation here, namely only that induced by the CKM matrix. Taking into account constraint from $b\to s \gamma$, $\delta\rho$ as well as experimental constraints on the MSSM spectrum, we show that the branching ratio of $(\Phi\to b\bar{s})$ and $(\Phi \to \bar{b}s)$ combined, for $\Phi$ being either one of the CP even Higgs states, can reach the order $10^{-4}$-$10^{-3}$ for large $\tan\beta$, large $\mu$, and large $A_t$. The result illustrates the significance of minimal flavor violation scenario which can induce competitive branching fraction for flavor changing Higgs decays. This can be compared with the previous studies where similar branching fraction has been reported, but with additional sources of flavor violations in squark mass matrices. We also discuss some basic features of the flavor violating decays in the generic case.Comment: 16 pages on Revtex, with 5 figures from 10 eps files incorporated; discussion on issues related more precise calculations elaborated; proof-edited version to appear in Phys. Lett.

Strong CP and Low-energy Supersymmetry

A spontaneously-broken CP provides an alternative to the KM mechanism for CP violation with the advantage that the strong CP problem is solved. We consider, for such a model with a new gauged U(1), the incorporation of low-energy supersymmetry and find the constraints on alignment and squark degeneracy. The conclusion is that although the $\bar{\theta}$ constraints are much less severe than in other generic schemes with supersymmetry breaking and spontaneous CP violation, one restriction remains stronger than needed in the MSSM for suppression of FCNC.Comment: Title changed. Discussions added. Version to appear in Phys. Lett.

Health economic evaluation of a nurse-assisted online eye screening in home healthcare to reduce avoidable vision impairment (iScreen):study protocol for a cluster randomized controlled trial

Background: Among older people undiagnosed and untreated vision impairment and blindness are common. The leading causes are uncorrected refractive errors and cataracts. Vision problems are associated with a lower quality of life, several health problems, and a higher chance of falling accidents and fractures. To eliminate avoidable vision impairment and blindness, targeted eye screening programs are recommended. Older patients, receiving home healthcare, have not yet been considered as a population at risk who could benefit from eye screening. Methods: A cluster-randomized controlled trial will be conducted to investigate the cost-effectiveness and cost-utility of online nurse-assisted eye screening in home healthcare, compared to care as usual, in reducing avoidable vision impairment. A healthcare and societal perspective will be used. The study will be performed in collaboration with several home healthcare organizations in the Netherlands. The online eye screening consists of near and distance visual acuity, followed by an Amsler grading test. Measurements in both groups will take place at baseline and after 6 and 12 months of follow-up. A total of 240 participants will be recruited. Older men and women (65 +), who receive home-based nursing and are cognitively able to participate, will be included. The primary outcome will be the change of two lines or more on the Colenbrander-1 M visual acuity chart between baseline and 12-month follow-up. Discussion: An eye screening for populations at risk contributes to the detection of undiagnosed and untreated vision impairment. This may reduce the health-related consequences of vision loss and the high economic burden associated with vision impairment. Trial registration: ClinicalTrials.gov NCT06058637. Registered on 27 September 2023.</p

Baseline radiomics features and MYC rearrangement status predict progression in aggressive B-cell lymphoma

We investigated whether the outcome prediction of patients with aggressive B-cell lymphoma can be improved by combining clinical, molecular genotype, and radiomics features. MYC, BCL2, and BCL6 rearrangements were assessed using fluorescence in situ hybridization. Seventeen radiomics features were extracted from the baseline positron emission tomography–computed tomography of 323 patients, which included maximum standardized uptake value (SUV(max)), SUV(peak), SUV(mean), metabolic tumor volume (MTV), total lesion glycolysis, and 12 dissemination features pertaining to distance, differences in uptake and volume between lesions, respectively. Logistic regression with backward feature selection was used to predict progression after 2 years. The predictive value of (1) International Prognostic Index (IPI); (2) IPI plus MYC; (3) IPI, MYC, and MTV; (4) radiomics; and (5) MYC plus radiomics models were tested using the cross-validated area under the curve (CV-AUC) and positive predictive values (PPVs). IPI yielded a CV-AUC of 0.65 ± 0.07 with a PPV of 29.6%. The IPI plus MYC model yielded a CV-AUC of 0.68 ± 0.08. IPI, MYC, and MTV yielded a CV-AUC of 0.74 ± 0.08. The highest model performance of the radiomics model was observed for MTV combined with the maximum distance between the largest lesion and another lesion, the maximum difference in SUV(peak) between 2 lesions, and the sum of distances between all lesions, yielding an improved CV-AUC of 0.77 ± 0.07. The same radiomics features were retained when adding MYC (CV-AUC, 0.77 ± 0.07). PPV was highest for the MYC plus radiomics model (50.0%) and increased by 20% compared with the IPI (29.6%). Adding radiomics features improved model performance and PPV and can, therefore, aid in identifying poor prognosis patients

Health economic evaluation of a nurse-assisted online eye screening in home healthcare to reduce avoidable vision impairment (iScreen): study protocol for a cluster randomized controlled trial

Background: Among older people undiagnosed and untreated vision impairment and blindness are common. The leading causes are uncorrected refractive errors and cataracts. Vision problems are associated with a lower quality of life, several health problems, and a higher chance of falling accidents and fractures. To eliminate avoidable vision impairment and blindness, targeted eye screening programs are recommended. Older patients, receiving home healthcare, have not yet been considered as a population at risk who could benefit from eye screening. Methods: A cluster-randomized controlled trial will be conducted to investigate the cost-effectiveness and cost-utility of online nurse-assisted eye screening in home healthcare, compared to care as usual, in reducing avoidable vision impairment. A healthcare and societal perspective will be used. The study will be performed in collaboration with several home healthcare organizations in the Netherlands. The online eye screening consists of near and distance visual acuity, followed by an Amsler grading test. Measurements in both groups will take place at baseline and after 6 and 12 months of follow-up. A total of 240 participants will be recruited. Older men and women (65 +), who receive home-based nursing and are cognitively able to participate, will be included. The primary outcome will be the change of two lines or more on the Colenbrander-1 M visual acuity chart between baseline and 12-month follow-up. Discussion: An eye screening for populations at risk contributes to the detection of undiagnosed and untreated vision impairment. This may reduce the health-related consequences of vision loss and the high economic burden associated with vision impairment. Trial registration: ClinicalTrials.gov NCT06058637. Registered on 27 September 2023