16,946,329 research outputs found

    Identifying acne treatment uncertainties via a James Lind Alliance Priority Setting Partnership

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    Objectives: The Acne Priority Setting Partnership (PSP) was set up to identify and rank treatment uncertainties by bringing together people with acne, and professionals providing care within and beyond the National Health Service (NHS). Setting: The UK with international participation. Participants: Teenagers and adults with acne, parents, partners, nurses, clinicians, pharmacists, private practitioners. Methods: Treatment uncertainties were collected via separate online harvesting surveys, embedded within the PSP website, for patients and professionals. A wide variety of approaches were used to promote the surveys to stakeholder groups with a particular emphasis on teenagers and young adults. Survey submissions were collated using keywords and verified as uncertainties by appraising existing evidence. The 30 most popular themes were ranked via weighted scores from an online vote. At a priority setting workshop, patients and professionals discussed the 18 highest-scoring questions from the vote, and reached consensus on the top 10. Results: In the harvesting survey, 2310 people, including 652 professionals and 1456 patients (58% aged 24 y or younger), made submissions containing at least one research question. After checking for relevance and rephrasing, a total of 6255 questions were collated into themes. Valid votes ranking the 30 most common themes were obtained from 2807 participants. The top 10 uncertainties prioritised at the workshop were largely focused on management strategies, optimum use of common prescription medications and the role of nondrug based interventions. More female than male patients took part in the harvesting surveys and vote. A wider range of uncertainties were provided by patients compared to professionals. Conclusions: Engaging teenagers and young adults in priority setting is achievable using a variety of promotional methods. The top 10 uncertainties reveal an extensive knowledge gap about widely used interventions and the relative merits of drug versus non-drug based treatments in acne management

    Complete 1-Loop Calculation of the T-violating D-Parameter in Neutron Decay in the MSSM

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    We investigate the violation of time reversal invariance in the decay of the free neutron in the framework of the Minimal Supersymmetric Standard Model (MSSM). The coefficient of the triple product of the neutron spin and the momenta of electron and neutrino, the so called D parameter, is computed at one loop order including all diagrams. We find that D is mainly sensitive to the trilinear A coupling in the squark sector and to the phase of the coefficient \mu which mixes the two Higgs superfields. The maximal MSSM contribution using parameters still allowed by experiment is however at D \approx 10^{-7}, while QED final state interactions give a value of D_{fsi} = - 2.3 * 10^{-5}. Explicit expressions for all relevant diagrams are given in an Appendix.Comment: 24 pages, 14 figures; Improved scanning of parameter space leads to some numerical change, but the basic conclusion remains unchange

    A Systematic Study of Neutrino Mixing and CP Violation from Lepton Mass Matrices with Six Texture Zeros

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    We present a systematic study of 400 combinations of the charged lepton and neutrino mass matrices with six vanishing entries or texture zeros. Only 24 of them, which can be classified into a few distinct categories, are found to be compatible with current neutrino oscillation data at the 3σ3\sigma level. A peculiar feature of the lepton mass matrices in each category is that they have the same phenomenological consequences. Taking account of a simple seesaw scenario for six parallel patterns of the charged lepton and Dirac neutrino mass matrices with six zeros, we show that it is possible to fit the experimental data at or below the 2σ2\sigma level. In particular, the maximal atmospheric neutrino mixing can be reconciled with a strong neutrino mass hierarchy in the seesaw case. Numerical predictions are also obtained for the neutrino mass spectrum, flavor mixing angles, CP-violating phases and effective masses of the tritium beta decay and the neutrinoless double beta decay.Comment: 35 pages, 15 figures, minor change

    Quantum mechanics in curved space-time

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    In this paper, the principles of the general relativity are used to formulate quantum wave equations for spin-0 and spin-1/2 particles. More specifically, the equations are worked in a Schwarzschild-like metric. As a test, the hydrogen atom spectrum is calculated. A comparison of the calculated spectrum with the numerical data of the deuterium energy levels shows a significant improvement of the accord, and the deviations are almost five times smaller then the ones obtained with the Dirac theory. The implications of the theory considering the strong interactions are also discussed

    Sum rules for total hadronic widths of light mesons and rectilineal stitch of the masses on the complex plane

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    Mass formulae for light meson multiplets derived by means of exotic commutator technique are written for complex masses and considered as complex mass sum rules (CMSR). The real parts of the (CMSR) give the well known mass formulae for real masses (Gell-Mann--Okubo, Schwinger and Ideal Mixing ones) and the imaginary parts of CMSR give appropriate sum rules for the total hadronic widths - width sum rules (WSR). Most of the observed meson nonets satisfy the Schwinger mass formula (S nonets). The CMSR predict for S nonet that the points (m,Γ)(m,\Gamma{}) form the rectilinear stitch (RS) on the complex mass plane. For low-mass nonets WSR are strongly violated due to ``kinematical'' suppression of the particle decays, but the violation decreases as the mass icreases and disappears above 1.5GeV\sim 1.5 GeV. The slope ksk_s of the RS is not predicted, but the data show that it is negative for all S nonets and its numerical values are concentrated in the vicinity of the value -0.5. If ksk_s is known for a nonet, we can evaluate ``kinematical'' suppressions of its individual particles. The masses and the widths of the S nonet mesons submit to some rules of ordering which matter in understanding the properties of the nonet. We give the table of the S nonets indicating masses, widths, mass and width orderings. We show also mass-width diagrams for them. We suggest to recognize a few multiplets as degenerate octets. In Appendix we analyze the nonets of 1+1^+ mesons.Comment: 20 pages, 3 figures; title and discussion expanded; additional text; final version accepted for publication in EPJ

    Fock States of Flavor Neutrinos are Unphysical

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    It is shown that it is possible to construct an infinity of Fock spaces of flavor neutrinos depending on arbitrary unphysical mass parameters, in agreement with the theory of Blasone and Vitiello in the version proposed by Fujii, Habe and Yabuki. However, we show that these flavor neutrino Fock spaces are clever mathematical constructs without physical relevance, because the hypothesis that neutrinos produced or detected in charged-current weak interaction processes are described by flavor neutrino Fock states implies that measurable quantities depend on the arbitrary unphysical flavor neutrino mass parameters.Comment: 11 page

    Flavor changing neutral currents from lepton and B decays in the two Higgs doublet model

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    Constraints on the whole spectrum of lepton flavor violating vertices are shown in the context of the standard two Higgs doublet model. The vertex involving the eτe-\tau mixing is much more constrained than the others, and the decays proportional to such vertex are usually very supressed. On the other hand, bounds on the quark sector are obtained from leptonic decays of the Bd,s0B_{d,s}^{0} mesons and from ΔMBd0\Delta M_{B_{d}^{0}}. We emphasize that although the Bd0Bˉd0B_{d}^{0}-\bar{B}_{d}^{0} mixing restricts severely the % d-b mixing vertex, the upper bound for this vertex could still give a sizeable contribution to the decay Bd0μμˉB_{d}^{0}\to \mu \bar{\mu} respect to the standard model contribution, from which we see that such vertex could still play a role in the phenomenology.Comment: 9 pages, 2 figures, LaTeX2e. Minor typos corrected. References added and corrected. Introduction change

    A New Application of the Gursey and Radicati Mass Formula

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    We study the spin- and flavour- dependent SU(6) violations in the baryon spectrum by means of a G\"ursey Radicati mass formula. The average energy of each SU(6)-multiplet is described using the SU(6) invariant interaction given by a hypercentral potential containing a linear and a hypercoulomb term. We show that the non strange and strange baryon masses are in general fairly well reproduced and moreover that the G\"ursey Radicati formula holds in a satisfactory way also for the excited states up to 2 GeV. The coefficients of the G\"ursey Radicati SU(6) breaking part obtained by the fit of the three-quark spectrum can be used to evaluate in first approximation the splitting within multiplets also for exotic baryon systems.Comment: 9 pages, 2 figures, 2 table, submitted to Eur. Phys. J.

    Bosonic corrections to the effective leptonic weak mixing angle at the two-loop level

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    Details of the recent calculation of the two-loop bosonic corrections to the effective leptonic weak mixing angle are presented. In particular, the expansion in the difference of the W and Z boson masses is studied and some of the master integrals needed are given in analytic form.Comment: 5 pages, 4 figures, to appear in the proceedings of the 7th International Symposium on Radiative Corrections (RADCOR05), Shonan Village, Japan, 200
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