Considerations on the quantum double-exchange Hamiltonian

Schwinger bosons allow for an advantageous representation of quantum double-exchange. We review this subject, comment on previous results, and address the transition to the semiclassical limit. We derive an effective fermionic Hamiltonian for the spin-dependent hopping of holes interacting with a background of local spins, which is used in a related publication within a two-phase description of colossal magnetoresistant manganites.Comment: 7 pages, 3 figure

Electroweak Phase Transitions in left-right symmetric models

We study the finite-temperature effective potential of minimal left-right symmetric models containing a bidoublet and two triplets in the scalar sector. We perform a numerical analysis of the parameter space compatible with the requirement that baryon asymmetry is not washed out by sphaleron processes after the electroweak phase transition. We find that the spectrum of scalar particles for these acceptable cases is consistent with present experimental bounds.Comment: 20 pages, 5 figures (included), some comments added, typos corrected and new references included. Final version to appear in PR

Neutrino Masses, Mixing and New Physics Effects

We introduce a parametrization of the effects of radiative corrections from new physics on the charged lepton and neutrino mass matrices, studying how several relevant quantities describing the pattern of neutrino masses and mixing are affected by these corrections. We find that the ratio omega = sin theta / tan theta_atm is remarkably stable, even when relatively large corrections are added to the original mass matrices. It is also found that if the lightest neutrino has a mass around 0.3 eV, the pattern of masses and mixings is considerably more stable under perturbations than for a lighter or heavier spectrum. We explore the consequences of perturbations on some flavor relations given in the literature. In addition, for a quasi-degenerate neutrino spectrum it is shown that: (i) starting from a bi-maximal mixing scenario, the corrections to the mass matrices keep tan theta_atm very close to unity while they can lower tan theta_sol to its measured value; (ii) beginning from a scenario with a vanishing Dirac phase, corrections can induce a Dirac phase large enough to yield CP violation observable in neutrino oscillations.Comment: 14 pages, 21 figures. Uses RevTeX4. Added several comments and references. Final version to appear in PR

Impact of a cancer diagnosis on educational, employment, health-related quality of life, and social outcomes among young adults: A matched cohort study of 401 cancer survivors aged 15–24 in England

Background Globally, cancer incidence is rising fastest among young people. Existing literature on acute health shocks, including cancer diagnoses, focuses on older working-aged adults. Methods Matched cohort study involving 401 young cancer survivors (aged 15–24) in the BRIGHTLIGHT study and 765 UK Household Longitudinal Study controls without cancer between 2013 and 2018. Participants were matched on sex, age, ethnicity, index of multiple deprivation (IMD) quintile, non-cancer health conditions, and follow-up duration. Regression models assessed economic, educational, social, health-related quality of life (HRQoL), and mental health outcomes at 6(T1), 12–18(T2), and 24–36 months (T3) post-diagnosis. Results Compared to matched controls, those with cancer were: less likely to be in employment, education, or training at T1 (OR = 2.03, p < 0.001) but not at T3 (OR = 0.96, p = 0.18), because transitioning from unemployment or economic inactivity into education was more common (24 % vs 3 % between T1 and T3); less likely to live in parental households at T1 (OR = 0.54, p < 0.001) and T3 (OR = 0.59, p < 0.001); and more likely to experience relationship breakdown (23 % vs 12 % between T1 and T3). Differences in mental health and HRQoL declined over time (mean difference compared to matched controls: T1: −0.07, p < 0.001; T2 and T3: −0.01 p ≥ 0.55). Economic outcomes, mental health and HRQoL utility scores were persistently worse among more severe cancer cases. Conclusions Despite having initially poorer health and economic outcomes, cancer survivors in this cohort caught up with their peers within 3 years. Linked clinical data showed those with more severe diagnoses were affected most, indicating scope for improved psychosocial and economic support

Statistical shape modeling of the hip and the association with hip osteoarthritis: a systematic review

Objective: To summarize available evidence on the association between hip shape as quantified by statistical shape modeling (SSM) and the incidence or progression of hip osteoarthritis. Design: We conducted a systematic search of five electronic databases, based on a registered protocol (available: PROSPERO CRD42020145411). Articles presenting original data on the longitudinal relationship between radiographic hip shape (quantified by SSM) and hip OA were eligible. Quantitative meta-analysis was precluded because of the use of different SSM models across studies. We used the Newcastle–Ottawa Scale (NOS) for risk of bias assessment. Results: Nine studies (6,483 hips analyzed with SSM) were included in this review. The SSM models used to describe hip shape ranged from 16 points on the femoral head to 85 points on the proximal femur and hemipelvis. Multiple hip shape features and combinations thereof were associated with incident or progressive hip OA. Shape variants that seemed to be consistently associated with hip OA across studies were acetabular dysplasia, cam morphology, and deviations in acetabular version (either excessive anteversion or retroversion). Conclusions: Various radiographic, SSM-defined hip shape features are associated with hip OA. Some hip shape features only seem to increase the risk for hip OA when combined together. The heterogeneity of the used SSM models across studies precludes the estimation of pooled effect sizes. Further studies using the same SSM model and definition of hip OA are needed to allow for the comparison of outcomes across studies, and to validate the found associations

A Measurement of the Proton Structure Function F ⁣2(x,Q2)F_{\!2}(x,Q^2)

A measurement of the proton structure function $F_{\!2}(x,Q^2)$ is reported for momentum transfer squared $Q^2$ between 4.5 $GeV^2$ and 1600 $GeV^2$ and for Bjorken $x$ between $1.8\cdot10^{-4}$ and 0.13 using data collected by the HERA experiment H1 in 1993. It is observed that $F_{\!2}$ increases significantly with decreasing $x$, confirming our previous measurement made with one tenth of the data available in this analysis. The $Q^2$ dependence is approximately logarithmic over the full kinematic range covered. The subsample of deep inelastic events with a large pseudo-rapidity gap in the hadronic energy flow close to the proton remnant is used to measure the "diffractive" contribution to $F_{\!2}$.Comment: 32 pages, ps, appended as compressed, uuencoded fil