Probing the Chromoelectric and Chromomagnetic dipole moments of the Top quark at Hadronic Colliders

We study the effects of the anomalous chromoelectric and chromomagnetic dipole moments of the top quark on the top-pair production, on the top-pair plus 1jet production, and on their ratios, as well as their dependence on the transverse momenta of the top quark and the jet. We also construct CP-odd and $\hat T$-odd observables to probe the dispersive part of the chromoelectric form factor of the top quark, and compare their sensitivities in both top-pair and top-pair plus 1 jet production.Comment: 21 pages, 9 figures, in LaTeX using epsf.tex. This is the published version in PRD (April

Anisotropic dark energy stars

A model of compact object coupled to inhomogeneous anisotropic dark energy is studied. It is assumed a variable dark energy that suffers a phase transition at a critical density. The anisotropic Lambda-Tolman-Oppenheimer-Volkoff equations are integrated to know the structure of these objects. The anisotropy is concentrated on a thin shell where the phase transition takes place, while the rest of the star remains isotropic. The family of solutions obtained depends on the coupling parameter between the dark energy and the fermion matter. The solutions share several features in common with the gravastar model. There is a critical coupling parameter that gives non-singular black hole solutions. The mass-radius relations are studied as well as the internal structure of the compact objects. The hydrodynamic stability of the models is analyzed using a standard test from the mass-radius relation. For each permissible value of the coupling parameter there is a maximum mass, so the existence of black holes is unavoidable within this model.Comment: 12 pages, 6 figures, final manuscript, Accepted for publication in Astrophysics & Space Scienc

Criticality and Bifurcation in the Gravitational Collapse of a Self-Coupled Scalar Field

We examine the gravitational collapse of a non-linear sigma model in spherical symmetry. There exists a family of continuously self-similar solutions parameterized by the coupling constant of the theory. These solutions are calculated together with the critical exponents for black hole formation of these collapse models. We also find that the sequence of solutions exhibits a Hopf-type bifurcation as the continuously self-similar solutions become unstable to perturbations away from self-similarity.Comment: 18 pages; one figure, uuencoded postscript; figure is also available at http://www.physics.ucsb.edu/people/eric_hirschman

CP--odd Correlation in the Decay of Neutral Higgs Boson into ZZZZ, W+W−W^+W^-, or ttˉt{\bar t}

We investigate the possibility of detecting CP--odd angular correlations in the various decay modes of the neutral Higgs boson including the modes of a $ZZ$ pair, a $W^+W^-$ pair, or a heavy quark pair. It is a natural way to probe the CP character of the Higgs boson once it is identified. Final state interactions (i.e. the absorptive decay amplitude) is not required in such correlations. As an illustrative example we take the fundamental source of the CP nonconservation to be in the Yukawa couplings of the Higgs boson to the heavy fermions. A similar correlation in the process $e^+e^- \to l^+ l^- H$ is also proposed. Our analysis of these correlations will be useful for experiments in future colliders such as LEP II, SSC, LHC or NLC.Comment: 16 pages, plus 8 postscript graphs not posted befor

Health-related quality of life outcomes among breast cancer survivors

Background: Data from a nationwide sample of US breast cancer survivors were used to examine associations between patient characteristics (breast cancer clinical features, prognostic factors, and treatments) and health-related quality of life (HRQOL). Associations between postdiagnosis HRQOL and mortality were then evaluated. Methods: The authors identified female breast cancer survivors (n = 2453) from the Sister Study or Two Sister Study who were at least 1 year from breast cancer diagnosis and who had responded to a survivorship survey in 2012. HRQOL was assessed with the Patient-Reported Outcomes Measurement Information System (PROMIS) Global 10 measures. Multivariable linear regression was used to assess predictors associated with HRQOL. Cox regression was used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between HRQOL and all-cause mortality. Results: HRQOL, assessed an average of 4.9 years after the cancer diagnosis (standard deviation of 1.9 years), was negatively associated with a higher cancer stage at diagnosis; a higher comorbidity score at the survey; experience of surgical complications; dissatisfaction with breast surgery; and experience of any recent recurrence, metastasis, or secondary malignancy. Since the completion of the survey, there were 85 deaths (3.5%) during a mean follow-up of 4 years (standard deviation of 0.5 years). In multivariate models, decreases in PROMIS physical T scores and mental T scores were associated with increased mortality (HR for physical T scores, 1.08; 95% CI, 1.05-1.11; HR for mental T scores, 1.03; 95% CI, 1.01-1.06). Conclusions: Prognostic and cancer treatment–related factors affect HRQOL in breast cancer survivors and may inform targeted survivorship care. PROMIS global health measures may offer additional insights into patients' well-being and mortality risk. Lay Summary: Findings from a study suggest that prognostic and cancer treatment–related factors affect health-related quality of life (HRQOL) in breast cancer survivors and that poor HRQOL may increase the mortality risk. The evaluation of HRQOL is important because it may hold potential as a tool for optimizing survivorship care

Early-life Farm Exposure and Ovarian Reserve in a US Cohort of Women

Background: In a previous exploratory study, we reported lower concentrations of the ovarian reserve biomarker anti-Müllerian hormone (AMH) in adulthood with prenatal farm exposure. We now examine this association as well as childhood farm exposure using enrollment data from the Sister Study, a large US cohort of women. Methods: We collected prenatal and childhood farm exposure data by questionnaire and telephone interview. However, serum AMH data were available only for a nested subset: premenopausal women ages 35-54 subsequently diagnosed with breast cancer (n = 418 cases) and their matched controls (n = 866). To avoid potential bias from restricting analyses to only premenopausal controls, we leveraged the available cohort data. We used data from both premenopausal cases and controls as well as postmenopausal women ages 35-54 (n = 3,526) (all presumed to have undetectable AMH concentrations) and applied weights to produce a sample representative of the cohort ages 35-54 (n = 17,799). The high proportion of undetectable AMH concentrations (41%) was addressed using reverse-scale Cox regression. An adjusted hazard ratio (HR) <1.0 indicates that exposed individuals had lower AMH concentrations than unexposed individuals. Results: Prenatal exposure to maternal residence or work on a farm was associated with lower AMH concentrations (HR 0.66; 95% confidence intervals [CI] = 0.48 to 0.90). Associations between childhood farm residence exposures and AMH were null or weak, except childhood contact with pesticide-treated livestock or buildings (HR 0.69; 95% CI = 0.40 to 1.2). Conclusions: Replication of the prenatal farm exposure and lower adult AMH association raises concern that aspects of prenatal farm exposure may result in reduced adult ovarian reserve

Chiral Perturbation Theory for SU(3) Breaking in Heavy Meson Systems

The SU(3) breaking effects due to light quark masses on heavy meson masses, decay constants ($F_{D}, F_{D_{s}}$) and the form factor for semileptonic $\overline{B}\rightarrow D^{(\ast)} l\bar{\nu}_{l}$ transitions are formulated in chiral perturbation theory, using a heavy meson effective Lagrangian and expanding in inverse powers of the heavy meson mass. To leading order in this expansion, the leading chiral logarithms and the required counterterms are determined. At this level, a non-analytic correction to the mass splittings of ${\cal O}(p^3)$ appears, similar the the one found in light baryons. The correction to $F_{D_{s}}/F_{D}$ is roughly estimated to be of the order of $10\%$ and, therefore, experimentally accessible, while the correction to the form factor is likely to be substantially smaller. We explicitly check that the heavy quark symmetry is preserved by the chiral loops.Comment: 21 page

Topcolor-Assisted Supersymmetry

It has been known that the supersymmetric flavor changing neutral current problem can be avoided if the squarks take the following mass pattern, namely the first two generations with the same chirality are degenerate with masses around the weak scale, while the third generation is very heavy. We realize this scenario through the supersymmetric extension of a topcolor model with gauge mediated supersymmetry breaking.Comment: 12 pages, latex, no figure

Nonlinear Realization of Chiral Symmetry on the Lattice

We formulate lattice theories in which chiral symmetry is realized nonlinearly on the fermion fields. In this framework the fermion mass term does not break chiral symmetry. This property allows us to use the Wilson term to remove the doubler fermions while maintaining exact chiral symmetry on the lattice. Our lattice formulation enables us to address non-perturbative questions in effective field theories of baryons interacting with pions and in models involving constituent quarks interacting with pions and gluons. We show that a system containing a non-zero density of static baryons interacting with pions can be studied on the lattice without encountering complex action problems. In our formulation one can also decide non-perturbatively if the chiral quark model of Georgi and Manohar provides an appropriate low-energy description of QCD. If so, one could understand why the non-relativistic quark model works.Comment: 34 pages, 2 figures, revised version to be published in J. High Energy Phys. (changes in the 1st paragraph, additional descriptions on the nature of the coordinate singularities in Sec.2, references added

Fertility-related experiences after breast cancer diagnosis in the Sister and Two Sister Studies

Background: Commonly used chemotherapies can be toxic to the ovaries. To the authors’ knowledge, the majority of studies evaluating receipt of fertility counseling for women in their reproductive years have been performed in specific settings, thereby limiting generalizability. Methods: A nationwide sample of US women diagnosed with breast cancer before age 45 years completed a survey assessing the prevalence of fertility counseling. Age-adjusted log-binomial regression was used to estimate prevalence ratios (PRs) and 95% CIs for fertility counseling. Results: Among 432 survivors diagnosed between 2004 and 2011, 288 (67%) had not discussed the effects of treatment on fertility with a health care provider before or during treatment. Fertility discussion was associated with younger age (PR, 3.49 [95% CI, 2.66-4.58] for aged <35 years vs ≥40 years) and lower parity (PR, 1.81 [95% CI, 1.29-2.53] for parity 1 vs 2). Approximately 20% of respondents reported that they were interested in future fertility (87 of 432 respondents) at the time of their diagnosis, but not all of these individuals (66 of 87 respondents) received counseling regarding the impact of treatment on their fertility, and few (8 of 87 respondents) used fertility preservation strategies. Among 68 women with a fertility interest who provided reasons for not taking steps to preserve fertility, reasons cited included concern for an adverse impact on cancer treatment (56%), lack of knowledge (26%), decision to not have a child (24%), and cost (18%). Conclusions: Across multiple treatment settings, the majority of women of reproductive age who are diagnosed with breast cancer did not discuss fertility with a health care provider or use fertility preservation strategies. Discussing the potential impact of cancer treatment on future fertility is an important aspect of patient education