Relativistic Faddeev approach to a non-local NJL model

The diquark and nucleon are studied in a non-local NJL model. We solve the relativistic Faddeev equation and compare the results with the ordinary NJL model. Although the model is quark confining, it is not diquark confining in the rainbow-ladder approximation. We show that the off-shell contribution to the diquark $T$ matrix is crucial for the structure of the nucleon: without its inclusion the attraction in the scalar channel is too weak to form a three-body bound state.Comment: 5 pages (AIP style), 3 figures, Talk presented at the " Xth International Conference on Hadron Spectroscopy (HADRON '03) ", August 31-September 6, 2003, Aschaffenburg, German

The quadratic extension extractor for (hyper)elliptic curves in odd characteristic

We propose a simple and efficient deterministic extractor for the (hyper)elliptic curve C, defined over Fq2, where q is some power of an odd prime. Our extractor, for a given point P on C, outputs the first Fq-coefficient of the abscissa of the point P. We show that if a point P is chosen uniformly at random in C, the element extracted from the point P is indistinguishable from a uniformly random variable in Fq

A light-front coupled-cluster method for the nonperturbative solution of quantum field theories

We propose a new method for the nonperturbative solution of quantum field theories and illustrate its use in the context of a light-front analog to the Greenberg--Schweber model. The method is based on light-front quantization and uses the exponential-operator technique of the many-body coupled-cluster method. The formulation produces an effective Hamiltonian eigenvalue problem in the valence Fock sector of the system of interest, combined with nonlinear integral equations to be solved for the functions that define the effective Hamiltonian. The method avoids the Fock-space truncations usually used in nonperturbative light-front Hamiltonian methods and, therefore, does not suffer from the spectator dependence, Fock-sector dependence, and uncanceled divergences caused by such truncations.Comment: 11 pages, 4 figures, RevTeX 4.1; expanded description of method and replaced QED with simpler model for illustratio

Feminist Perspectives on Disaster, Pandemics, and Intimate Partner Violence

The COVID-19 pandemic brought international awareness to the likelihood of increased abuse of those in abusive intimate partner relationships because of the forced confinement with their abusers (Bettinger-Lopez and Bro, A double pandemic: domestic violence in the age of COVID 19, Council on Foreign Relations. https://www.cfr.org/in-brief/double-pandemic-domestic-violence-age-covid-19, 2020). While this awareness was much discussed, assistance to survivors of abuse was limited because survivors often could not reach out for help, nor could advocates wishing to offer assistance safely reach in to advise them (Taub, A new Covid-19 crisis: domestic abuse rises worldwide. https://www.nytimes.com/2020/04/06/world/coronavirus-domestic-violence.html, 2020). The ever-present influence of the abuser prevented or limited the delivery of effective aid in many cases (Taub, A new Covid-19 crisis: domestic abuse rises worldwide. https://www.nytimes.com/2020/04/06/world/coronavirus-domestic-violence.html, 2020). But this was not the first disaster to place those experiencing intimate partner abuse at greater risk. Other disasters have in various ways increased women’s safety risks both during and after crisis. Other crises routinely resulted in increased abuse of survivors in intimate partner relationships including sexual and other assault by intimate partners (Rao 2020; Sohrabizadeh Prehosp Disaster Med, 31(4):407–412. https://www.ncbi.nlm.nih.gov/pubmed/27212204, 2016). This chapter briefly identifies some forms of abuse experienced by women outside of the home during times of crisis and their connection to intimate partner abuse. Then, the impact of COVID-19 on intimate partner survivors will be explored and some of their experiences described. Gaps and flaws in nations’ approaches to gender violence are often highlighted during and after disasters. Lack of planning to protect survivors of intimate partner violence and other highly vulnerable populations during crises was exacerbated by the additional dangers brought by COVID-19. Primarily, the heightened dangers resulted from stay-at-home orders, which made services for abused partners more difficult to obtain and highlighted the possibility of unintended consequences resulting from policies designed to protect the public as a whole (Godin 2020). This chapter concludes by considering what has been lacking in strategic disaster planning, including what lessons have been learned thus far through the COVID-19 experience. Recommendations for effective disaster planning to protect survivors of intimate partner abuse, while also protecting other vulnerable populations, are suggested. This information is presented with the caution that as of this writing the global pandemic continues to limit access to hard data. Long-term analysis of the implications of the pandemic on Intimate Partner Violence (IPV) survivors awaits the passage of time

Baryon structure in a quark-confining non-local NJL model

We study the nucleon and diquarks in a non-local Nambu-Jona-Lasinio model. For certain parameters the model exhibits quark confinement, in the form of a propagator without real poles. After truncation of the two-body channels to the scalar and axial-vector diquarks, a relativistic Faddeev equation for nucleon bound states is solved in the covariant diquark-quark picture. The dependence of the nucleon mass on diquark masses is studied in detail. We find parameters that lead to a simultaneous reasonable description of pions and nucleons. Both the diquarks contribute attractively to the nucleon mass. Axial-vector diquark correlations are seen to be important, especially in the confining phase of the model. We study the possible implications of quark confinement for the description of the diquarks and the nucleon. In particular, we find that it leads to a more compact nucleon.Comment: 21 pages (RevTeX), 18 figures (eps

A light-front coupled cluster method

A new method for the nonperturbative solution of quantum field theories is described. The method adapts the exponential-operator technique of the standard many-body coupled-cluster method to the Fock-space eigenvalue problem for light-front Hamiltonians. This leads to an effective eigenvalue problem in the valence Fock sector and a set of nonlinear integral equations for the functions that define the exponential operator. The approach avoids at least some of the difficulties associated with the Fock-space truncation usually used.Comment: 8 pages, 1 figure; to appear in the proceedings of LIGHTCONE 2011, 23-27 May 2011, Dalla

Anti-Acanthamoeba effects of silver and gold nanoparticles and contact lenses disinfection solutions

Background: This study aimed to investigate the anti-Acanthamoeba effects of the most used marketed disinfecting solutions in Iran. Moreover, the efficacy of some nano-compounds was tested against pathogenic Acanthamoeba. Methods: The present study was conducted in the School of Public Health, Tehran University of Medical sciences, Tehran, Iran during 2015-2016. Cysts of Acanthamoeba T4 genotype (7 x 104/ml) mixed at the equal volume with contact lens solutions including Opti-free, Ginza, ReNu, Maxima, Light, and Cyclean for the recommended time by the manufacturers. Nano-silver and nano-gold compounds were also treated with the amoebae. Chlorhexidine 0.02 and normal saline were used as positive and negative controls, respectively. Dead and alive amoebae were determined using vital stain and suspension was cultured in non-nutrient agar. The entire process was repeated at least three times. Results: In none of the solutions in the manufacturer's brochure recommended time, full cytotoxic effect was observed on the cysts of Acanthamoeba. Opti free express solution destroyed the cysts after 6 days. Nanosilver and nano-gold compounds showed no cytotoxic effect on the cysts of Acanthamoeba. Conclusion: None of the Nanoparticles compounds as well as contact lenses disinfecting solutions which studied was effective on Acanthamoeba cysts in the manufacturer's brochure recommended time. However, continuing study on Nano-silver and Nano-gold compounds to find effective ingredients against Acanthamoeba are highly recommended. © 2018, Tehran University of Medical Sciences (TUMS). All rights reserved