Barrier modification in sub-barrier fusion reactions using Wong formula with Skyrme forces in semiclassical formalism

We obtain the nuclear proximity potential by using semiclassical extended Thomas Fermi (ETF) approach in Skyrme energy density formalism (SEDF), and use it in the extended $\ell$-summed Wong formula under frozen density approximation. This method has the advantage of allowing the use of different Skyrme forces, giving different barriers. Thus, for a given reaction, we could choose a Skyrme force with proper barrier characteristics, not-requiring extra ``barrier lowering" or ``barrier narrowing" for a best fit to data. For the $^{64}$Ni+$^{100}$Mo reaction, the $\ell$-summed Wong formula, with effects of deformations and orientations of nuclei included, fits the fusion-evaporation cross section data exactly for the force GSkI, requiring additional barrier modifications for forces SIII and SV. However, the same for other similar reactions, like $^{58,64}$Ni+$^{58,64}$Ni, fits the data best for SIII force. Hence, the barrier modification effects in $\ell$-summed Wong expression depends on the choice of Skyrme force in extended ETF method.Comment: INPC2010, Vancouver, CANAD

Duality violations and spectral sum rules

We study the issue of duality violations in the VV-AA vacuum polarization function in the chiral limit. This is done with the help of a model with an expansion in inverse powers of the number of colors, Nc, allowing us to consider resonances with a finite width. Due to these duality violations, the Operator Product Expansion (OPE) and the moments of the spectral function (e.g. the Weinberg sum rules) do not match at finite momentum, and we analyze this difference in detail. We also perform a comparative study of many of the different methods proposed in the literature for the extraction of the OPE parameters and find that, when applied to our model, they all fare quite similarly. In fact, the model strongly suggests that a significant improvement in precision can only be expected after duality violations are included. To this end, we propose a method to parameterize these duality violations. The method works quite well for the model, and we hope that it may also be useful in future determinations of OPE parameters in QCD.Comment: 29 pages, 9 figures, LateX file. Small changes to match journal versio

A Machine Learning Approach to Predicting Single Event Upsets

A single event upset (SEU) is a critical soft error that occurs in semiconductor devices on exposure to ionising particles from space environments. SEUs cause bit flips in the memory component of semiconductors. This creates a multitude of safety hazards as stored information becomes less reliable. Currently, SEUs are only detected several hours after their occurrence. CREMER, the model presented in this paper, predicts SEUs in advance using machine learning. CREMER uses only positional data to predict SEU occurrence, making it robust, inexpensive and scalable. Upon implementation, the improved reliability of memory devices will create a digitally safer environment onboard space vehicles

Observation of Many-body Dynamical Delocalization in a Kicked Ultracold Gas

Contrary to a driven classical system that exhibits chaos phenomena and diffusive energy growth, a driven quantum system can exhibit dynamical localization that features energy saturation. However, the evolution of the dynamically localized state in the presence of many-body interactions has long remained an open question. Here we experimentally study an interacting 1D ultracold gas periodically kicked by a pulsed optical lattice, and observe the interaction-driven emergence of dynamical delocalization and many-body quantum chaos. The observed dynamics feature a sub-diffusive energy growth manifest over a broad parameter range of interaction and kick strengths, and shed light on an area where theoretical approaches are extremely challenging.Comment: 14 pages, 11 figures including supplementary material

Association of cataract and sun exposure in geographically diverse populations of India: The CASE study. First Report of the ICMR-EYE SEE Study Group.

PURPOSE: To determine the prevalence of cataract and its association with sun exposure and other environmental risk factors in three different geographically diverse populations of India. DESIGN: Population based cross sectional study during 2010-2016. PARTICIPANTS: People aged ≥ 40 years residing in randomly sampled villages were enumerated (12021) and 9735 (81%) underwent ophthalmic evaluation from plains, hilly and coastal regions (3595, 3231, 2909 respectively). METHODS: A detailed questionnaire-based interview about outdoor activity in present, past and remote past, usage of sun protective measures, exposure to smoke, and detailed ophthalmic examination including assessment of uncorrected and best corrected visual acuity, measurement of intraocular pressure, slit lamp examination, lens opacities categorization using LOCS III and posterior segment evaluation was done. Lifetime effective sun exposure was calculated using Melbourne formula and expressed as quintiles. These were supplemented with physical environmental measurements. MAIN OUTCOME MEASURES: Lifetime sun exposure hours, smoking, indoor kitchen smoke exposure and their association with cataract and subtypes. Prevalence of cataract calculated based on lens opacities or evidence of cataract surgery. RESULTS: Cataract was identified in 3231 (33.3%) participants. Prevalence of cataract in males (32.3%) and females (34.1%) was similar. Nuclear cataract was the commonest sub-type identified in 94.7% of affected eyes. Sun exposure had a significant association with cataract with odds ratio (OR) increasing from 1.6 (95% Confidence Intervals [CI]: 1.4, 1.9) in 3rd quintile, to 2.6 (CI: 2.2, 3.1) in 4th quintile and 9.4 (CI: 7.9, 11.2) in 5th quintile (p<0.0001). Cataract also showed a significant association with smoking (OR: 1.4, CI: 1.2, 1.6) and indoor kitchen smoke exposure (OR: 1.2, CI: 1.0-1.4). Nuclear cataract showed a positive association with increasing sun exposure in 3rd (β coefficient 0.5, CI:0.2-0.7), 4th (β: 0.9, CI: 0.7-1.1) and 5th (β: 2.1, CI:1.8-2.4) quintiles of sun exposure, smoking (β: 0.4, CI: 0.2-0.6) and indoor kitchen smoke exposure (β: 0.3, CI: 01-0.5) while cortical cataract showed a positive association with sun exposure only in 5th quintile (β: 2.6, CI:1.0-4.2). Posterior subcapsular cataract was not associated with any of the risk factors. CONCLUSION: Cataract is associated with increasing level of sun exposure, smoking and exposure to indoor kitchen smoke

Evidence for a Many-Body Anderson Metal-Insulator Transition using Kicked Quantum Gases

Understanding the interplay of interactions and disorder in quantum transport poses long-standing fundamental challenges for theory and experiment. Despite remarkable advances using ultracold atomic platforms combining atomic interactions with spatially disordered lattices, many-body effects on quantum transport phenomena in high-dimensional disordered systems, such as the three-dimensional (d = 3) Anderson metal-insulator transition (MIT), have largely remained unexplored. Here we utilize a momentum space lattice platform using quasi-periodically kicked ultracold atomic gases as a quantum simulator to experimentally investigate the role of many-body interactions in the d = 3 Anderson MIT. We observe interaction-driven sub-diffusive delocalization and find a divergence of the delocalization onset time as kick strength approaches the many-body phase boundary. By modifying the kick quasi-periodicity, we demonstrate interaction-driven sub-diffusion in d = 2 and d = 4. Our numerical simulations using a mean-field treatment exhibit an interaction-induced shift of the d = 3 transition boundary and many-body delocalization dynamics, that are both in qualitative agreement with experimental observations. However, there are significant quantitative deviations between experiment and mean-field theory which increase with higher interaction strengths, calling for further study of the underlying many-body physics.Comment: 15 pages, 11 figures, 2 tables, including supplementary material

Combating Acid Violence in Bangladesh, India and Cambodia

This Report is the first comprehensive, comparative study of acid violence that examines the underlying causes, its consequences, and the multiple barriers to justice for its victims. Acid attacks, like other forms of violence against women, are not random or natural phenomena. Rather, they are social phenomena deeply embedded in a gender order that has historically privileged patriarchal control over women and justified the use of violence to “keep women in their places.” Through an in-depth study of three countries, the authors of the Report argue that the due diligence standard can be a powerful tool for state and non-state actors to prevent and adequately respond to acid violence with the aim of combating it. In this respect, they identify key ways in which acid violence can be addressed by governments and corporations