We present a complete and independent set of dimension-7 operators in the low energy effective field theory (LEFT) where the dynamical degrees of freedom are the standard model five quarks and all of the neutral and charged leptons. All operators are non-Hermitian and are classified according to their baryon (∆B) and lepton (∆L) numbers violated. Including Hermitian-conjugated operators, there are in total 3168, 750, 588, 712 operators with (∆B, ∆L) = (0, 0), (0, ±2), (±1, ∓1), (±1, ±1) respectively. We perform the tree-level matching with the standard model effective field theory (SMEFT) up to dimension-7 (dim-7) operators in both LEFT and SMEFT. As a phenomenological application we study the effective neutrino-photon interactions due to dim-7 lepton number violating operators that are induced and much enhanced at one loop from dim-6 operators that in turn are matched from dim-7 SMEFT operators. We compare various neutrino-photon scattering cross sections with their counterparts in the standard model and highlight the new features. Finally, we illustrate how these effective interactions could arise from ultraviolet completion.

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publisher: Elsevier articletitle: Tin ingots from a probable Bronze Age shipwreck off the coast of Salcombe, Devon: Composition and microstructure journaltitle: Journal of Archaeological Science articlelink: http://dx.doi.org/10.1016/j.jas.2016.01.018 content_type: article copyright: Copyright © 2016 Elsevier Ltd. All rights reserved

Chloride-contaminated archaeological iron is unstable and problematic to store and display within museum collections. Reducing its chloride ion content using aqueous desalination followed by storage in controlled relative humidity offers one treatment option. This study reports a quantitative assessment of chloride extraction by aqueous deoxygenated alkaline desalination solutions from 120 individual archaeological iron nails. The three treatment methods comprised alkaline sulphite solution (0.1 M NaOH/0.05 M Na 2 SO 3 ) at room temperature and at 60°C and sodium hydroxide solution (0.1 M) deoxygenated using a nitrogen gas positive pressure system at room temperature. Chloride extraction was monitored using a specific ion meter. The nails were digested after treatment to measure their residual chloride content. A wide range of extraction patterns emerged, with the majority of individual treatments extracting 60-99% of the chloride present. Residual chloride levels for 87% of the objects fell below 1000 ppm and 42% were below 200 ppm. Although no treatment extracted 100% of the chloride in the object, alkaline desalination produced very significant reductions in chloride content. The impact of this on future corrosion of the objects is discussed. This quantitative and statistically viable assessment of deoxygenated desalination treatments provides evidence to support their use in conservation practice, which will impact on procedures for the preservation and management of archaeological heritage.

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