The Black Dream of Gerrit Smith, New York Abolitionist

This article tells the story of Gerrit Smith, a New York abolitionist who had been loosely linked to the raid on Haper\u27s Ferry by John Brown. Shortly after the insurrection Smith was committed to an insane asylum by his family, and the scandal faded after John Brown\u27s execution. Through their research in the Syracuse University Special Collections, the authors have uncovered much evidence affirming the financial link between Smith and John Brown. The authors also determined that the mental state of Smith seemed rather genuine, and he might have suffered from bipolar disorder. The fallout of the Smith scandal received much attention in the partisan newspapers of the time

The two-loop axial anomaly in N = 1 supersymmetric Yang-Mills theory

We calculate the two loop correction to the divergence of the axial current inN = 1 supersymmetric Yang-Mills theory. We find that, if we use supersymmetric dimensional regularization, the anomaly is proportional to the [beta]-function, a result we interpret as evidence that the supermultiplet nature of the trace, axial and supersymmetry anomalies persists at the two- loop level. Thus it appears that the Adler-Bardeen theorem is not valid in supersymmetric theories.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/24036/1/0000285.pd

Dimensional regularization and the two-loop axial anomaly in abelian, non-abelian and supersymmetric gauge theories

The two-loop corrections to the axial anomaly are calculated for a non-abelian gauge theory with fermions using both conventional and supersymmetric dimensional regularization. In both cases we find results consistent with the Adler-Bardeen theorem if we use non-anticommuting [gamma]5 of 't Hooft and Veltman. Expectations (based on the supermultiplet structure of the anomalies) that there exists in N = 1 supersymmetric Yang-Mills theory an axial current J5 such that are discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/23832/1/0000071.pd

Observations on horizontal symmetries and flavor changing neutral currents

We present a detailed study of the possibility of having a horizontal gauge symmetry, in addition to SU(3)c x SU(2)L x U(1). Grand unification is not used as a constraint. We concentrate on the horizontal group SU(3)H. There are two main results. (i) The horizontal symmetry might break on two mass scales, one heavy and the other of order mz or a few mz. The KL-KS mass difference and other rare kaon and muon transitions are protected by a residual symmetry, but other flavor changing processes not involving the lightest fermion of each charge can be orders of magnitude larger, e.g. and some others are forbidden). Some sectors should have relatively large flavor changing neutral currents. (ii) There is not enough new physics in the approach to explain fermion masses, but the structure of the model suggests that the lighter masses and the KM quark mixing angles might be generated radiatively. Unfortunately, careful analysis shows that the same symmetry that protects the KL-KS mass difference requires that the Cabibbo angle be identically zero to all orders. This suggests that it may be extremely difficult to make a realistic fundamental or effective SU(3) horizontal symmetry. While the model fails to generate the CKM angles, it is consistent with all low energy data and suggests a number of interesting reactions that might occur.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/24006/4/1-s2.0-0550321382905430-main.pd

Jarosite in Gale Crater, Mars: The Importance of Temporal and Spatial Variability and Implications for Habitiability

The Curiosity rover has recently found evidence for small amounts of jarosite, a ferric sulfate, in the Pahrump Hills region at the base of Aeolis Mons (Mount Sharp), Gale crater. While jarosite has been described previously at other locations on Mars, including several sites at Meridiani Planum (explored by the Opportunity rover; and Mawrth Vallis (by remote MRO-CRISM observations; this is the first identification in Gale. Jarosite is interpreted to be a mineral indicator of acidic conditions (pH less than 4; on Earth, it is most commonly found in acid rock-drainage or acid sulfate soil environments. However, jarosite has also been described from a number of terrestrial environments where widespread acidic conditions are not prevalent. As a case study, we describe here an occurrence of sedimentary pyrite nodules that have been variably oxidized in situ to gypsum, schwertmannite, K-/Na-jarosite and iron oxides in a polar desert environment on Devon Island, Nunavut, Canada. Remarkably, these nodules occur in loosely consolidated carbonate sediments, which would have required a higher pH environment at their time of formation and deposition. Thus, acidic conditions may only exist at a small (sub-cm) scale or in a restricted temporal window in an otherwise well-buffered environment. On Devon Island, the jarosite occurs in the most oxidized nodules and is never associated directly with pyrite. Schwertmannite, a metastable iron oxyhydroxysulfate that can form at pH higher than that required for jarosite, occurs in association with partially oxidized pyrite. The paragenetic sequence observed here suggests initial formation of schwertmannite and late-stage precipitation of jarosite in restricted micro-environments, possibly forming via transformation of an amorphous schwertmannite-like phase. While the carbonate environment on Devon Island differs significantly from that of Gale crater, i.e., where we find predominantly basaltic sedimentary rocks, this terrestrial analog provides insight into the significance of jarosite with respect to habitability. For example, the variable abundance of jarosite on Mars and possibly in Gale crater points to potentially localized conditions favorable for jarosite formation. Interestingly, small amounts of sulfide minerals have also been detected by Curiosity at Yellowknife Bay; oxidation of sulfide minerals at Pahrump could explain the presence of small amounts of jarosite. The iron-rich rocks at Pahrump may also represent relatively altered basaltic sediments, or they could be sediments that were altered further by a fluid with a distinct, possibly more acidic, composition. In addition, the abundance of iron-rich amorphous material in Gale rocks allows for the possibility that pre-cursor, iron-bearing phases transform to jarosite post-depositionally. Thus, the occurrence of jarosite at Pahrump could reflect changing paleoenvironmental conditions, though continuing study of its context and textural relationships should provide a fuller understanding of the significance of this mineral to past fluid compositions and past habitability at Gale crater

Fluids, evaporation and precipitates at Gale Crater

The Mars Science Laboratory (MSL) mission landed in Gale Crater, Mars, on 6th August 2012, and has explored the Yellowknife Bay area. The detailed mineralogical and sedimentological studies provide a unique opportunity to characterise the secondary fluids associated with this habitable environment

Muon anomalous magnetic moment in string inspired extended family models

We propose a standard model minimal extension with two lepton weak SU(2) doublets and a scalar singlet to explain the deviation of the measured anomalous magnetic moment of the muon from the standard model expectation. This scheme can be naturally motivated in string inspired models such as E_6 and AdS/CFT.Comment: 9 pages, RevTeX, 2 figures, version to be published in Phys. Rev.