17179805
Twisted baryon number in N = 2 supersymmetric QCD
Abstract We show that the baryon number of N = 2 supersymmetric QCD can be twisted in order to couple the topological field theory of non-abelian monopoles to Spin c -structures. To motivate the construction, we also consider some aspects of the twisting procedure as a gauging of global currents in two and four dimensions, in particular the role played by anomalies.
59152872
AN INTRODUCTION TO DONALDSON-WITTEN THEORY
In these lecture notes a pedagogical introduction to Donaldson-Witten theory is given. After a survey of four-manifold topology, some basic aspects of Donaldson theory are presented in detail. The physical approach to Donaldson theory is based on topological quantum field theory (TQFT), and some general properties of TQFT’s are explained. Finally, the TQFT underlying Donaldson theory (which is usually called Donaldson-Witten theory) is constructed in detail by twisting N = 2 super Yang-Mills theory. ∗ marcos@lorentz.harvard.edu
17509654
Twisted N=2 Supersymmetry with Central Charge and Equivariant Cohomology

Abstract: We present an equivariant extension of the Thom form with respect to a vector field action, in the framework of the Mathai-Quillen formalism. The associated Topological Quantum Field Theories correspond to twisted N=2 supersymmetric theories with a central charge. We analyze in detail two different cases: topological sigma models and non-abelian monopoles on four-manifolds.

53394947
Resumming the string perturbation series
A bstractWe use the AdS/CFT correspondence to study the resummation of a perturbative genus expansion appearing in the type II superstring dual of ABJM theory. Although the series is Borel summable, its Borel resummation does not agree with the exact non-perturbative answer due to the presence of complex instantons. The same type of behavior appears in the WKB quantization of the quartic oscillator in Quantum Mechanics, which we analyze in detail as a toy model for the string perturbation series. We conclude that, in these examples, Borel summability is not enough for extracting non-perturbative information, due to non-perturbative effects associated to complex instantons. We also analyze the resummation of the genus expansion for topological string theory on local ℙ1×ℙ1$$ {\mathrm{\mathbb{P}}}^1\times {\mathrm{\mathbb{P}}}^1 $$, which is closely related to ABJM theory. In this case, the non-perturbative answer involves membrane instantons computed by the refined topological string, which are crucial to produce a well-defined result. We give evidence that the Borel resummation of the perturbative series requires such a non-perturbative sector.
119202302
A one-loop test of quantum supergravity
The partition function on the three-sphere of ABJM theory and its generalizations has, at large N, a universal, subleading logarithmic term. Inspired by the success of one-loop quantum gravity for computing the logarithmic corrections to black hole entropy, we try to reproduce this universal term by a one-loop calculation in Euclidean 11-dimensional supergravity on AdS4 × X7. We find perfect agreement between the results of ABJM theory and the 11-dimensional supergravity.
14678443
Towards vacuum superstring field theory: The supersliver
We extend some aspects of vacuum string field theory to superstring field theory in Berkovits’ formulation, and we study the star algebra in the fermionic matter sector. After clarifying the structure of the interaction vertex in the operator formalism of Gross and Jevicki, we provide an algebraic construction of the supersliver state in terms of infinite–dimensional matrices. This state is an idempotent string field and solves the matter part of the equation of motion of superstring field theory with a pure ghost BRST operator. We determine the spectrum of eigenvalues and eigenvectors of the infinite–dimensional matrices of Neumann coefficients in the fermionic matter sector. We then analyze coherent states based on the supersliver and use them in order to construct higher–rank projector solutions, as well as to construct closed subalgebras of the star algebra in the fermionic matter sector. Finally, we show that the geometric supersliver is a solution to the superstring field theory equations of motion,...
35493425
A magnetically shielded room with ultra low residual field and gradient.
A versatile and portable magnetically shielded room with a field of (700 ± 200) pT within a central volume of 1 m × 1 m × 1 m and a field gradient less than 300 pT/m, achieved without any external field stabilization or compensation, is described. This performance represents more than a hundredfold improvement of the state of the art for a two-layer magnetic shield and provides an environment suitable for a next generation of precision experiments in fundamental physics at low energies; in particular, searches for electric dipole moments of fundamental systems and tests of Lorentz-invariance based on spin-precession experiments. Studies of the residual fields and their sources enable improved design of future ultra-low gradient environments and experimental apparatus. This has implications for developments of magnetometry beyond the femto-Tesla scale in, for example, biomagnetism, geosciences, and security applications and in general low-field nuclear magnetic resonance (NMR) measurements.
24822628
Results from a search for light-mass dark matter with a p-type point contact germanium detector.
We report on several features in the energy spectrum from an ultralow-noise germanium detector operated deep underground. By implementing a new technique able to reject surface events, a number of cosmogenic peaks can be observed for the first time. We discuss an irreducible excess of bulklike events below 3 keV in ionization energy. These could be caused by unknown backgrounds, but also dark matter interactions consistent with DAMA/LIBRA. It is not yet possible to determine their origin. Improved constraints are placed on a cosmological origin for the DAMA/LIBRA effect.
118323618
Search for An Annual Modulation in Three Years of CoGeNT Dark Matter Detector Data
Weakly Interacting Massive Particles (WIMPs) are well-established dark matter candidates. WIMP interactions with sensitive detectors are expected to display a characteristic annual modulation in rate. We release a dataset spanning 3.4 years of operation from a low-background germanium detector, designed to search for this signature. A previously reported modulation persists, concentrated in a region of the energy spectrum populated by an exponential excess of unknown origin. Its phase and period agree with phenomenological expectations, but its amplitude is a factor �4-7 larger than predicted for a standard WIMP galactic halo. We consider the possibility of a non-Maxwellian local halo velocity distribution as a plausible explanation, able to help reconcile recently reported WIMP search anomalies.
118586433
The MGDO software library for data analysis in Ge neutrinoless double-beta decay experiments
The Gerda and Majorana experiments will search for neutrinoless double-beta decay of 76Ge using isotopically enriched high-purity germanium detectors. Although the experiments differ in conceptual design, they share many aspects in common, and in particular will employ similar data analysis techniques. The collaborations are jointly developing a C++ software library, MGDO, which contains a set of data objects and interfaces to encapsulate, store and manage physical quantities of interest, such as waveforms and high-purity germanium detector geometries. These data objects define a common format for persistent data, whether it is generated by Monte Carlo simulations or an experimental apparatus, to reduce code duplication and to ease the exchange of information between detector systems. MGDO also includes general-purpose analysis tools that can be used for the processing of measured or simulated digital signals. The MGDO design is based on the Object-Oriented programming paradigm and is very flexible, allowing for easy extension and customization of the components. The tools provided by the MGDO libraries are used by both Gerda and Majorana.
9512698
Astroparticle physics with a customized low-background Broad Energy Germanium detector
We have found that modified Broad Energy Ge detectors produced by CANBERRA have several promising features, including large mass, low electronic noise, and excellent pulse-shape analysis capabilities. Modified BEGe detectors obtain these capabilities due to their low-capacitance “point-contact” electrode configuration. Modified BEGes are also the only point-contact design fabricated on a commercial basis. We have deployed a modified BEGe, named “MALBEK” in a low-background cryostat and shield in the Kimballton Underground Research Facility, located in Ripplemead, Virginia at a depth of 1450 meters water equivalent. We will focus on detector characteristics, data acquisition, and analysis techniques used with MALBEK.