Occam’s Reader: The First Library-Developed Ebook Interlibrary Loan System

An ebook interlibrary loan system called “Occam’s Reader” was developed through collaboration among libraries of the Greater Western Library Alliance. The first of its kind, Occam’s Reader has proved to be a great success due in no small measure to thorough planning, testing, implementation and development through 2012 to 2104. A new version of the system, Occam’s Reader 2.0 is planned for later in 2015. As libraries band together to accomplish a collaborative goal, there really is nothing that can hold them bac

Evidence for a Nonplanar Amplituhedron

The scattering amplitudes of planar N = 4 super-Yang-Mills exhibit a number of remarkable analytic structures, including dual conformal symmetry and logarithmic singularities of integrands. The amplituhedron is a geometric construction of the integrand that incorporates these structures. This geometric construction further implies the amplitude is fully specified by constraining it to vanish on spurious residues. By writing the amplitude in a dlog basis, we provide nontrivial evidence that these analytic properties and “zero conditions” carry over into the nonplanar sector. This suggests that the concept of the amplituhedron can be extended to the nonplanar sector of N = 4 super-Yang-Mills theory

Book Raider: Connecting Patrons of Texas Tech University Libraries with Resources Anytime, Anywhere

Given the mandate of Texas Tech University to expand its research mission, Texas Tech University Libraries developed new library services through the Book Raider project that allows patrons to use mobile apps to check library holdings and to order materials through interlibrary loan. Library literature shows an increasing desire among patrons to use this type of technology and suggests an open door exists for librarians to create these new modes of access and delivery. Book Raider, a collaborative project of several departments of Texas Tech University Libraries, involved the development of various types of apps across several technology platforms, a project that grows in popularity among students and faculty of the University

CHY representations for gauge theory and gravity amplitudes with up to three massive particles

We show that a wide class of tree-level scattering amplitudes involving scalars, gauge bosons, and gravitons, up to three of which may be massive, can be expressed in terms of a Cachazo-He-Yuan representation as a sum over solutions of the scattering equations. These amplitudes, when expressed in terms of the appropriate kinematic invariants, are independent of the masses and therefore identical to the corresponding massless amplitudes.Comment: 20 pages, 1 figure; v2: minor typos corrected, published versio

Developing a Novel Queen Honey Bee Treatment to Support Reproduction

Honey bees (Apis mellifera) are social insects that rely on cooperative behaviors regulated through pheromone signaling between colony members as well as hormone levels in individuals to meet the needs of the colony as a whole. Juvenile hormone (JH) is a ubiquitous insect hormone known to regulate aspects of development and adult reproduction. In honey bees, the role of JH in reproduction is not well-explored, though JH levels are correlated with many social behaviors and developmental pathways. A recent study demonstrated that queen exposure to the JH mimic, pyriproxyfen, leads to higher egg hatching rates, and that the exposed queens’ offspring perform more queen supportive behaviors than the offspring of control queens. The goal of this research is to further investigate the effects of queen exposure to pyriproxyfen as a potential queen treatment, using laboratory and field-based assays. Primarily, this work focuses on pyriproxyfen-treated queens by investigating the competency of their offspring as nurse bees, and the health and longevity of their hives. In the laboratory, this research found that pyriproxyfen-treated queens lay more eggs than those in the control group, yet offspring from control queens were longer lived and reared more brood than those from treated queens. In the field, colonies with pyriproxyfen-treated queens had higher worker bee populations late in the season, although the amount of brood remained the same between the colonies in treatment and control groups. These results are discussed along with the potential implications for colony health and reproduction

Four Generations: SUSY and SUSY Breaking

We revisit four generations within the context of supersymmetry. We compute the perturbativity limits for the fourth generation Yukawa couplings and show that if the masses of the fourth generation lie within reasonable limits of their present experimental lower bounds, it is possible to have perturbativity only up to scales around 1000 TeV. Such low scales are ideally suited to incorporate gauge mediated supersymmetry breaking, where the mediation scale can be as low as 10-20 TeV. The minimal messenger model, however, is highly constrained. While lack of electroweak symmetry breaking rules out a large part of the parameter space, a small region exists, where the fourth generation stau is tachyonic. General gauge mediation with its broader set of boundary conditions is better suited to accommodate the fourth generation.Comment: 27 pages, 5 figure

Theory and phenomenology of two-Higgs-doublet models

We discuss theoretical and phenomenological aspects of two-Higgs-doublet extensions of the Standard Model. In general, these extensions have scalar mediated flavour changing neutral currents which are strongly constrained by experiment. Various strategies are discussed to control these flavour changing scalar currents and their phenomenological consequences are analysed. In particular, scenarios with natural flavour conservation are investigated, including the so-called type I and type II models as well as lepton-specific and inert models. Type III models are then discussed, where scalar flavour changing neutral currents are present at tree level, but are suppressed by either specific ansatze for the Yukawa couplings or by the introduction of family symmetries. We also consider the phenomenology of charged scalars in these models. Next we turn to the role of symmetries in the scalar sector. We discuss the six symmetry-constrained scalar potentials and their extension into the fermion sector. The vacuum structure of the scalar potential is analysed, including a study of the vacuum stability conditions on the potential and its renormalization-group improvement. The stability of the tree level minimum of the scalar potential in connection with electric charge conservation and its behaviour under CP is analysed. The question of CP violation is addressed in detail, including the cases of explicit CP violation and spontaneous CP violation. We present a detailed study of weak basis invariants which are odd under CP. A careful study of spontaneous CP violation is presented, including an analysis of the conditions which have to be satisfied in order for a vacuum to violate CP. We present minimal models of CP violation where the vacuum phase is sufficient to generate a complex CKM matrix, which is at present a requirement for any realistic model of spontaneous CP violation.Comment: v3: 180 pages, 506 references, new chapter 7 with recent LHC results; referee comments taken into account; submitted to Physics Report

Physics searches at the LHC

With the LHC up and running, the focus of experimental and theoretical high energy physics will soon turn to an interpretation of LHC data in terms of the physics of electroweak symmetry breaking and the TeV scale. We present here a broad review of models for new TeV-scale physics and their LHC signatures. In addition, we discuss possible new physics signatures and describe how they can be linked to specific models of physics beyond the Standard Model. Finally, we illustrate how the LHC era could culminate in a detailed understanding of the underlying principles of TeV-scale physics.Comment: 184 pages, 55 figures, 14 tables, hundreds of references; scientific feedback is welcome and encouraged. v2: text, references and Overview Table added; feedback still welcom