Theoretical High Energy Physics Research Articles

6th Asian Physics Symposium

Preface: The 6th Asian Physics Symposium 2015 (APS 2015)The 6th Asian Physics Symposium 2015 (APS 2015) is organized by the Physics Department, Faculty of Mathematics and Natural Sciences, Bandung Institute of Technology, in collaboration with HFI (Indonesian Physical Society), PAPSI (Physics and Applied Physics Society of Indonesia), HANI (Indonesian Nuclear Scientist Society), HRMI (Indonesian Material Research Society), HAGI (Indonesian Geophysicist Society) - West Java Chapter, and HFMBI (Indonesian Medical Physicist and Biophysicist Society).APS 2015 is aimed at providing a forum of scientific communication and interaction among distinguished scientists working in physics and its related fields. In this scientific event the latest research will be presented, and state-of-the-art developments in the field discussed, to help to guide our future research directions. It is also designed to offer the opportunity for young Indonesian scientists and students to make direct contacts with well-known scientists abroad and thereby foster the existing research collaborations and extend international research networking for the future.The scope of research presented and discussed in this symposium covers theoretical high energy physics, materials sciences and technology, biophysics and medical physics, nuclear science and engineering, earth and planetary sciences, computational physics, instrumentation and measurement, physics education, and interdisciplinary physics.The program of APS 2016 features 6 invited talks and 208 contributed oral presentations, which come from 7 different countries: Japan, South Korea, Singapore, Malaysia, Iraq, Ethiopia, and Indonesia. All papers have been reviewed after they are presented in this event. Selected papers are published in this Institute of Physics (IoP) Conference Series.Finally, I would like to express my sincere appreciation to all of authors for their valuable contributions and also to the members of the committee for their excellent work in preparing and finalizing this document.

Surveys in Theoretical High Energy Physics 2

Surveys in Theoretical High Energy Physics 2

Bruno Touschek: From Betatrons to Electron–Positron Colliders

Bruno Touschek’s life as a physicist spanned the period from World War II to the 1970s. He was a key figure in the developments of electron–positron colliders and storage rings, and made important contributions to theoretical high energy physics. Storage rings, initially developed for high energy physics, are being widely used in many countries as synchrotron radiation sources and are a tool for research in physics, chemistry, biology, environmental sciences and cultural heritage studies. We describe Touschek’s life in Austria, where he was born, in Germany, where he participated in the construction of a betatron during WWII, and in Italy, where he proposed and led to completion the first electron–positron storage ring in 1960, in Frascati. We highlight how his central European culture influenced his lifestyle and work, and his main contributions to physics, such as the discovery of the Touschek effect and beam instabilities in the larger storage ring ADONE.

Aztec castles and the dP3 quiver

Bipartite, periodic, planar graphs known as brane tilings can be associated to a large class of quivers. This paper will explore new algebraic properties of the well-studied del Pezzo 3 (dP3) quiver and geometric properties of its corresponding brane tiling. In particular, a factorization formula for the cluster variables arising from a large class of mutation sequences (called τ-mutation sequences) is proven; this factorization also gives a recursion on the cluster variables produced by such sequences. We can realize these sequences as walks in a triangular lattice using a correspondence between the generators of the affine symmetric group and the mutations which generate τ-mutation sequences. Using this bijection, we obtain explicit formulae for the cluster that corresponds to a specific alcove in the lattice. With this lattice visualization in mind, we then express each cluster variable produced in a τ-mutation sequence as the sum of weighted perfect matchings of a new family of subgraphs of the dP3 brane tiling, which we call Aztec castles. Our main result generalizes previous work on a certain mutation sequence on the dP3 quiver in Zhang (2012 Cluster Variables and Perfect Matchings of Subgraphs of the dP3 Lattice http://www.math.umn.edu/~/REU/Zhang2012.pdf), and forms part of the emerging story in combinatorics and theoretical high energy physics relating cluster variables to subgraphs of the associated brane tiling.This article is part of a special issue of Journal of Physics A: Mathematical and Theoretical devoted to ‘Cluster algebras in mathematical physics’.

Vector Bundles and Gromov–Hausdorff Distance

AbstractWe show how to make precise the vague idea that for compact metric spaces that are close together for Gromov–Hausdorff distance, suitable vector bundles on one metric space will have counterpart vector bundles on the other. Our approach employs the Lipschitz constants of projection-valued functions that determine vector bundles. We develop some computational techniques, and we illustrate our ideas with simple specific examples involving vector bundles on the circle, the two-torus, the two-sphere, and finite metric spaces. Our topic is motivated by statements concerning “monopole bundles” over matrix algebras in the literature of theoretical high-energy physics.

Positional effects on citation and readership in arXiv

AbstractarXiv.org mediates contact with the literature for entire scholarly communities, providing both archival access and daily email and web announcements of new materials. We confirm and extend a surprising correlation between article position in these initial announcements and later citation impact, due primarily to intentional “self‐promotion” by authors. There is, however, also a pure “visibility” effect: the subset of articles accidentally in early positions fared measurably better in the long‐term citation record. Articles in astrophysics (astro‐ph) and two large subcommunities of theoretical high energy physics (hep‐th and hep‐ph) announced in position 1, for example, respectively received median numbers of citations 83%, 50%, and 100% higher than those lower down, while the subsets there accidentally had 44%, 38%, and 71% visibility boosts. We also consider the positional effects on early readership. The median numbers of early full text downloads for astro‐ph, hep‐th, and hep‐ph articles announced in position 1 were 82%, 61%, and 58% higher than for lower positions, respectively, and those there accidentally had medians visibility‐boosted by 53%, 44%, and 46%. Finally, we correlate a variety of readership features with long‐term citations, using machine learning methods, and conclude with some observations on impact metrics and the dangers of recommender mechanisms.

Casimir effect with non-local boundary conditions

Non-local boundary conditions have been considered in theoretical high-energy physics with emphasis on one-loop quantum cosmology, one-loop conformal anomalies, Bose-Einstein condensation models and spectral branes. In the present paper, for the first time in the literature, the Wightman function, the vacuum expectation values of the field square and the energy-momentum tensor are investigated for a massive scalar field satisfying non-local boundary conditions on a single plate and on two parallel plates. The vacuum forces acting on the plates are evaluated. Interestingly, suitable choices of the kernel in the non-local boundary conditions lead to forces acting on the plates that can be repulsive for intermediate distances. It is then possible to obtain a locally stable equilibrium value of the interplate distance stabilized by the vacuum forces.

The apeNEXT project

Numerical simulations in theoretical high-energy physics (Lattice QCD) require huge computing resources. Several generations of massively parallel computers optimised for these applications have been developed within the APE (array processor experiment) project. Large prototype systems of the latest generation, apeNEXT, are currently being assembled and tested. This contribution explains how the apeNEXT architecture is optimised for Lattice QCD, provides an overview of the hardware and software of apeNEXT, and describes its new features, like the SPMD programming model and the C compiler.

Nichtkommutative Geometrie

Noncommutative geometry applies ideas from geometry to mathematical structures determined by noncommuting variables. Within mathematics, it is a highly interdisciplinary subject drawing ideas and methods from many areas of mathematics and physics. Natural questions involving noncommuting variables arise in abundance in many parts of mathematics and quantum mathematical physics. On the basis of ideas and methods from algebraic topology and Riemannian geometry, as well as from the theory of operator algebras and from homological algebra, an extensive machinery has been developed which permits the formulation and investigation of the geometric properties of noncommutative structures. Areas of intense research in recent years are related to topics such as index theory, K-theory, cyclic homology, quantum groups and Hopf algebras, the Novikov- and Baum-Connes conjectures as well as to the study of specific questions in other fields such as number theory, modular forms, topological dynamical systems, renormalization theory, theoretical high-energy physics and string theory. The meeting was attended by 45 participants, including a fair number of young mathematicians but also many of the leading experts in the field. The exchange of ideas was very lively and quite a few significant new results were presented in the talks, which covered many of the aspects of noncommutatve geometry mentioned above.

Theoretical high energy physics: formal theory

This article summarizes the research carried out in the Theory Division of CERN during the last 25 years, and in particular the more formal developments in High Energy Physics.

EqRank

A new method of hierarchical clustering of graph vertexes is suggested. The method is motivated by applications to searches of scientific papers in electronic libraries (in these applications, the clustered graph is the citation graph). In the method, the graph partition is determined with an equivalence relation. Iterative application of the partitioning yields a hierarchical clustering of graph vertexes. The method is applied to the citation graph of hep-th, which is an electronic archive of papers on theoretical high energy physics at http://xxx.lanl.gov. The outcome is a two-level classification scheme for the subject field presented in hep-th, and indexing of the papers from hep-th in this scheme. A number of tests show that the classification obtained is adequate.

Exploiting relational structure to understand publication patterns in high-energy physics

We analyze publication patterns in theoretical high-energy physics using a relational learning approach. We focus on four related areas: understanding and identifying patterns of citations, examining publication patterns at the author level, predicting whether a paper will be accepted by specific journals, and identifying research communities from the citation patterns and paper text. Each of these analyses contributes to an overall understanding of theoretical high-energy physics.

Q & A

Q & A

Anforderungen an eine physikalische Fundamentaltheorie

Requirements for a Fundamental Physical Theory. The search for a so-called ‘Theory of Everything’ which should lead to the unification of all fundamental forces is seen, at present, as a matter of priority within theoretical high-energy physics. Some physicist identify this Theory of Everything today with aspecific type of superstring theory or its intended conceptual continuation, called M-Theory. The objective of this article is the discussion of the requirements a fundamental physical theory has to comply with. This question can only be clarified if one takes into account that the claim that a physical theory is all-encompassing takes forgranted some tacit prerequisites which concern the conceptual and epistemological foundations of science and, not least, the question for the realizability of its reductionistic unity.

Civic Engagement, Shared Governance, and Community Colleges

of us who have spent our professional lives in community colleges tend to think of our institutions as occupying a unique place in the American higher education landscape. These colleges are sometimes labeled democracy's colleges, and a strong argument can be made that, at their best, they embody the best values of American pragmatism. Many of our faculty members tend to be pragmatists, unfettered by dogma or tradition and concerned mainly about providing their students with the practical knowledge and material expertise that make for better lives and livelihoods. Much community college teaching is shaped by techniques that AAUP founder John Dewey, a philosopher of education, would recognize, such as active and collaborative learning and clinical and intern ex eriences that are immediately useful in a life or in a career. Coming of age at a time when the country's great external threats were communism and national socialism, belief systems that champion the goals of the state at the expense of those of the individual, the American community college promotes the ascendancy of the individual. Programs are often strongly workplace oriented and supportive of upward socioeconomic mobility. Community college faculties include many adjuncts whose main employment is not with the college, but in a profession, business, or industry to which students aspire. Many of the students are older than traditional-age college students and Carol Lucey is president of Western Nevada Community College. She served formerly as an academic administrator at Alfred State College of Technology of the State University of New York and at Jamestown Community College. She has a Ph.D. in theoretical high-energy physics. This article is based on an address delivered at the

The information exchange groups experiment

From 1961 through 1966, the National Institutes of Health operated a facility for the rapid distribution of unevaluated preprints to research workers—an obvious precursor of many of the activities taking place today on the Internet. The experiment began with 32 researchers in a single Information Exchange Group (IEG). It grew to seven IEGs with total membership over 3600. During 1966, more than 1.5 million copies of preprints were produced and distributed. Considerable enthusiasm was generated among researchers who valued the speed of dissemination. Critics charged that the quality of the average preprint deteriorated with increased participation. They also noted that the unplanned burdens on production had often delayed receipt of the preprints until after they had appeared as formally reviewed journal papers. During this period, the Atomic Energy Commission had mounted a similar experimental program of “written informal communications” that was limited to theoretical high energy physics.

Loose ends of the theory of everything

In August 1984 Michael Green of Queen Mary College, London, and John Schwarz of the California Institute of Technology, wrote a paper which sent a wave of excitement through the theoretical physics community. Indeed, submissions to the main journals in theoretical high-energy physics fell dramatically in the period following publication as many physicists dropped whatever they were working on at the time and frantically learned about the subject of the paper: string theory.

Scientometric indicators for a specialty in theoretical high-energy physics: Monte Carlo methods in lattice field theory

Publication and citation data are used to analyse the dynamics of the theoretical highenergy physics specialty “Monte Carlo methods in lattice field theory”. The present study is based on a comprehensive bibliography of the given subject area for the six-year period 1979–1984 and the 1979–1985 citations to these papers. The application of a recently introduced set of scientometric indicators provides clues to undertanding the growth of a new research specialty from a core body of seminal literature.

Authors

Authors

Use of New Computer Technologies in Elementary Particle Physics

Problems requiring the use of computers in experimental and theoretical high energy physics come from the complexity and the amount of data which must be analyzed in large center of mass energy experiments and from the development of lattice gauge solutions to QCD. The problems of triggering and event processing via new processor technology and high level language (FORTRAN) are reviewed. FORTRAN and parallel computer technology used in lattice gauge calculations are reviewed. (AIP)