Supergravity and the quest for a unified theory

A recollection of some theoretical developments that preceded and followed the first formulation of supergravity theory is presented. Special emphasis is placed on the impact of supergravity on the search for a unified theory of fundamental interactions.Comment: 15 pages, late

SIGNALS FOR MINIMAL SUPERGRAVITY AT THE CERN LARGE HADRON COLLIDER: MULTI-JET PLUS MISSING ENERGY CHANNEL,

We use ISAJET to perform a detailed study of the missing transverse energy \eslt plus multi-jet signal expected from superparticle production at the CERN LHC. Our analysis is performed within the framework of the minimal supergravity model with gauge coupling unification and radiative electroweak symmetry breaking. We delineate the region of parameter space where the \eslt supersymmetry signal should be observable at the LHC and compare it to the regions explorable via searches for sleptons and for chargino/neutralino production. We confirm that, given a data sample of 10~\fb^{-1}, $m_{\tg}\sim 1300$ GeV can be explored if m_{\tq}\gg m_{\tg}, while $m_{\tg}\sim 2000$ GeV can be probed if m_{\tq}\simeq m_{\tg}. We further examine what information can be gleaned from scrutinizing this event sample. For instance, the multi-jet multiplicity yields information on whether squark production makes a significant contribution to the observed \eslt sample. Furthermore, reconstructing hemispheric masses may yield a measure of $m_{\tg}$ to $\sim 15-25\%$. Finally, for favourable ranges of parameters, by reconstructing masses of tagged $b\bar{b}$ jet pairs, it may be possible to detect Higgs bosons produced via sparticle cascade decay chains.Comment: 22 pages (REVTEX); a PS text file (etmiss.ps) and 12 figures (etlhc.uu or etlhc.ps) can be obtained via anonymous ftp at ftp://hep.fsu.edu/anonymous.bae

Asymptotic Freedom: From Paradox to Paradigm

Asymptotic freedom was developed as a response to two paradoxes: the weirdness of quarks, and in particular their failure to radiate copiously when struck; and the coexistence of special relativity and quantum theory, despite the apparent singularity of quantum field theory. It resolved these paradoxes, and catalyzed the development of several modern paradigms: the hard reality of quarks and gluons, the origin of mass from energy, the simplicity of the early universe, and the power of symmetry as a guide to physical law.Comment: 26 pages, 10 figures. Lecture on receipt of the 2004 Nobel Prize. v2: typo (in Ohm's law) correcte

The (Non) Impact of UN Sanctions on North Korea

This study finds that North Korea's nuclear test and the imposition of UN Security Council sanctions have had no perceptible effect on North Korea's trade with its two largest partners, China and South Korea. Before North Korea conducted an underground nuclear test, it was widely believed that such an event would have cataclysmic diplomatic ramifications. However, beginning with visual inspection of data and ending with time-series models, no evidence is found to support the notion that these events have had any effect on North Korea's trade with its two principal partners. In retrospect, North Korea may have calculated quite correctly that the direct penalties for establishing itself as a nuclear power would be modest (or, alternatively, put such a high value on demonstrating its nuclear capability that it outweighed the downside risks, however large). If sanctions are to deter behavior in the future, they will have to be much more enthusiastically implemented.Sanctions, North Korea, Nuclear, United Nations, Trade equations

Test of the German Resilience

From its early post-war catch-up phase, Germany’s formidable export engine has been its consistent driver of growth. But Germany has almost equally consistently run current account surpluses. Exports have powered the dynamic phases and helped emerge from stagnation. Volatile external demand, in turn, has elevated German GDP growth volatility by advanced countries’ standards, keeping domestic consumption growth at surprisingly low levels. As a consequence, despite the size of its economy and important labor market reforms, Germany’s ability to act as global locomotive has been limited. With increasing competition in its traditional areas of manufacturing, a more domestically-driven growth dynamic, especially in the production and delivery of services, will be good for Germany and for the global economy. Absent such an effort, German growth will remain constrained, and Germany will play only a modest role in spurring growth elsewhere