22,919 research outputs found

    Hidden symmetry of the quantum Calogero-Moser system

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    Hidden symmetry of the quantum Calogero-Moser system with the inverse-square potential is explicitly demonstrated in algebraic sense. We find the underlying algebra explaining the super-integrability phenomenon for this system. Applications to related multi-variable Bessel functions are also discussed.Comment: 16 pages, latex, no figure

    750 GeV Diphotons from a D3-brane

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    Motivated by the recently reported diphoton excess at 750 GeV observed by both CMS and ATLAS, we study string-based particle physics models which can accommodate this signal. Quite remarkably, although Grand Unified Theories in F-theory tend to impose tight restrictions on candidate extra sectors, the case of a probe D3-brane near an E-type Yukawa point naturally leads to a class of strongly coupled models capable of accommodating the observed signature. In these models, the visible sector is realized by intersecting 7-branes, and the 750 GeV resonance is a scalar modulus associated with motion of the D3-brane in the direction transverse to the Standard Model 7-branes. Integrating out heavy 3-7 string messenger states leads to dimension five operators for gluon fusion production and diphoton decays. Due to the unified structure of interactions, these models also predict that there should be additional decay channels to ZZ and Z gamma. We also comment on models with distorted unification, where both the production mechanism and decay channels can differ.Comment: v3: 12 pages, 1 figure, clarifications adde

    Radio frequency baseband recording technique

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    Technique uses a helical-scan video recorder with auxiliary signal-conditioning equipment to provide an inexpensive, high-capacity magnetic tape recording of a 112 channel, phase-locked, multiplexed, baseband signal

    “Forty-Seven Days: How Pershing’s Warriors Came of Age to Defeat the German Army in World War I (Book Review)” by Mitchell Yockelson

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    Review of Forty-Seven Days: How Pershing’s Warriors Came of Age to Defeat the German Army in World War I by Mitchell Yockelso

    Particle Physics Implications of F-theory

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    We review recent progress in realizing Grand Unified Theories (GUTs) in a strongly coupled formulation of type IIB string theory known as F-theory. Our main emphasis is on the expected low-energy phenomenology of a minimal class of F-theory GUTs. We introduce the primary ingredients in such constructions, and then present qualitative features of GUT models in this framework such as GUT breaking, doublet-triplet splitting, and proton decay. Next, we review proposals for realizing flavor hierarchies in the quark and lepton sectors. We discuss possible supersymmetry breaking scenarios, and their consequences for experiment, as well as geometrically minimal realizations of F-theory GUTs which incorporate most of these features.Comment: v2: 42 pages, 3 figures, submitted to Annu. Rev. Nuc. Part. Sci, improved formatting and small clarification
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