Quark-gluon Jet Discrimination At CMS

Many physics analyses at the LHC are looking into processes where the signal jets are originating from quarks, while jets in the background are more gluon enriched. Based on observables sensitive to fundamental differences in the fragmentation properties of gluons and quarks, a likelihood discriminant is constructed to distinguish between jets originating from quarks and gluons. The performance of the tagger is evaluated using Z+jets and dijet events produced in proton-proton collisions at a centre-of-mass energy of 8 TeV, recorded by the CMS experiment at the LHC.Comment: Proceedings for LHCP201

Beam-Beam Effects in the SPS Proton-Anti Proton Collider

During the proton-anti proton collider run several experiments were carried out in order to understand the effect of the beam-beam interaction on backgrounds and lifetimes. In this talk a selection of these experiments will be presented. From these experiments, the importance of relative beam sizes and tune ripple could be demonstrated.Comment: 3 pages, contribution to the ICFA Mini-Workshop on Beam-Beam Effects in Hadron Colliders, CERN, Geneva, Switzerland, 18-22 Mar 201

Locke's Criterion for the Reality of Ideas: Unambiguous but Untenable

The paper argues against the claim held, e.g., by Leibniz, that Locke employs a double standard for determining whether an object before the mind (i.e., an idea) is real. Using Locke's ectype-archetype distinction it is shown that this charge is the result of confusing Locke's criterion of reality with its application. Depending on whether it applies to a simple, substance or mode idea, the criterion works out differently. Next it is argued that although Locke maintains only a single criterion, this criterion is untenable, since it fails to properly distinguish real from fantastical ideas

THE IMPACT OF MANURE PRODUCTION RIGHTS ON CAPITAL INVESTMENT IN THE DUTCH PIG SECTOR

In this paper the effect of manure production rights on investment decisions of Dutch pig farmers is examined. A dynamic optimization model of investment that explicitly takes zero investments into account is augmented by a constraint on production arising from the introduction of manure production rights. In the theoretical model it is shown that such a constraint has a reducing effect on investment. The presence of this constraint is tested for using GMM structural break tests. The results provide evidence for the hypothesis that manure production rights have reduced investments through its effect on production.Investment, manure production rights, Euler equation, GMM, structural break testing, panel data, pig farms, Livestock Production/Industries,

Capacitive MEMS-based sensors : thermo-mechanical stability and charge trapping

Micro-Electro Mechanical Systems (MEMS) are generally characterized as miniaturized systems with electrostatically driven moving parts. In many cases, the electrodes are capacitively coupled. This basic scheme allows for a plethora of specifications and functionality. This technology has presently matured and is widely employed in industry. \ud A voltage across the electrodes will attract the movable part. This relation between electric field and separation (or capacitance) can be conveniently employed to sense tiny displacements (less than 1 pm) or for example as a through sensor for electromagnetic power through a coplanar waveguide (CPW).\ud The design involves often dielectric layers, whether accidental (native oxide) or intentional. During fabrication and / or operation of the device, trapped charge can uncontrollably accumulate and decumulate in these layers, causing parasitic forces on the device. These parasitic forces can influence the device beyond acceptable limits. The research described in this thesis approaches this phenomenon in two ways: a) device level and b) fundamental level. \ud a) Device level: Complete MEMS structures. The thesis contains theory of capacitive MEMS, including amongst others pull-in voltage, electrostatically loaded clamped-clamped beams, and electro-mechanical resonance, as well as the origin, dynamics and influence of trapped charges, in conjunction with built-in voltage. A cryogenic experimental study has been done on the effect of charge trapping on two types of MEMS-based RF power sensors. New structures have been realized with far better thermo-mechanical immunity. These structures are the first to involve double beam springs, which are fabricated by wet KOH etching of silicon. It is demonstrated that even an ultrathin aluminum oxide (native, ~ 2 nm) can harbor significant charge trapping. The dynamics are found to slow down considerably at cryogenic temperatures. At last, a study is done on when charge trapping actually limit the performance of real MEMS devices: a gravity gradiometer and an RF power sensor. \ud b) Fundamental level. Existing measurements and imaging of local trapped charges by conducting atomic force microscopy (AFM) are reinterpreted by a new model. This multi mirror model calculates the electrostatic interaction (force, gradient and contact potential difference) between the sample surface containing the trapped charge and the tip of the AFM, represented by a conducting sphere. This model improves drastically over existing calculations. Some interesting theoretical approximations of quantities describing this interaction have been found

Self-assembling multiblock amphiphiles: Molecular design, supramolecular structure, and mechanical properties

We perform off-lattice, canonical ensemble molecular dynamics simulations of the self-assembly of long segmented copolymers consisting of alternating, tunably attractive and hydrophobic {\em binder} domains, connected by hydrophilic {\em linker} chains whose length may be separately controlled. In such systems, the molecular design of the molecule directly determines the balance between energetic and entropic tendencies. We determine the structural phase diagram of this system, which shows collapsed states (dominated by the attractive linkers' energies), swollen states (dominated by the random coil linkers' entropies) as well as intermediate network hydrogel phases, where the long molecules exhibit partial collapse to a {\em single molecule network} state. We present an analysis of the connectivity and spatial structure of this network phase, and relate its basic topology to mechanical properties, using a modified rubber elasticity model. The mechanical properties are further characterized in a direct computational implementation of oscillatory rheology measurements. We find that it is possible to optimize the mechanical performance by an appropriate choice of molecular design, which may point the way to novel synthetics that make optimal mechanical use of constituent polymers

Nonparametric Testing of the High-Frequency Efficiency of the 1997 Asian Foreign Exchange Markets

For the first time, non-parametric statistical tests, originally developed by Sherry (1992) to test the efficiency of information processing in nervous systems, are used to ascertain if the Asian FX rates followed random walks. The stationarity and serial independence of the price changes are tested on minute-by-minute data for nine currencies for the period from January 1, 1997 to December 30, 1997. Tested were the Thai baht, Indonesian rupiah, Malaysian ringgit, Philippines' peso, Singapore dollar, Taiwan dollar and the Hong Kong dollar, with the Japanese Yen and German Deutschmark as benchmarks (The U.S. Dollar is the base currency). The efficiency of these FX markets before and after the onset of the Asian currency turmoil (i.e., January 1 - June 30, 1997 and July 1 - December 30, 1997) are compared. The Thai baht, Malaysian ringgit, Indonesian rupiah and Singapore dollar exhibited non-stationary behavior during the entire year, and gave evidence of a trading regime break, while the Phillipines' peso, Taiwan dollar, Yen and Deutschmark remained stationary (The Hong Kong dollar was pegged). However, each half-year regime showed stationarity by itself, indicating stable and nonchaotic trading regimes for all currencies, despite the high volatilities, except the Malaysian ringgit, which exhibited non-stationarity in the second half of 1997. The Thai baht traded nonstationarily in the first half of 1997, but stationarily in the second half, while the Taiwan dollar reversed that trading pattern. Regarding Sherry's four serial independence tests of differential spectrum, relative price changes, temporal trading windows of at least 20 minutes long and price change category transitions: none of the currencies exhibited complete independence. Thus no Asian currency market - including the Yen - exhibited complete efficiency in 1997 regarding both stationarity and independence, in particular when compared with the highly efficient Deutschmark. But, remarkably, the Phillippines' peso remained as efficient as the Japanese Yen throughout 1997.

Valuation of Six Asian Stock Markets: Financial System Identification in Noisy Environments

The open financial economic systems of six Asian countries Taiwan, Malaysia, Singapore, Philippines, Indonesia and Japan - over the period 1986 through 1995 are identified from empirical data to determine how their stock markets, economies and financial markets are interrelated. The objective is to find rational stock market valuations using a country's nominal GDP and a short term interest rate, based on a modified version of the Dividend Discount Model. But our empirical results contradict such conventional financial economic theory. Various methods are used to analyze the 3D data covariance ellipsoids: spectral analysis, analysis of information matrices, 2D and 3D noise/signal determination and ''super-filter'' system identification based on 3D projections. The new ''super-filter'' method provides the sharpest identification of the Grassmanian invariant q of the empirical systems and the best computation of the finite boundaries of the empirical parameter ranges. All six Asian systems are high noise environments, in which it is very difficult to separate systematic signals from noise. Because of these high noise levels, spectral analysis is not reliable. By plotting all 3D q = 2 {Complete} Least Squares projections we find that only Taiwan has a clear q = 2 system, i.e., Taiwan's stock market, economy and financial market are rationally coherent. In contrast, Malaysia, Singapore, Philippines and Indonesia have q = 1 systems, in which stock markets and economies are closely related, but unrelated to the respective domestic financial markets. Several possible economic explanations are provided. We also quantitatively establish the incoherence of Japan's financial economic system. Japan's stock market operates independently from its economy and from its financial market, which are mutually unrelated.

Catch Bonding in the Forced Dissociation of a Polymer Endpoint

Applying a force to certain supramolecular bonds may initially stabilize them, manifested by a lower dissociation rate. We show that this behavior, known as catch bonding and by now broadly reported in numerous biophysics bonds, is generically expected when either or both the trapping potential and the force applied to the bond possess some degree of nonlinearity. We enumerate possible scenarios, and for each identify the possibility and, if applicable, the criterion for catch bonding to occur. The effect is robustly predicted by Kramers theory, Mean First Passage Time theory, and finally confirmed in direct MD simulation. Among the catch scenarios, one plays out essentially any time the force on the bond originates in a polymeric object, implying that some degree of catch bond behavior is to be expected in {\em any} protein-protein bond, as well as in more general settings relevant to polymer network mechanics or optical tweezer experiments