Next-to-Leading order Higgs + 2 jet production via gluon fusion

We present phenomenological results for the production of a Higgs boson in association with two jets at the LHC. The calculation is performed in the limit of large top mass and is accurate to next-to-leading order in the strong coupling, i.e. ${\cal O}(\alpha_s^6)$Comment: 13 pages, 6 figures; v2: references added, modified acknowledgments, final version as published in JHE

Duality without Supersymmetry: The Case of the SO(16)xSO(16) String

We extend strong/weak coupling duality to string theories without spacetime supersymmetry, and focus on the case of the unique ten-dimensional, nonsupersymmetric, tachyon-free $SO(16)\times SO(16)$ heterotic string. We construct a tachyon-free heterotic string model that interpolates smoothly between this string and the ten-dimensional supersymmetric $SO(32)$ heterotic string, and we construct a dual for this interpolating model. We find that the perturbative massless states of our dual theories precisely match within a certain range of the interpolation. Further evidence for this proposed duality comes from a calculation of the one-loop cosmological constant in both theories, as well as the presence of a soliton in the dual theory. This is therefore the first known duality relation between nonsupersymmetric tachyon-free string theories. Using this duality, we then investigate the perturbative and nonperturbative stability of the $SO(16)\times SO(16)$ string, and present a conjecture concerning its ultimate fate.Comment: 15 pages, LaTeX, 3 figure

Euclidean Calculation of Feature Points of a Rotating Satellite: A Daisy Chaining Approach

The occlusion of feature points and/or feature points leaving the field of view of a camera is a significant practical problem that can lead to degraded performance or instability of visual servo control and vision-based estimation algorithms. By assuming that one knownEuclidean distance between two feature points in an initial view is available, homography relationships and image geometry are used in this paper to determine the Euclidean coordinates of feature points in the field of view. A new daisy-chainingmethod is then used to relate the position and orientation of a plane defined by the feature points to other feature-point planes that are rigidly connected. Through these relationships, the Euclidean coordinates of the original feature points can be tracked even as they leave the field of view. This objective is motivated by the desire to track the Euclidean coordinates of feature points on one face of a satellite as it continually rotates and feature points become self-occluded. A numerical simulation is included to demonstrate that the Euclidean coordinates can be tracked even when they leave the field of view. However, the results indicate the need for amethod to reconcile any accumulated errorwhen the feature points return to thefield of view. Nomenclature A = intrinsic camera-calibration matrix dj = distance to j plane along nj F j, Fj = frames attached to the j and j planes Gj = projective homography matrix of the jth frame Hj = Euclidean homography matrix of the jth frame I = fixed coordinate frame attached to the camera mji, m ji = normalized Euclidean coordinate of the ith feature point of the j and j planes expressed in

Dynamic nuclear polarization at the edge of a two-dimensional electron gas

We have used gated GaAs/AlGaAs heterostructures to explore nonlinear transport between spin-resolved Landau level (LL) edge states over a submicron region of two-dimensional electron gas (2DEG). The current I flowing from one edge state to the other as a function of the voltage V between them shows diode-like behavior---a rapid increase in I above a well-defined threshold V_t under forward bias, and a slower increase in I under reverse bias. In these measurements, a pronounced influence of a current-induced nuclear spin polarization on the spin splitting is observed, and supported by a series of NMR experiments. We conclude that the hyperfine interaction plays an important role in determining the electronic properties at the edge of a 2DEG.Comment: 8 pages RevTeX, 7 figures (GIF); submitted to Phys. Rev.

The Ursinus Weekly, October 21, 1976

Ursinus news in brief: Parsons recovering; Damage fines abolished; Young Democrats revived; Homecoming planned; Voter registration held; MBA fair planned • Messiah cut back • Placement meetings set • Commuters organize • SAC reports • Comment: The ugly American lives on • Richter talks to freshmen • Comment: Alumni-student relations • Rheinpfalz folk culture • Bob Dean: Artist • proTheatre produces one acts • Beautiful noise • Operation: White Cloud • Coming campus events • Handwerk replaces Fry • Soccer drops three • Bears lose • X-Country splits • Kang\u27s return • McGinnis views NBA and Sixershttps://digitalcommons.ursinus.edu/weekly/1059/thumbnail.jp

Grand Unification at Intermediate Mass Scales through Extra Dimensions

One of the drawbacks of conventional grand unification scenarios has been that the unification scale is too high to permit direct exploration. In this paper, we show that the unification scale can be significantly lowered (perhaps even to the TeV scale) through the appearance of extra spacetime dimensions. Such extra dimensions are a natural consequence of string theories with large-radius compactifications. We show that extra spacetime dimensions naturally lead to gauge coupling unification at intermediate mass scales, and moreover may provide a natural mechanism for explaining the fermion mass hierarchy by permitting the fermion masses to evolve with a power-law dependence on the mass scale. We also show that proton-decay constraints may be satisfied in our scenario due to the higher-dimensional cancellation of proton-decay amplitudes to all orders in perturbation theory. Finally, we extend these results by considering theories without supersymmetry; experimental collider signatures; and embeddings into string theory. The latter also enables us to develop several novel methods of explaining the fermion mass hierarchy via $D$-branes. Our results therefore suggest a new approach towards understanding the physics of grand unification as well as the phenomenology of large-radius string compactifications.Comment: 65 pages, LaTeX, 20 figure

The Ursinus Weekly, September 30, 1976

Ursinus news in brief: Times cites college depression; 76\u27ers arrive for training; Simon participates in mission; Absentee ballots explained; Richter named Ursinus President • \u2776 enrollment drops • Dorm letter drafted • SFARC year opens • Comment: Action, not promises • Cheap shot commentators • Cost comparisons • Movie controversy • The Last hurrah: An introduction to Ursinus romance • Legal society success • Coming campus events • Teacher knows best! • Record review • Curriculum addition in history • Campaign-advance Ursinus • Phils to see red • Gurzynski retires from X-country • Soccer drops two • F.&M. beats Ursinus • Karas regime opens • Harriers 3 and 1 • What lies ahead • Hockey still winning • Saturday\u27s gamehttps://digitalcommons.ursinus.edu/weekly/1057/thumbnail.jp

Can we set a global threshold age to define mature forests?

Globally, mature forests appear to be increasing in biomass density (BD). There is disagreement whether these increases are the result of increases in atmospheric CO2 concentrations or a legacy effect of previous land-use. Recently, it was suggested that a threshold of 450 years should be used to define mature forests and that many forests increasing in BD may be younger than this. However, the study making these suggestions failed to account for the interactions between forest age and climate. Here we revisit the issue to identify: (1) how climate and forest age control global forest BD and (2) whether we can set a threshold age for mature forests. Using data from previously published studies we modelled the impacts of forest age and climate on BD using linear mixed effects models. We examined the potential biases in the dataset by comparing how representative it was of global mature forests in terms of its distribution, the climate space it occupied, and the ages of the forests used. BD increased with forest age, mean annual temperature and annual precipitation. Importantly, the effect of forest age increased with increasing temperature, but the effect of precipitation decreased with increasing temperatures. The dataset was biased towards northern hemisphere forests in relatively dry, cold climates. The dataset was also clearly biased towards forests <250 years of age. Our analysis suggests that there is not a single threshold age for forest maturity. Since climate interacts with forest age to determine BD, a threshold age at which they reach equilibrium can only be determined locally. We caution against using BD as the only determinant of forest maturity since this ignores forest biodiversity and tree size structure which may take longer to recover. Future research should address the utility and cost-effectiveness of different methods for determining whether forests should be classified as mature

NLO Higgs boson production plus one and two jets using the POWHEG BOX, MadGraph4 and MCFM

We present a next-to-leading order calculation of Higgs boson production plus one and two jets via gluon fusion interfaced to shower Monte Carlo programs, implemented according to the POWHEG method. For this implementation we have used a new interface of the POWHEG BOX with MadGraph4, that generates the codes for generic Born and real processes automatically. The virtual corrections have been taken from the MCFM code. We carry out a simple phenomenological study of our generators, comparing them among each other and with fixed next-to-leading order results.Comment: 27 pages, 21 figure