90,929 research outputs found
Higgs Boson And Scattering At Colliders
We discuss the Standard-Model Higgs boson production in the channels
, , and W^-W^-H^{--}e^-e^-$ Workshop, Santa Cruz, CA,
Sept. 4--5, 1995. 13 pages, 5 figs, LaTeX; postscript file available via
anonymous ftp at ftp://ucdhep.ucdavis.edu/han/sews/emem_sc.p
Drell-Yan plus missing energy as a signal for extra dimensions
We explore the search sensitivity for signals of large extra dimensions at
hadron colliders via the Drell-Yan process pp -> l+ l- + E_T(miss) X (l = e,mu)
where the missing transverse energy is the result of escaping Kaluza-Klein
gravitons. We find that one is able to place exclusion limits on the gravity
scale up to 560 GeV at the Fermilab Tevatron, and to 4.0 (3.3) TeV at the CERN
LHC, for n = 3 (4) extra dimensions.Comment: 5 pages, 2 PS figs, revised verseion to be published in Physics
Letters
Measuring CP Violating Phases at a Future Linear Collider
At a future Linear Collider one will be able to determine the masses of
charginos and neutralinos and their pair production cross sections to high
accuracies. We show how systematically including the cross sections into the
analysis improves the measurement of the underlying mass parameters, including
potential CP violating phases. In addition, we investigate how experimental
errors will affect the determination of these parameters. We present a first
estimate on the lower limit of observable small phases and on the accuracy in
determining large phases.Comment: 10 pages, 6 figures, RevTeX3.1, Version to be published in Physics
Letters B, physics setup improved, figures added, conclusions unchange
A variational approach for continuous supply chain networks
We consider a continuous supply chain network consisting of buffering queues and processors first proposed by [D. Armbruster, P. Degond, and C. Ringhofer, SIAM J. Appl. Math., 66 (2006), pp. 896–920] and subsequently analyzed by [D. Armbruster, P. Degond, and C. Ringhofer, Bull. Inst. Math. Acad. Sin. (N.S.), 2 (2007), pp. 433–460] and [D. Armbruster, C. De Beer, M. Fre- itag, T. Jagalski, and C. Ringhofer, Phys. A, 363 (2006), pp. 104–114]. A model was proposed for such a network by [S. G ̈ottlich, M. Herty, and A. Klar, Commun. Math. Sci., 3 (2005), pp. 545–559] using a system of coupling ordinary differential equations and partial differential equations. In this article, we propose an alternative approach based on a variational method to formulate the network dynamics. We also derive, based on the variational method, a computational algorithm that guarantees numerical stability, allows for rigorous error estimates, and facilitates efficient computations. A class of network flow optimization problems are formulated as mixed integer programs (MIPs). The proposed numerical algorithm and the corresponding MIP are compared theoretically and numerically with existing ones [A. Fu ̈genschuh, S. Go ̈ttlich, M. Herty, A. Klar, and A. Martin, SIAM J. Sci. Comput., 30 (2008), pp. 1490–1507; S. Go ̈ttlich, M. Herty, and A. Klar, Commun. Math. Sci., 3 (2005), pp. 545–559], which demonstrates the modeling and computational advantages of the variational approach
TeV resonances in top physics at the LHC
We consider the possibility of studying novel particles at the TeV scale with
enhanced couplings to the top quark via top quark pair production at the LHC
and VLHC. In particular we discuss the case of neutral scalar and vector
resonances associated with a strongly interacting electroweak symmetry breaking
sector. We constrain the couplings of these resonances by imposing appropriate
partial wave unitarity conditions and known low energy constraints. We evaluate
the new physics signals via WW -> tt~ for various models without making
approximation for the initial state W bosons, and optimize the acceptance cuts
for the signal observation. We conclude that QCD backgrounds overwhelm the
signals in both the LHC and a 200 TeV VLHC, making it impossible to study this
type of physics in the tt~ channel at those machines.Comment: 15p, add. comments to clarify model, +2 ref., version to appear PR
Ill-posedness of the hydrostatic Euler and singular Vlasov equations
In this paper, we develop an abstract framework to establish ill-posedness in
the sense of Hadamard for some nonlocal PDEs displaying unbounded unstable
spectra. We apply it to prove the ill-posedness for the hydrostatic Euler
equations as well as for the kinetic incompressible Euler equations and the
Vlasov-Dirac-Benney system
Instabilities in the mean field limit
Consider a system of particles interacting through Newton's second law
with Coulomb interaction potential in one spatial dimension or a
smooth potential in any dimension. We prove that in the mean
field limit , the particles system displays instabilities
in times of order for some configurations approximately distributed
according to unstable homogeneous equilibria.Comment: minor typos corrected; Journal of Statistical Physics, accepte
Equivalence of weak and strong modes of measures on topological vector spaces
A strong mode of a probability measure on a normed space can be defined
as a point such that the mass of the ball centred at uniformly
dominates the mass of all other balls in the small-radius limit. Helin and
Burger weakened this definition by considering only pairwise comparisons with
balls whose centres differ by vectors in a dense, proper linear subspace of
, and posed the question of when these two types of modes coincide. We show
that, in a more general setting of metrisable vector spaces equipped with
measures that are finite on bounded sets, the density of and a uniformity
condition suffice for the equivalence of these two types of modes. We
accomplish this by introducing a new, intermediate type of mode. We also show
that these modes can be inequivalent if the uniformity condition fails. Our
results shed light on the relationships between among various notions of
maximum a posteriori estimator in non-parametric Bayesian inference.Comment: 22 pages, 3 figure
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