16,402 research outputs found
FormCalc 8: Better Algebra and Vectorization
We present Version 8 of the Feynman-diagram calculator FormCalc. New features
include in particular significantly improved algebraic simplification as well
as vectorization of the generated code. The Cuba Library, used in FormCalc,
features checkpointing to disk for all integration algorithms.Comment: 7 pages, LaTeX, proceedings contribution to ACAT 2013, Beijing,
China, 16-21 May 201
Third generation sfermions decays into Z and W gauge bosons: full one-loop analysis
The complete one-loop radiative corrections to third generation scalar
fermions into gauge bosons Z and W^\pm is considered. We focus on \wt{f}_2 \to
Z \wt{f}_1 and \wt{f}_i \to W^\pm \wt{f'}_j (f,f'=t,b). We include both
SUSY-QCD, QED and full electroweak corrections. It is found that the
electroweak corrections can be of the same order as the SUSY-QCD corrections.
The two sets of corrections interfere destructively in some region of parameter
space. The full one loop correction can reach 10% in some SUGRA scenario, while
in model independent analysis like general MSSM, the one loop correction can
reach 20% for large \tan\beta and large trilinear soft breaking terms A_b.Comment: Latex file, 18 pages, 8 figures, version to appear in PR
Evaluating Potential Climate Change Impacts on Water Resource Systems Operations: Case Studies of Portland, Oregon and Central Valley, California
Gauge Invariant Cutoff QED
A hidden generalized gauge symmetry of a cutoff QED is used to show the
renormalizability of QED. In particular, it is shown that corresponding Ward
identities are valid all along the renormalization group flow. The exact
Renormalization Group flow equation corresponding to the effective action of a
cutoff lambda phi^4 theory is also derived. Generalization to any gauge group
is indicated.Comment: V1: 18 pages, 2 figures; V2: Discussions improved. Version accepted
for publication in Physica Script
Echo spectroscopy and Atom Optics Billiards
We discuss a recently demonstrated type of microwave spectroscopy of trapped
ultra-cold atoms known as "echo spectroscopy" [M.F. Andersen et. al., Phys.
Rev. Lett., in press (2002)]. Echo spectroscopy can serve as an extremely
sensitive experimental tool for investigating quantum dynamics of trapped atoms
even when a large number of states are thermally populated. We show numerical
results for the stability of eigenstates of an atom-optics billiard of the
Bunimovich type, and discuss its behavior under different types of
perturbations. Finally, we propose to use special geometrical constructions to
make a dephasing free dipole trap
A probabilistic analysis of argument cogency
This paper offers a probabilistic treatment of the conditions for argument cogency as endorsed in informal logic: acceptability, relevance, and sufficiency. Treating a natural language argument as a reason-claim-complex, our analysis identifies content features of defeasible argument on which the RSA conditions depend, namely: change in the commitment to the reason, the reason’s sensitivity and selectivity to the claim, one’s prior commitment to the claim, and the contextually determined thresholds of acceptability for reasons and for claims. Results contrast with, and may indeed serve to correct, the informal understanding and applications of the RSA criteria concerning their conceptual dependence, their function as update-thresholds, and their status as obligatory rather than permissive norms, but also show how these formal and informal normative approachs can in fact align
Loop-induced photon spectral lines from neutralino annihilation in the NMSSM
We have computed the loop-induced processes of neutralino annihilation into
two photons and, for the first time, into a photon and a Z boson in the
framework of the NMSSM. The photons produced from these radiative modes are
monochromatic and possess a clear "smoking gun" experimental signature. This
numerical analysis has been done with the help of the SloopS code, initially
developed for automatic one-loop calculation in the MSSM. We have computed the
rates for different benchmark points coming from SUGRA and GMSB soft SUSY
breaking scenarios and compared them with the MSSM. We comment on how this
signal can be enhanced, with respect to the MSSM, especially in the low mass
region of the neutralino. We also discuss the possibility of this observable to
constrain the NMSSM parameter space, taking into account the latest limits from
the FERMI collaboration on these two modes.Comment: 18 pages, 3 figures. Minor clarifications added in the text. Typing
mistakes and references corrected. Matches published versio
Production of the neutral top-pion in association with a high- jet at the
In the framework of the topcolor-assisted technicolor model, we study
production of the neutral top-pion in association with a
high- jet at the , which proceeds via the partonic processes
, ,
, , and . We find
that it is very challenging to detect the neutral top-pion via
the process , while the
possible signatures of might be detected via the process
at the .Comment: 13 pages, 4 figures; typos correcte
NLO QCD Corrections to -to-Charmonium Form Factors
The meson to S-wave Charmonia transition form factors are
calculated in next-to-leading order(NLO) accuracy of Quantum
Chromodynamics(QCD). Our results indicate that the higher order corrections to
these form factors are remarkable, and hence are important to the
phenomenological study of the corresponding processes. For the convenience of
comparison and use, the relevant expressions in asymptotic form at the limit of
for the radiative corrections are presented
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