3,303 research outputs found
Nonlinear hydroelastic waves on a linear shear current at finite depth
This work is concerned with waves propagating on water of finite depth with a constant-vorticity current under a deformable flexible sheet. The pressure exerted by the sheet is modelled by using the Cosserat thin shell theory. By means of multi-scale analysis, small amplitude nonlinear modulation equations in several regimes are considered, including the nonlinear Schrödinger equation (NLS) which is used to predict the existence of small-amplitude wavepacket solitary waves in the full Euler equations and to study the modulational instability of quasi-monochromatic wavetrains. Guided by these weakly nonlinear results, fully nonlinear steady and time-dependent computations are performed by employing a conformal mapping technique. Bifurcation mechanisms and typical profiles of solitary waves for different underlying shear currents are presented in detail. It is shown that even when small-amplitude solitary waves are not predicted by the weakly nonlinear theory, we can numerically find large-amplitude solitary waves in the fully nonlinear equations. Time-dependent simulations are carried out to confirm the modulational stability results and illustrate possible outcomes of the nonlinear evolution in unstable cases
Transverse momentum resummation for color sextet and antitriplet scalar production at the LHC
We study the factorization and resummation of the transverse momentum
spectrum of the color sextet and antitriplet scalars produced at the LHC based
on soft-collinear effective theory. Compared to Z boson and Higgs production, a
soft function is required to account for the soft gluon emission from the
final-state colored scalar. The soft function is calculated at the
next-to-leading order, and the resummation is performed at the approximate
next-to-next-to-leading logarithmic accuracy. The non-perturbative effects and
PDF uncertainties are also discussed.Comment: 20 pages, 7 figure
Threshold resummation for the production of a color sextet (antitriplet) scalar at the LHC
We investigate threshold resummation effects in the production of a color
sextet (antitriplet) scalar at next-to-next-to-leading logarithmic (NNLL) order
at the LHC in the frame of soft-collinear effective theory. We show the total
cross section and the rapidity distribution with NLO+NNLL accuracy, and we
compare them with the NLO results. Besides, we use recent dijet data at the LHC
to give the constraints on the couplings between the colored scalars and
quarks.Comment: 21 pages,9 figures,3 tables; Version published in EPJ
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