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Full-Text Articles in Physics
Model For Ultrashort Laser-Pulse Induced Ionization Dynamics In Transparent Solids, Jeremy R. Gulley, Thomas E. Lanier
Model For Ultrashort Laser-Pulse Induced Ionization Dynamics In Transparent Solids, Jeremy R. Gulley, Thomas E. Lanier
Faculty and Research Publications
A comprehensive model of ultrafast laser-induced plasma generation intended for coupling with pulse propagation simulations in transparent solids is introduced. It simultaneously accounts for the changing spectrum of a propagating ultrashort laser pulse while coupling to the evolution of the energy-resolved nonequilibrium free-carrier distribution. The presented results indicate that strong pulse chirps lead to ionization dynamics that are not captured by the standard monochromatic treatment of laser-induced plasma formation. These results have strong implications for ultrafast laser-solid applications that depend on ionization in a strong nonlinear focus.
Soft-Gluon Corrections In Fcnc Top-Quark Production Via Anomalous Gluon Couplings, Nikolaos Kidonakis, Elwin Martin
Soft-Gluon Corrections In Fcnc Top-Quark Production Via Anomalous Gluon Couplings, Nikolaos Kidonakis, Elwin Martin
Faculty and Research Publications
We present a calculation of soft-gluon corrections in FCNC top-quark production via anomalous t-q-g couplings. The soft anomalous dimension matrix is explicitly calculated at one-loop accuracy. This calculation allows threshold resummation at next-to-leadinglogarithm accuracy. We also derive expressions for the soft-gluon corrections at NLO and at NNLO.
Nnll Threshold Resummation For Top-Pair And Single-Top Production, Nikolaos Kidonakis
Nnll Threshold Resummation For Top-Pair And Single-Top Production, Nikolaos Kidonakis
Faculty and Research Publications
I discuss threshold resummation at NNLL accuracy in the standard moment-space approach in perturbative QCD for top-pair and single-top production. For top quark pair production I present new approximate NNLO results for the total cross section and for the top quark transverse momentum and rapidity distributions at 8 TeV LHC energy. I discuss the accuracy of the soft-gluon approximation and show that the NLO and NNLO approximate results from resummation are practically indistinguishable from exact NLO and partial NNLO results. For single top production I present new approximate NNLO results for the total cross sections in all three channels at …
Constraints Of The Radio-Loud/Radio-Quiet Dichotomy From The Fundamental Plane, David Garofalo, Matthew I. Kim, Damian J. Christian
Constraints Of The Radio-Loud/Radio-Quiet Dichotomy From The Fundamental Plane, David Garofalo, Matthew I. Kim, Damian J. Christian
Faculty and Research Publications
The Fundamental Plane for black hole activity constitutes a tight correlation between jet power, X-ray luminosity, and black hole mass. Under the assumption that a Blandford–Znajek-type mechanism, which relies on black hole spin, contributes non-negligibly to jet production, the sufficiently small scatter in the Fundamental Plane shows that black hole spin differences of |Δa| ∼ 1 are not typical among the active galactic nuclei population. If – as it seems – radio-loud and radio-quiet objects are both faithful to the Fundamental Plane, models of black hole accretion in which the radio-loud/radio-quiet dichotomy is based on a spin dichotomy of a∼1/a∼0, …
Nnnlo Soft-Gluon Corrections For The Top-Antitop Pair Production Cross Section, Nikolaos Kidonakis
Nnnlo Soft-Gluon Corrections For The Top-Antitop Pair Production Cross Section, Nikolaos Kidonakis
Faculty and Research Publications
I present a calculation of next-to-next-to-next-to-leading-order (NNNLO) soft-gluon corrections for top-antitop pair production in hadronic collisions. Approximate NNNLO (aNNNLO) results are obtained by adding the NNNLO soft-gluon corrections to the complete next-to-next-to-leading-order (NNLO) cross section. Theoretical predictions are shown for the total aNNNLO tt¯cross section at LHC and Tevatron energies. The aNNNLO cross sections are larger but have smaller theoretical uncertainties than at NNLO.
Nnlo Soft-Gluon Corrections For The Z-Boson And W-Boson Transverse Momentum Distributions, Nikolaos Kidonakis, Richard J. Gonsalves
Nnlo Soft-Gluon Corrections For The Z-Boson And W-Boson Transverse Momentum Distributions, Nikolaos Kidonakis, Richard J. Gonsalves
Faculty and Research Publications
We present results for the Z-boson and W-boson transverse momentum (pT ) distributions for large pT at LHC and Tevatron energies. We calculate complete next-to-leadingorder (NLO) QCD corrections as well as soft-gluon corrections at next-to-next-to-leadingorder (NNLO) to the differential cross section. The NNLO soft-gluon contributions are derived from next-to-next-to-leading-logarithm (NNLL) resummation at two loops. We find enhancements of the pT distributions and reductions of the scale dependence when the NNLO corrections are included.
Plasma Generation By Ultrashort Multi-Chromatic Pulses During Nonlinear Propagation, Jeremy R. Gulley, Jiexi Liao, Thomas E. Lanier
Plasma Generation By Ultrashort Multi-Chromatic Pulses During Nonlinear Propagation, Jeremy R. Gulley, Jiexi Liao, Thomas E. Lanier
Faculty and Research Publications
The use of femtosecond lasers in industrial, biomedical, and defense related applications during the last 15 years has necessitated a detailed understanding of pulse propagation coupled with ultrafast laser-material interactions. Current models of ultrashort pulse propagation in solids describe the pulse evolution of fields with broad spectra and are typically coupled to models of ionization and laser-plasma interaction that assume monochromatic laser fields. In this work we address some of the errors introduced by combining these inconsistent descriptions. In particular, we show that recently published experiments and simulations demonstrate how this contradiction can produce order-of-magnitude errors in calculating the ionization …