Higher-order QCD corrections for the W-boson transverse momentum distribution

We present results for W-boson production at large transverse momentum at LHC and Tevatron energies. We calculate complete next-to-leading-order (NLO) QCD corrections and higher-order soft-gluon corrections to the differential cross section. The soft-gluon contributions are resummed at next-to-next-to-leading-logarithm (NNLL) accuracy via the two-loop soft anomalous dimensions. Both NLO and approximate next-to-next-to-leading-order (NNLO) p_T distributions are presented. Our numerical results are in good agreement with recent data from the LHC.Comment: 15 pages; 11 figures; v2 has new results at 8 TeV LHC energy, more details on scale variation, and calculations of PDF uncertainties; v3 has a new presentation of the figures and a comparison to LHC dat

NNLL resummation for W-boson production at large pT

We present new results for W-boson production at large transverse momentum at the LHC and the Tevatron. The contribution of soft-gluon corrections is derived from NNLL resummation and added to the exact NLO result. Numerical results and their uncertainties for the approximate NNLO W-boson transverse momentum distributions are derived and compared to recent data from the LHC.Comment: 6 pages, 6 figures; presented at ICHEP 2012, Melbourne, Australia, July 4-11, 201

NNLO soft-gluon corrections for the Z-boson and W-boson transverse momentum distributions

We present results for the $Z$-boson and $W$-boson transverse momentum ($p_T$) distributions for large $p_T$ at LHC and Tevatron energies. We calculate complete next-to-leading-order (NLO) QCD corrections as well as soft-gluon corrections at next-to-next-to-leading-order (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 $p_T$ distributions and reductions of the scale dependence when the NNLO corrections are included.Comment: 17 pages, 14 figure

W-boson production with large transverse momentum at the LHC

We study W-boson production with large transverse momentum, Q_T, in pp collisions at the LHC. We calculate the complete NLO corrections and the soft-gluon NNLO corrections to the differential cross section. The NLO corrections are large but they do not reduce the scale dependence relative to LO, while the NNLO soft-gluon corrections, although small, significantly reduce the scale dependence and thus provide a more stable result.Comment: 5 pages, 3 figures, presented at the XIV International Workshop on Deep Inelastic Scattering (DIS 2006), Tsukuba, Japan, April 20-24, 200

High-sensitivity plasma density retrieval in a common-path second-harmonic interferometer through simultaneous group and phase velocity measurement

Precise measurements of the plasma density in ionized gas cells and discharged capillaries are critical to the design and operation of plasma-based accelerators, active plasma lenses, and plasma-based radiation sources. In this manuscript, a spectral-domain common-path second-harmonic interferometer is upgraded with the simultaneous measurement of the group and phase velocity, allowing for high-sensitivity density characterization (from the phase velocity advance) without the need for phase tracking from zero-density (enabled by the group velocity delay). The technique is applied to 1.5-cm-long plasma structures, without density ambiguity in parameter scans with >2π phase jumps. The single-shot sensitivity in phase retrieval is demonstrated at 63 mrad, equivalent to a density-length product of 1.8·1015 cm -2 . This is an improvement of ×45 compared to group velocity analysis alone

Surveying on the Side: A Study in the Implementation of a Tilted Multibeam Transducer in an Ultra-Shallow Riverine Environment

In 2008, students of the University of Southern Mississippi surveyed a portion of the Pearl River. Due to the ultra-shallow nature of the survey area, a multibeam mount was constructed that tilted the transducer 35o to the side with respect to nadir. Such an orientation had predicted gains of 60% in the center of the channel and facilitated the collection of data further inshore than otherwise possible. To compensate for excessive outer beam noise, a CUBE surface filtering regime was adopted. Crosscheck analysis showed the acquired data easily met IHO S-44 1a standards. This paper details the evaluation and results of such a non-traditional mount.En el 2008, unos alumnos de la Universidad del Sur de Misisipí levantaron un sector del Río Pearl. Debido a la naturaleza de las aguas ultra-someras de la zona del levantamiento, una estructura multihaz fue construida de forma tal que el transductor se inclinaba a 35° con respecto al nadir. Una orientación similar había pronosticado aumentos del 60 % en el centro del canal y facilitó la recogida de datos más cerca de la costa, que era posible de otra forma. Para compensar el exceso de ruido del haz externo, se adoptó un régimen “CUBE” de filtrado de superficie. El análisis de verificaciones cruzadas mostró que los datos obtenidos cumplían fácilmente la norma S-44 de la OHI. Este documento detalla la evaluación y los resultados de un montaje similar no tradicional.En 2008, des étudiants de l’University of Southern Mississippi ont exécuté des levés hydrographiques dans une partie du fleuve Pearl. En raison de la nature extrêmement peu profonde de la zone hydrographiée, une structure multifaisceaux a été construite de manière à ce que le transduceur soit incliné de 35° par rapport au nadir. Cette orientation avait permis de prévoir une augmentation de 60% au centre du canal et permis la collecte de données plus proches de la côte que ce qui aurait été possible, autrement. Afin de compenser le bruit excessif du faisceau externe, un régime de filtrage de surface CUBE a été adopté. L’analyse par recoupement a montré que les données acquises étaient sans nul doute conformes à la S-44 de l’OHI. Cet article donne le détail de l’évaluation et des résultats de ce type de structure non traditionnelle

W production at large transverse momentum at the Large Hadron Collider

We study the production of W bosons at large transverse momentum in pp collisions at the Large Hadron Collider (LHC). We calculate the complete next-to-leading order (NLO) corrections to the differential cross section. We find that the NLO corrections provide a large increase to the cross section but, surprisingly, do not reduce the scale dependence relative to leading order (LO). We also calculate next-to-next-to-leading-order (NNLO) soft-gluon corrections and find that, although they are small, they significantly reduce the scale dependence thus providing a more stable theoretical prediction.Comment: 12 pages, 7 figure