arXiv subjects

Richard J. Gonsalves

Publications and source records attributed to Richard J. Gonsalves.

8 recordsLinked to original sources

arXiv2014

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.

hep-ph↗

arXiv2012

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.

hep-ph↗

arXiv2012

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.

hep-ph↗

arXiv2011

Two-loop corrections to W and Z boson production at high pT

We present new results for the complete two-loop corrections in the soft approximation for W and Z boson production at large transverse momentum. Analytical expressions for the NNLO approximate corrections are used to calculate transverse momentum distributions. Results for the W boson pT distribution at Tevatron and LHC energies are presented.

hep-ph↗

arXiv2008

Perturbative QCD at High Energy Colliders

Selected applications of perturbative Quantumchromodynamics (QCD) to predictions of the Standard Model for processes at high energy colliders are reviewed with emphasis on past successes and future problems. This is a personal retrospective is not intended to be a comprehensive review of the field.

hep-ph↗

arXiv2006

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.

hep-ph↗

arXiv2005

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.

hep-ph↗

arXiv1996

Chromo-electroweak interference and parity-violating asymmetries in the production of an electroweak boson + two jets in hadron collisions

In the Standard Model the process $q\bar{q}\rightarrow q\bar{q}V$ (where $V=W^\pm,Z^0$ or $γ$) can occur via gluon exchange and also via $W^\pm$ or $Z^0$ exchange. The corresponding chromodynamic and electroweak amplitudes can interfere with one another. These interference cross sections are largest when the exchanged $W^\pm$ or $Z^0$ is on-shell when they are also odd under parity. Interference cross sections computed using helicity-amplitude techniques are presented for all interesting subprocesses as well as for the processes $q\bar{q}\rightarrow q\bar{q} l\bar{l}$ in which the lepton pair $l\bar{l}$ comes from the decay of $V$ on-shell. Parity-violating asymmetries are defined and presented at the parton level and for the hadronic processes $pp$ or $p\bar{p}\rightarrow V$ + 2 jets or $l\bar{l}$ + 2 jets. These asymmetries are independent of the polarizations of all particles involved, and do not require that the flavors of the jet partons be measured. They are generally of order 0.01 pb at energies $\sqrt{s} \gtrsim 1$ TeV.

hep-ph↗