413 research outputs found
W hadroproduction at large transverse momentum beyond next-to-leading order
We study the production of W bosons at large transverse momentum in p pbar
collisions. We show that the next-to-leading order cross section at large
transverse momentum is dominated by threshold soft-gluon corrections. We add
next-to-next-to-leading-order soft-gluon corrections to the exact
next-to-leading-order differential cross sections. We find that these
higher-order corrections provide modest enhancements to the transverse momentum
distribution of the W at the Tevatron, and reduce significantly the dependence
on the factorization and renormalization scales.Comment: 17 pages, 8 figure
Charged Higgs production via bg -> tH- at the LHC
I present a calculation of QCD radiative corrections to charged Higgs
production via the process bg -> tH-. I show that the cross section is
dominated by soft-gluon corrections, which are computed through
next-to-next-to-leading order. Results for charged Higgs production at the LHC
are presented, including the dependence of the cross section on the charged
Higgs mass, the top quark mass, the factorization and renormalization scales,
and tan beta.Comment: 11 pages, 8 figure
Top quark total and differential cross sections at NNLO and NNLL
I present recent NNLO-NNLL results for top quark hadroproduction at the
Tevatron. The total cross section as well as transverse momentum and rapidity
distributions are shown.Comment: 4 pages LaTeX, 2 figures; presented at DPF2000, to appear in the
Proceeding
Single top quark production at the Tevatron: threshold resummation and finite-order soft gluon corrections
I present a calculation of threshold soft-gluon corrections to single top
quark production in ppbar collisions via all partonic processes in the t and s
channels and via associated top quark and W boson production. The soft-gluon
corrections are formally resummed to all orders, and finite-order expansions of
the resummed cross section are calculated through
next-to-next-to-next-to-leading order (NNNLO) at next-to-leading logarithmic
(NLL) accuracy. Numerical results for single top quark production at the
Tevatron are presented, including the dependence of the cross sections on the
top quark mass and on the factorization and renormalization scales. The
threshold corrections in the t channel are small while in the s channel they
are large and dominant. Associated tW production remains relatively minor due
to the small leading-order cross section even though the K factors are large.Comment: 24 pages, 19 figures; some changes and additional results;
uncertainty in t channel corrected; to appear in Phys. Rev.
Theoretical status of the top quark cross section
We discuss the most recent calculations of the top quark total cross section
and transverse momentum distributions at the Tevatron and the LHC. These
calculations include the soft-gluon corrections at next-to-next-to-leading
order (NNLO). The soft NNLO corrections stabilize the scale dependence of the
cross section.Comment: 4 pages, 2 figures, presented at DPF 2004, Riverside, California,
August 26-31, 200
Understanding Bottom Production
We describe calculations of b b-bar production to next-to-next-to-leading
order (NNLO) and next-to-next-to-leading logarithm (NNLL) near threshold in pp
interactions. Our calculations are in good agreement with the b b-bar total
cross section measured by HERA-B.Comment: contribution to the proceedings of Quark Matter'02, 4 pages, 1 .eps
figure, uses special included style fil
Effects of Higher-Order Threshold Corrections in High-E_T Jet Production
Results for higher-order threshold enhancements in high-E_T jet production in
hadron-hadron collisions are presented. Expressions are given for the
next-to-next-to-leading order (NNLO) threshold corrections to the single-jet
inclusive cross section at next-to-leading logarithmic (NLL) accuracy. The
corrections are found to be small for the specific choice of E_T/2 for the
factorization and renormalization scales, and the corrected cross section shows
a substantial reduction of the scale dependence. A comparison to experimental
results from the Tevatron is presented.Comment: 24 pages LaTeX, 5 figure
NNLL resummation for s-channel single top quark production
I present the next-to-next-to-leading-logarithm (NNLL) resummation of soft
and collinear gluon corrections to single top quark production in the s
channel. Attaining NNLL accuracy involves the calculation of the two-loop soft
anomalous dimension for the partonic subprocesses. Finite-order expansions of
the resummed cross section are calculated through next-to-next-to-leading order
(NNLO). Numerical results are presented for s-channel single top quark
production at the Tevatron and the LHC, including the dependence of the cross
sections on the top quark mass and the uncertainties in the theoretical
prediction. The higher-order corrections are significant for energies at both
colliders and they decrease the theoretical uncertainty.Comment: 17 pages, 12 figures; added figures and discussio
Soft-gluon resummation for heavy quark production in hadronic collisions
We discuss the heavy quark production cross section near partonic threshold
in hadronic collisions, including the resummation of leading and
next-to-leading logarithms arising from soft gluon emission. We show how to
handle the complications due to the non-universal non-leading logarithms. We
give analytical results for the partonic subprocess and numerical
results in the DIS scheme for top quark production at the Fermilab Tevatron
where the channel dominates.Comment: 16 pages LaTeX including 4 eps figures, a few equations and some text
added, figure 3 corrected, other small change
Next-to-next-to-next-to-leading-order soft-gluon corrections in hard-scattering processes near threshold
I present a unified calculation of soft-gluon corrections to hard-scattering
cross sections through next-to-next-to-next-to-leading order (NNNLO). Master
formulas are derived, from a threshold resummation formalism, that can be
applied to total and differential cross sections for hard-scattering processes
in hadron colliders. I also present numerical results for charged Higgs
production at the LHC where these corrections are large, and for top quark
production at the Tevatron where these corrections greatly reduce the scale
dependence of the cross section.Comment: 22 pages, 3 figure
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