Abstract: A summary is given of the current status of the next-to-leading order (NLO) parton-level integrator MCFM. Some details are given about the Higgs + 2-jet process and the production and decay of $t \bar{t}$, both of which have recently been added to the code. Using MCFM, comparisons between the Tevatron running at $\sqrt{s}=2$~TeV and the LHC running at $\sqrt{s}=7$~TeV are made for standard model process including the production of Higgs bosons. The case for running the Tevatron until 16fb${-1}$ are accumulated by both detectors is sketched.
The paper demonstrates enhanced MCFM capabilities by integrating NLO computations for Higgs plus two jets and top quark pair production and decay.
It employs an effective Lagrangian approach with analytic one-loop calculations to significantly improve computational efficiency.
It compares Tevatron and LHC performance, revealing competitive q̄q initiated process insights and guiding future collider experiment analyses.
Analysis of MCFM for the Tevatron and the LHC
The paper presents a detailed exploration of the capabilities and recent updates of the MCFM (Monte Carlo for FeMtobarn processes) software package, a next-to-leading order (NLO) parton-level event integrator. It examines its deployment in evaluating standard model processes at the Tevatron and the Large Hadron Collider (LHC), with a specific focus on the software's application to new processes such as Higgs boson production in association with two jets and top quark pair production and decay.
Overview of MCFM's Capabilities
MCFM provides NLO calculations for a variety of processes, particularly those involving W, Z, and Higgs bosons, as well as heavy quarks like c, b, and t. The recent updates, introduced in version 5.8, include new processes such as Higgs production with two jets and top quark pair production involving decay. MCFM enables comparisons between the Tevatron at s=2 TeV and the LHC at s=7 TeV, focusing on differences in standard model process cross-sections arising from parton luminosities.
Focus on Higgs + Two Jets
The paper highlights the addition of the Higgs plus two jets process in MCFM, leveraging NLO computations facilitated by an effective Lagrangian approach using gluon-Higgs coupling. The inclusion of analytic calculations of one-loop Higgs plus four-parton amplitudes noticeably increases computational efficiency. This process is crucial not only for understanding Higgs production at the LHC but also at the Tevatron, where it contributes significantly to experimental analyses due to its distinctive kinematic structure.
Top Quark Pair Production and Decay
The paper further elaborates on top quark pair production and decay processes being integrated into MCFM with NLO precision. It maintains the top quarks on-shell, ensuring separate gauge-invariant production and decay processes while incorporating full spin correlations. This enhancement is indispensable due to the role of top pair production as a background process across various collider experiments.
Comparative Performance at the Tevatron and LHC
With the advent of the LHC, a comparison of parton luminosities indicates that the Tevatron remains competitive for qqˉ initiated processes due to advantageous luminosity in certain energy ranges. Calculations suggest that, particularly for processes like vector boson fusion, the Tevatron can offer significant insights and opportunities for discovery, even when LHC accumulations at s=7 TeV are considered.
Implications and Future Prospects
The integration of new processes into MCFM opens avenues for more refined and accurate phenomenological studies, essential for validating theoretical predictions with experimental data. These improvements have implications for ongoing and future research activities at both the Tevatron and the LHC, especially in contexts such as Higgs and top physics. While the Tevatron's continued operation can yield complementary data, the ongoing increase in LHC capabilities will eventually provide more comprehensive insight into high-energy physics phenomena.
Overall, the paper underlines the significance of refining computational tools like MCFM, enabling the physics community to leverage precise theoretical models to juxtapose with the increasingly complex data emerging from modern collider experiments. These advancements are instrumental in driving theoretical and experimental high-energy physics synergy forward.
