- The paper implements the POWHEG method for NLO Higgs production, yielding positively weighted events integrated with various shower Monte Carlo programs.
- It validates the approach by comparing kinematic distributions, noting discrepancies such as differences in high-transverse momentum jets relative to MC@NLO.
- The study enhances radiation pattern modeling through Sudakov form factors, partially recovering NNLO contributions for improved collider predictions.
Next-to-Leading Order Higgs Boson Production via Gluon Fusion Matched with Shower in POWHEG
This paper presents a comprehensive next-to-leading order (NLO) calculation of Higgs boson production via gluon fusion, interfaced with shower Monte Carlo programs using the POWHEG method. The aim of the paper is to provide a tool that generates events with positive and consistent weights, improving upon existing implementations by not being tied to a specific shower Monte Carlo program, thus enhancing its applicability to contemporary shower generators.
The dominant production mechanism both at the Tevatron and LHC involves Higgs boson production predominantly through gluon fusion. Large radiative corrections are characteristic of this process, necessitating precise computational models for experimental analyses. The POWHEG method, first proposed by Nason, facilitates the integration of NLO cross-sections with parton shower simulations effectively, offering improvements over existing methods by avoiding negative weight events prevalent in alternative approaches like MC@NLO.
Key Contributions and Comparisons:
- Implementation and Validation: The paper implements the POWHEG approach for Higgs boson production, allowing integration with different shower Monte Carlo programs. Key comparisons are made with MC@NLO and standalone NLO computations to validate the implementation's consistency and precision. Specifically, events are interfaced with both HERWIG and PYTHIA, delivering consistent results while maintaining the integrity of NLO computations.
- Phenomenological Results: A detailed phenomenological analysis is provided for both the Tevatron and LHC scenarios, comparing various kinematic distributions, including rapidity and transverse momentum of the Higgs boson and accompanying jets. Notable discrepancies in high-transverse-momentum jets between POWHEG and MC@NLO point to inherent differences in NNLO contributions captured by POWHEG, which are not included directly in NLO computations.
- Sudakov Resummation and NNLO Effects: The paper highlights the enhanced description of radiation patterns, especially in high transverse momentum regions, and confirms compatibility with NNLO results. The POWHEG implementation's treatment of Sudakov form factors allows partial recovery of NNLO contributions, offering a notable improvement over traditional NLO results, aligning closer to NNLO predictions. This is directly corroborated with HNNLO comparisons.
- Addressing Rapidity Discrepancies: The persistent rapidity distribution discrepancies, such as dips in the difference between the hardest jet and Higgs boson rapidity, echo previous observations in related studies. These distinctive features are attributed to the specifics of the POWHEG algorithm and indicate areas for potential refinement in future implementations.
Implications and Future Developments:
The research underscores POWHEG's advantage in generating positively weighted events with enhanced flexibility for integration with modern shower schemes, thereby providing a robust tool for theoretical and experimental Higgs physics analyses. As collider experiments advance, the ability to simulate Higgs production with refined accuracy is vital, and extensions to account for further NNLO corrections within POWHEG are anticipated. Future developments could focus on refining rapidity predictions and optimizing scale choices within the Sudakov implementations to enhance predictive accuracy further.
In conclusion, this paper's implementation of POWHEG for Higgs boson production establishes a foundational tool that enhances the precision of theoretical predictions for collider experiments, reflecting substantial progress in computational methods in collider physics. The ongoing exploration of NNLO corrections and continuous validation against empirical data remain vital as theoretical models evolve alongside advancing collider capabilities.