Proceedings of the Erice Workshop: A new baseline for the hybrid, asymmetric, linear Higgs factory HALHF

TL;DR

This paper presents a new optimized baseline design for the HALHF Higgs factory that improves luminosity, reduces energy boost, and adds polarization features, while remaining cost-effective compared to other proposals.

Contribution

The paper introduces a revised HALHF design addressing previous weaknesses, enhancing performance and features, and providing detailed discussions on practicality and optimization.

Findings

Higher luminosity achieved in the new baseline

Reduced center-of-mass energy boost

Inclusion of positron and electron polarization

Abstract

The HALHF collaboration has discussed a new baseline for the project, taking into account comments from the accelerator community on various aspects of the original design. In particular, these concerned the practicality of the dual-purpose linac to accelerate both colliding positron bunches and the drive beams required for the plasma linac. In addition, many other aspects of the project were also considered; the discussion and conclusions are documented in this paper. Finally, a new baseline is outlined that has been optimised and addresses several weaknesses in the original design, has higher luminosity, reduced centre-of-mass energy boost and additional features such as positron polarization as well as electron polarization. Although HALHF has become longer and more expensive, it remains significantly smaller and cheaper than other mature Higgs factory designs currently under discussion.