SAPPHiRE: a Small Gamma-Gamma Higgs Factory

TL;DR

The paper proposes a cost-effective gamma-gamma collider design using recirculating linacs to study the Higgs boson in detail, offering a new approach for Higgs physics research.

Contribution

It introduces the SAPPHiRE design, a novel recirculating linac-based gamma-gamma collider for Higgs studies, with detailed parameters and potential physics applications.

Findings

Achieves a gamma-gamma luminosity of 0.36 x 10^34/cm^2/s at 125 GeV

Enables precise measurements of Higgs mass and decay channels

Suggests synergies with other collider projects like LHeC, ILC, and CLIC

Abstract

A new particle with mass ~ 125 GeV that resembles the Higgs boson has recently been discovered by ATLAS and CMS. We propose a low-energy gamma-gamma collider as a cost- and time-efficient option for a Higgs factory capable of studying this particle in detail. In the past, this option has been suggested as a possible application of the CLIC two-beam accelerator technology (the CLIC Higgs Experiment, CLICHE) or as an option for the ILC. Here we propose a design based on a pair of \sim 10 GeV recirculating Linacs (Small Accelerator for Photon-Photon Higgs production using Recirculating Electrons, SAPPHiRE) similar in design to those proposed for the LHeC. We present parameters for the e- beams and sketch a laser backscattering system capable of producing a gamma-gamma peak luminosity of 0.36 \times 10^34/cm2/s with E_CM (gamma-gamma) \sim 125 GeV. A gamma-gamma collider with such a luminosity could be used to measure accurately the mass, bbar, WW\ast, and gamma-gamma decays of the Higgs boson. We also comment on possible synergies with other projects such as LHeC, the ILC or CLIC, and on other physics prospects in gamma-gamma and e-gamma collisions.