arXiv subjects

Jim Brau

Publications and source records attributed to Jim Brau.

4 recordsLinked to original sources

arXiv2022

Expected Sensitivity to Invisible Higgs Boson Decays at the ILC with the SiD Detector (A Snowmass White Paper)

In the Standard Model (SM) of particle physics, the branching ratio for Higgs boson decays to a final state which is invisible to collider detectors, $H \rightarrow ZZ^{\star} \rightarrow \nu \bar{\nu} \nu \bar{\nu}$, is order 0.10%. In theories beyond the SM (BSM), this branching ratio can be enhanced by decays to undiscovered particles like dark matter (DM). At the Large Hadron Collider (LHC), the current best upper limit on the branching ratio of invisible Higgs boson decays is 11% at 95% confidence level. We investigate the expected sensitivity to invisible Higgs decays with the Silicon Detector (SiD) at the International Linear Collider (ILC). We conclude that at $\sqrt{s}=250$ GeV with 900 fb$^{-1}$ integrated luminosity each for $e_{L}^-e_{R}^+$ and $e_{R}^-e_{L}^+$ at nominal beam polarization fractions, the expected upper limit is 0.16% at 95% confidence level.

hep-ph↗

arXiv2022

Strategy for Understanding the Higgs Physics: The Cool Copper Collider

A program to build a lepton-collider Higgs factory, to precisely measure the couplings of the Higgs boson to other particles, followed by a higher energy run to establish the Higgs self-coupling and expand the new physics reach, is widely recognized as a primary focus of modern particle physics. We propose a strategy that focuses on a new technology and preliminary estimates suggest that can lead to a compact, affordable machine. New technology investigations will provide much needed enthusiasm for our field, resulting in trained workforce. This cost-effective, compact design, with technologies useful for a broad range of other accelerator applications, could be realized as a project in the US. Its technology innovations, both in the accelerator and the detector, will offer unique and exciting opportunities to young scientists. Moreover, cost effective compact designs, broadly applicable to other fields of research, are more likely to obtain financial support from our funding agencies.

hep-ex↗

arXiv2021

H$\rightarrow$invisible at the ILC with SiD

The Standard Model (SM) predicts a branching ratio of the Higgs boson decaying to invisible particles of $\mathcal{O}$(0.001), though current measurements have only set upper limits on this value. The small SM-allowed rate can be enhanced if the Higgs boson decays into new particles such as dark matter. Upper limits have been placed on BR(H$\rightarrow$inv.) by ATLAS and CMS at $\mathcal{O}$(0.1), but the hadron environment limits precision. The ILC `Higgs factory' will provide unprecedented precision of this electroweak measurement. Studies of the search for H$\rightarrow$invisible processes in simulation are presented with SiD, a detector concept designed for the ILC. Preliminary results for expected sensitivity are provided, as well as studies considering potential systematics limitations.

hep-ex↗

arXiv2013

The International Linear Collider

We present a brief summary of the International Linear Collider as documented in the 2013 Technical Design Report. The Technical Design Report has detailed descriptions of the accelerator baseline design for a 500 GeV e+e- linear collider, the R&D program that has demonstrated its feasibility, the physics goals and expected sensitivities, and the description of the ILD and SiD detectors and their capabilities.

physics.acc-ph↗