We are back!

The various stages of the ILC. Image: Rey.Hori

You may be wondering what has happened to LC NewsLine over the past few months. Before I explain what has been going on, I am sure that you will all join me in offering our heartiest congratulation to Barry Barish for his award of part of the 2017 Nobel.

During the time that we have been off the air, there have been a few new developments on the ILC side. The most important of these were an extensive discussion in the community of the merit of a 250 GeV centre-of-mass Higgs Factory, which has the possibility of reducing the cost by up to 40 percent, leaving open the possibility of upgrading the machine to higher energy in the future, and an optimisation of the machine design for 250 GeV. Starting with a smaller machine that will still deliver great science, especially for studying the Higgs, seems like an ideal compromise to us. The reduced cost will make it easier for all countries involved to commit to it, and I think we agree that building it is better than not building it at all. It would not be the first science project that is conceived that way.

At the ICFA Seminar held in Ottawa from 6 to 9 November, two papers were presented to the meeting of  the Linear Collider Board and ICFA which took place in the sidelines of the Seminar. The first concerned the scientific justification for the 250-GeV machine which confirms and extends the compelling scientific case. The second was an annex to the TDR of the machine design which describes the optimisation for 250 GeV with a few options which would allow an upgrade to higher energy with minimum perturbation. The ICFA statement on the ILC-250 is reproduced below.

ICFA Statement on the ILC Operating at 250 GeV as a Higgs Boson Factory 

The discovery of a Higgs boson in 2012 at the Large Hadron Collider (LHC) at CERN is one of the most significant recent breakthroughs in science and marks a major step forward in fundamental physics.

Precision studies of the Higgs boson will further deepen our understanding of the most fundamental laws of matter and its interactions.

The International Linear Collider (ILC) operating at 250 GeV center-of-mass energy will provide excellent science from precision studies of the Higgs boson. Therefore, ICFA considers the ILC a key science project complementary to the LHC and its upgrade.

ICFA welcomes the efforts by the Linear Collider Collaboration on cost reductions for the ILC, which indicate that up to 40% cost reduction relative to the 2013 Technical Design Report (500 GeV ILC) is possible for a 250 GeV collider.

ICFA emphasizes the extendibility of the ILC to higher energies and notes that there is large discovery potential with important additional measurements accessible at energies beyond 250 GeV.

ICFA thus supports the conclusions of the Linear Collider Board (LCB) in their report presented at this meeting and very strongly encourages Japan to realize the ILC in a timely fashion as a Higgs boson factory with a center-of-mass energy of 250 GeV as an international project (1), led by Japanese initiative.

Ottawa, November 2017

 (1) In the LCB report the European XFEL and FAIR are mentioned as recent examples for international projects.

So 2018 will be a critical year for the ILC.

I wish you all the very best and hope for a positive outcome.

Oh, for those who were wondering where NewsLine had been all this time: Until recently the LC NewsLine web pages were supported by Maura Barone at Fermilab. Maura has now moved on to other things – thank you, Maura, for all your effort over the years! – so a new home had to be found. At the same time, it was decided to better integrate the ILC and CLIC activities into a common platform, so the web support for both CLIC and ILC has been moved to CERN. This took some time to set up but now we are up and running once more. You may experience some changes to the website soon, too.