1. High Energy Physics, Past, Present and Future Hirotaka Sugawara, OIST Abdus Salam Symposium, Singapore, Jan. 2016

2. 1.Past, Present and Future of Physical Constants 1a. C, ħ and G 1b. Inflation vs. Planck length 1c. Higgs potential vs. Planck length 2. Past, Present and Future of VBA 2a. Failure of SSC 2b. How we proceeded with ILC? 2c. Comparison of SPPC(FCC-hh) with SSC 2d. Comparison of CEPC(FCC-ee) with ILC

3. c (light velocity) We can eliminate c from above equations by setting, This means the unification of space and time to 4 dimensions. We can also eliminate c from relativity- modified Newton’s equation by using proper time. When the gravity is included, c is absorbed in the metric. Thus c is completely eliminated from theory. -  C is the vacuum value of the velocity of light.

4. G (gravitational constant ) The meaning of G was completely change by Einstein equation: Energy-momentum is related to the curvature of space-time. G is the transformation factor. In general, it is not possible to absorb G to eliminate it from the equation.

5. ħ (Planck constant) Originally, ħ was introduced as, Transformation factor of frequency and energy. Feynman path integral interprets ħ to be a unit of an action: Question: Is it possible to eliminate ħ from theory?

6. Example: QED By redefining, We get, We cannot eliminate h but we can absorb it to other constants.

7. Example 2: 11-dimensional supergravity

8. We can easily prove that can be absorbed into the field variables by redefining them. This means that there are no fundamental constants in low energy realization of string theory. One can show that this is true for the string theory itself. All three fundamental constants are dynamical meaning they are vacuum value of something. -  Moduli We need to understand the dynamic of/in moduli space.

9. Inflation and the Planck scale Hubble constant H :

10. 1.In case of radiation dominance, the relevant time(temperature) is far away from the Planck time (Planck energy). 2. In case of vacuum (inflation) putting is completely ad-hoc. We use only classical theory in Inflation. What is important is the flat potential which gives slow roll resulting in huge entropy production. There is no Planck length in the inflation model. There is no Planck length in the string inflation model where modulei dynamics is used.

11. Higgs potential and the Planck scale From Iso’s calculation

12. This indicates that we may use the Higgs potential at high mass as the inflaton with experimental input of near Planck scale. It also implies another solution to the hierarchy problem(other than supersymmetry (W. Bardeen) But this is very mysterious.

13. Failure of SSC From the 10,13 August 1983 ICFA meeting: DISCUSSION ON THE RECCOMENDATIONS OF THE WOODS HOLE SUB-PANEL TO HEPAP. Several speakers expressed their unhappiness that the recent US development had taken place without any previous discussion in ICFA or sufficient consultation between the regions. A long discussion then ensued on the possible role of ICFA in the future in promoting more inter-regional collaboration and consultation.

14. In the report by ICFA Chair Telegdi to the 12 October 1984 ICFA meeting: It had in fact been recognized at the ICFA meeting held at Fermilab in August 1983 that ICFA’s original charge, i.e. to promote the construction of a “World Accelerator”, the so-called VBA, could not be realistically pursued at present, since some current regional projects (e.g. the SSC in the USA) were already of the size originally envisaged for the VBA, and hence appeared to banish the “real” VBA into a future too distant for constructive discussion at present.

15. RESOLUTION IN SUPPORT OF INTERNATIONAL PARTICIPATION IN THE SSC (L. Pondrom, Paper dated 1 June 1989) After a frank discussion, during which several members pointed out that it was not ICFA’s role to comment on the merits of regional plans for future accelerators, L. Pondrom agreed to withdraw his draft resolution. However, ICFA reiterated its belief that international participation in the construction and exploitation of future accelerators in the different regions should be strongly encouraged.

16. In a summary of ICFA activities in March 1991, ICFA Chair Skrinsky said: ICFA expresses its strong support for the ongoing efforts towards extensive international collaboration for the construction and exploitation of the next generation of high energy hadron accelerators… In a summary of ICFA Activities in July 1992, ICFA Chair Skrinsky said: ICFA further recommends that the design and use of future large high-energy physics facilities, including the appropriate R&D, should have international participation from the start to ensure that the full intellectual capabilities of the international community are utilized.

17. ILC project It was started as a fully international project and still it is. ICFA has been taking the initiative Under ICFA we created ILCSC(steering committee) We also created FALC(funding agency for LC) Under ILCSC we created ITRP(International Technology Recommendation Panel)

18. ITRP ---------------- Linear Collider Technology Recommendation ---- Barry Barish ILCSC/ICFA Special Meeting IHEP, Beijing 19-Aug-04

19. Jean-Eudes Augustin (FRANCE) Jonathan Bagger (USA) Barry Barish (USA) - Chair Giorgio Bellettini (ITALY) Paul Grannis (USA) Norbert Holtkamp (USA) George Kalmus (UK) Gyung-Su Lee (KOREA) Akira Masaike (JAPAN) Katsunobu Oide (JAPAN) Volker Soergel (Germany) Hirotaka Sugawara (JAPAN) David Plane - Scientific Secretary The ITRP Members

21. We recommend that the linear collider be based on super- conducting rf technology (from Exec. Summary) –This recommendation is made with the understanding that we are recommending a technology, not a design. We expect the final design to be developed by a team drawn from the combined warm and cold linear collider communities, taking full advantage of the experience and expertise of both (from the Executive Summary). –We submit the Executive Summary today to ILCSC & ICFA –Details of the assessment will be presented in the body of the ITRP report to be published around mid September –The superconducting technology has features that tipped the balance in its favor. They follow in part from the low rf frequency. The Recommendation

22. This recommendation had a huge effect on the LC activities SLAC stopped the entire LC activities based on X-band technology DESY continued but switched to FEL KEK changed the policy from warm to cold (painstaking but KEK was technically advanced in “cold” also. )

23. International Linear Collider Design Completion Ceremony 15 December 2012 in Tokyo Hirotaka Sugawara Okinawa Institute for Science and Technology (OIST)

24. Congratulations to all involved in the GDE activities lead by Barry Barish ! After five years of hard work by an international team they have completed their findings in two crucial reports: The ILC Technical Design Report and The ILC Detailed Baseline Design Report

25. The next step is to create a new organization, led by Lyn Evans. Working closely with ICFA and ILCSC they will: 1. Continue the current R/D effort 2. Concretely shape the International Linear Collider Laboratory 3. Determine the ILC site 4. Finalize the ILC technology 5. Determine the initial ILC energy 6. Work hard to finance the ILC project

26. Robert Aymar RE: linear collider June 18, 2004 12:05 AM Dear Prof. Sugawara, Thank you for your cordial letter of May 21 st about future accelerators, with which I am largely in agreement. You are surely correct that the best way to ensure a healthy future for our field is to adopt and maintain a unified approach. In that respect, I am very glad that representatives of funding agencies, including that of Japan, were able to take important steps towards such a unified view at their recent meeting in London. As you say, an important aspect of this unified view is that the LHC will need to be complemented by a linear electron-positron collider. It was generally recognized at the London meeting that final approval for its construction is likely to be realistic only after the first results from the LHC become available, and that the desirable energy scale may need to be reviewed in light of LHC results. It seems that you agree with me on at least the first part of this point, in view of the American and Japanese situations, even if you would have preferred an earlier go-ahead. In the mean time, thanks in large part to your personal efforts, Japan has an exciting programme of neutrino physics in front of it. You may be assured that CERN will do its best to help secure approval of a linear collider, first by completing the LHC and extracting key physics information from it, and secondly by striving to convince the world’s political authorities of the importance of our common endeavour. I look forward to working together to ensure the continuing vitality of our field. Yours sincerely, Robert Aymar

27. SPPC(CEPC) or FCC-hh(ee) and SSC(ILC)

28. CEPC-SPPC Preliminary Conceptual Design Report Volume II – Accelerator The CEPC-SPPC Study Group March 2015

29. Acknowledgements The CEPC-SPPC Preliminary Conceptual Design Report (Pre- CDR) was prepared and written by the CEPC-SPPC Study Group. The study was organized and led by the Institute of High Energy Physics (IHEP) of the Chinese Academy of Sciences (CAS) in collaboration with a number of institutions from various countries. The study was partially supported by the CAS/SAFEA International Partnership Program for Creative Research Teams. The current volume is on the accelerators. There will be a separate volume on physics and the detectors. This volume was authored by about 300 scientists and engineers from 57 institutions in 9 countries (China, US, France, UK, Germany, Italy, Russia, Japan, and Australia). It has been reviewed by an International Review Committee before its release in March 2015.

30. SPPCSSC CM energy71.2 TeV40 TeV circumference54.4 km83 km Dipole field20T6.6T luminocity1.2x10**35 cm**2.sec**-1 10**33 cm**2.sec**-1 Both machines are unilaterally proposed by one country and,interestingly, both machines were (are) in competition with CERN’s future project.

31. SSC ( M.Pearl, SLAC) Beam Parameters: This proton-proton collider has a maximum energy of 40 TeV and a maximum luminosity of 1O33cm-“s-l. This luminosity is obtained when there are 1.2 x 1014 protons in each main ring, distributed over 1.7 x lo4 bunches. Main Rings: The two main rings, arranged one above the other, with a circumference of 83 km (Fig. 1) are in a tunnel at least 7 m underground. As shown in Fig. 1 the six experimental halls, the beam injection and abort areas, and the RF cavities are arranged in two sections called the East and West Clusters. This arrangement provides operating efficiency and economic advantages. The aperature of the main rings has a diameter of 3.3 cm. Main Ring Bending Magnets: These superconducting magnets have niobium-titanium coils. As shown in Fig. 2 the coils, stainless steel coil-retaining collars, and the iron flux return are all at a liquid He temperature of 4.35 OK. The magnets are 17.3 m long and provide a field of 6.6 T. Each ring has its own magnets, about 3800 per ring.

32. CEPC and ILC 240GeV circular machine is not far from LEP(207GeV).Therefore, not much technical issue is involved unless we try to deploy some new feature like a single ring for e+ and e-, in which case the issue of pretzel scheme will be formidable. The big difference between ILC and CEPC is in the power consumption. CEPC (240GeV)---500MW ILC (500GeV)---160MW This makes it almost impossible for circular machine to go beyond 240GeV. Radiation loss is E**4 (3.11GeV/sec at 240 GeV/sec and 14.6GeV at 350 GeV)

33. Physics Understanding of the Higgs potential is the most important issue. For this purpose, we must know the precise top quark mass, requiring at least 350GeV e+e- energy. Higgs self-coupling must be studied which also cannot be done by 240 GeV machine. Many Higgs parameters can be better studied at higher than 240 GeV.

34. My friendly advice 1.~100TeV hadron machine is more or less the consensus of the community. Global effort towards the 20T Nb(3)Sn superconducting magnet must be started as soon as possible to finish the work in 10 years. IHEP(Beijing) and CERN should take the initiative under the supervision of ICFA. 2.US, Japan and other countries must be involved. 3.Test stands may be constructed in IHEP, CERN, Femilab, KEK etc.. (Going from 13T(HL-LHC), 16T( FCC-hh) to 20T is an increasingly steeper up-hill process.)

35. 4. As for the CEPC (FCC-ee), I advise ICFA to form an international panel (like ITRP) to discuss whether it is a good idea to have a lepton machine before going to ~100 TeV hadron machine. 5. The panel must be composed of theorists, experimentalists and accelerator physicists as ITRP. (What I am afraid is that 240 GeV e+e- machine may not produce much physics output but simply delays the construction of ~100TeV hadron machine.)