High Energy Physics, Past, Present
and Future
Hirotaka Sugawara, OIST
Abdus Salam Symposium, Singapore,
Jan. 2016
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
c (light velocity)
We can eliminate c from above equations by setting,
cdt ® dx 0,cB ® B
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.
G (gravitational constant)
V = G
mm¢
r
The meaning of G was completely
change by Einstein equation:
Rmn -
1
Rgmn = 8p GTmn
2
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.
ħ (Planck constant)
Originally, ħ was introduced as,
E = hn = w
Transformation factor of
frequency and energy.
Feynman path integral
interprets ħ to be a unit of an
action:
i
S = [exp( ò L )]dpath
Question:
Is it possible to eliminate ħ
from theory?
Example: QED
S=
1
ò [F
mn
mn
m
m
F + y (ig m¶ + m + eg m A )y ]
By redefining,
Am
® Am ,
ym
® ym
We get,
S = ò [Fmn F + y (ig m¶ +
mn
m
m
+
e
g m Am )y ]
We cannot eliminate h but we can
absorb it to other constants.
Example 2: 11-dimensional supergravity
S = exp{
i
ò
L}
L = LB + LF
LB = -
1
1 M1N1 M 2 N2 M 3N3 M 4 N4
eR
G G G G FM1M 2M 3M 4 FN1N2 N3N4
2
k
48
k M1
e
3456
M11
FM1M 2 M3M 4 FM 5M 6 M 7M8 AM 9M10 M11
1
LF = - ey M1 G M1M 2 M3 DM 2 y M 3
2
-
k
e(y M1 G M1M 2 M 3M 4 M 5M 6 y M 6 +12g M 2 N1 g N 2 M 5y N1 G M 3M 4 y N 2 )
384
(F + F̂)M 2 M 3M 4 M 5
We can easily prove that , k
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.
Inflation and the Planck scale
Hubble constant H:
R - do min ance
H
2
» Gr = Gr R
\
H »
T2
cM pl
Vacuum
M4
r =V =
( c)3
\
H »
M2
cM pl
T4
=G
( c)3
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
V =M
( c)3
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.
V £ Dt, V £ (Dt)2
V
V
There is no Planck length in the inflation model.
There is no Planck length in the string inflation model
where modulei dynamics is used.
Higgs potential and the Planck scale
From Iso’s calculation
• 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.
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.
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.
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.
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.
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)
ITRP
---------------Linear Collider Technology
Recommendation
---Barry Barish
ILCSC/ICFA Special Meeting
IHEP, Beijing
19-Aug-04
The ITRP Members
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 Recommendation
• We recommend that the linear collider be based on superconducting 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.
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. )
International Linear Collider
Design Completion Ceremony
15 December 2012 in Tokyo
Hirotaka Sugawara
Okinawa Institute for
Science and Technology (OIST)
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
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
Robert Aymar <Robert.Aymar@cern.ch>
RE: linear collider
June 18, 2004 12:05 AM
Dear Prof. Sugawara,
Thank you for your cordial letter of May 21st 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 agenci
including that of Japan, were able to take important steps towards such a unified view at their rec
meeting in London.
As you say, an important aspect of this unified view is that the LHC will need to be complemented
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 se
that you agree with me on at least the first part of this point, in view of the American and Japanes
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 forw
to working together to ensure the continuing vitality of our field.
Yours sincerely,
Robert Aymar
SPPC(CEPC) or FCC-hh(ee) and
SSC(ILC)
CEPC-SPPC
Preliminary Conceptual
Design Report
Volume II – Accelerator
The CEPC-SPPC Study Group
March 2015
Acknowledgements
The CEPC-SPPC Preliminary Conceptual Design Report (PreCDR) 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.
SPPC
SSC
CM energy
71.2 TeV
40 TeV
circumference
54.4 km
83 km
Dipole field
20T
6.6T
luminocity
1.2x10**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.
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.
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)
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.
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.)
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+emachine may not produce much physics
output but simply delays the construction
of ~100TeV hadron machine.)