Views from KEK• Introduction• Basic strategy• Project priority (FY2003)• Organization/management– Appendix 1– Appendix 2

J-PARC IAC / Y.T.

1

Organization (till the end of FY 2003)
KEK

Institute of Particle and Nuclear Studies

Institute of Material Structure Science

Accelerator Laboratory

Applied Research Laboratory

J-PARC Project Office

Engineering Department

Administration Bureau

J-PARC IAC / Y.T.

2

BELLEKEKB (8GeVe-x3.5GeVe+)
K2K νµ beamline

6.5GeV AR

12GeV PS

2.5GeV PF

e+ & e- LINAC

J-PARC IAC / Y.T.

3

LINAC

PS + νµ line

6.5 GeV AP

J-PARC IAC / Y.T.

4• J-PARC is, to KEK, a new accelerator added tothe existing accelerator complex• Yet J-PARC is a joint project of JAERI and KEK,
and KEK wishes to take advantage of the close
cooperation with JAERIJ-PARC IAC / Y.T.

5

Basic strategy• Institute of Particle and Nuclear Studies at KEK
will make a full use of the 50 GeV PS for particle/ nuclear experiments• The neutron group at Institute of Material
Structure Science will closely cooperate with the
JAERI counterpart for 3GeV spallation neutron
source• Yet the KEK neutron group will make a healthy
competition with JAERI• KEK will be responsible for the low-energy muon
facility
J-PARC IAC / Y.T.

6

• Credits of experimental results obtained by KEK
personnel should be given to KEK• KEK keeps the principle of “Joint university use”;– University people, domestic or international, areallowed to submit proposals to use neutron/muon
beam lines, or to do particle/nuclear experiments– Proposals from industry are also encouraged– KEK supports domestic travel expenses and a part ofexperimental apparatus for approved proposals

J-PARC IAC / Y.T.

7

Project priority (FY2004)• 1st Priority for KEK’s FY2004 budget proposal for JPARC will be the neutrino oscillation experiment• Reason:– The JHEPC (Japanese high energy physics committee)
recommends so [appendix 1]– Recommendation from the Research Plan Committee ofInstitute for Particle and Nuclear Studies, KEK [appendix 2]– Priority set within KEK, repeatedly stated by the KEK-DG• KEK appreciates IAC’s continuous support for theneutrino oscillation experiment

J-PARC IAC / Y.T.

8

[2] Request for the early construction of the neutrino beam line at JHF (J-PARC)(High Energy News vol.21, no. 3, Oct.2002 p88)
J une 25, 2002
Japan High Energy Physics Committee
The constructions of JHF (J-PARC) is in the second year and a little more than four years
left before the start of experiments.
The future of JHF (J-PARC) and other accelerator plans depend on whether JHF (J-PARC)
can successfully produce physics results that can be recognized internationally at theearliest possible time after the commissioning. The early realization of neutrino experimentis indispensable.
With limited financial resources, it is necessary to set priorities based on physics
evaluation that can be recognized internationally. The LOI for the JHF neutrino experiment
was submitted to Dr. Nagamiya, Director of JHF (J-PARC) in 2000. The contents werereported at the workshop, which was held January 2000 (High Energy News vol.18, No.5,p135). The committee concluded ‘The JHF neutrino is the experiment that is feasible inearly stage of the JHF project and has enough potential to compete internationally.’ Also,
the international advisory committee, held in April 2002, reported that the neutrino
experiment should have first priority among the JHF projects.
In addition, the recent results on solar neutrinos reported by SNO, Super-Kamiokande,
and other radio-chemical experiments show that the mixing angle in solar neutrinos israther large. The other mixing angle, which is measured in muon-neutrino disappearance
in atmospheric neutrinos, has been shown to be large and confirmed in K2K experiment.
The measurement of the third mixing angle, which is one of the main goal of the first stageof JHF neutrino experiment, become more important and urgent
High Energy Physics Committee requests the project office of JHF (J-PARC) to makeevery effort toward the early realization of the JHF neutrino experiment.

J-PARC IAC / Y.T.

9

4 Recommended Grand Plan for the JHF Programs
Based on our basic guidelines, and the review and recommendations on each physics program, werecommend the following grand plan for the 50GeV PS at JHF. Figure 1 shows the timeline of theplan.
1. Build the neutrino beam line as soon as possible, and push the neutrino oscillation program with the highest
priority.
2. In order to support wide variety of nuclear physics and high energy physics experiments, start strangenessnuclear physics and rare K decay (e.g. continuation of E391a experiment at JHF) experiments from Phase 1,
as they are expected to produce steady results.
3. The muon program must be developed to get physics output in Phase 2. It should start identifying andstudying technological problems and test the feasibility (phase A study).

For Phase 2, the B-line/C-line and the extension of the counter hall should be constructed as originallyplanned, as these are required for running K decay, strangeness nuclear physics, and hadron
physics experiments.
4. While continuing the above programs, run series of hadron physics experiments in the latter half of Phase 1
and Phase 2.
5. Depending on the plans made for foreign anti-p projects, start the anti-p experiments from Phase 2.

All these programs should be reviewed at proper stages and this overall plan should be revised if
necessary. In particular, we recommend to give a higher priority to the muon program if its phase
A studies give promising results. These recommendations are made mainly based on the physics
importance. Technical reviews should be planned in the future, in order to closely examine
feasibility of each experiment once LOIs or proposal are submitted. We will also have to take into
account the actual accelerator performance.

J-PARC IAC / Y.T.

10

Figure 1: The timeline of the overall plan of JHF programs. The muon program in Phase 2 depends
on the result of phase A study. The anti-p science program depends on the plan of foreign competing
projects.

J-PARC IAC / Y.T.

11

New Organization in FY2004
KEK Agency
Accelerator Laboratory(Established by Ministerial Ordinance)
Applied Research Laboratory
Institute of Particle and Nuclear Studies
J-PARC Project Office(KEK Tokai Branch)Institute of Material Structure Science

Engineering Department
J-PARC Organization
Administration Bureau
JAERI
J-PARC IAC / Y.T.

12

Organization/management• Discussion is still under way on the Organization /management issues of J-PARC after commissioning– KEK task force for organizational issue– Joint task force for organizational issue• It must fulfill the basic strategy of KEK– KEK prefers J-PARC not being a new, autonomous instituteindependent of JAERI and KEK– Man power at KEK, especially the accelerator group, should not
be divided in two independent groups• The accelerator complex must be operated through asingle hierarchy• Also a single group must be responsible for the radiation
safetyJ-PARC IAC / Y.T.

13

Appendix-1: workshop and recommendations fromJHEPC
Developments – Past

The neutrino program has been one of the main motivations of building a high intensity proton
synchrotron since the JHF project was first proposed in 1995. The possible neutrino experiments
were first discussed in 1996 at INS symposium. The JHF project was proposed as the joint projectof KEK and JAERI in 1998. The construction of the accelerator was formally approved in 2000
and the construction started in 2001.
Due to rapid progress of neutrino physics in the world, it became necessary to re-evaluate thephysics goals for the next generation neutrino oscillation experiment. The JHF neutrino
experiment-working group was formed in 1999 to formulate our strategy. The results of the studies
were reported at JHF-workshop, promoted by Japan High Energy Physics Committee (JHEPC)*.
The workshop was held on January 7, 2000, in order to review high-energy physics programs at
JHF (J-PARC) by Japanese high-energy physicist community and the neutrino project received
strong endorsement [1]. The Expression of Interest was submitted to the director JHF project inJanuary 2000. The first LOI was published in 2001.
In 2002, two international workshops were held. The attendants include physicists from Canada,
France, Italy, Korea, Russia, Spain, UK and US, and an international working group has been
formed. JHEPC requested the project office of JHF (J-PARC) to make every effort toward theearly realization of the JHF neutrino experiment [2].
[1] An extraction from the conclusion of JHF workshop(High Energy News vol.18, no. 5, Feb. 2000 p135)
The studies reported at the workshop show that the neutrino experiment at JHF has high feasibility
from the beginning of JHF. The studies also showed the concrete physics goal and strong
competitiveness.
J-PARC IAC / Y.T.
14

[2] Request for the early construction of the neutrino beam line at JHF (J-PARC)(High Energy News vol.21, no. 3, Oct.2002 p88)
J une 25, 2002
Japan High Energy Physics Committee
The constructions of JHF (J-PARC) is in the second year and a little more than four years
left before the start of experiments.
The future of JHF (J-PARC) and other accelerator plans depend on whether JHF (J-PARC)
can successfully produce physics results that can be recognized internationally at theearliest possible time after the commissioning. The early realization of neutrino experimentis indispensable.
With limited financial resources, it is necessary to set priorities based on physics
evaluation that can be recognized internationally. The LOI for the JHF neutrino experiment
was submitted to Dr. Nagamiya, Director of JHF (J-PARC) in 2000. The contents werereported at the workshop, which was held January 2000 (High Energy News vol.18, No.5,p135). The committee concluded ‘The JHF neutrino is the experiment that is feasible inearly stage of the JHF project and has enough potential to compete internationally.’ Also,
the international advisory committee, held in April 2002, reported that the neutrino
experiment should have first priority among the JHF projects.
In addition, the recent results on solar neutrinos reported by SNO, Super-Kamiokande,
and other radio-chemical experiments show that the mixing angle in solar neutrinos israther large. The other mixing angle, which is measured in muon-neutrino disappearance
in atmospheric neutrinos, has been shown to be large and confirmed in K2K experiment.
The measurement of the third mixing angle, which is one of the main goal of the first stageof JHF neutrino experiment, become more important and urgent
High Energy Physics Committee requests the project office of JHF (J-PARC) to makeevery effort toward the early realization of the JHF neutrino experiment.

J-PARC IAC / Y.T.

15

Appendix: Japan High Energy Physics Committee (JHEPC)The JHEPC was formed in April 4, 1968 based on Japan Association of High Energy Physicist(JAHEP), in order to represent the intent of high-energy physicists, to make recommendations andto express their opinions.
The members of JAHEP elect the JHEPC committee every two years. The JAHEP consists ofhigh-energy physicists who have been working in this field for more than two years, where thehigh-energy physics is the experimental research mainly based on high-energy accelerator anddetector technologies. The JAHEP also include physicists of high-energy accelerators anddetector developments.

J-PARC IAC / Y.T.

16

Appendix: Recommendations from the Research Plan Committee of Institutefor Particle and Nuclear Physics, KEK

H. Enyo (RIKEN), Y. Okada (KEK), Y. Kamiya (KEK), S. Kim (Tsukuba),
S. Kurokawa (KEK), K. Kondo (KEK), H. Sakurai (Tokyo), T. Takahashi (ISAS),
H. Tamura (Tohoku), M. Nakahata (Tokyo), T. Nakaya (Kyoto), M. Nojiri (Kyoto),
M. Hazumi (KEK), T. Hatsuda (Tokyo), K. Hikasa (Tohoku), K. Fujii (KEK, Secretary),
H. Miyatake (KEK), T. Yamanaka (Osaka, Chair), and K. Yoshimura (KEK)
September 23, 2002

Introduction
The charge of Research Plan Committee of the Institute of Particle and Nuclear Studies (IPNS) is
defined 1 as follows. ”Upon request of the director of IPNS, the committee (1) investigates longrange physics research programs and related projects, and (2) examines the progress andoutcome of current research activities and makes recommendations for improvements.” Among
various future projects of IPNS we decided to investigate the most urgent issue. How should IPNS
conduct experiments at the 50GeV proton synchrotron (hereafter abbreviated as the 50GeV PS)
at JHF? We had meetings that totaled 10 days in the period of October 2001 to September 2002.
We first invited 19 experts in various fields of particle and nuclear physics to give reviews on thecurrent status and future prospect of their field. We then discussed from various aspects on how
to select and carry out experiments at the JHF 50 GeV PS, in light of their physics importance.
Here we report our view and unanimous conclusions.

J-PARC IAC / Y.T.

17

1 Grand View of Particle and Nuclear Physics, and JHF
The goal of particle and nuclear physics is to understand the ultramicroscopic world, i.e., the mostfundamental level of Nature. In the second half of the 20th century this field made a rapid progress asa result of rapid advances in accelerator capabilities. Discoveries and measurements of newelementary particles have uncovered the fundamental interactions and their symmetries. Together
with studies on hadronic and nuclear structures, we have obtained a unified picture of the basic
structure of matter and the history of the universe founded on quantum theory and relativity.
In spite of such major efforts to understand Nature, a multitude of challenging questions remain.
Some of them are deeply connected to the basis of our very existence: the mass generation
mechanism of fundamental particles, the origin of fundamental interactions, matter-antimatterasymmetry, the hierarchy problem between weak force and gravity, and the source of spacetime
structure. It has also became clear that multi-particle systems have a variety of quantum phenomena:
new forms of nuclear matter appear under extreme conditions, as do exotic nuclear structures ofhypernuclei and nuclei far from stability. These questions stimulate more than ever the intellectual
curiosity of humanity. As we enter the 21st century, we are about to step into a new stage tochallenge these unsolved problems.
The most direct means to look into the ultramicroscopic world is through energy frontier experimentswith high energy accelerators. While Tevatron is now at the frontier, the LHC (under construction) andlinear colliders (being planned) will push this energy frontier back and lead us to deeper
understanding of Nature. However, raising energy is not the only way to do this. Even at a relatively
low energy, one can still study physics at high energy scale by searching for rare phenomena withlarge data sets from intense beams. Neutrino oscillation and B factory experiments good examples. In
fact, such luminosity or intensity frontier experiments are the only means to access physics at energy
scales beyond the reach of the highest energy colliders.

J-PARC IAC / Y.T.

18

For elucidation of matter phases under extreme conditions and new phenomena in quantum
manybody systems it is important to have ystematic studies that vary parameters such astemperature, baryon density, strangeness, spin, and isospin. The same duality exists on the
microscopic nuclear scale. For instance, the experiments for producing quark-gluon plasma withhigh energy heavy ion collisions at RHIC or LHC aim at investigating phase transitions of nuclear
matter at high temperature. These are energy frontier experiments in the field of nuclear physics.
On the other hand, nuclear physics experiments utilizing strangeness or hadrons as a probe, andexperiments producing unstable nuclei by RI beams, can study various nuclei and nuclear matter
phases that appear in neutron stars and supernovae. These are intensity frontier experiments innuclear physics. As shown above, high intensity accelerators are needed for a wide range ofparticle and nuclear physics. The proton synchrotron at JHF will deliver the world’s highest
intensity (0.75 MW) beam, with 3£1014 50GeV protons every 3.4 s. This machine will make animportant contribution to the world-wide physics community by offering a unique facility that opens
a new high intensity frontier of particle and nuclear physics.
In particle physics, the JHF will contribute to neutrino oscillation physics, precision CP violation
studies, and searches for flavor violation. In nuclear physics, the JHF can study multi-body systemof quarks and gluons by using strangeness and hadrons as probes. In addition, mass productionof antiprotons will open up a new era of antiproton science. The JHF will have many research
programs that are expected to produce high quality results. These programs will complement
other domestic and international energy frontier experiments and together will accelerate theprogress of particle and nuclear physics in this country.
We should also stress that the JHF will also serve as a base to grow new generation of talented
particle and nuclear physicists.

J-PARC IAC / Y.T.

19

2 Basic Guidelines for the JHF 50GeV PS Programs
We recommend the following two basic guidelines for the JHF 50GeV PS to maximize the physics
output from Phase 1 and Phase 2. 2.
1. High priority should be given to scientifically important and urgent programs which Japan can take leadership.
2. Research programs should be established to pursue wide variety of physics utilizing the characteristics of JHF.
The timeline of these programs should be optimized to maximize the overall effciency.

3 Review and Recommendations for Each Program
Based on the basic guidelines described above, we have grouped experiments that had been
considered into the following six programs for our reviews and discussions.
z
z
z
z
z
z

Neutrino oscillation experiments (ν)
Rare K decay experiments (K decay)High intensity muon physics (µ)
Strangeness nuclear physics (Strangeness)
Hadron physics (hadron)
Antiproton science (anti-p)

Details of each program and its review are described in the full report (KEK Report 2002-11, only
available in Japanese). Here we list the executive summary of our review and recommendations
on each program.

J-PARC IAC / Y.T.

20

Neutrino oscillation experiments
Japan has been leading the field of neutrino oscillation and recent observations have establishedthe first signature of physics beyond the standard model. The mixing between generations in theneutrino sector was found to have a totally different structure from mixing in the quark sector. Thissuggest that an unknown physics mechanism is behind neutrino oscillation. Neutrino physics
should be pursued further, since the overall structure of neutrino mixing is still unclear; e.g. νµ Æ νeoscillation has not been observed yet. JHF can shoot neutrinos to Super Kamiokande with anintensity >100 times that of K2K. Not only will experiments with JHF measure the oscillation
parameters accurately, they will have ultimately the potential to discover CP violation in the lepton
sector. Considering the importance of this physics, its future potential, and the competing
experiments in the world, this program should be given high priority and the construction of thebeam line should be started as soon as possible.
Rare K decay experiments
CP violation due to Kobayashi-Maskawa mechanism has been established by the e’/emeasurements at CERN and Fermilab and by the high luminosity B factories at KEK and SLAC.
The next step is to search for CP violation caused by a physics beyond the standard model. Thesecan be searched for with precise measurements of the branching ratios of KL Æ π0νν and K+ Æ
π+νν and with a search for T-violation in K + Æ π0µ+νν. Although it is ideal to do all theseexperiments, the kaon community should choose one of them for the start up phase of JHF,
considering the cost and manpower. The committee recommends the K L Æ π0νν experiment. The
experiment has a potential to achieve the first observation of the decay by upgrading the current
KEK PS E391a experiment for JHF Phase I, and further more could establish a base for a precise
measurement of the branching ratio. Of course, before continuing on to Phase 2, the experimental
plan must be reviewed for its feasibility.

J-PARC IAC / Y.T.

21

High intensity muon physics
Supersymmetry is a promising model to solve the hierarchy problem. This model predicts new
phenomena beyond the Standard Model such as the lepton number violating transition, µ Æ e.
JHF can cover a wide range of predicted µ Æ e transition rates by using high quality and high rate
muon beams. The proposed plan uses ambitious technologies such as PRISM 3 to achieve an
intensity 104 times larger than existing facilities. The R&D necessary for the µ Æ e search should
start immediately. These new technologies are not limited to the µ Æ e experiment; they can beapplied to high intensity muon facilities and such facilities can evolve into a neutrino factory andhigh energy frontier experiments. Consequently the high intensity muon physics program has
strategic importance and can make international contributions to the future of the particle andnuclear physics.
Strangeness nuclear physics
Japan has been leading the study of nuclear forces involving strangeness by developing
innovative experimental methods, and this has been acknowledged internationally. At JHF, highintensity secondary beams will allow further systematic studies of the structure of hypernuclei andhyperon–nucleon scattering. By describing the properties of nuclear matter with strangeness,these studies will lead to a better understanding of the nuclear forces. In addition they will offer
important information required to build theoretical models for high density nuclear matter such as
neutron stars. Since many of the proposed experiments are expected to produce new results
quickly, they should be prioritized properly and run in series from the JHF start up time. The entire
program should be further developed by introducing new detectors and secondary beamline(s).

J-PARC IAC / Y.T.

22

Hadron phyiscs
Hadron physics experiments can open a unique field utilizing the high intensity beams from JHF.
The main focus will be the study of structure functions of nucleons and nuclei, and the observationof non-perturbative QCD phenomena such as partial restoration of chiral symmetry in nuclei.
These will be studied by observing lepton pairs produced by high intensity primary or secondary
beams. The program covers wide variety of studies including some proposals from foreigncountries. Therefore, multi-purpose beamline and detectors should be built and the program
should be continued in a long time span. Heavy ion acceleration for producing high density
nuclear matter could lead to a new physics frontier, but our competitiveness vis-a-vis that of GSI
should be taken into account.
Antiproton science
One of the antiproton programs at CERN lead by a core Japanese group recently succeeded in
mass-production of anti-hydrogen. This success marks a new era in the antiproton science. The
high-intensity antiproton beam at JHF can contribute to a wide field of science, ranging from basic
science to various applications: tests of CPT, measurement of neutron-matter distributions inunstable nuclei, medical applications, etc.. The decision to build an antiproton facility at JHF willvery much depend on the future plans of similar facilities around the world. JHF can produce a low
energy high intensity beam in DC mode and this feature should be a part of the plan for the JHFanti-p program to be competitive.

J-PARC IAC / Y.T.

23

The star rating of each program is shown in Table 1.
Program

Importance ofphysics for the
first stage of
JHF

Cost
Urgency

FeasibilityFacility

Detectors# physicists

Comments

ν

****

***

***

\\\

\\

MMM

K decay

**

***

**

\ Æ \\\ Æ \\

MM

1)µ++++ see 2)

*

\\\

\\

MM

3)

Strangeness
Hadrons

***

**

***

\ Æ \\\ Æ \\

MMM

4)

**

*

**

\\

\

MM

Anti-p

*

*

***

\\\

\

MM

5)

Table 1: Star ratings of the JHF programs”Importance of physics for the first stage of JHF” includes the international competitiveness.
”Urgency” takes international competition into account.
”Feasibility” takes into account the amount of required R& D work.
”Facility” and ”Detector” show rough costs estimated by the committee; \: <$10M, \\: $10 >>50M, \\\: $>50M (assuming $1M = 100M yen).
”#Physicists” shows the estimated number of physicists who will work on the program; MM:O(10), MMM:O(100).
1) The program is assumed to take two steps, and shown in a format: step 1 Æ step 2.
2) Since this program has a potential to lead to a new generation of particle and nuclear physics experiments, we rated the importance ofstarting R&D early.
3) It is too early to judge feasibility. This proposal should be reviewed after proving the basic idea and studying technological problems. The”Facility” includes the cost for the experimental hall.
4) The costs are shown in a format: Phase 1 Æ Phase 2. Phase 1 uses the existing detectors moved from KEK. Phase 2 assumes the
upgrade / construction of beam line and detectors. The extension of K-Hall is also necessary for Phase 2.
5) The importance and the number of users will increase if GSI and CERN decide not to have anti-p programs.

J-PARC IAC / Y.T.

24

4 Recommended Grand Plan for the JHF Programs
Based on our basic guidelines, and the review and recommendations on each physics program, werecommend the following grand plan for the 50GeV PS at JHF. Figure 1 shows the timeline of theplan.
1. Build the neutrino beam line as soon as possible, and push the neutrino oscillation program with the highest
priority.
2. In order to support wide variety of nuclear physics and high energy physics experiments, start strangenessnuclear physics and rare K decay (e.g. continuation of E391a experiment at JHF) experiments from Phase 1,
as they are expected to produce steady results.
3. The muon program must be developed to get physics output in Phase 2. It should start identifying andstudying technological problems and test the feasibility (phase A study).

For Phase 2, the B-line/C-line and the extension of the counter hall should be constructed as originallyplanned, as these are required for running K decay, strangeness nuclear physics, and hadron
physics experiments.
4. While continuing the above programs, run series of hadron physics experiments in the latter half of Phase 1
and Phase 2.
5. Depending on the plans made for foreign anti-p projects, start the anti-p experiments from Phase 2.

All these programs should be reviewed at proper stages and this overall plan should be revised if
necessary. In particular, we recommend to give a higher priority to the muon program if its phase
A studies give promising results. These recommendations are made mainly based on the physics
importance. Technical reviews should be planned in the future, in order to closely examine
feasibility of each experiment once LOIs or proposal are submitted. We will also have to take into
account the actual accelerator performance.

J-PARC IAC / Y.T.

25

Figure 1: The timeline of the overall plan of JHF programs. The muon program in Phase 2 depends
on the result of phase A study. The anti-p science program depends on the plan of foreign competing
projects.

J-PARC IAC / Y.T.

26