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Overview of Particle Physics Experiments In the-35-year History of KEK-PS Yorikiyo Nagashima Osaka University Jan. 22, 2008. Options discussed 12GeV; high intensity 40GeV; conventional 80GeV; cascade. Dumping the cyclotron in Tokyo bay. Historical Background of PS construction.
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Overview of Particle Physics Experiments • In the-35-year History of KEK-PS • Yorikiyo Nagashima • Osaka University • Jan. 22, 2008 PS REVIEW 080122
Options discussed • 12GeV; high intensity • 40GeV; conventional • 80GeV; cascade Dumping the cyclotron in Tokyo bay Historical Background of PS construction. • Pre-history of PS • 1937: 1st Cyclotron at RIKEN , Osaka U. • 1943: 60 inch Cyclotron (2nd to Berkeley) • 1941-45: World War II • 1945: Destruction of the cyclotron. Reconstruction banned by the Occupation Army • 1952: Peace Treaty ; the end of Occupation • 1956: Electron Synchrotron started (0.75 1.3 GeV) • History of PS Construction • 1958: Discussion started • 1962: Proposal of PS • 1964: Preliminary approval • 1966: 12GeV 40 GeV Big debate in HEP community. • 1970: 40GeV 8 GeV, ¼ budget , ¼ manpower Big debate in the academic community • 1971: Construction started. • 1977: Beam commissioning (812 GeV) PS REVIEW 080122
Progress of Particle Physics in Japan JPARC InfancyYouthMaturity Discovery of the Electro-weak Theory The Standard Model Established PSI: Training Period. +International Collaborations PSII: Frontier for NP, Survival for Particle Physics +TRISTAN PSIII: A New Frontier and World Leading Expts. (n-oscillation, K-decays)+KEKB, SK PS REVIEW 080122
1st Experiments:pN Reactions • Counter Experiments; E19, E21 • Bubble Chamber; E6 , E12 1m Bubble Chamber TARGET BEAM E19: K.Miyake: p-p Charge Exchange Scattering BEAM Polarized Tgt. MAGNET PS REVIEW 080122 R.Kajikawa: E21: pp Elastic Scattering
ICHEP78, Tokyo, Japanese Debut in HEP club. Summary Talk by Y.Nambu The Standard Model was firmly established in this conference. PS REVIEW 080122
PS Review ’81 after 4 years of Operation By Nambu, Kitagaki, Yamaguchi Significance Purpose Problem PS REVIEW 080122
Polarized Target Horizontal Type He3-He4 Dilution Refrigerated Special Features circa 1975 that were hoped to make the late comer PS competitive. High Quality Low Energy Separated Beams For Precision Data and Decays Pol. Tgt. aimed at performing Precision Hadron Dynamics K2 And also Bubble Chamber Later K3 PS REVIEW 080122 1978
A Track of PSfrom Particle Physics Point of View (1a) Did the Strategy work ? See the Achievement in the first 10 years in advance. PS-Ia: 1977-78 • Significance: Training and Obtaining Self-confidence • Debut in HEP Society at ICHEP’78 in Tokyo • Strategy to make PS competitive: • Pre-construction emphasis: • Resonance Hunting andPrecision Hadron Dynamics 40’’ Bubble Chamber and Polarized Target Obsolete after SM was established during the construction • After Beam Commissioning : Emphasis onSM test Exotic Resonances, Weak Decays • High Quality Low Energy Separated Beam PS REVIEW 080122 10-12
PSachievement in the 1st 10 years reviewed in 1990 PS REVIEW 080122
The following sample are picked up entirely with my personal prejudice. • My apology for not covering many works that achieved important contributions. PS REVIEW 080122
Experiments in the first Period PSI (1977-84): Hadron Reactions Resonance Hunting Decays Others • Note:The Bubble Chamber was very productive during 1960’s. • So it was one of special-feature projects in the construction stage. • However, most basic resonances that contributed to the discovery • of the Quark Model were already found and the emphasis shifted • to exotics by the time PS started operation. • The BC without external trigger was no match against counter experiments • in the field of high statistics battle, and was shut down in 1982. • Nevertheless, there were some experiments that did well. PS REVIEW 080122
An Example of Bubble Chamber Experiments E57S.S.Yamamoto: “An Experiment that provided a basic set of data and also excluded the existence of I=1 dibaryons(2240), (2320)” D-dominance Model Models including Di-Baryon s(ppp0) s(pnp+) Spires2008 PS REVIEW 080122
Hadron Reactions Resonance Hunting Decays Others 2/3 Hadronic, very little interest in Weak Decays in the beginning
A Flagship Experiment during the early PSI period. C-type Magnet Polarized Target Beam Beam PS REVIEW 080122
E34 results Phase Shift Analysis of the Reaction K+NKN below 1.6 GeV/cPLB112(1982)80 A kind of perfect experiment, but this one also looked for possible S=1 exotic baryons And found none. • Note: Emphasis before construction was on the “Perfect Experiment” • To determine the complex scattering amplitudes precisely, • 2 Complex Amplitudes in p(K)N Scattering • Need Cross sections, Polarized target Data and Polarization of scattered particles. • To determine exact locations of the resonances, • with hope to elucidate the underlying dynamics. • However, QCD was established ~1973. PS REVIEW 080122
Many experiments targeted specific Resonances E33 T.Kamae,E74 K.Nakamura: E68 M.Kobayashi Dotted lines observed by B.Richter et al., PRLB126(1983)284 “Disproof of S-resonance(1936) claimed by several groups” Spires “Disproof of other barioniums” PS REVIEW 080122 Spires2008
An Example of Deacay Experiments E10 Y.Nagashima: A Table–top experiment : An extinct species of HEP apparatus PS REVIEW 080122
KEK/PS:E10 BR(K+p+nn): “World’s best limit for nearly 10 years.” BR(K+p+axion): “An experiment that killed the original axion.” PS REVIEW 080122 Spires2008
PDG2006 Another Example of Weak Decays during PSI period Measurements of Asymmetry in Σ+ → pγ Decay “QCD Effect” E92 K.Miyake: PS REVIEW 080122
Summary of PSIb: 1979-84 Making efforts to catch up with the world level . Emphasis on intense K beams and Polarized target Hunt for exotic resonances: Test of SM or looking for a clue BSM in weak decays: Caveat: As the only national HE machine, the demand for PS was big. Beam delivery was not enough and approval criteria was somewhat lenient to satisfy the need of users Important Events outside KEK/PS: In 1972: Prof. Koshiba initiated U. Tokyo-DESY collaboration. In 1978: Prof. Koshiba began to construct Kamiokande. In 1979: Japan-US collaboration program started (all major universities). In 1981: TRISTAN was approved. A Track of PSfrom Particle Physics Point of View (1b) PS REVIEW 080122 16-19
A Track of PSfrom Particle Physics Point of View (2) • Features in PSII Period: 1985-1998 • The Main Force TRISTAN+Overseas Collaborations • PS : Frontier for Nuclear Physics ( Talk by Nakai) • :Survival War for Particle Physics • Still behind BNL and CERN, Groped the way of Uniqueness and Originality • Strategy:Ample Machine Time for a small number of Groups Systematic Approach in series of experiments High Statistics and Precision Tests of and beyond SM • Managed to produce some world competitive Results PS REVIEW 080122
Hadron Reactions Resonance Hunting Decays Others PS REVIEW 080122
An Example of series of Experiment : “Exotic Resonance Search in pp channel” PS I EraE64 (pI-I) T.Tsuru PS II EraE121 pI-II, E135 pI-III, E179 hp: T.Tsuru and T.Inagaki Studies of 2p, 3p States in p-p Charge Exchange Reactions. Search for the ηπ Resonance with I=1, JPC=1-+ PS REVIEW 080122
Contributions in the glueball-hybrid-4q sector. • Confirmation of IG(JPC)=0+0-+Resonances in hpp system • known today as h(1295) and h(1405) PRL57(1986)1296, PLB267(1991)293 • Indication of 1-1-+ Resonance in hp- system • known today as p1(1400) PLB267(1991)293 f1(1285) Spires2008 • Note: • h(1295) is probably a radial excitation of h. • Old i(1460) in KKp is now h(1405). • It does not fit in quark model levels and has a large gluon component. • An excellent candidate for the 0-+ glueball in the flux tube model. • However, lattice QCD *does not favor the interpretation. • p1(1400), having I=1 cannot be a glueball, but • a possible candidate for a hybrid or 4q state. PS REVIEW 080122
Another Systematic Approach: Km2 Decay Experiments PSI Era E89, E104: T.Yamazaki: “Search for a Heavy Neutrino in K+m+n, me+nn” E89 Spires2008 PS REVIEW 080122
Km2 Decay Experiments : PS II Era TRIUMF E195 E195 setup PDG2006 E99 R.Hayano, E195 J.Imazato: Search for Right-Handed Currents in the Decay Chain K+m+n, m+e+nn “Lower Limit on the Mass of WR As a function of mixing angle” PS REVIEW 080122
Other Competitive Decay Experiments E137 T.Inagaki: Search for Rare Decays KLme and KLee “Lepton Flavor Violation” PDG2006 E162 N.Sasao: Observation of the decay mode KL → π+π-e+e- “CP Violating Effect + Higher Order Effect QCD” PDG2006 PS REVIEW 080122
PSII Summary • PSII Period: 1985-1998 • The Main Force TRISTAN+Overseas Collaborations • PS : Frontier for Nuclear Physics :Survival War for Particle Physics • Still behind BNL and CERN, Groped the way of Uniqueness and Originality • Strategy:Ample Machine Time for a small number of Groups A series of Experiments for Systematic Research High Statistics and Precision Tests of and beyond SM • Managed to produce some world competitive Results PS REVIEW 080122 24-27
Decays Others A Track of PSfrom Particle Physics Point of View (3) • 3rd Period: 1999-2005 • International Collaboration • Frontier and World Leading Experiments (Parallel activities: BELLE and SK) • Some Experiments will be continued at JPARC • K2KT2K (E11), E391aE14, E246 E06 PS REVIEW 080122
PS is a Front Runner in the Internationalization A Historical Event in the Japanese Culture. • Genuine International Collaborative Researches • ==================== ============== • E246 (Imazato) • Japan-Russia(INR)-Canada-Korea-Taiwan • MOU between KEK-INR in 1992 • The Majority Members are from Abroad • K2K (Nishikawa) • K2K-I: Japan-US-Korea (1995) • K2K-II: Japan-US-Korea-Italy-France-Spain • -Russia-Switzerland-Poland-Canada (2002) • The Majority Members are from abroad. • E391a(Inagaki) • PAC advised to strengthen the group • Japan-US-JINR-Korea-Taiwan • K.Nakamura: Jan. 14, 2006 PS REVIEW 080122
E246 PDG2006 PS REVIEW 080122
E391a n1 g1 g2 KL n2 E391a Detector • Experimental challenge; meager positive signal • Use Pencil beam • Detector with complete veto system • High PT selection • Step by step approach • KEK-PS E391a JPARC PS REVIEW 080122
PS REVIEW 080122 ADOPTED FROM T.SUMIDA; 070316
E326 (K2K): World’s 1st Long Baseline n Oscillation Experiment. • Confirmed the n oscillation discovered by SuperKAMIOKANDE. PS REVIEW 080122
KEK ニュートリノビーム 250km SuperKAMIOKANDE PS REVIEW 080122
The Success of K2K enabled us to draw a definite future plan. Neutrino Physics T2K REACH K2K K2K T2K T2KK? PS REVIEW 080122
T2K 1 MW 50 GeV PS Kamioka JPARK Super-K: 50 kton Water Cherenkov ~1GeV n beam 4 MW Hyper-K: 1 Mton T2KK A Future Plan K2KT2KT2KK Beam: 1MW4MW Detector: Super-KHyper-K (50 kton 1 Mton) Split it into 2 and place one in Korea K2K PS REVIEW 080122
Summary IA Track of PS from Particle Physics Point of View • Pre PS : 1952-1976: • Long Hard Labor for HEP Accelerator Re-construction • 1st Period: 1977-84 • Training Period: Debut in HEP Society at ICHEP’78 in Tokyo • Pre-construction emphasis: Resonance Hunting and Precision Hadron Dynamics a 40’’ Bubble Chamber and a Polarized Target Out-of-date after SM was established during the construction • After Beam Commissioning : Emphasis on SM test • Exotic Resonances, Weak Decays • Pbar pbarionium, K+p+nn, p+axion, mn • 2nd Period: 1985-1998 • The Main Force TRISTAN+Overseas Collaborations • PS : Groping the way of Uniqueness and Originality • Systematic Approach and Precision Tests: • K0pm, K+m+n • Nuclear Experiments • 3rd Period: 1999-2005 • Frontier and World Leading Experiments (in parallel with BELLE and SK) • T in K0pmn, K2K (LBL n oscillation), CP in K0p0nn • International Collaborations PS REVIEW 080122
Summary II • KEK/PS, 15 years behind the world fronts like CERN/PS, BNL/AGS, could not expect a bright future. • However, it fulfilled its primary purpose to become a partner in the world HEP society, and to educate young people who are working actively at today’s frontier. • As a bonus it provided a new frontier for nuclear physics. • As the second bonus, KEK/PS even produced some forefront particle physics results, including the renowned long baseline neutrino oscillation experiment. • Waves of Internationalization have reached KEK/PS. • The PS Experiments owe their Success to the stable operation of the Accelerator throughout its Life. • The success of late time PS activities paved a road to JPARC and other future projects. PS REVIEW 080122 32-35