Particle and Nuclear Physics at J-PARC July 16, 2003 Lattice 2003 Jun Imazato KEK, IPNS

Outline Overview of J-PARC (Japan Proton Accelerator Research Complex) Strong interaction physics program –Nuclear physics –Hadron physics Other particle physics program –Kaon and muon decay physics –Neutrino oscillation Construction status etc. Summary

Project overview J-PARC is a high-intensity proton accelerator complex in Japan now under construction consisting of: MeV linac 2.3 GeV rapid cycling synchrotron 3.50 GeV main synchrotron 4.Experimental facilities ■ Joint project of High Energy Accelerator Research Organization (KEK) and Japan Atomic Energy Research Institute (JAERI) ■ Construction started in 2001 at JAERI Tokai site and completion will be in ■ A variety of sciences ranging from particle physics to materials and life sciences will be researched.

Configuration of the accelerators Neutron Muon

Proton accelerators in the world

Bird’s-eye view of J-PARC Japan Atomic Energy Research Institute (JAERI) Tokai Site Particle Nuclear Physics 50 GeV Synchrotron Neutrino Life & Material Science 3 GeV Synchrotron Linac Nuclear Transmutation

Physics at 50-GeV PS Nuclear (strong interaction) physics & Particle physics with K, π, ,  pbar, and other secondary beams –Hypernuclear spectroscopy –Hyperon-nucleon scattering –Mesons in nuclear matter –Hadron spectroscopy –Neutrino oscillation experiment using Super-Kamiokande –Kaon rare decays to measure CKM matrix elements –CP violation and other symmetry breaking –Low energy QCD in meson decays –Flavor mixing and other topics beyond the Standard Model Nuclear physics with primary beams –Physics with proton beams (polarized beams in the future) –High-density matter with heavy-ion beams in the future

Experimental hall plan

Strong interaction physics Strangeness nuclear physics Hadron physics

Strangeness nuclear physics Nuclear physics from nuclear surface to nuclear matter: –Does a nucleon keep its identity in deep nuclear matter? Hyperon imbedded into deep nuclear matter (Hypernucleus) : –Bound in deep states without Pauli blocking –Spectroscopy → mass, potential, YN interaction etc. –Decay study → decay width, moment etc. Hypernuclei produced in secondary beam reactions: (K,  ), ( ,K), (K -,K + ) etc. –Only poor data until now due to limited beam intensity Qualitative data improvements expected at J-PARC

Hypernuclear spectroscopy S=-1 So far  and  hypernuclear spectroscopy using (K,  ) and ( ,K) reactions and    Potential (  ) and shell structure (  ),  N spin-spin interaction, from splitting, etc. Weak force from decays J-PARC High resolution spectroscopy of  nuclei ->core excitation, width High-resolution  spectroscopy in  nuclei -> YN interaction etc. B(E2), B(M1) Deeply-bound kaonic nuclear states ->cold &dense nuclear matter ■ S=-2 : Spectroscopic study of the S=-2 system using (K -, K + ) ■ reactions will be a new field, which is impossible now with the ■ current beam intensities. expectation of  transitions

Spectroscopy of S=-2 systems  hypernuclei and  double hypernuclei  double hypernuclear spectroscopy : only several events reported until now.  hypernuclear spectroscopy : discovery of a  hypernucleus expected. mixed states of ,  and H states ? K. Ikeda et al., Prog. Theor. Phys. 91 (1994) 747 (K -, K + ) reaction at 1.8 GeV/c needs high beam intensity Small cross section e.g. 208 Pb(K -,K + ) with 2g/cm 2 thick target  ~6 events/MeV/day S=-3  - nuclei, charmed-hypernuclei etc.

(K -,K + ) spectroscopy of  -hypernuclei ∆E~ 2 MeV (FWHM) BL= 6 Tm K-K- K+K+ 1.8 GeV/c M HY - M A expectation

Hyperon-nucleon scattering Understanding of the flavor SU(3) baryon-baryon interaction. –YN, YY < NN ? –Repulsive or attractive ? –Repulsive cores in YN/YY ? What is the origin ? –Spin-dependent forces in YN/YY. –Dibaryons ? ■ Recent data from KEK 12-GeV PS (E251, E289, E452) Goto et al., NP A648(1999)263 Kondo et al., NP A676(2000)371 still poor data =====>

Proton beam physics Proposals to study: Meson mass in nuclear matter (next slide) –Partial restoration of chiral symmetry breaking Dimuon production from Drell-Yan process and J/  _ _ –d/u asymmetry (DY) –Antiquak distibution, etc. (DY) –Quark energy loss in nuclei (DY) –Quarkonium production (J/  ) Analyzing power A n at large p ⊥ 2 using polarized beam –Comparison with PQCD and other models Intermediate-mass nuclear fragmentation –Nuclear liquid-gas phase transition

Hadrons in nuclear matter Methods to study the origin of hadron mass: – Lattice QCD (theory) – Implantation of a hadron in nuclear matter (J-PARC) ■ Change of meson mass in nuclear matter due to “partial restoration of chiral symmetry”. Vector meson decay  → l + l - KEK E325 ; K. Ozawa, et al., Phys. Rev. Lett. 86, 5019 (2001). T.Hatsuda and S.H.Lee, Phys.Rev. C46, R34 (1992) Muroya et al., hep-lat/

Hadron spectroscopy Proposals to look for: Gluonic degrees of freedom and exotic states Search for glueballs: gg, ggg –scalar glueball (0 ++ ): 1.5~1.8 GeV/c 2 –tensor glueball (2 ++ ): > 2.0 GeV/c 2 Search for hybrids and exotics _ –ssg, ccg _ _ _ –qqqq, qqqqq, qqqqqq _ Studies of charmonium (cc) and charmed baryons ■ Missing baryon states in SU(3) Data with high statistics at J-PARC are essential. 10 GeV K - beam with > 10 6 /sec 20 GeV π ± beam, ● GeV p beam antiproton beam

Kaon and muon decay physics

Kaon decay physics at J-PARC ■ High precision frontier using high-intensity beams ■ Test of the Standard Model and search for new physics ■ Complementary to B physics and to the energy frontier CKM matrix determination and test of unitary triangle Unitarity relation V ud V ub * + V cd V cb * + V td V tb * =0 Usefullness of FCNC decays _ K 0 L →     K + →   (0,0)(1,0)  ) V ud V ub * V cd V cb * V td V tb *

Proposed K decay experiments ■ CP violation ■ _ ■ K 0 L →   ■  re d  ca  ■ 1000 events ■ ∝  2 A 4 X 2 (x t ) ■ Standard Model ■ _ ■ K + →     re d  ca  100  ∝ [       ] A 4 X 2 (x t ) ■ T violation (muon polarization) ■ K + →     ;  P T ≦ ■ K + →    ;  P T ~ ■ K decay form factors

T violation in K + →     decay Search for new physics beyond the SM Multi-Higgs doublet model Leptoquark model R -parity violating SUSY etc. ■ P T in K + →     also measured. ■ Muon transverse polarization P T  P T ~ at J-PARC BNL-E923?

   BR and    ■ So many channels of leptonic, semileptonic, hadronic and radiative decays Decay modes with small branching ratio will become possible to explore with high intensity beams at J-PARC. e.g. : K l 4 、 K l 3  、 K  ■ Good field to test effective theories of low energy QCD Analysis with Chiral Perturbation Theory e.g. of recent KEK data: K  direct emission with chiral anomaly (KEK E470)  scattering length using final state interactions with more than two pions : K  3, K e4,.. ■ Test of fundamental couplings in the weak decay Tensor and scalar contribution? ( Recent KEK data on K e3 ) CKM matrix unitarity? (Proposal to determine V us from K e3 )  (K e3 ) ~ | f + (0) V us | 2 : accuracy of f + (0) calculation needed.

Example: some issues in K→  l ■ M ∝ [ f + (q 2 ) (p K + p  ’) + f - (q 2 ) (p K - p  ’)] f + (q 2 ) = f + (0) [1 + + q 2 /m  2 ],  (q 2 ) = f - (q 2 )/f + (q 2 ) f 0 (q 2 ) = f + (q 2 ) +[q 2 /(m K 2 -m  2 ) ] f - ( q 2 ), f 0 (q 2 ) = f + (0) [1 + 0 q 2 /m  2 ] f + (0) : lattice calculation ( f + (0)=1 in SU(3) symmetry) + : experiment + = ± (PDG) 0 : ChPT 0 = ± ( 0 = + in SU(3) ) ■ Three experimental methods to measure  (0) ( or 0 ) 1)  (K  3 )/  (K e3 ) ( 0 =0.019±0.005(stat)±0.004 from recent KEK data ) 2) Dalitz spectrum 3)  polarization Large scattering of  (0) (or 0 ) values among experimental data and experimental methods? Settling at J-PARC is desirable.

Muon physics High intensity muon source –PRISM collaboration Lepton flavor violation  →e conversion at J-PARC sensitive to SUSY-GUT etc.  →e   →3e _ Mu-Mu conversion   -  + conversion Precise measurements g-2, EDM Michel parameters

Neutrino Oscillation

 beam of ~1GeV Kamioka JAERI (Tokai-mura)  → x  → x disappearance  → e  → e appearance NC measurement 0.75 MW 50 GeV PS Super-K: 50 kton Water Cherenkov ~Mt “Hyper Kamiokande” 4MW 50GeV PS CPV proton decay 1st Phase ( x 10 2 of K2K) 2nd Phase J-PARC-Kamioka neutrino experiment

 in    in   disappearance ■ Sensitivity at J-PARC   (sin 2 2   ) ~ 0.01   (  m 2 ) < 1×10 -4 ; in 5 years ~ (130 days/year) ■ Allowed region from SK and K2K  m 23 2 (eV 2 ) OAB-3 o  (  m 23 2 ) OAB-2 o  (sin 2 2   ) K2K SK JHF 

Sensitivity of n m  n e appearance ■ Discovery of n m  n e with a sensitivity at  m 2 ~3 x eV 2 down to sin 2 2   ~0.006 (90% C.L.) ■ Twenty times improvement over the past experiments Excluded by reactor exp’s x20 improvement

Construction status etc.

Construction of Phase 1

Preparation of experiments Call for Letter of Intent for experiments : July 2002 Submission of LoI : Dec.2002 –Strangeness nuclear physics : 6 –Hadron physics : 7 –Kaon decay : 5 –Neutrino oscillation : 1 –Muon decay : 3 –Facility : 9 Screening of LoI by pre-PAC : June 2003 Selection of a few candidates of Day1experiments Full experimental proposals and layout of beamlines : in 2004

Other facilities at J-PARC ■ Materials and Life Science Facility Use of 3 GeV RCS pulsed beam Neutron facility Scattering Diffraction Radiography …… Muon facility  SR Condensed matter, soft matter, Structual biology, Industrial application, … ■ Nuclear Waste Transmutation (ADS) Technical development using the linac beam Pulse n Peak intensity  J-PARC 1MW = ~200×  ILL 2nd

Neutron diffraction from protein From structure to function Hen Egg-White Lysozyme Water molecules observed with neutrons X-rays Neutrons タンパク質 DNA A protein molecule moving along the DNA chain Protein Hydrogen (H) Oxygen (O)

Summary J-PARC is now under construction aiming for the completion of Phase 1 in It will deliver many kinds of hadron beams with the world highest intensity. Not only neutrino oscillation and rare decay physics, but also a variety of strong interaction physics (QCD and nuclear) will be main projects at the 50 GeV proton synchrotron. J-PARC aims for an international research center in many science fields.

End of Slides