Hadron Spectroscopy with high momentum beam line at

Hadron Spectroscopy with high momentum beam line at J-PARC K. Ozawa (KEK) Contents Charmed baryon spectroscopy New experiment at J-PARC

On-going Joint Project • Joint project between J-PARC theory center, KEK, and RCNP. – Proposing construction of new high-momentum high-resolution beam line • Collaboration – H. Kamano, T. Nakano, H. Noumi, A. Hosaka (RCNP), T. Sato (Osaka) – M. Oka, T. Hyodo (TIT), D. Jido(Kyoto) – K. Ozawa, S. Yasui (KEK) 2012/2/10 Future prospect of Hadron physics 2

Hadron Physics • Origin of Hadron interaction? – Nuclear Force inside nuclei – Meson-Baryon, Baryon-Baryon interaction • Property of Nuclear (QCD) matter? – Origin of hadron mass – Neutron Star • Inside structure of Hadron? – Naïve quark model needs to be extended – Roper, Penta quark , Exotic mesons @ Belle 2012/2/10 Future prospect of Hadron physics 3

Beyond the quark model Roper Width v. s. Mass[Me. V] of Excited Nucleon • According to the naïve quark picture, the first excited state should be negative. • However, observed state is positive. (It’s called Roper. ) – Long standing problem Exotics Y Belle, PRL 99(2007), 142002 2012/2/10 Θ+ LEPS, PRC 79, 025210 • In addition, several exotic hadrons are observed recently. Future prospect of Hadron physics Need further study. 4

Issues and Solution • Several effects are competed in light hadrons – Gluon interaction , Chiral properties, Di-quark correlation, Three body effects, Spin dependent interaction, Dynamical orbital excitation • Current experimental data includes all above effects. – Every effect should be measured separately. • Heavy Quark spectroscopy is key! – Many of above complex effects are suppressed. – Spin dependent interaction, Three body effects, Chiral effects 2012/2/10 Future prospect of Hadron physics Ｃ 5

Ｃ ＣＣ Ｃ 2012/2/10 Charmed Baryons • Wccc : Triple charmed baryon – It only have color interactions. – Experimentally, it’s not observed yet. • Xcc : Doubly charmed baryons – – Effects of chiral symmetry are suppressed. Other effects can be studied easily. One experiment (SELEX) reported. It can be produced at J-PARC. • L+c, Sc : Charmed baryons – Spin dependent interaction is suppressed – Interactions can be simplified. – Let’s start here! Future prospect of Hadron physics 6

Single charmed Baryons Predicted states using a quark model (L. A. Copley et. al, Phys. Rev. D 20 (1979) 768) Observed charmed baryons Threshold Several states are missing DN Sc p Lc p 2012/2/10 Future prospect of Hadron physics 7

Di-quark correlation? Charmed baryon system can be understood as Heavy Quark – di-quark system “Roper” 2012/2/10 ? Future prospect of Hadron physics 8

In addition, exotics in charm sector • If exotic baryons exist in charm sector, it can be observed easily compared to light quarks. – Narrow width – Large mass window below DN threshold Candidate of exotics 2012/2/10 Mass window for exotics Future prospect of Hadron physics 9

Charm Baryon spectroscopy @ J-PARC Several missing states and exotic candidates Roper candidate Purpose Observe all excited states of single charmed baryon below 3 Ge. V. • Mass Spectra of excited charmed baryon contains basic information of quark interaction • Many states are still missing – Few states are observed in invariant mass plot. • Observed states has relatively narrow width – Good for spectroscopy! Observed charmed baryons 2012/2/10 Future prospect of Hadron physics 10

Beam New Experiment @ J-PARC p- p -> S 0 c + D 0 p+ n(d) -> L+c + D 0 -> p+ KDetect p, K and reconstruct D meson. Then, missing mass is calculated. Construct new high resolution, high momentum beam line 2012/2/10 Future prospect of Hadron physics Dispersive Focal Point Dp/p~0. 1% 11

Experimental Setup p- p -> S 0 c + D 0 p+ n(d) -> L+c + D 0 Candidate 1: Solenoid type D 0 -> p+ KDetect p, K and reconstruct D meson. Then, missing mass is calculated. Candidate 2: Dipole type dp/p ~ 1% is required 1 m Size of inside coil 1 m Size of Gap f 2 m 2 m • • • 2 m Magnetic field: 1 [T] • Magnetic field: 1 [T] 50% of D meson can be detected • 50% of D meson can be detected Poor mom. res. at very forward 2012/2/10 Future prospect of Hadron physics 12 Particle identification and trigger scheme are issues for both cases.

Kinematics & Acceptance • Beam Momentum: 15 Ge. V/c • Lc (2940 ) (Roper candidate) is assumed. p from D 0 decays PT PZ K acc. is similar Both p and K are in acceptance Solenoid D-magnet 0 2012/2/10 2 [Ge. V/c] Future prospect of Hadron physics 1 0 4 8 [Ge. V/c] 13

Momentum Resolution • Beam Momentum: 15 Ge. V/c • Lc (2940 ) (Roper candidate) is assumed. p from D 0 decays Dp. Z/ pz K is similar Both p and K are in acceptance Dx = 100 mm Solenoid D-magnet configuration has better momentum resolution. Further check for the 2012/2/10 calculation is needed. -0. 1 0 Future prospect of Hadron physics 0. 1 14

Decay products from Lc PT PZ p from Lc(2940) 3 body decays PT PZ p from L decays 2012/2/10 PT PZ p from Lc(2286) decays PT PZ Proton from L decays Future of Hadron physicsthe same configuration. Decayed products can beprospect measured using 15

Summary • To understand structure of light hadrons, charmed baryon spectroscopy is an important tool. • charmed baryon spectroscopy can give basic information about Roper state, Exotic state, and di-quark correlations. • A new beam line and new experiment is proposed to perform charmed baryon spectroscopy. 2012/2/10 Future prospect of Hadron physics 16

Physics topics @ new beam line • • • Charm baryon bound state Color transparency Short range structure Drell-Yan process (P 04) c-bar c contents in nuclei Multi-fragmentation omega bound state (E 26) and eta’ Basic cross section of pi N -> pi pi N Exotic in light quark Mass modification of f (E 16) Heavy ion physics 2012/2/10 Future prospect of Hadron physics 17

BACK UP 2012/2/10 Future prospect of Hadron physics 18

Note: Existing experimental results • Currently, charmed baryons are identified using its decays in collider experiments. N ~ 4600 • Our experiment measure productions of baryons and it gives different information. • Statics will be similar • Intensity of 107 ~ 108 / spill • Sensitive to relatively wide width states • Background will be suppressed at threshold region. Ba. Bar, Lc -> LK 0 s. K+ (Phys. Rev. D 72 052006) 2012/2/10 • Exclusive measurements can be done. • Decays can also be measured. Future prospect of Hadron physics 19

The J-PARC E 16 spectrometer Magnet (used for KEK E 325) X 26 Candidates of large D-magnet spectrometer 20

Cross Section & Yield • No reliable calculation in such threshold region – At least, 10 nb can be assumed. • Yield – Lq H 2 1 g/cm 2 – 107 / spill, 6 second – 1 baryons per spill • D meson Branch and acceptance – 1% • Integrated Yield per month – ~ 102 per month 2012/2/10 Future prospect of Hadron physics 21

Note: Doubly charmed meson • Threshold of p momentum: 27. 5 Ge. V – p+ + p -> D 0 + Xcc++ • After upgrade of MR energy to 50 Ge. V, there is a hope. 2012/2/10 Future prospect of Hadron physics 22