Progress & issues in Strangeness NP Avraham Gal, Hebrew - PowerPoint PPT Presentation

Progress & issues in Strangeness NP Avraham Gal, Hebrew University, Jerusalem dynamics of Λ hypernuclei ( A • S = − 1: Λ Z ) (i) Λ few-body & (ii) neutron-rich systems (iii) Λ and other hyperons in neutron stars? • ΛΛ hypernuclei: long-lived H dibaryon? • Hyperons ( Λ , Σ , Ξ ) in nuclear matter |S| → ∞ : strange hadronic matter? K − quasibound states? • Kaons in nuclei: Θ + (1530) traces in K + nuclear dynamics? • SNP Special Issue: Nucl. Phys. A 881 (2012) Proc. HYP 2012: Nucl. Phys. A 914 (2013) 1

Λ hypernuclear dynamics 2

Studies of Λ hypernuclei • ( K − , π − ) – emulsions, CERN, BNL, KEK, LNF, J-PARC • ( π + , K + ) – BNL, KEK, J-PARC • ( π + , K + γ ) – KEK & ( K − , π − γ ) – BNL, J-PARC with Hyperball-J • ( e, e ′ K + ) – JLab, Hall A and Hall C; now also at MAMI stop , π + • DCX: ( π − , K + ) – KEK, J-PARC & ( K − prod π − decay ) – LNF Scheduled experiments at J-PARC using meson beams: • E13: γ -ray spectroscopy of Λ hypernuclei • E10: DCX studies of neutron-rich A Λ Z ( 6 Li , 9 Be & 10 B targets) • E18: 12 Λ C weak decays • E22: weak interactions in 4 Λ H − 4 Λ He Studies of exotica & light hypernuclei lifetimes by heavy ions: • In GSI, the HypHI Experiment, 6 Li on C at 2 A GeV • In LHC, the ALICE Collaboration, Pb-Pb at √ s NN =2.76 TeV 3

Observation of Λ single-particle states KEK E369 89 Y( π + ,K + ) 180 f Λ 160 ∆ E=1.63 MeV FWHM 140 V e d Λ 120 M 5 100 2 . 0 80 / s t n p Λ 60 u o C 40 s Λ s Λ 20 0 -10 -5 0 5 10 15 20 25 30 Excitation Energy (MeV) H. Hotchi et al., Phys. Rev. C 64 (2001) 044302 B Λ = 23 . 11 ± 0 . 10 MeV T. Motoba, D.E. Lanskoy, D.J. Millener, Y. Yamamoto, NPA 804 (2008) 99: negligible Λ spin-orbit splittings, 0.2 MeV for 1 f Λ 4

Update: Millener, Dover, Gal PRC 38, 2700 (1988) Λ Single Particle States (pi,K) 30 208 (e,e’K) 139 Emulsion Binding Energy (MeV) 89 (K,pi) 51 4032 20 28 s Λ 16 131211 10 10 d Λ 8 7 f Λ p Λ g Λ 0 0 0.05 0.1 0.15 0.2 0.25 A − 2 / 3 Woods-Saxon V = 30 . 05 MeV, r = 1 . 165 fm, a = 0 . 6 fm Textbook example of shell model at work. SHF studies suggest Λ NN repulsion. 5

Hyperon puzzle: QMC calculations 60.0 exp 50.0 N N + NN (I) 40.0 N + NN (II) B [MeV] 30.0 20.0 10.0 0.0 0.0 0.1 0.2 0.3 0.4 0.5 A -2/3 PRL 114 (2015) 092301 Lonardoni et al, PRC 89 (2014) 014314 Λ NN effect on neutron stars Λ NN effect on B Λ (g.s.) • Adding Λ NN (and YY) stiffens EOS of neutron stars. • Σ & Ξ hyperons need to be considered too. • YY add 0.3M ⊙ to M max (Rijken-Schulze 2016). 6

6 Li( K − stop , π + ) 6 6 Λ H → 6 He + π − FINUDA: p π + vs. p π − in Λ H, T ( π + ) + T ( π − ) =202–204 MeV (l.h.s.) 200–206 MeV (r.h.s.) Red rectangles: p π + =250–255, p π − =130–137 MeV/c. The 3 events in red are stable against T ( π + ) + T ( π − ) cuts. 6 Λ H not confirmed in ( π − , K + ) by J-PARC E10. 7

FINUDA+Gal (2012) [PRL 108, 042501; NPA 881, 269] Λ H candidate events out of 2.7 x 10 7 K − • Three 6 stop . • B Λ ( 6 Λ H) constrains Λ N ↔ Σ N effects in neutron-rich A Λ Z . 8

Room for hypernuclear spectroscopy 12 C 0.9 g/cm 2 MeV 12 C E140a� ( π + ,K + ) Λ (arbitrary) nb ⋅ GeV 100� 4 2 sr 80� V E369 e exc M dE 5 60� 2 2 . 0 e dE / s σ t n d 40� K u Ω o c d e Ω 20� d 0 0 10 20 0� 170� 175� 180� 185� 190� 195� 200� 205� Excitation Energy (MeV) M HY - M A (MeV) H. Hotchi et al., PRC 64 (2001) 044302 M. Iodice et al., PRL 99 (2007) 052501 12 Λ B in ( e, e ′ K + ), Jlab Hall A 1 s Λ − 1 p Λ intermediate structure energy resolution 1.6 MeV → 0.6 MeV [PRC 90 (2014) 034320] 9

Hypernuclear production in ( K − stop , π − ) , PLB 698 (2011) 219 & 226 2400 Events/0.5 MeV Events/0.5 MeV 7 Li Data Data 2200 7000 Knp → Σ p Knp p → Σ 2000 Kn → Λ π Kn → Λ π 6000 1800 Kp → Σ π K → µ ν 1600 K → µ ν 5000 Hypernuclei 1400 Hypernuclei Fit 4000 Fit 1200 1000 3000 800 2000 600 400 χ 2 /NDF: 0.99 1000 200 0 0 40 20 0 -20 -40 -60 -80 50 40 30 20 10 0 B (MeV) B (MeV) Λ Λ Production spectrum on 7 Li Three 7 Λ Li levels, δB Λ =0.4 MeV Formation rate 1 · 10 − 3 /K − FINUDA, DA Φ NE, Frascati stop A=7–16 data also indicate DEEP K − nuclear potential. 10

1.483 1 + 1 + 3 0 + 2.313 3.948 1/2 + T=1 3/2 + 6.176 0 N 14 3/2 + ,1/2 + 1/2 + + 1 - 1 + E2 5/2 + 0 11 B B 10 1/2 + 0 0 7/2 + - 3/2 2 - B 9 < 0.1 0 + M1 0.718 6.786 M1 2 - 1 - 2 + p 1 - 0.161 0 1.987 M1 Level energies in MeV 11 C 6.042 4.804 0.263 2.832 2.268 - 0 T=1 T=1 4.229 4.710 0 + p 3/2 M1 2.000 0 - 12 C 2 - - 1/2 1 - 3/2 3/2 + 6.562 3.068 0 + 5/2 + 3/2 + 9 Be Be 8 0 0 3.563 1/2 + T=1 M1 M1 3.88 E2 3.040 2 + 1/2 + 7/2 + E2 0 2.186 Li 6 + 1 5/2 + M1 + 3 0 0.692 2.050 3/2 + 1/2 + E2 2 + 0.026 M1 10.98 10.83 M1 0 16 1 - 1 - E2 0 - 1/2 - O 15 3/2 - 2 - 0 4.439 3.025 0 12 0 + 3/2 - 1/2 - 2012 13 C C 0 0 E1 E1 1/2 + 5/2 + 3/2 + 4.88 - 10 B Λ Λ 7 Li Λ Hypernuclear γ rays x Λ p1/2 x Λ p3/2 C Λ Λ 15 N Λ Λ O Λ Hypernuclear level schemes from γ -ray measurements (BNL, KEK) H. Tamura et al., Nucl. Phys. A 835 (2010) 3 [HYP09], updated at HYP12 Λ spin-orbit splitting: 150 keV in 13 Λ C & related 43 keV in 9 Λ Be 11

p-shell Λ hypernuclei V Λ N = V 0 ( r )+ V σ ( r ) s N · s Λ + V LS ( r ) l N Λ · ( s Λ + s N )+ V ALS ( r ) l N Λ · ( s Λ − s N )+ V T ( r ) S 12 V Λ N = ¯ For p N s Y : V + ∆ s N · s Λ + S Λ l N · s Λ + S N l N · s N + T S 12 R.H Dalitz, A. Gal, Ann. Phys. 116 (1978) 167 D.J. Millener, A. Gal, C.B. Dover, R.H. Dalitz, PRC 31 (1985) 499 ¯ N Λ- N Λ V ∆ S Λ S N T from A = 7 − 9 ( − 1 . 32) 0.430 − 0 . 015 − 0 . 390 0.030 fit A = 11 − 16 ( − 1 . 32) 0.330 − 0 . 015 − 0 . 350 0.024 fit N Λ- N Σ 1.45 3.04 − 0 . 085 − 0 . 085 0.157 input (in MeV) D.J. Millener, Nucl. Phys. A 804 (2008) 84 12

Doublet spacings in p-shell hypernuclei (in keV) D.J. Millener, NPA 881 (2012) 298 J π J π ∆ E th ∆ E exp ΛΣ ∆ S Λ S N T u l 7 3 / 2 + 1 / 2 + Λ Li 72 628 − 1 − 4 − 9 693 692 7 7 / 2 + 5 / 2 + Λ Li 74 557 − 32 − 8 − 71 494 471 8 Λ Li 2 − 1 − 151 396 − 14 − 16 − 24 450 (442) 9 3 / 2 + 5 / 2 + Λ Be − 8 − 14 37 0 28 44 43 11 7 / 2 + 5 / 2 + Λ B 56 339 − 37 − 10 − 80 267 264 11 3 / 2 + 1 / 2 + Λ B 61 424 − 3 − 44 − 10 475 505 12 Λ C 2 − 1 − 61 175 − 22 − 13 − 42 153 161 3 / 2 + 1 / 2 + 15 Λ N 65 451 − 2 − 16 − 10 507 481 2 2 16 Λ O 1 − 0 − − 33 − 123 − 20 1 188 23 26 16 1 − Λ O 2 − 92 207 − 21 1 − 41 248 224 2 ΛΣ coupling contributions normally are below 100 keV 13

The lightest, s-shell, Λ hypernuclei A J π J π Λ Z T B Λ (MeV) E x (MeV) g . s . exc . 3 1 / 2 + Λ H 0 0.13(5) 4 Λ H– 4 0 + 1 + Λ He 1/2 2.04(4)–2.39(3) 1.09(2)–1.406(3) 5 1 / 2 + Λ He 0 3.12(2) • No Λ N and no Λ nn bound state are expected. • ∆ B Λ ( 4 Λ He– 4 Λ H)=0.35(5) MeV: very large CSB. Recent A = 3 , 4 few-body calculations • A. Nogga, NPA 914 (2013) 140 Faddeev & Faddeev-Yakubovsky (chiral LO & NLO). • E. Hiyama et al., PRC 89 (2014) 061302(R) Jacobi-coordinates Gaussian basis (Nijmegen soft-core). • R. Wirth et al., PRL 113 (2014) 192502. ab-initio Jacobi-NCSM (chiral LO). 14

Λ H– 4 4 Λ He levels before and after J-PARC E13 exp. T. O. Yamamoto et al., J-PARC-E13, PRL 115 (2015) 222501 3 H + � 3 He + � 0 + 1 0.96 �} 0.04 + 1 4 He( K � � 1.24 �} 0.05 , ) � ( p =1.5 GeV/ ) c K M1 + 1/2 1 + 1 + 1.08 �} 0.02 0.95 0.04 0.98 0.03 M1 + 1/2 1.15 �} 0.04 1/2 + + 1/2 + 3 H 0 E � = 1.09 + 3 E � = 1 406 . 0 He 0.02 2.04 �} 0.04 3 H 0 002 . 3 He 4 0 002 . 2.39 �} 0.03 H 0 + [present] 4 He Λ 2.04 0.04 0 + Λ 4 H B Λ 2.39 0.03 4 He (MeV) B [MeV] MAMI’s new value B Λ ( 4 Λ H)=2.12 ± 0.01 ± 0.09 MeV, consistent with emulsion value, obtained by measuring decay π − in 4 Λ H → 4 He+ π − [PRL 114 (2015) 232501]. CSB is strongly spin dependent, dominantly in 0 + g . s . 350 ± 60 keV in 4 Λ H- 4 Λ He vs. ≈− 70 keV in 3 H- 3 He. 15

Relating Λ - Σ 0 CSB mixing to ΛΣ SI coupling Σ 0 Λ Λ • δM V Λ N − Σ N N N Dalitz-von Hippel (1964): “applies to any isovector meson exchange, π , ρ ...” & also to χ EFT contact interactions. Applied systematically by A. Gal, PLB 744 (2015) 352 (also in p-shell) & D. Gazda, A. Gal, arXiv:1512.01049. 16

A=4 CSB: D. Gazda, A. Gal, arXiv:1512.01049 B Λ (0 + ) ≈ cutoff-independent (dispersion ∼ 100 keV) B Λ (1 + ) is cutoff-dependent (dispersion ∼ 0.5 MeV) but ∆ B Λ (0 + 1 + ) cutoff – (in) dependent. 17

D. Gazda, A. Gal, arXiv:1512.01049 EFT LO cutoff momentum ( Λ ) dependence of E x (0 + → 1 + ) hω =30,32 MeV. [exp: E x ( 4 at HO ¯ Λ He)=1.41 ± 0.02 MeV] CSB Λ - Σ 0 mixing is correlated with SI ΛΣ coupling. Λ =600 MeV: ∆ E x =0.33 ± 0.03 MeV [exp: 0.32 ± 0.02 MeV] 18

ΛΛ hypernuclei 19