with Electron/Photon Beams SATOSHI N. NAKAMURA TOHOKU UNIVERSITY - PowerPoint PPT Presentation

25 th November 2019 Strangeness Nuclear Physics with Electron/Photon Beams SATOSHI N. NAKAMURA TOHOKU UNIVERSITY

Current problems on L hypernuclei Hypertriton Puzzle Hyperon Puzzle CSB of L Hypernuclei p Λ Shallow bound n Short lifetime ? 3 𝑜 Puzzle p p Bound? p Λ n L Resonance? n L n n Not Exist? Λ Λ Why massive n NS exists? A =3 A ~ 10 57 10 −15 m 10 4 m

Current problems on L hypernuclei Hypertriton Puzzle Hyperon Puzzle CSB of L Hypernuclei MAMI p Shallow bound Λ JLab n Short lifetime ELPH ? 3 𝑜 Puzzle p p p Λ n L Bound? n L n n Resonance? Λ Λ Why massive Not Exist? n NS exists? JLab A =3 A ~ 10 57 10 −15 m 10 4 m

Electron beam vs. meson beams ( e,e’K + ) Excellent mass resolution ~ 0.5 MeV Absolute energy calibration p( e,e’K + ) L, S 0 Thin target (isotopically enriched) eg. 40,48 Ca, 3 H (K - , p - ) 1-2 MeV resolution Normalized to 12 L C mass ( p + , K + )

( e,e’K + ) reaction spectroscopy

12 C( e,e’K + ) 12 Λ B 0.5 MeV (FWHM) 0.7 MeV (FWHM) Absolute MM calibration KEK-PS 12 C( 𝜌 + ,K + ) 12 Λ C E369 1.45 MeV (FWHM) L C gs energy 12 from emulsion

12 C( e,e’K + ) 12 Λ B 0.5 MeV (FWHM) 0.7 MeV (FWHM) Nucl. Phys. A (1988) 520. Absolute MM calibration 12 C (emulsion) Λ := 10.76 ± 0.19MeV KEK-PS 12 C( 𝜌 + ,K + ) 12 Λ C E369 1.45 MeV (FWHM) L C gs energy 12 from emulsion

12 C( e,e’K + ) 12 Λ B 0.5 MeV (FWHM) 0.7 MeV (FWHM) Nucl. Phys. A (1988) 520. Absolute MM calibration 12 C (emulsion) Λ := 10.76 ± 0.19MeV 0.5-0.6MeV shift KEK-PS 12 C( 𝜌 + ,K + ) 12 Λ C T.Gogami et al. PRC93(2016). E369 E.Botta et al. NPA969 (2017). 1.45 MeV (FWHM) L C gs energy 12 from emulsion

Hyperon Puzzle Many talks in this WS JLab Hypernuclear Collaboration n n Λ Two solar mass neutron stars E12-15-008: 40,48 Ca targets 3 𝑜 Puzzle C12-19-002 Light targets Λ Tang’s talk Gogami’s talk P12-18-004 Heavy targets

Hyperon Puzzle Based on our knowledge on Baryonic Force: Hyperon naturally appear at high density ( r =2~3 r 0 ) AFDMC by Lonardoni J0740+6620 (2019/9/18 2.14 𝑁 ⨀ sol, Green Bank Obs.) Too Soft EOS Contradict to observation ２ 𝑁 ⨀ Neutron Stars Additional Force to make EOS stiff AFDMC by Lonardoni et al. PRL114 (2015) 092301, updated (2016) ESC08c + 3B/4B RF : G-Matrix Calc. by Yamamoto et al., PRC 90 (2014) 045805. Variational Meth. + AV18+UIX by Togashi et al., PRC 93 (2016) 035808

From Hypernuclei to NS E12-15-008 C12-19-002 P12-18-004

Phenomenological 3 BRF+AFDMC D.Lonardoni C T :Parameter to gauge L nn contribution in L NN potential 40 Ca(e , e ′ K + ) 40 L K and , 48 Ca(e, e′ K + ) 48 L K E12-15-008 accepted with GRADE A. Other calculations are important to analyze new data.

New setup for E12-15-008 PCSM New Pair Charge Sep. Mag. 40,48 Ca targets under construction JLab E12-15-008

To be done before E12-15-008 beamtime Item Status Schedule Pair of Charge Sep. Magnets Contracted Will complete Under const. 16 Mar. 2020. Vacuum Chamber For Solid targets Und. Design For Cryo. targets Depends on PAC48 Targets 40,48 Ca ready HKS Water Cerenkov Prototype ready Spring 2020 Stand for HKS Sieve slits, collimators Analysis/Simulation codes Under develop. In 2020 Ready for Beam in 2021

3 H puzzle Λ 3 H JLab 3 He ( e,e’K + ) Λ Small B L ( Gogami’s talk) MAMI decay p p (Herrmann’s talk) Λ n Proposed at J-PARC Short t 3 H and 3 He ( p - , K 0 ) Λ 3 H 3 He (K - , p 0 ) Λ Partially approved, under preparation at ELPH 3,4 H 3,4 He ( 𝛿 ,K + ) Λ ELPH NKS2 Collaboration Exp# 2895, S.Nagao et al.

Lifetime measurement of Λ 3 H , Λ 4 H with 3,4 H reaction 3,4 He ( 𝛿 ,K + ) Λ K + TOF NKS2 Magnet Liq. He AC γ beam BLT Tracking 4π decay detector Chamber 1 m p.16

Comparison 𝑓, 𝑓 ′ 𝐿 + , (𝛿, 𝐿 + ) reactions (e,e'K + ) ( g ,K + ) 10 13 ～ 14 e - 10 7 g Beam Intensity → 10 9 g * Target Thickness 0.1 g/cm 2 > g/cm 2 Energy resolution 10 -4 10 -3 ～ -2 ～ 10 msr Spectrometer >100 msr Solid angle Yield a few 100 / week a few 100 / week Modest Resolution, but less BG No need to Measure Suitable for decay study of hypernuclei Neutral particles cf) 3 He (K - , p 0 ) Λ 3 H 1.1~1.5 GeV tagged photon beam 3 He ( p - , K 0 ) Λ 3 H 2019/3/5 RCNP 研究会

Photon Beam Facility (ELPH, Tohoku Univ.) BST Ring p.18

Hypernuclear experiment at ELPH BST Ring NKS2 Forward K + Spectrometer • Large Solid Angle • Δp /p ~ 1% • http://hayabusa1.lns.tohoku.ac.jp/ 4π Decay counter Detecting decay particle from hypernuclei • Large Solid Angle • Good time resolution & e ー π ー p separation • Range counter for PID • p.19

Lifetime measurement of Λ 3 H ( Λ 4 H ) Missing Mass ( Λ 3 H ID) K + TOF Missing Mass spectrum NKS2 Magnet q.f . Λ Counts / MeV 3 H (650 / 50 days Λ Liq. 3 He AC γ beam BLT B Λ (MeV) Tracking 4π decay counter Chamber 1 m

Lifetime measurement of Λ 3 H ( Λ 4 H ) Decay Time T ge gen TDL BLT K + = T deca = cay - T gen K + γ beam gen TOF NKS2 Magnet 𝟒 𝐈 𝚳 Decay time spectrum 100 T de Counts / 20 ps decay Δτ = 10 ps (τ= 200ps) Liq. 3 He AC AC 10 π － Drift Chamber γ beam BLT BLT 1 -0.5 0.0 0.5 1.0 1.5 2.0 Decay time (ns) Tracking 4π decay counter Chamber 1 m Range Counter 1 m p.21

Fast timing detector (TDL) 4π good time resolution detector ➢ Φ=9 cm, L=20 cm ➢ 48 x scintillator bar 5x5x20 mm 3 each • ➢ 48 x 2-series connection SiPM MPPC S13360-3050CS • MPPC 4ch diff. Amp. Scintillator p.22

Schedule 4 He target for Λ 4 H lifetime measurement : Feasibility test 2017 Λ lifetime Detector Construction 2018-2019 Λ lifetime 2019 2020 𝟓 𝐈 lifetime 𝚳 𝟒 𝐈 lifetime 2021 𝚳 p.23 2019/3/5 RCNP 研究会 RCNP

SNP study with e, g beams JLab E12-15-008( e,e’K + ) E12-17-003 (nn L ) MAMI -Mainz ELPH -Tohoku First Isospin dependence Decay p Spectroscopy of of medium heavy HY Elementary electroproduced HY w/ best resolution Strangeness 3 L H Binding E. photo-production Study of L N through nn L Light 3 L H lifetime Hypernuclei FSI L N int. Compare experimental results with Theoretical Predictions of Binding Energies and Cross Sections Deduce ΛN interaction including many -body forces Challenge Hyperon, nn L , 3 L H, CSB Puzzles!