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

SATOSHI N. NAKAMURA TOHOKU UNIVERSITY

Strangeness Nuclear Physics with Electron/Photon Beams

25th November 2019

Current problems on L hypernuclei

10−15 m 104 m

A=3 A~1057

Λ

3𝑜 Puzzle

CSB of L Hypernuclei Hyperon Puzzle Hypertriton Puzzle

p n Λ Λ n n Λ n p L L

?

p n p n

Shallow bound Short lifetime Bound? Resonance? Not Exist? Why massive NS exists?

Current problems on L hypernuclei

10−15 m 104 m

A=3 A~1057

Λ

3𝑜 Puzzle

CSB of L Hypernuclei Hyperon Puzzle Hypertriton Puzzle

p n Λ Λ n n Λ n p L L

?

p n p n

Shallow bound Short lifetime Bound? Resonance? Not Exist? Why massive NS exists?

JLab MAMI ELPH JLab

Electron beam vs. meson beams

(e,e’K+) Excellent mass resolution

~ 0.5 MeV

Absolute energy calibration

p(e,e’K+) L, S0

(K-, p-) (p+, K+)

1-2 MeV resolution Normalized to 12

LC mass

Thin target (isotopically enriched)

• eg. 40,48Ca, 3H

(e,e’K+) reaction spectroscopy

0.5 MeV (FWHM) 1.45 MeV (FWHM)

12C(𝜌+,K+)12 ΛC

KEK-PS E369

Absolute MM calibration

12 LCgs energy

from emulsion 0.7 MeV (FWHM)

12C(e,e’K+)12 ΛB

1.45 MeV (FWHM)

12C(𝜌+,K+)12 ΛC

KEK-PS E369

Absolute MM calibration

12 LCgs energy

from emulsion 0.7 MeV (FWHM)

12C(e,e’K+)12 ΛB

0.5 MeV (FWHM)

Λ 12C (emulsion)

:= 10.76 ± 0.19MeV

• Nucl. Phys. A (1988) 520.

1.45 MeV (FWHM)

12C(𝜌+,K+)12 ΛC

KEK-PS E369

Absolute MM calibration

12 LCgs energy

from emulsion 0.7 MeV (FWHM)

12C(e,e’K+)12 ΛB

0.5 MeV (FWHM)

Λ 12C (emulsion)

:= 10.76 ± 0.19MeV

• Nucl. Phys. A (1988) 520.

0.5-0.6MeV shift

T.Gogami et al. PRC93(2016). E.Botta et al. NPA969 (2017).

Hyperon Puzzle

Two solar mass neutron stars n n Λ

Λ

3𝑜 Puzzle

Tang’s talk

JLab Hypernuclear Collaboration

E12-15-008: 40,48 Ca targets C12-19-002 Light targets Gogami’s talk P12-18-004 Heavy targets

Many talks in this WS

Hyperon Puzzle

Based on our knowledge on Baryonic Force:

Hyperon naturally appear at high density (r=2~3r0)

２ 𝑁⨀ Neutron Stars

Too Soft EOS Contradict to

• bservation

Additional Force to make EOS stiff

AFDMC by Lonardoni

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

J0740+6620 (2019/9/18 2.14 𝑁⨀sol, Green Bank Obs.)

From Hypernuclei to NS

E12-15-008 C12-19-002

P12-18-004

Phenomenological 3 BRF+AFDMC

E12-15-008 accepted with GRADE A.

40Ca(e ,e′K+)40 LK and , 48Ca(e, e′K+)48 LK

CT :Parameter to gauge Lnn contribution in LNN potential

D.Lonardoni

Other calculations are important to analyze new data.

JLab E12-15-008

New Pair Charge Sep. Mag.

40,48Ca targets

under construction

New setup for E12-15-008

PCSM

To be done before E12-15-008 beamtime

Item Status Schedule Pair of Charge Sep. Magnets Contracted Under const. Will complete 16 Mar. 2020. Vacuum Chamber For Solid targets

• Und. Design

For Cryo. targets Depends on PAC48 Targets

40,48Ca

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

ELPH NKS2 Collaboration

Exp# 2895, S.Nagao et al.

p n Λ

Λ

3H puzzle

JLab 3He(e,e’K+)Λ

3H

(Gogami’s talk)

MAMI decay p

(Herrmann’s talk)

Short t Small BL

Proposed at J-PARC

Partially approved, under preparation at ELPH

3He(K-, p0)Λ 3H and 3He(p-, K0)Λ 3H

3,4He(𝛿,K+) Λ 3,4H

Lifetime measurement of Λ

3H, Λ 4H with 3,4He(𝛿,K+) Λ 3,4H reaction

p.16

1 m

K+

NKS2 Magnet

TOF

• Liq. He

γ beam

4π decay detector Tracking Chamber BLT AC

Comparison 𝑓, 𝑓′𝐿+ , (𝛿, 𝐿+) reactions

2019/3/5 RCNP研究会

(e,e'K+) (g,K+) Beam Intensity 1013～14 e- → 109 g* 107 g Target Thickness 0.1 g/cm2 > g/cm2

Energy resolution

10-4 10-3～-2 Spectrometer Solid angle ～ 10 msr >100 msr Yield a few 100 / week a few 100 / week

Modest Resolution, but less BG

Suitable for decay study of hypernuclei 1.1~1.5 GeV tagged photon beam

No need to Measure Neutral particles cf) 3He(K-, p0)Λ

3H 3He(p-, K0)Λ 3H

Photon Beam Facility (ELPH, Tohoku Univ.)

p.18

BST Ring

Hypernuclear experiment at ELPH

p.19

http://hayabusa1.lns.tohoku.ac.jp/

BST Ring

NKS2

• Forward K+ Spectrometer
• Large Solid Angle
• Δp/p ~ 1%

4π Decay counter

• Detecting decay particle from hypernuclei
• Large Solid Angle
• Good time resolution & eーπーp separation
• Range counter for PID

Lifetime measurement of Λ

3H (Λ 4H)

1 m

K+

NKS2 Magnet

TOF

• Liq. 3He

γ beam

4π decay counter Tracking Chamber BLT AC

Missing Mass (Λ

3H ID)

Counts / MeV BΛ (MeV)

3H

Λ

q.f. Λ (650 / 50 days Missing Mass spectrum

Lifetime measurement of Λ

3H (Λ 4H)

p.21

1 m

K+

NKS2 Magnet

TOF

• Liq. 3He

γ beam

4π decay counter BLT AC

Decay Time = = Tdeca

cay - Tgen gen

1 m

Tracking Chamber

Drift Chamber Range Counter TDL BLT

𝚳 𝟒𝐈

π－

γ beam

K+

Tde

decay

Tge

gen

BLT AC

Decay time (ns)

• 0.5

0.0 0.5 1.0 1.5 2.0

100 10 1

Counts / 20 ps

Decay time spectrum Δτ = 10 ps (τ=200ps)

Fast timing detector (TDL)

p.22

4π good time resolution detector ➢ Φ=9 cm, L=20 cm ➢ 48 x scintillator bar

• 5x5x20 mm3 each

➢ 48 x 2-series connection SiPM

• MPPC S13360-3050CS

4ch diff. Amp. MPPC

Scintillator

Schedule

2019/3/5 RCNP RCNP研究会

p.23

4He target for Λ

4H lifetime measurement : Feasibility test

𝚳 𝟓𝐈 lifetime 𝚳 𝟒𝐈 lifetime

2017 2020 2021

Λ lifetime Detector Construction Λ lifetime

2019 2018-2019

SNP study with e,g beams

JLab E12-15-008(e,e’K+)

E12-17-003 (nnL)

MAMI-Mainz

Challenge Hyperon, nnL, 3

LH, CSB Puzzles!

ELPH-Tohoku

3 LH lifetime

FSI LN int. Light Hypernuclei

Decay p Spectroscopy of electroproduced HY

Compare experimental results with Theoretical Predictions of Binding Energies and Cross Sections Deduce ΛN interaction including many-body forces

First Isospin dependence

• f medium heavy HY

w/ best resolution

Elementary Strangeness photo-production

3 LH Binding E.

Study of LN through nnL