HLAB meeting 論文紹介18/Oct/2011Toshi Gogami

Title

Abstract

X-ray spectroscopy of kaonic atoms

• An accurate determination of the K-N iso-spin dependent scattering length

Strong constrains on the low-energy K-N dynamics ( S.Deser et al., Phys. Rev. 98(1954)774 )

Nuclear absorption

Width Γ1s

Shift ΔE1s

Strong interaction

2p

1s 2p-1s X-ray (~6 KeV)

Kaonic hydrogen

1s (only coulomb)

Results of KH from the past experiments

(1) Davies et al. 1979(2) Bird et al. 1983(3) Izycki et al. 1980

Repulsive AttractiveProgress in Particle and Nuclear Physics 61 (2008) 512-550

p

K-

Experimental setup

φ

K+

K-

Gaseous target

X-ray

e+ e-

Nuclear Instruments and Methods in PRA 581 (2007)326-329

What are differences ?KpX, 1998 DEAR, 2005 SIDDHARTA

Detector Si(Li) CCD SDD

Energy resolution [eV] (FWHM)

360 180 150

Thickness Sub 10 mm Sub mm Sub mm

Effective area [cm2] 120 116 114

Time resolution Sub μs ~ 30 sec Sub μs

Effciency @ 6 [keV] ~ 100% ~ 60% ~ 100%

Time gate

• K- K+ coincidence time WRT RF signal (~368MHz)

• K- K+ coin & x-ray

Result of the KH

• Γ1s = 541 ± 89(stat.) ± 22(sys.) [eV]

• ΔE1s = −283 ± 36(stat.) ± 6(sys.) [eV]

arXiv:1105.3090v2 (2011)9/Aug

Result of the KHarXiv:1105.3090v2 (2011)

• Γ1s = 541 ± 89(stat.) ± 22(sys.) [eV]

• ΔE1s = −283 ± 36(stat.) ± 6(sys.) [eV]

Kaonic He puzzle

• KEK-PS E570– 6467±2(stat.)±2(sys.) [eV]– ΔE2p = 2±2(stat.)±2(sys.) [eV]

8 SSDs, 1 months

Theories

PLB 653 (2007) 387-391

Results of Kaonic He

144 SSDs, a few days

Shift [eV] PublicationKEK E570 K4He +2±2(stat.)±2(sys.) PLB 653(2007)387

SIDDHARTA K4He (a part of dataset) +0±6(stat.)±2(sys.) PLB 681(2009)310

K4He (increased statistics) +5±3(stat.)±4(sys.) Preliminary (PLB 697(2011)199)

K3He -2±2(stat.)±4(sys.) PLB 697 (2011)199

Kaonic Helium4 Kaonic Helium3

Results of Kaonic He

144 SSDs, a few days

Shift [eV] PublicationKEK E570 K4He +2±2(stat.)±2(sys.) PLB 653(2007)387

SIDDHARTA K4He (a part of dataset) +0±6(stat.)±2(sys.) PLB 681(2009)310

K4He (increased statistics) +5±3(stat.)±4(sys.) Preliminary (PLB 697(2011)199)

K3He -2±2(stat.)±4(sys.) PLB 697 (2011)199

Kaonic Helium4 Kaonic Helium3SIDDHARTA

KEK E570

Summary• K-p ( arXiv:1105.3090v2 (2011) )– Γ1s = 541 ± 89(stat.) ± 22(sys.) [eV]– ΔE1s = −283 ± 36(stat.) ± 6(sys.) [eV]

• K-3He– The first time measurement (PLB 697 (2011)199)– -2±2(stat.)±4(sys.)

• K-4He – PLB 681(2009)310– +0±6(stat.)±2(sys.)

• K-d– The first exploratory measurement

SIDDHARTA-2 Collaboration, Proposal of Laboratori Nazionali di Frascati of INFN, The upgrade of the SIDDHARTA apparatus for an enriched scientific case (2010).

SIDDHARTA-2