Hyperon-Proton Scattering Experiments at the J-PARC Background l - PowerPoint PPT Presentation

Hyperon-Proton Scattering Experiments at the J-PARC Background l Available data — bubble chamber l — SCIFI&IIT @ KEK Experimental Objectives at J-PARC l Experiments l Requests & Works l M. Ieiri (KEK) K. Imai (Kyoto U.) B. Bassalleck (U.ofNM) P. Tlusty (NPI) JSPS meeting, September 10, 2003

Milestone Theory Experiment 1930 ('32 neutron) ('35 meson theory) 40 π + - meson) ('47 Idea '51hard-core 50 OPE @long-range established ••• pp, np scattering 60 ('64 Quark hypothesis) Support (YN scattering) 70 OBE ('74 J/ y ) Inspired '77H-particle 80 by SU(3) (Hypernuclei) QCM 90 E251, E289 (established) (established) E452 2000 •••Yp@KEK J-PARC

Available � YN � scatt. � Data � [1] — � Yp � scatt. � at � bubble � chamber � era � '60-'70s � — No Data for X - p @ p X ≤ 1 GeV/c @ 12 GeV KEK-PS since 1990 S + p elastic [11 events] E251 S - p elastic [30 events] E289 S + p elastic [in analysis] L p elastic [in analysis] S + p & L p elastic [in analysis] E452

Available � YN � scatt. � Data � [2] — � Yp � scatt. � at � the � present � 12 � GeV � KEK-PS � : � Method � — Scintillating Fiber (or Liquid Scintillator) with IIT-CCD Camera triggered by Spectrometer system Spectrometer 100 Magnet K+ 50 SciFi S - π- 0 p -50 S - π- -100 IITs -40 -20 0 20 40 (mm) Incident beam rate limit < 10 5 Hz

Available � YN � scatt. � Data � [3] — � Yp � scatt. � at � the � present � 12 � GeV � KEK-PS � : � Results � — l E251, E289 for d s /d W ( S + p & S - p) l E452 for polarization ( S + p & L p) 10 d s /d W (mb/sr) S- p Æ S- p elastic 9 400 < P S- < 700 MeV/c 8 .. E251, E289 7 Julich FSS 6 5 E289 4 3 2 1 0 -1.0 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1.0 cos q CM E289 (E452) E289 E452

List � of � Hyperon-proton � scatterings

Experimental � Objectives � at � J-PARC l S= - 2 pp, pn, nn S= 0 NN (T=1) S=-1 S N (T=3/2) S N- L N (T=1/2) 27s X - p S=-2 SS SS (T=2) X N- SL SL - SS SS (T=1) X N- SS SS - LL LL (T=0) S=-3 XS XS (T=3/2) XS XS - XL XL (T=1/2) S=-4 XX XX (T=1) pn S= 0 NN (T=0) 10a S=-1 S N- L N (T=1/2) X - p S=-2 X N- SL SL (T=1) S=-3 XS XS (T=3/2) S=-1 S N (T=3/2) X - p S=-2 X N- SL SL - SS SS (T=1) 10s S=-3 XS XS - XL XL (T=1/2) S=-4 XX XX (T=0) S=-1 S N- L N (T=1/2) X - p S=-2 X N- SL SL (T=1) X N- SS SS - LL LL (T=0) 8a S=-3 XS XS - XL XL (T=1/2) S=-1 S N- L N (T=1/2) X - p S=-2 X N- SL SL (T=1) X N (T=0) 8s S=-3 XS XS - XL XL (T=1/2) X - p S=-2 X N- SS SS - LL LL (T=0) 1a … better to wait for E452 results l Anti-symmetric spin-orbit 1 + s n 2 ) + b ( s n 1 - s n 2 ) + m s n 1 s n 2 + g( s P 1 s P 2 + s K 1 s K 2 ) M = a + c ( s n 1 s P 2 - s K 1 s K 2 ) +h( s P = 1/4 Tr(MM † s n 1 ) = 2 Re[(a+m)c* + (a -m)b*] I 0 P y T = 1/4 Tr(M s n 2 M † ) = 2 Re[(a+m)c* - (a -m)b*] ) ( I 0 A y

Calculation � by � Models S=-2 Polarization observables X - p ÆLL, X ÆLL, X - p Æ X X - p ( ≈ Anti-symmetric spin-orbit) 0.3 S +p ÆS +p p S = 450 MeV/c P S ( q ) QCM(RGM-H) 0.2 QCM(FSS) OBE(NSC) 0.1 OBE(Julich B) 0 -0.10 30 60 90 120 150 180 1.0 D L ( q ) 0.6 P L ( q ) 0.5 0.4 0.2 0.0 0 L p ÆL p L p ÆL p -0.5 -0.2 p L = 600 MeV/c p L = 600 MeV/c -0.4 -1.0 0 30 60 90 120 150 180 0 30 60 90 120 150 180 q CM (deg) q CM (deg)

Request � for � Secondary � Beam � Line � Momentum Î p(K - , K + ) X - p(K-, K+) X - 50 Berge et al. P K - � : � 1.6 � ~1.8 � GeV/c Dauber et al. 40 Burugun et al. ( � K - � / � p - � > � 1 � ) 30 20 10 0 1 1.5 2 2.5 P lab (GeV/c) Î p( p + , K + ) S + P p + � : � 1.5 � ~1.7 � GeV/c

Experimental � Method ...basically, "double scattering" technique hyperon production reaction hyperon scattering , and hyperon decay • Vertex image detector Scintillating Fiber at KEK since 1990 KEK-PS E251 for S +P E289 for S +p, S -p, L p Liquid Scintillator KEK-PS E452 for S +p, L p asymmetry • Liq. H2 + Cylindrical Drift Chamber X - p (developed by BNL E906 group)

X - p � scattering K - p Æ K + X - CDS X - p Æ X - p • Size radius 30 cm hight 60 cm Lp - • Solenoidal field 5 kG • Time resolution 150 ps p p - • Pos. resolution 200 µm X - p ÆLL π - π - p p - p p p p - 5 kG K- TOF Magnet WCs 25° K+ 20 cm 5m

Target � region π - X -p Æ Æ LL LL p π - p L C X - L K- B A q _spectrometer K+ 10 cm l Target 5 cm wide ¥ 20 cm long A: production 1 cm Liq. Hydrogen Vertical position [mm] Liquid Hydrogen B: degrader 0.5 cm Tungsten Tungsten C: scattering 2 cm Liq. Hydrogen 100 l K + spectrometer q _spectrometer ~ 25° at center l K - beam (assumption @ LOI) 10 7 K - /sec Intensity 0 Momentum 1.7 GeV/c Size s _horizontal 15 mm 0 400 800 1200 s _vertical 1 mm P X just before decay [MeV/c]

K1.8 � beam � line l Length 42.35 m l Intensity K1.8 Experimental 0.7 ¥ 10 7 K - /s@50GeV Area (1.0 ¥ 10 7 K - /s@37.5m&50GeV) Primary K1.8 (0.9 ¥ 10 7 K - /s@37.5m&40GeV) beam line Production target l Size@Liq.H 2 trial tuning just downstream of MS2 s x = 8.8 mm s q = 16.8 mr s y = 2.4 mm s f = 3.6 mr 94 % of K - beam pass through Liq. H 2 of 20cm long with 1cm thickness & 5cm width

Yields � estimation X -p Æ LL 1.0 • K - intensity [s -1 ] 10 7 LL 8.5 ¥ 10 23 • Number of Hydrogen [/cm2] cos q CM 0.5 • Spectrometer [deg] 25 • Spectrometer TOF [m] 5 0 • Trigger rate (K + ) [s -1 ] 11 X - • Momentum of X [MeV/c] 300 - 1100 -0.5 -1.0 200 400 600 800 1000 P X [MeV/c] X - p Æ X - p X -p Æ LL Æ LL [s -1 ] • reaction rate 0.009 0.0043 • 100 days 78000 37000 • Detectable number 2300 550

S + p � & � L p � : � Method R&D needed for … l Imaging device Improve rate limit 10 5 Hz 10 7 Hz A high-speed gateable image pipeline l Online trigger rate By Berkovski et. al. NIM A380(1996)537 — ( p , K) cut — Image brightness cut Assuming success of these R&D, … an estimation from KEK-E452 10000 S + p & L p elastic @10 7 p + /sec , in 10 days

Requests � & � Works for � X - p � (S= � -2), � S + p � & � L p � (Polarization � obs.) ——— � reasonably � doable � at � J-PARC � l Separated beam line around 1.5 - 1.8 GeV/c l K — intensity 10 7 /sec with K/ p > 1 l Liquid hydrogen facility l Review of E251, E289 & E452 @ KEK l Realistic Optimization of Setup l Background estimation (physical & instrumental) l Fast imaging device, Trigger consideration

If… (in the beginning) l K — intensity is low at around 10 6 /sec l No Liquid hydrogen facility X - p / 12 C(K - ,K + LL LL ) experiments with imaging device Scintillating Fiber Block for X p/ tracking X — Tracking device like silicon-strip X Production target K — K + When… l Polarized H 2 target available T , D T Measure A y

E289 � S - p � simulation � & � Proposal Incident π -/spill 1.5x10 5 2x10 5 l Shifts 80 100 l Total π - 8.6x10 10 14.4x10 10 l ( π -, K+) S - 5.8x10 5 9.6x10 5 l with vertex cut 2.8x10 5 S - p [from H] 70 240 l Eye-scan ,kinematical l 45 obtained @E289 30 from H 68 from C&H