Near threshold production of pseudoscalar mesons at the COSY-11 facility

Paweł Moskalon behalf of the COSY-11 collaboration

NSTAR 2007, Bonn 07.10.2007

Jagellonian University, Cracow, Poland Research Centre Jülich, Germany

D. Grzonka, K. Kilian, W.Oelert, J. Ritman, T. Sefzick, M. Wolke, P. Wüstner

IKP & ZEL, Research Centre Jülich, Germany

COSY-11 COLLABORATION

E. Czerwiński , R. Czyżykiewicz , D. Gil , M. Janusz ,L. Jarczyk, B. Kamys, P. Klaja , P. Moskal, C. Piskor-Ignatowicz ,

J. Przerwa , B. Rejdych , M. Silarski , J. Smyrski

H.-H. Adam , A. Khoukaz, A. Täschner

M. Siemaszko, W. Zipper

A. Budzanowski

IP, Jagellonian University, Cracow, Poland

IKP, Westfälische Wilhems-Universität Münster, Germany

I P, University of Silesia, Katowice, Poland

INP, Cracow, Poland

COoler SYnchrotron COSY

WASA

• polarised and unpolarised proton and deuteron beams

• stochastic and electron cooling

• momentum range: 600 – 3700 MeV/c

• meson production up to (1020)

COoler SYnchrotron COSY

COSY-11Clustertarget

driftchambers

scintillator

scintillator

dipoledipole

beambeam

KK--

ppppKK++drift chambersdrift chambers

S1S1

silicon pads + scintillatorsilicon pads + scintillator

COSY-11: C. Quentmeier et al., Phys. Lett. B 515 (2001) 276.

COSY-11: P. Winter et al., Phys. Lett. B 635 (2006) 23.

DISTO: F. Balestra et al., Phys. Rev. C 63 (2001) 024004.

σ = dVps |M|2F

1

|M|2 ~ |M0|2 |MFSI|2

HYPERON PRODUCTION

super cycle

σ = dVps |M|2F

1

|M|2 ~ |M0|2 |MFSI|2

dynamics |M0|2

interaction σ (Q)

COSY-11: T. Rożek et al., Phys. Lett. B 643 (2006) 251.COSY-11: P. Kowina et al., Eur. Phys. J. A 22 (2004) 293.COSY-11: S. Sewerin et al., Phys. Rev. Lett. 83 (1999) 682.COSY-11: J. Balewski et al., Eur. Phys. J. A 2 (1998) 1.COSY-11: J. Balewski et al., Phys. Lett. B 420 (1998) 211.COSY-11: J. Balewski et al., Phys. Lett. B 388 (1996) 859.

σ = dVps |M|2F

1

|M|2 ~ |M0|2 |MFSI|2

|MFSI|2 ~ |Mpp|2 |Mp1η|2 |Mp2η|2

dynamics |M0|2

interaction σ (Q)

CELSIUSWASA/CELSIUS: H. Calen et al., Phys. Lett. B 366 (1996) 39.WASA/CELSIUS: H. Calen et al., Phys. Rev. Lett. 79 (1997) 2642.

COSYCOSY-11: A. Khoukaz et al., Eur. Phys. J. A 20 (2004) 345.COSY-11: P. M. et al., Phys. Rev. C 69 (2004) 025203.COSY-11: P. M. et al., Phys. Lett. B 482 (2000) 356.COSY-11: P. M. et al., Phys. Lett. B 474 (2000) 416.COSY-11: J. Smyrski et al., Phys. Lett. B 474 (2000) 182.COSY-11: P. M. et al., Phys. Rev. Lett. 80 (1998) 3202.

SATURNEDISTO/SATURNE: F. Balestra et al., Phys. Lett. B 491 (2000) 29.SPES/SATURNE: F. Hibou et al., Phys Lett. B 438 (1998) 41.PINOT/SATURNE: E. Chiavassa et al., Phys. Lett. B 322 (1994) 270.SPES/SATURNE: A. M. Bergdold et al., Phys. Rev. D 48 (1993) R2969.SPES/SATURNE: R. Wurzinger et al., Phys. Lett. B 374 (1996) 283.

•COSY-11: P. M. et al., Phys. Rev. C 69 (2004) 025203.

EXPERIMENT Q = 15.5 MeV SIMULATION SIMULATION

EXPERIMENT Q = 15.5 MeV EXPERIMENT Q = 4.5 MeVEXPERIMENT Q = 10 MeV

- 3He interaction

• dp 3He above 3He- threshold

• dp 3He 3He o below 3He- threshold

d p o "

pp p - "

dp "

DEUTERON BEAM

COSY-11: J. Smyrski et al., Acta Phys. Slov. 56 (2006) 213 [nucl-ex/0603023]

COSY-11: J. Smyrski et al., nucl-ex/0702043

Internal beam: ~ 3x1010 deuterons

Δf= 0.2 MHz Δp = 1.7 MeV/cΔQ = 0.4 MeV

Frequency spectrum

t

Pbeam

[MeV/c]

Slow ramping

5 min

3099

3179

Q(dp3He ) [MeV]

9

0

-10

Missing mass

TOT (dp 3He)

COSY-11: J. Smyrski et al., nucl-ex/0702043

Test measurement of the p n → p n η

Integrated Luminosity = 2 ·1035 cm-2

p n → p n η’ Integrated Lumonosity from runs in 2004/2006 ≈ 100 · 1035 cm-2

Analysis in progress

•COSY-11: P. M. et al., J. Phys. G 32 (2006) 629.