HES HKS Analysis meeting

14/Dec/2012 @ JLabToshi Gogami

Preliminary results of p(γ*,K+)Λ

2012/9/14 JPS meeting in Kyoto , Toshi Gogami 2

Preliminary

JLab E05-115 (HES-HKS)192±6±89 [ nb / sr ]

SAPHIR : K.H.Glander et al. , Eur. Phys. J. A 19, 251-273 (2004)CLAS : R.Bradford et al. , Phys. Rev. C 73, 035202 (2006)

( JLab E05-115 , Q2 ~ 0.01 [GeV/c]2 )

Definition of cross section

Solid angle of HKSEvent by event

The number of VP• Including HES solid angle

and acceptanceNew way to estimate

VP flux factor

Γ ( Ee , ω , θe’ )• Ee = 2.344 GeV• ω = 1.5 GeV

Jab E05-115 , Polyethylene target

θe’ (lab)

VP flux factor vs. p and θ

~ 0.087

~ 0.01HES

HKS

Integrated VP flux factor

VP flux factor

Divided into 7 regions

1 3 4 52Jab E05-115 , Polyethylene target

6 7

θe’ (lab)

VP flux factor

Divided into 7 regions

1 3 4 52Jab E05-115 , Polyethylene target

0.00350.0043

0.00580.0081

0.0115 Q2 [GeV]2

6 7

0.0024 0.0160

Γ Γ’ ( Region 4 )

SIMULATION

0.790 – 0.844 GeV/c( 1.922 < W < 1.947 GeV)

Γ’ ~ 3.5543× 10-6 [ /Ne ]

Γ ~ 0.065 [ / GeV / sr / Ne ]

Number of VP ~ 6.2818×1012 ± 4.05189×1010

Resultsθe' (Lab) θgK (CM) Q2 [GeV]2 Γ Γ' Number of VP solid angles

(HES,HKS)[msr]NΛ Cross section [ nb/sr ]

0.030 - 0.040 0.3060.312±0.08

0.00242.45e-3±5.9e-4

0.221 4.27923e-06 7.52071e+12±1.05573e+11

0.3 , 8.4 384 +- 24 206.161 ( +- 13.1462 ) ( - 96.8266 ) ( + 97.1458 )

0.040 - 0.045 0.2980.305±0.08

0.00353.54e-3±2.6e-4

0.150 2.34783e-06 4.18425e+12±4.29365e+10

0.3 , 8.4 149 +- 17 144.837 ( +- 16.5421 ) ( - 61.9157 ) ( + 62.1365 )

0.045 - 0.050 0.3090.307±0.07

0.00434.30e-3±3.2e-4

0.121 2.25936e-06 3.98002e+12±4.30705e+10

0.3 , 8.4 142 +- 17 144.097 ( +- 17.6952 ) ( - 60.6333 ) ( + 60.8523 )

0.050 - 0.060 0.2980.298±0.08

0.00585.85e-3±8.3e-4

0.090 4.10857e-06 7.20095e+12±6.46153e+10

0.8 , 8.4 300 +- 24 169.896 ( +- 13.671 ) ( - 77.3213 ) ( + 77.5833 )

0.060 - 0.070 0.3120.312±0.09

0.00818.02±9.4e-4

0.065 3.5543e-06 6.26988e+12±3.97629e+10

1.0 , 8.4 307 +- 24 199.578 ( +- 15.6367 ) ( - 91.1819 ) ( + 91.4899 )

0.070 - 0.085 0.3160.312±0.08

0.01151.129e-2±1.629e-3

0.046 4.50219e-06 7.80142e+12±6.16911e+10

1.8 , 8.4 378 +- 27 196.161 ( +- 14.4697 ) ( - 90.3967 ) ( + 90.6998 )

0.085 - 0.100 0.3000.306±0.09

0.01601.593e-2±1.600e-3

0.033 2.7764e-06 4.78124e+12±9.17287e+10

1.6 , 8.4 215 +- 20 181.798 ( +- 17.2207 ) ( - 80.6174 ) ( + 80.8964 )

Angular dependence

SAPHIR : K.H.Glander et al. , Eur. Phys. J. A 19, 251-273 (2004)CLAS : R.Bradford et al. , Phys. Rev. C 73, 035202 (2006)

Q2 dependence

Q2 dependence

SAPHIR : K.H.Glander et al. , Eur. Phys. J. A 19, 251-273 (2004)

Coincidence cut for 52Cr

• TCut cut_1 = "abs(ctime+54.6)<1.0 && 75976.5<runnum && runnum<76049.5";

• TCut cut_2 = “abs(ctime+54.8)<1.0 && 76716.5<runnum &&　runnum<76802.5";

• TCut cut_3 = "abs(htimetar-etimetar+54.9)<1.0 && (76845.5<runnum && runnum<76937.5)";

• TCut cut_41 = "abs(htimetar-etimetar+54.9)<1.0 && (76947.5<runnum && runnum<77064.5)";

• TCut cut_42 = "abs(htimetar-etimetar+54.3)<1.0 && (runnum>77064.5)";

END

Comparison with data of JLab Hall-A Large longitudinal term

contributions?

p(γ*,K+)Λ ~ JLab E05-115 (HES-HKS)W ~ 1.9 GeVQ2 ~ 0.01 [GeV/c]2

Preliminary

p(γ*,K+)Λ ~ JLab E94-107W ~ 2.2 GeVQ2 ~ 0.07 [GeV/c]2

SAPHIR : K.H.Glander et al. , Eur. Phys. J. A 19, 251-273 (2004)CLAS : R.Bradford et al. , Phys. Rev. C 73, 035202 (2006)JLab E94-107 : P.Markoviz et al. , Proceedings of SENDAI08 (2009)

2012/9/14 JPS meeting in Kyoto , Toshi Gogami 17

Considered efficiencies

Simulation

2012/9/14 JPS meeting in Kyoto , Toshi Gogami 18

K+ production at small angles

TLTTLTfull )1(2 electroproduction

SL: 0.41 = 0.35 + 0.004 - 0.001 + 0.06 ( e = 0.7 )

a steep

Q2 dependence ?

P. Bydzovsky’s presentation at ECT* 2011

(g*,K+)JLab Hall-A

E05-115W=1.9 GeVQ2=0.01 (GeV/c)2

2012/9/14 JPS meeting in Kyoto , Toshi Gogami 19