Simultaneous phase shift analysis of 210 MeV nucleon-nucleon scattering

Simultaneous phase shift analysis of 210 MeV nucleon-nucleon scattering

~ Nuclear Physics B4 (1968) 527-533. North-Holland Publ. Comp., Amsterdam SIMULTANEOUS PHASE SHIFT NUCLEON-NUCLEON Z. JANOUT ANALYSIS OF 210 ...

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Nuclear Physics B4 (1968) 527-533. North-Holland Publ. Comp., Amsterdam

SIMULTANEOUS

PHASE

SHIFT

NUCLEON-NUCLEON Z. JANOUT

ANALYSIS

OF

210

MeV

SCATTERING

*, Yu. M. KAZARINOV, F. LEHAR *, P. WINTERNITZ Joint Institute f o r Nuclear Research Dubna, USSR

**

Received 2 January 1968

A b s t r a c t : P h a s e - s h i f t analysis at 210 MeV has been performed taking /max - 5. New data on the differential c r o s s section, polarization and triple scattering p a r a m e t e r s have been used and the procedure leads to a unique solution. The angular dependences of experimental quantities a r e shown in d i a g r a m s .

i . INTRODUCTION

T h e p h a s e - s h i f t a n a l y s i s of n u c l e o n - n u c l e o n s c a t t e r i n g d a t a a t 210 M e V h a s p r e v i o u s l y b e e n p e r f o r m e d in r e f s . [1-4]. S i n c e m a n y n e w e x p e r i m e n t a l d a t a h a v e b e e n o b t a i n e d r e c e n t l y , i t i s n e c e s s a r y to t a k e t h e s e into a c count and find more accurate phase-shifts at this energy. T h e p u r p o s e of t h i s i n v e s t i g a t i o n w a s , on one h a n d , to s p e c i f y the p r e v i o u s l y e x i s t i n g s e t of p h a s e - s h i f t s f o r / m a x = 3 a n d / m - x = 4. On t h e o t h e r h a n d t h e v a l u e / m a x , up to w h i c h the p h a s e s a r e v a r i e d ~ o r l > / m a x t h e y a r e c a l c u l a t e d u s i n g the o n e - p i o n e x c h a n g e a p p r o x i m a t i o n ) i s d e t e r m i n e d u s i n g v a r i o u s s t a t i s t i c a l c r i t e r i a a n d d e p e n d s on t h e a m o u n t a n d a c c u r a c y of t h e e x p e r i m e n t a l d a t a . T h u s t h e i n c l u s i o n of n e w d a t a u s u a l l y s h i f t s / m a x to h i g h e r v a l u e s , w h i c h c a n c a u s e t h e a p p e a r a n c e of new p h a s e - s h i f t s e t s . In the c o n s i d e r e d c a s e i t p r o v e d n e c e s s a r y to i n c r e a s e t h e a n g u l a r m o m e n t u m v a l u e to / m a x = 5. T h e a m b i g u i t y of t h e p h a s e - s h i f t a n a l y s i s f o r h i g h e r /max has not been investigated previously.

2. EXPERIMENTAL

DATA

AND

PHASE-SHIFT

ANALYSIS

T h e d a t a u s e d in t h e p h a s e - s h i f t a n a l y s i s a t 210 M e V [5-16] a r e g i v e n in t a b l e 1. T h e new d a t a on t h e d i f f e r e n t i a l c r o s s s e c t i o n f o r s m a l l s c a t t e r i n g a n g l e s [6], t h e p o l a r i z a t i o n in p , p [6] a n d n , p s c a t t e r i n g [13] a n d t h e t r i p l e s c a t t e r i n g p a r a m e t e r s D t ( r e f . [15]) a n d R t ( r e f . [16]) f o r t h e r e c o i l p a r t i c l e s * On leave of absence from the Faculty of Technical and Nuclear Physics, Technical University, Prague, Czechoslovakia. ** On leave of absence from the Nuclear R e s e a r c h Institute of the Czechoslovak A c a demy of Sciences, f~e~.

Z. JANOUT et al.

528

Table 1 The e x p e r i m e n t a l data, u s e d in the p h a s e - s h i f t a n a l y s i s at 210 MeV

Energy (MeV)

Angular r a n g e in degrees (c .m .s .)

Number

Measured quantity

ffpp

213

30-90

7

2.39

213

9-39

13

13.65

210

30-90

7

3.88

210

13-113

14

213

9-39

Ppp

Autho:rs

Refs

Konradi (1961)

[5]

M a r s h a l l et al. (1966)

[6]

Tinlot, W a r n e r (1961)

[7]

12.12

B a s k i r et al. (1957)

[8]

13

13.88

M a r s h a l l et al. (1966)

[6]

of points

AX2,

C oe nmt m a

b

217

60-120

7

6.42

Tinlot, Warner (1961)

[7]

Rpp

213

30-90

7

2.74

England et al. (1961)

[9]

App

213

30-90

7

5.51

c

England et al. (1961)

[9]

R' PP

213

30-90

5

3.36

d

G o t o w ,Lobkowicz (1964)

[10]

Dpp

213

30-90

7

4.80

Gotow et al. (1962)

[11]

~np

200

6-180

21

28.25

K a z a r i n o v , Simonov (1962)

[12]

P

199

77-158

7

7.20

Thorndike (1967)

[13]

Ppn

215

40-120

9

10.94

Tinlot, Warner (:1961)

[7]

Dpn

212

13-39

5

3.01

Warner, Tinlot (1962)

[14]

Dt

197

127-148

3

2.05

Spalding et al. (1967)

[15]

Rt

203

139-179

5

5.38

Reay et al. (1966)

[16]

(Ttnp

200

1

0.12

Kazarinov, Simonov (1962)

[12]

e

np

* The contribution to X 2 f o r the 1 - s t set.

f

PHASE SHIFT ANALYSIS

529

C o m m e n t s to t a b l e 1 a) Their data were multiplied by the correction factor 0.986 according to ref. [4]. b) The polarization data from ref. [8], which do not agree with the more accurate values obtained at 210 MeV (ref. [7]) in the angular region 50o-70 ° were not included in the phase-shift analysis. c) The values of the p a r a m e t e r Apo at 800 and 90 ° given in the original paper (see ref. [9]) were excluded since th6y differ by more than 3 standard deviations from the calculated values. Instead of these points we used the new data, as given by Thorndike (ref. [13]). In this case the contributions to X2 are equal to 1.58 and 0.06 for 80 ° and 90 ° , respectively. d) The values at the angles 60 ° and 70° had to be excluded since their contributions to X2 are equal to 12.9 and 16.3, respectively. The number of points in table 1 are shown without the excluded points. e) The values at the angle 86.6 ° had to be excluded because they differ by more than 3 standard deviations from the calculated values. f) The quantities P n - and R t were m e a s u r e d in the quasi-elastic scattering of protons on neutrons in deuteron nuclei. The measured values were corrected later by Koehler et al. (ref. [17]) taking the final S-state interaction into account. The corrected values of R t are in worse agreement with the calculated value, than the uncorrected data. This may be due to a systematical e r r o r of about 14% contained in the corrections (ref. [13]).

i n n , p s c a t t e r i n g , w e r e p r e v i o u s l y n o t i n c l u d e d i n the p h a s e - s h i f t a n a l y s i s . T h e t r i p l e s c a t t e r i n g p a r a m e t e r s f o r the r e c o i l p a r t i c l e a r e d i s c u s s e d i n d e t a i l i n r e f . [18] w h e r e a l l the f o r m u l a e u s e d i n t h i s p a p e r a r e g i v e n , taking r e l a t i v i s t i c effects into account. A l l the e x p e r i m e n t a l d a t a a r e c o n c e n t r a t e d i n the e n e r g y r e g i o n 1 9 7 - 2 1 7 MeV. T h e m e a s u r e d v a l u e s w e r e not n o r m a l i z e d to the m e a n e n e r g y 210 MeV. T h e p h a s e - s h i f t a n a l y s i s w a s c a r r i e d out a c c o r d i n g to the p r o g r a m m e , d e s c r i b e d i n d e t a i l i n r e f . [1]. Hundred searches from random initial parameters were made, from w h i c h t h r e e s o l u t i o n s with ×2 = 127.3, 159.8 a n d 190.4 w e r e o b t a i n e d i n the X2 --< 2X-2 r e g i o n ( t a b l e s 2 a n d 3). It s h o u l d be n o t e d t h a t a l l the o b t a i n e d s o l u t i o n s c o r r e s p o n d to the p h a s e - s h i f t s s e t s o b t a i n e d p r e v i o u s l y i n the f i r s t a n a l y s i s of p , p a n d n , p d a t a a t t h i s e n e r g y [1] ( s o l u t i o n s b, b I a n d c, r e s p e c t i v e l y ) . T h e s e a r c h f o r the s o l u t i o n s f r o m r a n d o m i n i t i a l p a r a m e t e r s w a s p e r f o r m e d u s i n g a l l the a v a i l a b l e d a t a a n d the p o i n t s m e n t i o n e d i n the c o m m e n t s to t a b l e 1 w e r e e x c l u d e d only d u r i n g the s p e c i f i c a t i o n of the o b t a i n e d s o l u t i o n s . T h e s e p o i n t s did n o t a g r e e with a n y of the t h r e e s o l u t i o n s i n the r e g i o n . S o l u t i o n 3 i n t a b l e 2 (×2 = 190.4) c a n b e r e j e c t e d a c c o r d i n g to the ×2 c r i t e r i o n m a k i n g a m e a n s q u a r e e r r o r s m a l l e r t h a n 10-3%. T h e e r r o r due to the r e j e c t i o n of the f i r s t a n d s e c o n d s o l u t i o n i s P(X 2 = 127.3) = 14% a n d p(×2 >I 159.8) = 0.14%, r e s p e c t i v e l y . It s h o u l d b e n o t e d , t h a t i n r e j e c t i n g

530

Z. JANOUT e t al. Table 2 The p h a s e - s h i f t s in d e g r e e s (the Stapp e t al. [19] p a r a m e t r i z a t i o n ) f o r 210 MeV nucleon-nucleon scattering P r e s e n t solution Phase shifts ± A5

Solution f r o m r e f . [2]

Solution f r o m r e f . [3]

5 ± A5

5 ± A5

1S 0

4.99

0.46

5.14

0.49

5.18

0.57

3S 1

15.44

1.84

17.11

2.87

18.23

3.10

3P 0

-1.34

0.50

-1.02

0.51

-0.79

0.61

lP 1

-23.99

2.56

-30.34

1.80

-23.37

8.01

3P 1

-22.46

0.20

-22.04

0.15

-21.59

0.60

3P 2

15.73

0.14

16.14

0.12

15.89

0.27

5.77

0.81

1.22

1.88

3.13

2.87

E3 3D 1

-19.84

1.64

-22.40

2.58

-22.98

4.04

1D 2

6.96

0.24

7.10

0.18

7.02

0.32

3D 2

27.09

2.06

22.47

3.58

23.39

4.33

3D 3

4.20

0.91

2.36

1.36

2.82

1.66

E2

-2.62

0.12

-2.76

0.11

-2.78

0.19

3F 2

1.32

0.21

1.56

0.25

1.58

0.34

1F 3

-4.72

1.35

-2.98

1.42

-5.53

2.78

3F 3

-2.62

0.17

-2.44

0.17

-2.58

0.21

3F 4

2.19

0.11

2.14

0.16

2.32

0.20

~3 3G 3

6.36

0.83

5.87

1.04

7.09

0.96

-1.66

0.95

0.13

1.11

-0.42

1.50

1G 4

1.10

0.09

1.08

0.13

1.04

0.16

3G 4

5.48

1.13

4.08

1.66

4.40

2.60

3G 5

-0.12

0.67

1.55

1.15

0.00

1.50

c4

-0.87

0.08

-0.94

0.09

3H 4

-0.06

0.21

0.47

0.36

1H 5

-0.54

0.66

-

-

3H 5

-0.96

0.17

-0.64

0.22

3H 6

0.00

0.13

0.41

0.27

f2

0.063

0.008

0.071

fix.

0.064

0.006

PHASE S H I F T ANALYSIS

531

Table 3 T h e p h a s e - s h i f t s in d e g r e e s (the Stapp e t al. [19] p a r a m e t r i z a t i o n ) f o r 210 MeV nucleon-nucleon scattering The rejected solutions Phase shifts

2nd s e t 5 ~: A 5

1S 0

5.41

0.50

3S 1

14.20

31) 0

3.13

3rd set 5 + A5 -15.27

0.71

2.15

8.77

4.17

0.54

-25.71

0.65

11) 1

-19.92

2.34

-0.02

2.06

31) 1

-20.26

0.19

-2.40

0.41

31) 2

17.51

0.15

18.83

0.36

6.78

0.82

29.65

1.46

E1 3D 1

-17.47

1.31

-9.73

2.73

1D 2

7.95

0.20

3.96

0.18

3D 2

29.26

1.63

16.32

1.22

3D 3

0.92

1.20

0.91

1.22

-1.83

0.15

-6.65

0.20

3F 2

-1.67

0.19

0.58

0.47

1F 3

-6.08

1.43

2.81

1.27

3F 3

-2.01

0.16

-1.64

0.16

3F 4

-0.02

0.14

1.25

0.36

E2

c3

6.33

0.79

10.08

0.72

3G 3

-4.13

0.72

-2.44

0.81

1G 4

0.86

0.09

1.24

0.17

3G 4

6.62

0.89

4.57

0.56

0.08

0.73

-0.47

0.53

-1.07

0.08

-0.78

0.12

3G 5 ~4 3H 4

0.33

0.15

-0.21

0.16

1H 5

-0.44

0.60

-2.00

0.81

3H 5

-0.64

0.15

-0.62

0.09

3H 6

0.51

0.10

-0.22

0.15

f2

0.077

0.008

0.067

0.010

o

~I .JJ; ~ ~J:_--~:.-* -~

,'/," ~ , , N

O

PHASE SHIFT ANALYSIS

533

s o l u t i o n 2 i t w o u l d b e m o r e c o r r e c t to u s e a d i f f e r e n t c r i t e r i o n [20]. It follows from this discussion that for /max = 5 the phase-shift analysis a t 210 M e V r e m a i n s u n a m b i g u o u s .

3. R E S U L T S T h e s e t of p h a s e - s h i f t s w i t h ×2 = 127.3 i s g i v e n in t a b l e 2. T h e p r e v i o u s l y k n o w n s e t s of K a z a r i n o v e t al. [2] a n d A r n d t a n d M c G r e g o r [3] a r e g i v e n in t h e s a m e t a b l e f o r c o m p a r i s o n . It m a y b e s e e n f r o m t h e t a b l e , t h a t the m e a n v a l u e s of t h e p h a s e - s h i f t s h a v e n o t c h a n g e d v e r y m u c h , but t h e i r e r r o r s h a v e decreased considerably. On t h e b a s i s of p h a s e - s h i f t s e t 1 t h e a n g u l a r d e p e n d e n c e s of the e x p e r i m e n t a l v a l u e s w e r e c a l c u l a t e d t o g e t h e r w i t h t h e i r c o r r i d o r of e r r o r s . T h e c o r r i d o r of e r r o r s r e p r e s e n t s t h e m e a n s q u a r e e r r o r a t e a c h p o i n t of the c a l c u l a t e d c u r v e . T h e m o s t i n t e r e s t i n g e x p e r i m e n t a l v a l u e s u s e d in t h e p r e s e n t p h a s e - s h i f t a n a l y s i s (D t a n d Rt) a r e g i v e n in t h e g r a p h s on f i g . 1. F o r t h e r e m a i n i n g q u a n t i t i e s c o n f r o n t r e f . [18]. In c o n c l u s i o n t h e a u t h o r s e x p r e s s t h e i r d e e p g r a t i t u d e to S. M. B i l e n k y , L. I. L a p i d u s , A. P a z m a n , R. M. R y n d i n a n d J. A. S m o r o d i n s k y f o r h e l p f u l d i s c u s s i o n s , F. L o b k o w i c z f o r a p r i v a t e c o m m u n i c a t i o n a n d to E. D u d o v a , J. F i n g e r o v a a n d N. V. V o l c h k o v a f o r h e l p in t h e w o r k .

RE FERENCES

[1] Yu. M. Kazarinov, I. N. Silin, J E T P 43 (1962) 692. [2] Yu. M. Kazarinov, V.S. Kiselev, Yu. N. Simonov, P r e p r i n t JINR P-2241, Dubna 1965. [3] R. A. Arndt, M.H. MacGregor, Phys. Rev. 141 {1966) 873. [4] P . S i g n e l l , N . R . Y o d e r , J. E. Matos, Phys. Rev. 135 (1964) Bl128. [5] A. Konradi, T h e s i s , University of Rochester, 1961 {unpublished) [6] J. F. Marshall, C.N. Brown, F . L . Lobkowicz, Phys. Rev. 150 (1966} 1119. [7] J. H. Tinlot, R. E. W a r n e r , Phys. Rev. 124 (1961) 890. [8] E. B a s k i r , E. M. Hafner, A. Roberts, J. H. Tinlot, Phys. Rev. 106 {1957) 564. [91 A. C. England, W.A. Gibson, K. Gotow, E. Heer, J. H. Tinlot, Phys. Rev. 124 (1961) 561. [10] K. Gotow, F. Lobkowicz, Phys. Rev. 136 (1964) B1345; F. Lobkowicz, p r i v a t e communication. [11] K. Gotow, F. Lobkovicz, E. Heer, Phys. Rev. 127 {1962} 2206. [12] Yu. M. Kazarinov, Yu. N. Simonov, J E T P 43 (1962} 35. [13] E. H. Thorndike, Rev. Mod. Phys. 39 (1967) 513. [14] R. E. W a r n e r , J . H . Tinlot, Phys. Rev. 125 (1962) 1028. [15] D. Spalding, A. Thomas, E. Thorndike, Phys. Rev. 158 (1967} 1338. [16] N. W. Reay, E.H. Thorndike, D. Spalding, A.R. Thomas, Phys. Rev. 150 {1966} 801. [17] P. Koehler, E . T h o r n d i k e , A. C r o m e r , Phys. Rev. 134 (1964)B1030. [18] Z. Janout, Yu. M. Kazarinov, F. L e h a r , P. Winternitz, p r e p r i n t JINR E1-3345, Dubna 1967. [19] H. P. Stapp, T. Ypsilantis, N. Metropolis, Phys. Rev. 105 {1957) 302. [20] Yu. M. Kazarinov, V. S. Kiselev, A. M. Rozanova, I. N. Silin, P r e p r i n t JINR E13268, Dubna 1967.