snd binp - struttura · snd detector august,30,2001 in tegrated luminosit y experimental years...

viewofresultsfrom

SND

detector

August,30,2001

Review

ofresultsfrom

SND

detector

T.Dimova

BINP,Novosibirsk,Russia

D

BINP,Novosibirsk

Page1

view of results from SND detector August,30,2001

VEPP-2M e+e� collider

,

Beam energy, MeV 180-700

Peak luminosity (Eb = 500MeV), cm�1s�1 3 � 1030

Energy spread (Eb = 500MeV), keV 300

Beam current, mA 50

Time between collisions, ns 60

Bunch length, cm 2

D BINP,Novosibirsk


SND Detector

3

4

5

1

26

10

9

7

13

12

8

11

0 20 40 60 80 100 cm

e e+-

2

3

1

6

8

7

9

11

1 - beam pipe, 2 - drift chambers, 3 - scintillation counter,4 - lightguides, 5 - PMTs, 6 - NaI(Tl)

crystals, 7 - vacuum phototriodes, 8 - iron absorber, 9 - streamer tubes, 10 - 1 cm iron plates, 11 -

scintillation counters, 12 and 13 - collider magnets.

D BINP,Novosibirsk

viewofresultsfrom

SND

detector

August,30,2001

ListofSND

parameters:Calorimeter:

TotalnumberofNaI(Tl)counters

1632

Angularsizeofthecounter

�'=�#=9�

Energyresolutionfor 's

�E=E=

4:2%

4 p(E(GeV)

Angularresolutionfor 's

�'

=

0:82 �

pE

(G

eV

)�0:63�

Minimalspatialanglefor

twophotonsseparation

�'��#�18�

D

BINP,Novosibirsk

Page4


SND calorimeter performance

Invariant-mass spectra in �0 ! decay Invariant-mass spectra in K

S

! �

0�

0 decay

Mπγ, MeV

Even

ts

0

100

200

300

400

700 750 800 850

Invariant-mass spectra in ! ! �

0 decay

mπππ (MeV)

EV

EN

TS

EXP

- MC

0

100

200

300

400

450 500 550 600 650

Invariant-mass spectra in � ! 3�0 decay

D BINP,Novosibirsk

viewofresultsfrom

SND

detector

August,30,2001

ListofSND

parameters:Driftchambers:

��distributionfore+e�

!

�+��

��distributionfore+e�

!

�+��

Spatialresolutionfortracks

�'

=0:54�

,

(P=300MeV/c)

�#

=1:9�

Minimalazimuthangleforchargedparticlesseparation

�'�18�

Materialbeforethechamber

0.27g=cm2

Probabilityof -conversionbeforethechamber

0.57%

D

BINP,Novosibirsk

Page6

viewofresultsfrom

SND

detector

August,30,2001

SND

trackingsystem

performance

dE=dxdistributionfor

e�and��

dE=dxdistributionfor

��andK�p

s�1GeV

�dE=dx�

30%

D

BINP,Novosibirsk

Page7


Integrated Luminosity

Experimental Years

IL(p

b)-1

per

Yea

r

0

5

10

15

20

2 4 6

Integrated luminosity collected by SND per

experimental year

√s-- (MeV)

IL (

pb

)-1

10-2

10-1

1

500 750 1000 1250

Integrated luminosity collected by SND in the energy

regionps = 360 { 1380 MeV

Total integrated luminosity IL ' 30 (pb)�1 (1995 { 2000 )

Luminosity measurement:

e+e� ! e+e�, e+e� !

Accuracy � 1.5% { 2%

D BINP,Novosibirsk


Electric dipole radiative decays

V S γ

l=0,s=1 l=1,s=1V ! S

(V = �; !; �)

(S = f0(980); a0(980); �(?))

SND study:

e+e� ! �! �0�0 , ��0

e+e� ! ! ! �0�0 ,

e+e� ! �! �0�0

D BINP,Novosibirsk


Electric dipole radiative decays of � meson

m ππ , MeV

dB(

φπ0 π

0 γ)/d

mπ

π10

8 MeV

-1

f 0γ + ρ0π

0

0

20

40

60

80

400 600 800 1000

x

xmηπ , MeV

dΒ(φ

ηπγ)/

dm10

7 MeV

-1

0

5

10

15

700 800 900 1000

B(�! �0�0 ) = (1:22� 0:12) � 10�4

B(�! ��0 ) = (0:88� 0:17) � 10�4

B(�! f0 ) = (3:5� 0:3�1:30:5) � 10�4

B(�! a0 ) = (0:88� 0:17) � 10�4

D BINP,Novosibirsk

viewofresultsfrom

SND

detector

August,30,2001

Electricdipoleradiativedecaysof�

meson

SND

CMD-2

KLOE(�

)

B(�!�0�0 )(�10�

4)

1:034�0:066�0:046

0:92�0:08�0:06

0:79�0:02�0:08

m��

>700MeV

B(�!��0 )

0:88�0:17

0:90�0:24�0:10

0:74�0:05�0:07

(�10�

4)

B(�!f0 )

3:5�0:3+1:3

�

0:5

2:90�0:21�1:54

2:37�0:06�0:24

(�10�

4)

B(�!a0 )

0:88�0:17

0:58�0:05�0:06

(�10�

4)

(*)-systematicerrorwassetto10%

D

BINP,Novosibirsk

Page11


�, ! ! �0�0 decays

E, MeV

Cro

ss s

ecti

on, n

b

0

0.1

0.2

0.3

0.4

0.5

0.6

600 650 700 750 800 850 900 950

e+e� ! �

0�

0 cross-section

SND results (IL = 9 (pb)�1):

B(! ! �0�0 ) = (6:3� 1:4� 0:8) � 10�5

B(�! �0�0 ) = (4:0�1:00:9 �0:4) � 10�5

B(�! S ! �0�0 ) = (2:0�0:80:7 �0:3) � 10�5

D BINP,Novosibirsk


Magnetic dipole radiative decays

V P γ

l=0,s=1 l=0,s=0V ! P

(V = �; !; �)

(P = �0; �; �0)

SND study:

e+e� ! �! �0 , �0 , � ,

e+e� ! ! ! �0 , �

e+e� ! �! �0 , �

D BINP,Novosibirsk


�! �0

EntriesMeanRMS

17 937.8 33.70

0

0.5

1

1.5

2

2.5

3

860 880 900 920 940 960 980

�0

! �+��

�; � ! :

B(�! �0

) = (6:7�3:4

2:9) � 10�5

�0

! �0�0�; � ! :

B(�! �0

) = (4:3� 1:6� 0:9) � 10�5

SND CMD2 KLOE

B(�! �0 ) � 105 4:9�1:61:5 6:4� 1:6 6:8� 0:8

D BINP,Novosibirsk


�; !; �! �

2E 0, MeV

σ, n

b

0

0.5

1

1.5

2

2.5

3

3.5

4

700 720 740 760 780 800 820 840

2E 0, MeV

0

10

20

30

40

50

60

1000 1005 1010 1015 1020 1025 1030 1035 1040

B(�! � )(�10�2)

� ! : 1:34� 0:01� 0:05

� ! �+��

�0:1:26� 0:03� 0:06

� ! �0�0�0:1:35� 0:01� 0:05

Average: 1:310� 0:045

B(�! � ) = (2:77� 0:26� 0:16) � 10�4

B(! ! � ) = (4:22� 0:47� 0:17) � 10�4

Experimental ratio of the partial width:

�!� : �� : �� = 1 : (11:7� 1:9) : (15:9� 1:9)

Prediction of the simple quark model: 1:8:12

D BINP,Novosibirsk


�; !; �! �0

√s-, MeV

σ, n

b

1

10

10 2

600 700 800 900 1000B(�! �0 ) = (5:03� 1:17� 0:83) � 10�4

B(! ! �0 ) = (9:17� 0:16� 0:46) � 10�2

B(�! �0 ) = (1:23� 0:04� 0:09) � 10�3

Experimental ratio of the partial width:

�!�0 : ��0 : ��0 = 1 : (0:97� 2:8) : (7� 0:6) � 10�3

Prediction of the quark model: 1 : 1/9 : 0.01

D BINP,Novosibirsk


Conversion decays �! �e+e�; �! �0e+e�; � ! e+e�

*-

+e

e

γ

(γ)PV(P)

F(q )2

Branching Ratios

�! �e+e�

� ! e+e� �! �0e+e�

(�10�4) (�10�3) (�10�5)

SND 1:19� 0:22 5:15� 0:96 1:05� 0:37

CMD-2 1:17� 0:12 7:10� 0:79 1:22� 0:40

SND&CMD-2 1:18� 0:11 6:31� 0:61 1:13� 0:27

Theory 1:10� 0:1 6.5{6.8 1.3{1.6

PDG(2000) 1:3+0:8�0:6 4:9� 1:1 < 1:2 � 10�4

q2

dq2

+-

dB(V

Pee

)

32

1

e2(2m )

Transition Form Factors Slopes

�! �e+e�

� ! e+e� �! �0e+e�

GeV�2 GeV�2 GeV�2

SND 3:8� 1:8 1:6� 2:0 |

Theory (VDM) 1.0 1.8

Previous

measurement | �0:7� 1:5 |

D BINP,Novosibirsk


OZI and G-parity suppressed �! !�0 and �+�� decays

E, MeV

σvi

s,n

b

0

5

10

15

20

25

980 1000 1020 1040 1060

e+

e�

! �+

��

E, MeVV

isib

le c

ro

ss s

ecti

on

, n

b

0

0.2

0.4

0.6

0.8

1

1.2

1.4

980 1000 1020 1040 1060

e+

e�

! !�0

�(s) = �0(s)�

��

��

��1� Z

m��

D�(s)�

��

��

�2

�+

��

!�0

Re(Z) 0:061� 0:006 0:108� 0:16

Im(Z) �0:041� 0:007 �0:125� 0:020

B(�! X) � 105 7:1� 1:4 5:2�1:3

1:1

D BINP,Novosibirsk

viewofresultsfrom

SND

detector

August,30,2001

�m

eson

param

etersstudy

e+

e�

!�+

��

�0,

K

+

K

�

,

K

S

K

L

980

�ps

�1060

MeV

IL

=

8:5

(pb)�

1

N

K

+

K

�

=

106

N

K

S

K

L

=

0:5

�106

N

3�

=

0:4

�106

D

BINP,Novosibirsk

Page19

viewofresultsfrom

SND

detector

August,30,2001

�

mesonparametersstudy

SND

PDG-2000

m

�

,MeV

1019:42�0:05

1019:417�0:014

��

,MeV

4:21�0:04

4:458�0:032

B

(�

!e+e�

)�104

2:93�0:14

2:91�0:07

B

(�

!K

+K

�

),%

47:6�1:7

49:2�0:7

B

(�

!K

S

K

L

),%

35:1�1:3

33:8�0:6

B

(�

!3�),%

15:9�0:8

15:5�0:6

B

(�

!� ),%

1:33�0:06

1:297�0:033

g�

K

+

K

�

g�

K

S

K

L

1

pZ

(m

�

)

0:92�0:03

0:95�0:01

D

BINP,Novosibirsk

Page20

viewofresultsfrom

SND

detector

August,30,2001

�

mesonparametersstudy

4 5

CMD2-01

SND-00

CMD2-98

CMD2-95

SPEC-86

AEMS-82

OLYA-81

WIRE-80

OLYA-78

CNTR-74

OSPK-71

OSPK-70

Γφ(MeV)

D

BINP,Novosibirsk

Page21

viewofresultsfrom

SND

detector

August,30,2001

e+e�annihilationintohadronsabove1GeV

SND

studiesofthee+e �!

hadrons:

�

e+e �!

��;!�!

�+��0

�

e+e �!

!�!

�0�0

�

e+e �!

��!

�+��+��

�

e+e �!

!�;��;�+��!

�+��0�0

�

e+e �!

!��;��!

�+��+��0

�

e+e �!

K

SK

L

D

BINP,Novosibirsk

Page22


e+e�! �0�0

SNDDM2CMD2CLEO

E, MeV

Cro

ss s

ecti

on, n

b

0

0.5

1

1.5

1000 1200 1400 1600 1800 2000 2200

e+e� ! !� ! �0�0

Systematic error: 5 %

D BINP,Novosibirsk


e+e�! �+��0�0

√s-- (MeV)

σ (n

b) SND

SND, ωπo→ πoπoγ CLEO, τ→ ωπoντ CMD2 DM2

0

5

10

15

20

25

1000 1250 1500 1750 2000

√s-- (MeV)

σ (n

b)

SND CLEO, τ→ 3ππoντ CMD2 DM2

0

5

10

15

20

25

1000 1250 1500 1750 2000

e+

e� ! !�0

Systematic error: 20 % (ps < 1150 MeV)

15 % (ps > 1150 MeV)

e+

e� ! �+

��2�0

(!�0

subtracted)


D BINP,Novosibirsk


e+e�! �+��+��

√s-- (MeV)

σ (n

b)

SND CLEO, τ→ 3ππoντ CMD2 DM2

0

10

20

30

40

1000 1250 1500 1750 2000

√s-- (MeV)

σ 2π+

2π- /

σπ+

π- 2πo

1

2

3

1100 1200 1300 1400

e+

e� ! �+

��

�+

��

Systematic error: 12 % (ps < 1150 MeV)

8 % (ps > 1150 MeV)

��+��+��

=��+��0�0

D BINP,Novosibirsk


e+e�! �+��+��0

√s-- (MeV)

σ (n

b)

SND CMD2 DM2

0

0.2

0.4

0.6

0.8

1

1200 1300 1400 1500

√s-- (MeV)

σ (n

b)

SND

CMD2

DM2

0

1

2

3

4

5

1200 1300 1400 1500

e+e� ! !�+��

e+e� ! ��+��

D BINP,Novosibirsk


e+e�! KSKL2E0, MeV

σ 0(e+

e- →K

SKL),

nb

SND VEPP2M'97-99 OLYA VEPP2M'82 DM1 DCI'80

10-2

10-1

1

10

10 2

10 3

1000 1200 1400 1600 1800 2000 2200

e+e� ! KSKL

(KS ! �0�0)

Systematic error: 7 % (p

s < 1100) MeV, 16 % (p

s > 1100) MeV

D BINP,Novosibirsk


e+e�! �+��0

2Eo, MeV

σ 3π, n

b

SND-2001

SND-1999

DM2-1992

0

1

2

3

4

5

6

7

8

1200 1400 1600 1800 2000


D BINP,Novosibirsk


e+e�! �+��0 + !�+��

√s-- (MeV)

σ (n

b)

SND DM2

0

2

4

6

8

1000 1250 1500 1750 2000

e+

e�

! �

+

�

�

�

0 √s-- (MeV)

σ (n

b)

SND

DM2

0

1

2

3

4

1250 1500 1750 2000

e+

e�

! !�

+

�

�

!1

!2

!3

m, MeV 1250�29 1400�19 1771�28

�, MeV 426�135 626�89 473�76

�(V ! ��), nb 0.56�0.25 3.90�0.39 2.28�0.46

�(V ! !��), nb 0 0.046�0.039 2.49�0.33

� � � 0

�(V ! e+

e�),eV � 25 � 300 � 470

D BINP,Novosibirsk

viewofresultsfrom

SND

detector

August,30,2001

New

project:VEPP-2000

Maximum

beam

energy{1GeV

Perimeter{24.388m

Timebetweencollisions{0.04�s

parametersatEbeam

=900MeV:

Luminosity{1�1032

Beam

current{200mA

Numberofparticlesinonebunch{1�1011

Bunchlength{3.3cm

Betafunctionatinteractionpoint{�x

=�z=6:3cm

Energyspread{�E

=6:4�10�

4

D

BINP,Novosibirsk

Page30


New project: SND Upgrade

3

2

1

µ−

µ+

4

6

5

7

9

3

1

2

4

8

7

5

10

6

9

0 20 40 60 80 100 cm

µ −

µ +

e e+-

1 - beam pipe, 2 - drift chamber, 3 - aerogel cherenkov counters, 4 - NaI(Tl) crystals, 5 - vacuum

phototriodes, 6 - iron absorber, 7 - streamer tubes, 8 - 1cm iron absorber, 9 - scintillation

counters, 10 - solenoids

D BINP,Novosibirsk

viewofresultsfrom

SND

detector

August,30,2001

New

project:SND

Upgrade

Driftchamber

�R�

�

=150�m;�z=1�1:5mm;

��

=��=0:25�

(jet,gasAr+10%CO2)

dE/dx:�=K

forjpj�300MeV;

=0:94�4�

Calorimeter

newphototriodsandelectronics

AerogelCounters

�=K

for250MeV<jpj<900MeV

Physicsprogram

�measurementofcrosssectionsofdi�erentprocesses,forexample,

e+e�

!2�;��;!�;KK;4�;KK�etc.;

�measurementoffullcrosssectione+e�

!hadrons;

�studyingofparametersofvectorresonancesinenergyrange1:2�2GeV;

�n�n,p�pform

factorsonthreshold;

�two-photonphysics:e+e�

!e+e�

+�0;�;�0;2�0

etc.

D

BINP,Novosibirsk

Page32

snd binp - struttura · snd detector august,30,2001 in tegrated luminosit y experimental years...

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