production rate s of strange and charmed baryons at belle
DESCRIPTION
Production rate s of Strange and Charmed baryons at Belle. Nuclear physics consortium . string. @ s = 10.52 GeV. Production rate of hadrons. Production rate s/s had /(2J+1) exp (- a m h ) due to linear potential. Slope of meson (qq bar ) is different from baryons (qqq). - PowerPoint PPT PresentationTRANSCRIPT
![Page 1: Production rate s of Strange and Charmed baryons at Belle](https://reader035.vdocuments.mx/reader035/viewer/2022062813/56816582550346895dd82650/html5/thumbnails/1.jpg)
Production rates of
Strange and Charmed baryons at Belle
1
string
@s = 10.52 GeV
Nuclear physics consortium
![Page 2: Production rate s of Strange and Charmed baryons at Belle](https://reader035.vdocuments.mx/reader035/viewer/2022062813/56816582550346895dd82650/html5/thumbnails/2.jpg)
Production rate of hadrons
2
Slope of meson (qqbar) is different from baryons (qqq).
Slope depends on quark counting
“4 or 5-quark state” do not lie on “3-quark state”?
L(1405), pentaquark, Q+?
Production rate s/shad/(2J+1) exp(-amh) due to linear potential
mh(mass of hadrons)[GeV]
s/s h
ad/(
2J+1
)
![Page 3: Production rate s of Strange and Charmed baryons at Belle](https://reader035.vdocuments.mx/reader035/viewer/2022062813/56816582550346895dd82650/html5/thumbnails/3.jpg)
3
s/s h
ad/(
2J+1
)
Mass of baryons (GeV)
Previous data
deviate
ARGUSs=10.5 GeV
Belle
L(g.s.)/L(1520) deviate in LEP good di-quark > bad di-quark?
L(1520)[3/2-] deviates in ARGUS [3/2-] state is special? L=0 ≠ L=1 ? L(1520) [3/2-] Lc*(2625)[3/2-] L(1405) [1/2-] Lc*(2595)[1/2-]
LEP s=92 GeV
R.L.Jaffe, Phys.Rept.409:1-45,2005
Error bar in ARGUS is large
More precise data
No series of charmed baryon First systematic measurement of production rate for charmed baryons.
![Page 4: Production rate s of Strange and Charmed baryons at Belle](https://reader035.vdocuments.mx/reader035/viewer/2022062813/56816582550346895dd82650/html5/thumbnails/4.jpg)
4
q
• Interaction between quarks• Diquark correlations
Charmed baryon (Lc[udc], Sc [udc])
Diquark correlation is enhanced by weak Color Magnetic Interaction with a heavy quark
mu, md << mc diquark + quark (qq) (Q)
qq ( ) S=0 “good” diquark qq ( ) S=1 “bad” diquark
Q
q q
Diquark picture
Strange baryons (L[uds], S[uds])
mu, md ≈ ms (qqq) uniform
![Page 5: Production rate s of Strange and Charmed baryons at Belle](https://reader035.vdocuments.mx/reader035/viewer/2022062813/56816582550346895dd82650/html5/thumbnails/5.jpg)
Strange baryon & Charmed baryon
5
L, S Lc, Sc
[qqs] uniform diquark + Quark [qq] [c]
Strange baryons Charmed baryons
Lc > Sc
good di-quark > bad di-quarkdue to strong attractive force of good diquark
L S
ud
s
ud
s c c
L L
u du d
S=0 S=1 S=0 S=1
![Page 6: Production rate s of Strange and Charmed baryons at Belle](https://reader035.vdocuments.mx/reader035/viewer/2022062813/56816582550346895dd82650/html5/thumbnails/6.jpg)
6
Systematic study of baryons to search for “exotic” baryons in strange and charmed baryons.
Information on diquark picture of charmed baryons in contrast with strange baryons.
L, S, S*, X, W , Lc, Lc* ,Sc ,Sc
*
First systematic measurement for series of charmed baryons.
It is interesting and important to look at the tendency of many baryons by precise measurement. Belle data, well constructed detectors and good statistics.
In this work
![Page 7: Production rate s of Strange and Charmed baryons at Belle](https://reader035.vdocuments.mx/reader035/viewer/2022062813/56816582550346895dd82650/html5/thumbnails/7.jpg)
Silicon Vertex Detector
Central Drift Chamber
Aerogel CerenkovTime Of Flight CsI calorimeter
S.C. solenoid
1.5T
KL μ system
8GeV e-
3.5GeV e+
Data of Belle
Integrated luminosity 79.366 fb-1 @ s = 10.52 GeV 702.623 fb-1 @ s = 10.58 GeV ϒ(4S)
7
![Page 8: Production rate s of Strange and Charmed baryons at Belle](https://reader035.vdocuments.mx/reader035/viewer/2022062813/56816582550346895dd82650/html5/thumbnails/8.jpg)
Good vertex reconstruction
SSD placed in 3cm/2cm from Interaction point (IP), and low materials. Resolution of reconstructed vertex for B J/Psi Ks is about 80 mm.Good for hyperon (long life) reconstruction.
Profile of interaction point (IP)
8
![Page 9: Production rate s of Strange and Charmed baryons at Belle](https://reader035.vdocuments.mx/reader035/viewer/2022062813/56816582550346895dd82650/html5/thumbnails/9.jpg)
Hyperon reconstruction
Dx
IPInteraction point
p
p-
momentum vector of L
Decay processes •L p p -
•S0 Lg•S*(1385)+ Lp+
p+
or g
(S0 ) (S
*+ )
ct=7.89cm
IP
X-/W-
ct = 4.91cm / 2.64cm
Lct = 7.89cm
p-
p p-
p+ for Wc0
Decay processes•X- Lp - •W - LK-
•W c0 W -p+
9
![Page 10: Production rate s of Strange and Charmed baryons at Belle](https://reader035.vdocuments.mx/reader035/viewer/2022062813/56816582550346895dd82650/html5/thumbnails/10.jpg)
L
Mass spectrum of L
L + Lbar = 373.9 ± 0.5 pb
“Inclusive” total cross sectionFeed down processes from higher states
ds/d
x p
Xp
L / Lbar
Scaled momentum, xp = pc.m. / pc.m. : momentum of baryons s : beam total energy M : mass of baryons
preliminary
10
![Page 11: Production rate s of Strange and Charmed baryons at Belle](https://reader035.vdocuments.mx/reader035/viewer/2022062813/56816582550346895dd82650/html5/thumbnails/11.jpg)
Mass spectra
real data events in 0.3 < xp <0.4
real data events in 0.3 < xp <0.4
S0(1192) Lg(BR~100%) S*(1383)+ Lp+
(BR=87%)
11
![Page 12: Production rate s of Strange and Charmed baryons at Belle](https://reader035.vdocuments.mx/reader035/viewer/2022062813/56816582550346895dd82650/html5/thumbnails/12.jpg)
“Inclusive” cross sections vs. xp
12
S0 +c.c. S*+ +c.c.
Xp Xp
preliminary
ds/d
x p
ds/d
x p
S0 + S0 = 97.0 ± 1.5 pb S* + S* = 33.2 ± 2.4 pb
Inclusive total cross section Inclusive total cross section
![Page 13: Production rate s of Strange and Charmed baryons at Belle](https://reader035.vdocuments.mx/reader035/viewer/2022062813/56816582550346895dd82650/html5/thumbnails/13.jpg)
direct cross section of L• feed-down were subtracted from inclusive cross sections.• Isospin symmetry was assumed for S* and X production cross-sections.
Result
-23.6 8.0 pb
(inclusive)
13
![Page 14: Production rate s of Strange and Charmed baryons at Belle](https://reader035.vdocuments.mx/reader035/viewer/2022062813/56816582550346895dd82650/html5/thumbnails/14.jpg)
direct S0 and S*+ production• feed-down were subtracted from inclusive cross sections.• Isospin symmetry was assumed for S* and X production cross-sections.
Result
S*+ + c.c. (direct) : 33.2 ± 2.4 pb S*+ + c.c. (inclusive) - 0.4 ± 0.06 pb L(1520) + c.c. = 32.8 ± 2.4 pb
14
![Page 15: Production rate s of Strange and Charmed baryons at Belle](https://reader035.vdocuments.mx/reader035/viewer/2022062813/56816582550346895dd82650/html5/thumbnails/15.jpg)
L(1520)
15
Select p and K- from IP with cuts for distance from IP ○○ (4S) data▽▽ Continuum data Y / anti-Y
preliminary
BR=22.5%L(1520)pK-
Mass spectrum of L(1520)
![Page 16: Production rate s of Strange and Charmed baryons at Belle](https://reader035.vdocuments.mx/reader035/viewer/2022062813/56816582550346895dd82650/html5/thumbnails/16.jpg)
Direct cross section L(1520)
16
L(1520)+c.c. (direct) = 15.3 ± 0.5 pb inclusive – 0.34 ± 0.17 pb Lc
+ = 15.0 ± 0.26 pb
![Page 17: Production rate s of Strange and Charmed baryons at Belle](https://reader035.vdocuments.mx/reader035/viewer/2022062813/56816582550346895dd82650/html5/thumbnails/17.jpg)
Mass spectrum of X- and W-
17
X- W-
![Page 18: Production rate s of Strange and Charmed baryons at Belle](https://reader035.vdocuments.mx/reader035/viewer/2022062813/56816582550346895dd82650/html5/thumbnails/18.jpg)
Cross sections of X and W
18
X / X W / W
X + Xbar inclusive cross section = 25.55 +- 0.64 pb
W + Wbar inclusive cross section = 1.15 +- 0.32 pb
●● @ 10.58, (4S) data○○ @ 10.52, Continuum data Y / anti-Y
preliminary
![Page 19: Production rate s of Strange and Charmed baryons at Belle](https://reader035.vdocuments.mx/reader035/viewer/2022062813/56816582550346895dd82650/html5/thumbnails/19.jpg)
Wc W-p+ +c.c.
19
s x BR (W-p+) + c.c. = 0.04 0.003 pb Wc W-X = 0.2 pb
BR 1.25±0.5% for W-X 0.25±0.12% for W-p+
by phenomenological calculation (ref. PDG)
Even
t rat
e / L
int.
Coun
ts
preliminary
Mass [GeV] xp
![Page 20: Production rate s of Strange and Charmed baryons at Belle](https://reader035.vdocuments.mx/reader035/viewer/2022062813/56816582550346895dd82650/html5/thumbnails/20.jpg)
Lc+, Lc
*+, Sc0, and Sc
*0
Decay process analyzed in this work• Lc
+ pK-p +
• Lc*(2625) Lc
+ p+ p-
• Sc0 Lc
+ p -
• Sc*(2520) Lc
+ p -
+ c.c.
Lc+
Mass plot
Mass spectrum of pKp
20
![Page 21: Production rate s of Strange and Charmed baryons at Belle](https://reader035.vdocuments.mx/reader035/viewer/2022062813/56816582550346895dd82650/html5/thumbnails/21.jpg)
21
Lc+(2625)
○○ (4S) data▽▽ Continuum data Y / anti-Y
Xp
ds/d
x p(nb)
preliminary
Lc(2595)+
Lc(2625)+
Lc+(2625)
Mass spectrum
![Page 22: Production rate s of Strange and Charmed baryons at Belle](https://reader035.vdocuments.mx/reader035/viewer/2022062813/56816582550346895dd82650/html5/thumbnails/22.jpg)
Mass spectrum
22
Sc(2455)0
Sc(2520)0
Lc+ p - decay processes
Exclude in analysis•Lc*(2595)+ Lc
+ p+ p-
•Lc*(2625)+ Lc+ p+ p-
![Page 23: Production rate s of Strange and Charmed baryons at Belle](https://reader035.vdocuments.mx/reader035/viewer/2022062813/56816582550346895dd82650/html5/thumbnails/23.jpg)
23
○○ (4S) data▽▽ Continuum data Y / anti-Y
Sc0(2520)
preliminary
Sc0(2455)
preliminary
Cross sections
![Page 24: Production rate s of Strange and Charmed baryons at Belle](https://reader035.vdocuments.mx/reader035/viewer/2022062813/56816582550346895dd82650/html5/thumbnails/24.jpg)
direct Lc and Sc production
24
• Lc+ + c.c. (direct)
= 189 ± 66 pb inclusive - (17.9 ± 6.0 pb ) x 3 Sc
0,+,++(2455) + c.c. - (18.8 ± 6.4 pb) x 3 Sc
0,+,++(2520) + c.c. - (31.3 ± 10 pb) Lc
+(2625) + c.c. = 47.6 ± 16.2 pb• Sc
0(2455) +c.c. (direct) = 17.9 ± 6.0 pb• Sc
0(2520) + c.c. (direct) = 18.8 ± 6.4 pb• Lc
+(2625) + c.c. (direct) = 31.3± 10 pb
Λc(2595) and Λc(2775) feed downare included.
![Page 25: Production rate s of Strange and Charmed baryons at Belle](https://reader035.vdocuments.mx/reader035/viewer/2022062813/56816582550346895dd82650/html5/thumbnails/25.jpg)
Result and discussion
25
Previous Belle work
This work (very preliminary)ARGUS
Mass dependence strange ≠ charm not lie on the same line Large discrepancy to ARGUS on L, and S* treatment of feed down?
Deviation of L(1520)[3/2-] is not clear.
W < L, S, X W[sss] with “ “ no good diquark
s/s h
ad/(
2J+1
)
Mass of baryons (GeV)
![Page 26: Production rate s of Strange and Charmed baryons at Belle](https://reader035.vdocuments.mx/reader035/viewer/2022062813/56816582550346895dd82650/html5/thumbnails/26.jpg)
26
Charmed baryons do not lie on “one” line. Jp : no measurement or not well measured quark-model prediction
Lc > Sc
good diquark > bad diquarkLarge rate of Lc(2625)[3/2-](L=1 state)
Prefer [3/2-] or L=1? Why?Rate of L(1520)[3/2-] is not large. Rates of Lc(2595)[1/2-](L=1 state)
and L(1405)[1/2-] are “key”.
Wc : no measurement of BR a plot with BR(0.24+-0.12%) by the phenomenological calculation. Production rate BR
Lc(g.s)[1/2+]
Lc(2625)[3/2-]
Sc0(2455)[1/2+]
Sc0(2520)[3/2+]
Sc(2800)[??] use 3/2
s/s h
ad/(
2J+1
)
Mass of baryons (GeV)
Charmed baryons
Wc
Results and discussion
Very preliminary
![Page 27: Production rate s of Strange and Charmed baryons at Belle](https://reader035.vdocuments.mx/reader035/viewer/2022062813/56816582550346895dd82650/html5/thumbnails/27.jpg)
States
27
L [1/2+]L(1405) [1/2-] L(1520) [3/2-]
S [1/2+] S(1385) [3/2+]
X [1/2+] X(1530) [3/2+]
W [3/2+]
Lc+ [1/2+]
Lc(2595)+ [1/2-] Lc(2625)+ [3/2-]
Sc(2455) [1/2+] Sc(2520) [3/2+]
Xc [1/2+] Xc*
W c [1/2+] W c
*On going Unknown J, BR
![Page 28: Production rate s of Strange and Charmed baryons at Belle](https://reader035.vdocuments.mx/reader035/viewer/2022062813/56816582550346895dd82650/html5/thumbnails/28.jpg)
M(Xp)
28
X(1530)
Xc
![Page 29: Production rate s of Strange and Charmed baryons at Belle](https://reader035.vdocuments.mx/reader035/viewer/2022062813/56816582550346895dd82650/html5/thumbnails/29.jpg)
Production rates
29
s/s h
ad/(
2J+1
)
Mass – Mass(g.s.) [GeV/c2]
![Page 30: Production rate s of Strange and Charmed baryons at Belle](https://reader035.vdocuments.mx/reader035/viewer/2022062813/56816582550346895dd82650/html5/thumbnails/30.jpg)
Summary
We measure production rates of strange and charmed baryons at s = 10.52 GeV at Belle.“Systematic” study provides information on quark structure of hadrons. Configuration and performance of Belle detector is good for long-life particles like L, X, and W. We observed ‘charmed baryons do not lie on one line’.
Can we explain by a diquark picture? Feed down processes Further study of many baryons with various spin-parity
is interesting to see their quark structures.
30