• Motivation; • CBM experimental setup, MVD+STS; •Open charm at SIS 100; •He cooling (no Beam Pipe) • Open charm at SIS 300 • D 0 K - + , D + K - + + , D s + K + K - + ; and + c pK - + • Open charm trigger; • {Ξ 0 Λ} b detectability study • Summary D 0 , D + , D s + , c , D * I.Vassiliev , Open charm physics at CBM sts K - + MVD + MAPS D + 13.06.22 1 CBM Split
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Motivation; CBM experimental setup, MVD+STS; Open charm at SIS 100; He cooling (no Beam Pipe)
sts. K -. +. +. MVD. MAPS. Open charm physics at CBM. I.Vassiliev ,. D 0 , D + , D s + , c , D *. Motivation; CBM experimental setup, MVD+STS; Open charm at SIS 100; He cooling (no Beam Pipe) Open charm at SIS 300 - PowerPoint PPT Presentation
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• Motivation;
• CBM experimental setup, MVD+STS;
•Open charm at SIS 100;
•He cooling (no Beam Pipe)
• Open charm at SIS 300
• D0K-+, D+K-+ +, Ds+ K+K-+;
and +c pK-+
• Open charm trigger;
• {Ξ0Λ}b detectability study
• Summary
D0, D+, Ds+ , c , D*
I.Vassiliev, Open charm physics at CBM
sts
K-
+
MVD +
MAPS
D+
21.04.23 1CBM Split
21.04.23 CBM Split 2
Charm production at threshold energies (motivation)
multiple track (particle) parameters based cuts: χ2
GEO geometrical constrained fit 3.0 χ2
TOPO topological constrained fit 2.0 signal particle primary vertex DCA < 30 m
21.04.23 CBM Split 22
D0 and D0 @ 25AGeV minv spectra
1010 events
21.04.23 CBM Split 23
D+ and D- @ 25AGeV minv spectra
21.04.23 CBM Split 24
Ds+ @ 25AGeV minv spectra
K+K-+ (5.3 ± 0.8)%
+(4.5 ± 0.4)%-> K+K-(2.2 ± 0.2)%
K+K*(892), K*(892) ->K-+(2.5)%
21.04.23 CBM Split 25
Ds+ @ 25AGeV minv spectra
Open Charm Trigger-algorithm
CbmL1TrackFinder
CbmL1TrackFitter
Charm Track Candidates Selection χ2prim > 3
Charm Pairs χ22geo
< 3.0, zv <1 cm χ2
topo < 3.0, minv > 1.3 GeV
Charm Triplets χ23geo+topo < 3.0 ☺
D+c Ds
☺D0☻☻
RFmb = 125RFcen = 14
21.04.23 26CBM Split
21.04.23 CBM Split 27
Detached Vertex Trigger: first results
D0+D0 D++D- Ds+ c
+
decay channel K-+ K-+ + K-K+ + p K-+
MHSD1.5·10-4 4.2·10-5 5.4·10-6
MSM8.2·10-4 8.4·10-5 1.4·10-4 4.9·10-4
BR(%) 3.8 9.5 5.3 5.0
geo. acc.(%) 39.9 45.5 32.8 55.5
s.t. rec. eff. 98 97.5 97.5 97.6
z-resolution (m) 47 47 60 58
total eff. (%) 4.4 2.6 1.0 0.2
m (MeV/c2) 10 10 10 10
S/B2 2.1/6.4 1.1/2.4 5.0 0.6
yield(K/1012cen) 56+174 103+195 2.9HSD 75SM51
Open charm properties table (25AGeV)
21.04.23 28CBM Split
{Ξ0Λ}b -dibaryon detectability study in the CBM experiment
{Ξ0Λ}b→ΛΛ→ pπ-pπ-
{Ξ0Λ}b
Λ
Λ
p
p
π-
π-
π-
π-p
p
{Ξ0Λ}b
Λ
Λ
STS
MAPS
Event topology:
π-
π-
π-
p
p
p
Λ2
Λ1
Λprim
{Ξ0Λ}b
χ2topo
χ2topo
pv
{Ξ0Λ}b -dibaryon signal and ΛΛ-background z vertex distribution
We use all cuts except cut on z vertex
Distribution was fitted with exponent
Integral under exponent from 3 to
was calculated.
To estimate amount of ΛΛ candidates
for 1012 events integral was multiplied
by 108
Reconstructed invariant mass distribution with theoretically predicted parameters
50K
50K
Reconstructed invariant mass detectability level (multiplicity few10-6)
M = 7·10-650
Summary
CBM detector is suitable for the Open charm measuring at SIS 100 and SIS 300 energiesHe inside MVD and STS isn’t good for the Open charm New Primary vertex finder has been developedNew KFParticleCBM detector can collect about 50K {Ξ0Λ}b -dibaryons per 1012 central collisions Au+Au 25 AGeVDetectability limit is about few·10-6 H-dibaryons per central event Plans:-electrons, pile-up, clustering in the MAPS, new detector geometries and passive materials;