Vasilisa Lenivenko G Musulmanbekov V Palichik M Patsyuk

Vasilisa Lenivenko, G. Musulmanbekov, V. Palichik, M. Patsyuk for the BM@N-SRC Collaboration 5 th BM@N Collaboration Meeting § April 20 th, 2020

• Using the model we want to estimate production of fragmentation in carbon proton collisions • DCM-SMM generator is suitable for the beam energy of the BM@N experiment • We start to compare the DCM-SMM model to 12 C fragmentation data 2

To. F DCH X Z Gem MWPC Pair 1 MWPC Pair 0 Analyzing magnet Y 1 BC 1 Ch 0 BC 2 Ch 1 T 0 X 1 -645 BC 3 BC 4 Ch 2 Ch 3 Target C beam BM@N Z=0 -858 -761 -428 X 2 Y 2 -364 -314 -214 Silicon Gem In red color: key detectors for further analysis In orange: trigger detectors To. F 3

* https: //arxiv. org/pdf/1912. 09277. pdf 4

Black: Blue: Green: Red: particles from target one of arms (To. Fs) in both arms (To. Fs) in DCH (w/o conditions) Protons and pions are separated in the arms Protons are identified in the arms: main aim of SRC analysis 5

Blue: if fired one of Tofs Green: if charged particles in both arms (left & right Tofs) Red: if protons in both arms (left & right Tofs) - SRC mainstream of analysis 6

BC 3 & BC 4 -> Zout (Sum of particles charge per event ) Reper runs C Reper runs Base runs SRC IT(Interact Trigger) = BC 1 & BC 2 & anti-BC 3 -Hi & anti-VC SRC BT (Beam Trigger) = BC 1 & BC 2 BC 1, 2, 3, 4 – time cuts , T 0 – One entry cut Base runs Light Nuclei B C 7

• Vertex reconstruction is needed to select interactions on LH (liquid hydrogen target) and not on the walls of the target • Methods: o Using arms : good vertex but very low statistics o MWPC(p 0)-Silicon vertex reconstruction : very small track angles o One arm and (Upstream or Silicon) vertex reconstruction : optimal choice 8

ry a n i m eli Pr MWPC(pair 0)track Min: 2 Si-tracks k 1 c a r t Si > 6 mrad Si-track 2 SRC data 75 K events with vertex out of = 377 K “good” trigged events Resolution is not good enough We will try another method : one arm and (Upstream or Silicon) tracks 9

SRC data Base Runs Ampcut for BC 3 [ADC] Nevents Zout<4. 4, BC 3< ampcut. BC 3 Nev Zout<4. 4 Knorm= Ni(ampl)/ Nreper(ampl) Eff= Ni(zcut)/ (Nreper(zcut)*K) 3054 1100 51880 63090 8. 5 0. 176 3056 1100 54740 66550 9. 0 0. 176 3057 1100 26400 31950 4. 3 0. 177 3138 1100 14 980 2. 0 0. 178 3139 1100 15540 2. 1 0. 176 12520 Reper 42040 3054 1100 84930 103700 8. 4 0. 178 3056 1100 89900 107300 8. 9 0. 174 3057 1100 43150 52220 4. 3 0. 175 3138 1100 24610 2. 0 0. 177 3139 1100 25100 2. 0 0. 181 Reper 20280 69350 BC 1, 2, 3, 4 – time cut !VETO - time cut T 0 – One entry cut BC 3 Efficiency =18% Low efficiency w/o vertex conditions BC 1, 2, 3, 4 – time cut !VETO - time cut T 0 – One entry cut 10

SRC data Base Runs Ampcut for BC 3 [ADC] Nevents Zout<4. 4, BC 3< ampcut. BC 3 Nev Zout<4. 4 Knorm= Ni(ampl)/ Nreper(ampl) Eff= Ni(zcut)/ (Nreper(zcut)*K) 3054 700 8299 10070 8. 98 0. 45 3056 700 8825 10730 9. 5 0. 45 3057 700 4240 5106 4. 6 0. 44 3138 700 1918 2368 2. 07 0. 46 3139 700 1999 2471 2. 16 0. 46 924 2506 Reper ~0. 452 3054 700 13970 16970 9. 1 0. 44 3056 700 14870 17880 9. 7 0. 44 3057 700 7091 8543 4. 6 0. 44 3138 700 4007 2. 1 0. 45 3139 700 4056 2. 1 0. 46 Reper 3279 4205 ~44. 6 BC 1, 2, 3, 4 – time cut !VETO - time cut T 0 – One entry cut With vertex conditions BC 3 Efficiency =45% With vertex conditions BC 1, 2, 3, 4 – time cut !VETO - time cut T 0 – One entry cut With vertex conditions 11

ry a n i m reli P Only base runs BC 1, 2, 3, 4 – time cut !VETO - time cut T 0 – One entry cut With vertex conditions SRC data DCM-SMM simulation in DCH B 11 1 track B 10/C 12 B 11 B 10 & C 12 don’t separated: need PID procedure – see next slide 12 12

nary i m i l Pre SRC data DCM-SMM simulation in DCH B 11 B 10 Data: G. Johansson Good agreement between simulation and data 13

nary i m i l Pre DCM-SMM simulation in DCH Be 9 Be 7 Be 9 Be 10 SRC data Be 7 Be 10 Be 9 Be 7 Data: G. Johansson Good agreement between simulation and data 14

ry a n i m reli P Base runs BC 1, 2, 3, 4 – time cut !VETO - time cut T 0 – One entry cut SRC data T T Be 10 Li 7, Be 9, B 11 D, He 4, Li 6, Be 7, C 11 B 10, C 12 He 3, B 8, C 10 DCM-SMM simulation in DCH T Be 10 Li 7, Be 9, B 11 D, He 4, Li 6, Be 7, C 11 D B 10, C 12 He 3, B 8, C 10 p pi+ The work needs some improvements in terms of details and data processing. That is to be done in the nearest future. Simulation shows us possibilities for different fragments identification: 15 adequate detector hits smearing is required

• Simulation shows us possibilities for different fragments identification • 11 B & 10 B and Be isotopes can be separated • BC 3 Trigger efficiency for “base runs” is estimated • Adequate detector hits smearing for simulation is required • To develop vertex reconstruction algorithm with one arm and one (Upstream or Silicon) tracks • To study data with at least one arm • Correct track angles before the magnet for PID are required • To use implemented PID algorithm (G. Johansson and V. Panin) vasilisa@jinr. ru Thank you for your attention

Base runs BC 1, 2, 3, 4 – time cut !VETO - time cut T 0 – 1 pic cut DCM-SMM simulation in DCH Average Xdch 18

ry a n i m reli P DCM-SMM simulation in DCH Base runs SRC data B 11 B 10 & C 12 don’t separated B 10 19 19

ry a n i m reli P DCM-SMM simulation in DCH Base runs BC 1, 2, 3, 4 – time cut T 0 – 1 pic cut With vertex conditions B 11 B 10 C 12 H 2, He, Li, etc. A/Z = (x. DCH +(tg. X(Si)-tg. X(DCh)*k 1 )*k 2 +k 3 k 1 = 1470. 88, k 2 = 0. 026106, k 3 = 4. 33385 +0. 18; 20 20

Number of particles in DCH if protons in both arms (left & right Tofs) 256 769 458 Generator author checked source files : For example event 68445: 12 С + p -> 11 С + p + pi. Reaction where a neutron interacts with a proton : n + p -> p + pi- 21

11 B p + 12 C 11 B + 2 p +X elastic: pp inelastic: pp pp. X: pΔ+ ppπ0 pp π0 11 C p + 12 C 11 C + 2 p +X inelastic: pn pp. X pΔ 0 ppπ- Δ+ Δ 0 ppπ Δ++ Δ- ppπ pp π- Cross sections ratio σel/ σin = 0. 46 22

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BC 1, 2, 3, 4 – time cut !VETO - time cut T 0 – 1 pic cut Zout < 4. 4 Integral (<1100) 6080 Integral (<1100) 11940 > 1100: K = 2. 0(!) 24

1100 25