News from ToF+dEdx analysis in Be+Be interactions. Magdalena Kuich - PowerPoint PPT Presentation

News from ToF+dEdx analysis in Be+Be interactions. Magdalena Kuich University of Warsaw May 19, 2016 1 / 45

Outline Data 1 Cuts 2 Procedure 3 Fits 4 Parameters 5 Spectra 6 Comparison with Emil 7 Comparison with EPOS 8 Transverse momentum spectra 9 10 Step 11 Horn 2 / 45

Data and statistic Analysed data come from last mass production: 056_14e_v1r3p0_pA_slc6_phys. Events: BeBe 40 BeBe 75 BeBe 150 Before cuts 3336913 3805609 3030496 After cuts 392722 426555 334118 Tracks: BeBe 40 BeBe 75 BeBe 150 Before cuts 5523945 8323675 8988740 After cuts 169985 399201 641214 3 / 45

Event cuts Event cuts - data Event cuts - MC Vertex track fitted to the main Target IN/OUT, vertex, BPD status, Vertex fit quality = ePerfect, BPD extrapolation, Fitted vertex position Beam Position, -580 ± 18 cm . S1 vs. Z, BPD charge vs. Z, Z off-time, WFA particles (4 . 5 µ s ), WFA interaction, T2 trigger, Vertex track fitted to the main vertex, Vertex fit quality = ePerfect, Fitted vertex position -580 ± 18 cm . 4 / 45

Track cuts Track cuts - data Track cuts - MC Track status, Track status, Charge ± 1, Charge ± 1, Rst, Rst, Total number of clusters, Total number of clusters, VTPCs+GapTPC clusters, VTPCs+GapTPC clusters, Number of dEdx cluster, Number of dEdx cluster, Last point in TPCs, Last point in TPCs, ToF acceptance, ToF acceptance, ToF Iflag, Decay probability, Good QDC, ToF dead and efficiency pixels, Track hit only 1 scintillator, Track hits 1 pixel Fitted phase space. Fit acceptance → transition from p-p T to y-p T phase space. 5 / 45

Fitting procedure phase space was divided to subspaces (bins) of size of 1 GeV/c in p tot and 0.1 GeV/c in p T in chosen bin a 2D gaussian function was fitted: ( m 2 − m 2 i ) 2 ( m 2 − m 2 i ) 2 − ( ( dEdx − dedxi ) 2 − ( ( dEdx − dedxi ) 2 + ) + ) 2 σ 2 2 σ 2 2 σ 2 2 σ 2 � dedx m 2 dedx m 2 G = A i ( fe + ( 1 − f ) e ) (1) 1 2 i = p ,π, K , e - 4 (3) amplitudes - 4 (3) dEdx positions - 4 (3) m 2 positions - 3 σ - 1 factor f Be+Be 150 GeV/ c 6 < p < 7 GeV/ c and 0 . 0 < p T < 0 . 1 GeV/ c 6 / 45

Fitting procedure dEdx starting values taken from SHINE module, momentum dependency taken into account, m 2 starting values taken from PDG database: ◮ proton m 2 = 0.880354 ( GeV / c 2 ) 2 ◮ pion m 2 = 0.0194798 ( GeV / c 2 ) 2 ◮ kaon m 2 = 0.243717 ( GeV / c 2 ) 2 ◮ electron m 2 = 2.6112 · 10 − 7 ( GeV / c 2 ) 2 starting value of factor f ∼ 0.9 starting value of amplitudes were estimated as a proportional contribution to analyzed histogram starting values of other parameters ( σ dEdx , σ m 1 , σ m 2 ) were tuned after first tests. identification was calculated: P j = G j (2) G Bins with more than 300 entries (tracks) were chosen to analyze. 7 / 45

Fit examples -BeBe 40 Positively charged particles 3 < p < 4 and 0 . 2 < p T < 0 . 3 Negatively charged particles 2 < p < 3 and 0 . 3 < p T < 0 . 4 8 / 45

Fit examples -BeBe 75 Positively charged particles 5 < p < 6 and 0 . 2 < p T < 0 . 3 Negatively charged particles 4 < p < 5 and 0 . 2 < p T < 0 . 3 9 / 45

Fit examples -BeBe 150 Positively charged particles 5 < p < 6 and 0 . 1 < p T < 0 . 2 Negatively charged particles 6 < p < 7 and 0 . 3 < p T < 0 . 4 10 / 45

Fitted dEdx positions: BeBe 40, BeBe 75, BeBe 150 Positively charged particles Negatively charged particles 11 / 45

Fitted mass positions: BeBe 40, BeBe 75, BeBe 150 Positively charged particles Negatively charged particles 12 / 45

Raw normalized spectra - positively charged particles BeBe 40 centrality 0-20 % p π + K + 13 / 45

MC corrections of spectra - protons BeBe 40 centrality 0-20 % MC GEN MC REC Ratio MC REC /MC GEN Corrected p spectra 14 / 45

MC corrections of spectra - positively charged pions BeBe 40 centrality 0-20 % MC GEN MC REC Corrected π + spectra Ratio MC REC /MC GEN 15 / 45

MC corrections of spectra - positively charged kaons BeBe 40 centrality 0-20 % MC GEN MC REC Corrected K + spectra Ratio MC REC /MC GEN 16 / 45

Raw normalized spectra - negatively charged particles BeBe 40 centrality 0-20 % ¯ p π − K − 17 / 45

MC corrections of spectra - antiprotons BeBe 40 centrality 0-20 % MC GEN MC REC Ratio MC REC /MC GEN Corrected ¯ p spectra 18 / 45

MC corrections of spectra - negatively charged pions BeBe 40 centrality 0-20 % MC GEN MC REC Corrected π − spectra Ratio MC REC /MC GEN 19 / 45

MC corrections of spectra - negatively charged kaons BeBe 40 centrality 0-20 % MC GEN MC REC Corrected K − spectra Ratio MC REC /MC GEN 20 / 45

Raw normalized spectra - positively charged particles BeBe 75 centrality 0-20 % p π + K + 21 / 45

MC corrections of spectra - protons BeBe 75 centrality 0-20 % MC GEN MC REC Ratio MC REC /MC GEN Corrected p spectra 22 / 45

MC corrections of spectra - positively charged pions BeBe 75 centrality 0-20 % MC GEN MC REC Corrected π + spectra Ratio MC REC /MC GEN 23 / 45

MC corrections of spectra - positively charged kaons BeBe 75 centrality 0-20 % MC GEN MC REC Corrected K + spectra Ratio MC REC /MC GEN 24 / 45

Raw normalized spectra - negatively charged particles BeBe 75 centrality 0-20 % ¯ p π − K − 25 / 45

MC corrections of spectra - antiprotons BeBe 75 centrality 0-20 % MC GEN MC REC Ratio MC REC /MC GEN Corrected ¯ p spectra 26 / 45

MC corrections of spectra - negatively charged pions BeBe 75 centrality 0-20 % MC GEN MC REC Corrected π − spectra Ratio MC REC /MC GEN 27 / 45

MC corrections of spectra - negatively charged kaons BeBe 75 centrality 0-20 % MC GEN MC REC Corrected K − spectra Ratio MC REC /MC GEN 28 / 45

Raw normalized spectra - positively charged particles BeBe 150 centrality 0-20 % p π + K + 29 / 45

MC corrections of spectra - protons BeBe 150 centrality 0-20 % MC GEN MC REC Ratio MC REC /MC GEN Corrected p spectra 30 / 45

MC corrections of spectra - positively charged pions BeBe 150 centrality 0-20 % MC GEN MC REC Corrected π + spectra Ratio MC REC /MC GEN 31 / 45

MC corrections of spectra - positively charged kaons BeBe 150 centrality 0-20 % MC GEN MC REC Corrected K + spectra Ratio MC REC /MC GEN 32 / 45

Raw normalized spectra - negatively charged particles BeBe 150 centrality 0-20 % ¯ p π − K − 33 / 45

MC corrections of spectra - antiprotons BeBe 150 centrality 0-20 % MC GEN MC REC Ratio MC REC /MC GEN Corrected ¯ p spectra 34 / 45

MC corrections of spectra - negatively charged pions BeBe 150 centrality 0-20 % MC GEN MC REC Corrected π − spectra Ratio MC REC /MC GEN 35 / 45

MC corrections of spectra - negatively charged kaons BeBe 150 centrality 0-20 % MC GEN MC REC Corrected K − spectra Ratio MC REC /MC GEN 36 / 45

Comparison with Emil’s π − , centrality 0-20 % BeBe 40 tof π − spectra Emil’s spectra of π − tof /h − 37 / 45

Comparison with Emil’s π − , centrality 0-20 % BeBe 75 tof π − spectra Emil’s spectra of π − tof /h − 38 / 45

Comparison with Emil’s π − , centrality 0-20 % BeBe 150 tof π − spectra Emil’s spectra of π − tof /h − 39 / 45

π ± spectra vs EPOS in ’banana acceptance’ Positively charged particles Negatively charged particles 40 / 45

K ± spectra vs EPOS in 0 . 0 < y < 0 . 2 Positively charged particles Negatively charged particles 41 / 45

p ± spectra vs EPOS in − 0 . 2 < y < 0 . 0 Positively charged particles Negatively charged particles 42 / 45

K ± p T spectra in 0 . 0 < y < 0 . 2 Positively charged particles Negatively charged particles 43 / 45

Step - inverse slop parameter in 0 . 0 < y < 0 . 2 T [MeV] T [MeV] - + 400 K 400 K ≈ ≈ y 0 y 0 200 200 Pb+PbAu+Au Be+Be p+p Pb+PbAu+AuBe+Bep+p SPS(NA61 Be+Be) SPS(NA61 Be+Be) SPS(NA61 p+p) SPS(NA61 p+p) WORLD(p+p) WORLD(p+p) AGS AGS SPS(NA49) SPS(NA49) RHIC RHIC LHC(ALICE) LHC(ALICE) 2 4 2 4 1 10 10 1 10 10 s [GeV] s [GeV] NN NN d 2 n � p 2 T + m 2 S p T K − m K dp T dy = exp ( − ) T 2 + T m K T 44 / 45

Horn - K π ratio in 0 . 0 < y < 0 . 2 0) 0) Pb+PbAu+Au Be+Bep+p ≈ ≈ (y (y SPS(NA61 Be+Be) + - SPS(NA61 p+p) π π π / / WORLD(p+p, 4 ) - + K K AGS 0.2 0.2 SPS(NA49) RHIC LHC(ALICE) 0.1 0.1 Pb+PbAu+AuBe+Bep+p SPS(NA61 Be+Be) SPS(NA61 p+p) π WORLD(p+p, 4 ) AGS SPS(NA49) RHIC LHC(ALICE) 0 0 2 4 2 4 1 10 10 1 10 10 s [GeV] s [GeV] NN NN Kaon multiplicity is obtained with tof − dEdx spectra in available accepcatne and exptrapoleted to p T = 1 . 2 . Pion multiplicity taken to these plots comes from h − analysis from Emil. 45 / 45