Projection for Run 3+4: hyper-nuclei yields vs minimum bias integrated Lumi

Scope: PWG
PWG-LF (Light Flavour Spectra)
Energy
5.5 TeV
System
Pb-Pb
Figure Image
Figure Caption

Expected yield of hyper-nuclei (3^LH, 3^LHe, 4^LHe) in 0-10% central Pb-Pb collisions in Run 3+4 as a function of the integrated minimum bias luminosity. The vertical dashed line represents the target luminosity of 10/nb from the upgrade LoI. 

 

Detail description

Expected yield of hyper-nuclei (3^LH, 3^LHe, 4^LHe) in 0-10% central Pb-Pb collisions in Run 3+4 as a function of the integrated minimum bias luminosity. The vertical dashed line represents the target luminosity of 10/nb from the upgrade LoI. 

The projections have been obtained according to the following recipe:
- expected yield are from thermal model predictions for T = 156 MeV. No error is given by the model.
- the values for the branching ratios are theoretical calculations with no error assigned from:

  • H. Kamada et al., PRC 57, 1595 (1998) for: 3^LH --> 3^He + pi- (25%) and 4^LH --> 4^He+pi- (50%)
  • H. Outa et al., NPA 639 (1998) 251-260 for: 4^LHe --> 3^He + p + pi- (32%)

- efficiencies are calculated starting from the effiicency for the 3^LH in 2 body-decay from the 2015 analysis, as follows. At the end of the procedure described below, in order to take into account the (~20%) increase in acceptance x efficiency expected from the ITS upgrade, a correction factor is applied that is estimated as the ratio of the efficiencies with the current detector and the upgraded ITS (ref. to dedicated productions used for this very same study for the ITS upgrade TDR).

3^LH CASE:
The starting point efficency is assumed to be the same for Run2 (2015) data analysis. The pT shape is taken from the Blast-Wave model, where the BW parameters are taken from the fit of π,K,p with the 3^LH mass. The y
ield is evaluated in the range 2-10 GeV/c (82% of the total yield) in |y|<0.5. 

4^LH CASE
The efficency is assumed to be the 3^LH efficiency from the Run2 (2015) data analysis, times a correction factor evaluated with dedicated simulations for the ITS Upgrade TDR  to be a flat. correction: Eff(4ΛH) = 0,87*(Eff 3ΛH). 
The pT shape is taken from the Blast-Wave model. The yield is evaluated in 2-10 GeV/c (89% of the total yield) in |y|<0,5.

4^LHe CASE
The efficiency is taken as Efficiency ~ Eff(3ΛH) x Eff(p) (~0,8). The remaining steps are common to the other particles.