1. M. Ohlerich, A. Raspiareza, W. Lohmann DESY and MPI Munich
Study of the process e+e Zh l+l- X using full detector simulation and event reconstruction
M. Ohlerich, A. Raspiareza, W. Lohmann
DESY and MPI Munich
5/1/2019
ACFA Linear Collider Workshop, Beijing

2. ACFA Linear Collider Workshop, Beijing
Motivation l -
Higgs strahlungs process:
Higgs Recoil Mass
Coupling Strength (model independent) Z l + H
5/1/2019
ACFA Linear Collider Workshop, Beijing

3. cross section expectation, SM
mh=120 GeV
see also the talk by F. Richard at the MDI sessions
5/1/2019
ACFA Linear Collider Workshop, Beijing

4. ACFA Linear Collider Workshop, Beijing
Method and Tools
Whizard, Pythia
BHWIDE
Mokka
Marlin / MarlinReco
Generated Events
Beamstrahlung, ISR, FSR
Full Detector
Simulation
Full Reconstruction
of isolated Leptons
dilepton Reconstruction
Higgs Recoil mass
5/1/2019
ACFA Linear Collider Workshop, Beijing

5. MethParticle Identification
simple approach ...
E(total)
E(ECAL)
> Threshold
E(ECAL)
< Threshold
E(total)
charged hadron,
muon
with Track
electron/positron
without Track
photon
neutral hadron
improved approach …
Likelihood method for each neutral and charged particles
5/1/2019
ACFA Linear Collider Workshop, Beijing

6. ACFA Linear Collider Workshop, Beijing
Likelihood Method
take M quantities
normalize histrograms for N particle types
create probability density functions
Likelihood function for a certain particle type
5/1/2019
ACFA Linear Collider Workshop, Beijing

7. ACFA Linear Collider Workshop, Beijing
Momentum Resolution
Tracking
with TPC only
Full LDC
Tracking
5/1/2019
ACFA Linear Collider Workshop, Beijing

8. Invariant Dilepton Mass
from e+e-
from μ+μ-
5/1/2019
ACFA Linear Collider Workshop, Beijing

9. ACFA Linear Collider Workshop, Beijing
Recoil Mass Spectra
Different CMS
energies
Different tracking
performance
Full LDC tracking and
at the maximum of the
Cross section
L = 500 fb-1
mrecoil = ± GeV
5/1/2019
ACFA Linear Collider Workshop, Beijing

10. ACFA Linear Collider Workshop, Beijing
background processes
cross section Generator
244.6 fb
PYTHIA 6.302
(100%)
2.179 pb
PYTHIA 6.302
(100%)
PYTHIA 6.302
2.63 pb
(15%)
914.1 fb
BHWIDE
(3.7%)
PYTHIA 6.302
2.179 pb
(not fully processed yet)
5/1/2019
ACFA Linear Collider Workshop, Beijing

11. Signal + Backgorund, ee and μμ separated
cuts:
WW and ee scaled from
low statistics!
5/1/2019
ACFA Linear Collider Workshop, Beijing

12. ACFA Linear Collider Workshop, Beijing
Signal + Background
ee and μμ combined
Uncertainty on the cross section: 7 %
Uncertainty on the mass ~70 MeV
5/1/2019
ACFA Linear Collider Workshop, Beijing

13. ACFA Linear Collider Workshop, Beijing
Still to do
increase background statistics of
missing background, e.g.
5/1/2019
ACFA Linear Collider Workshop, Beijing