Andreas ImhofECFA-DESY workshop, Amsterdam1 Measurement of the Higgs-bosons parity at TESLA Andreas Imhof 1,2 Klaus Desch 2, Thorsten Kuhl 1, T. Pierzcha ł a 3, Z. W ąs 4 and Malgorzata Worek 3 1 Deutsches Elektronen-Synchrotron DESY 2 University of Hamburg 3 Silesia University, Katowice, Poland 4 Institute of Nuclear Physics, Krakow, Poland

Andreas ImhofECFA-DESY workshop, Amsterdam2 Contents The observable Conditions for a measurement at TESLA Some aspects of the applicability First results from the reconstructed observable

Andreas ImhofECFA-DESY workshop, Amsterdam3 The observable For the  -decays into 2 or 3 pions via  -, or a 1 - resonances The momenta of the pions in the final state span planes Correlation sensitive to Higgs-parity : the acoplanarity .    00   00 ++ --

Andreas ImhofECFA-DESY workshop, Amsterdam4 The observable Problem: ambiguity for the measurement Additional criteria:  -energies 2 classes of events with y 1 ·y 2 0 Implementation for y 1 ·y 2 < 0 : acoplanarity = 2  -   one distribution for both classes

Andreas ImhofECFA-DESY workshop, Amsterdam5 Theoretical distributions and mixed channel:  1   ,  2  a 1      0

Andreas ImhofECFA-DESY workshop, Amsterdam6 Boundary conditions Limited statistics of these channels e.g.: for and  together approx. 500 events per 350 fb -1 Detector-resolution and -efficiency  use SIMDET Efficiency of the analysis Separation of signal from background (not included yet)

Andreas ImhofECFA-DESY workshop, Amsterdam7 Aspects of final-state- reconstruction for          0 ;  0   how to reconstruct the  0 ? red line shows angle, required, that 2 photons hit the ECAL with 3 cm distance granularity not properly implemented in Simdet.

Andreas ImhofECFA-DESY workshop, Amsterdam8 Aspects of final-state- reconstruction   -reconstruction ambiguity in 3-prong-final-state

Andreas ImhofECFA-DESY workshop, Amsterdam9 Tree vs. reconstructed for 150 years of TESLA-running..... solid: MC-data dashed: SIMDET-rec

Andreas ImhofECFA-DESY workshop, Amsterdam10 Distributions for 1000 fb -1 Observable is independent of the production-process. Here as example: SM-Higgstrahlung e + e -  Z 0 H 0  X  +  - with √s = 350 GeV and m H = 120 GeV N evt = 833 N evt = 666N evt = 133

Andreas ImhofECFA-DESY workshop, Amsterdam11 Asymmetry of  From large number of events with scaled errors: channelparityasymmetry -- H0H  A0A  a 1 -  H0H  A0A  a 1 -a 1 H0H  A0A  0.092

Andreas ImhofECFA-DESY workshop, Amsterdam12 Combined result Acoplanarities: H 0 :  A 0 :   > 8 σ at this point of the analysis

Andreas ImhofECFA-DESY workshop, Amsterdam13 Conclusion Acoplanarity: sensitive to CP-eigenstate of the Higgs- bosons  -  - and a 1 -  -channel allow measurement of the parity a 1 -a 1 -channel looks worse Still missing: background-studies Improvements possible, e.g. corrections on missing transverse neutrino-momenta SIMDET-ECAL-description too simple, need BRAHMS- study for  0 start systematic  -identification for TESLA