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v3.3.6-pre
Time to be confirmed
BR (phone) meeting with focus on the Dalitz decay - 23 September 2019
People connected: Alexander Mueck, Alexei Maslennikov, Andreay Pazdnyakov, Anthony Morley,
Artem Basalaev, Daniel Rauch, Daniela Rebuzzi (DR), Ansgar Denner, Fabio Cerutti (FC), Giacinto
Piacquadio, Hanna Borecka-Bielska, Hongtao Yang, Ivica Puljak, Jan Kretzschmar,
John Adams Villamoran, Joseph Cordero Mercado, Kerstin Tackmann, Kurt
Brendlinger, Mayda Velasco, Michael Spira (MS), Chia-Ming Kuo (CMK), Reisaburo Tanaka,
Robert Harlander, Ruggero Turra, Russel Turner, Shilpi (?), Sven Heinemeyer, Tom
Neep
DR: short introdution on motivation for this meeting
MS: theoretical updates on EW and Strong Dalitz processes. Details of the contributions that will be included in HDECAY:
(i) certain bins (to be chosen in an input file) in m_ff, i.e.
m_ff = M_H +- dM_H for "H -> ff"
m_ff = M_Z +- dM_Z for "H -> gamma Z"
m_ff < cut for "photon conversion".
The residual mass ranges in m_ff will then be given as separate contributions (integrated).
All these contributions will probably be given in a separate output file, i.e. not
added automatically to the primary output of Hdecay. In this way the user will have the option
to choose between omitting/including the Dalitz contributions. This is at least what MS has thought.
If this is wanted in a different way, please let us know.
(ii) Concerning the very first bin (m_ff = M_H +- dM_H) MS has to merge this with the elw.
(QED) corrections to H -> ff. He still has to think about the proper procedure, but very
likely this will not require an explicit cut on the photon energy (or M_fgamma).
Remember that Hdecay is *inclusive* (or semi-inclusive in this particular case.)
But this will probably result in a negative contribution to H -> ff in several cases (small but negative).
FC: it would be useful to have a tool that includes all the three contributions in pg 2, to evaluate them
MS: Careful on what is gauge invariant
CMK: CMS studies on H-> ll gamma with 2016 data
TO DO LIST:
- Giacinto + Kerstin + Fabio (ATLAS) - Mayda + Chia-Ming (CMS) --> agreement on
the cuts to define the phase space
Should be done independently:
- to assess the contamination from Dalitz H->ee to H->ee gamma to H->Z gamma phase space
- to allow for comparison to the theory prediction of Dalitz decay BR.
- MS --> implement in HDECAY the needed processes (H -> l^+l^-\gamma)
and the possibility to apply invariant mass cuts on M_{\gamma l^\pm} and M_{l^+l^-}.