Print

Print


   I had to disconnect at 3:00 p.m. for another meeting so did not know 
if we got around to discussing the below.

> -------------------------------------------------------------------------------
>
>  Questions to us from the Cosmic Frontier, to be discussed today:
>
> "HE1": • The message from the LHC seems to be that with data in hand,
> we consistently outperform expectations for extraction of Higgs
> properties. How much is there really for an ILC to contribute? What
> key assumptions are we making now that we could relax with ILC
> inputs?

   Adding to some of the other written input, a key assumption that will 
be made when enough stats are collected to allow access to all the other 
Br's at the LHC is that there are no invisible and/or 
exotic/undetectable Higgs decays adding to the total Higgs width.  In a 
number of projections, the assumption is often made that all the Br's 
(also from couplings) will add up to the 97-98% SM decays accessible to 
the LHC (i.e., removing charm).  A straightforward example of an exotic 
decay is if the Higgs decayed to non-SM particles that subsequently 
decayed hadronically (without heavy flavor) in a way that would be 
difficult or impossible to detect with QCD backgrounds at the LHC.

   Lepton Higgs factories can clearly relax this assumption since they 
can measure the total Higgs width in a model-dependent way, and would 
see _all_ possible Higgs decays recoiling against the tagged Z in hZ 
events.  The tremendous power of measuring (directly) the Z width at LEP 
was that it definitively tested for _all_ kinematically accessible Z 
decays.  The same level of test needs to be applied to the Higgs.

   Regards,
                 Rick

-- 
Rick Van Kooten  \ Telephone: (812) 855-2650  FNAL: (630) 840-3859
Dept. of Physics  \ HEP FAX:  (812) 855-0440
Indiana University \ e-mail:   [log in to unmask]
Swain Hall West 117 \ http://hep.physics.indiana.edu/~rickv/aboutme.html
Bloomington, IN 47405

########################################################################
Use REPLY-ALL to reply to list

To unsubscribe from the SNOWMASS-EF list, click the following link:
https://listserv.slac.stanford.edu/cgi-bin/wa?SUBED1=SNOWMASS-EF&A=1