Dear all,
We must be careful to consistently state our assumptions
about the Higgs cross section and production
rates in the Snowmass papers. In particular, numbers have
been quoted which do not properly account
for Initial State Radiation. Estia has just completed an
analysis to get a reasonable estimate of the
cross sections taking this into account and we need to make
sure the rates and timescales for locating
the Higgs are adjusted accordingly. Our goal is not to
change plots and analysis tables that are based
on looking at particular numbers of Higgs, but to state the
integrated luminosities required to get there
properly. The following table summarizes the numbers that
we will be using in the accelerator (ie, MASS)
white paper and which should also propagate to the Higgs
Factory notes.
First, here are some operating assumptions:
1) Run initially with a machine producing an average
luminosity of 1.7e31/cm^2/s and find the Higgs
2) Continue running on resonance in the initial
configuration for 1 year
3) Assume that the cooling channel and combiner ring
modifications to reach full luminosity are completed
during this running period
4) Then continue running for 5 years at full luminosity on
resonance
The relevant numbers for the 1+ 5 year scenario are in the
attached table. For each whitepaper, please
verify what language updates need to be made to bring your
contributions into consistency with these
overall assumptions.