Hi Rick,
I haven't followed the hadron collider Higgs self-coupling
discussion in detail, but from a quick reading of the
draft Higgs report and relevant papers (I couldn't find ref 69), it
seems clear that double-Higgs production statistics
is likely to be a strength of VLHC. But how much this translates into a
Higgs self coupling measurement
and in particular a model-independent measurement of the Higgs
self-coupling when there is a 30% error on
the theoretical cross-section and many different non HHH coupling
contributions to final states with HH is not clear at all.
So I don't think your "likely the best place for Higgs self-coupling" is
supported by the current documentation.
regards
Graham
On 8/23/2013 9:45 AM, Rick Van Kooten wrote:
> On 8/22/13 8:57 PM, Peskin, Michael E. wrote:
>>
>> Dear Colleagues,
>>
>> I attach the most recent versions of the Snowmass Executive Summary
>> and the
>> EF 5-page summary. We will discuss these in our meeting tomorrow.
>>
>> The Executive summary got somewhat rearranged. The frontier conveners
>> wanted the capabilities sections pulled out and merged into a common
>> section.
>> This means that the accelerator part of the LHC, ILC, and VLHC
>> discussion
>> occurs much later in the document. But, please look it over. I did
>> insert
>> language on the US leadership in high-field magnets.
>
> Regarding the current top-level executive summary, I would like to
> see the _unique_ capabilities of e+e- machines stressed, and as one
> example:
>
> "They can reach sub-percent precision in the Higgs boson properties,
> allowing discoveries of percent-level deviations predicted in
> theoretical models."
>
> to
>
> "They can reach sub-percent precision in the Higgs boson properties in
> a unique, model-independent way, allowing discoveries of percent-level
> deviations predicted in theoretical models."
>
> This is just transferring some wording from the longer summary. I
> believe that we are all agreed that an "all hadron" option, i.e.,
> HL-LHC -> HE-LHC/VLHC would definitely be missing out on important
> physics and capabilities and we want to make that clear.
>
> Also a small suggestion: adding "at least", i.e.,:
>
> "They can improve the precision of our knowledge of the $W$, $Z$, and
> top properties by at least an order of magnitude".
>
>>
>> As to the rest of the VLHC discussion, let's talk about it tomorrow.
>> The
>> new particles group would like a stronger endorsement of VLHC in the
>> executive
>> summary. I am rather cool to this, because the VLHC is not on the table
>> now. It would be good to get more opinions from the members of
>> our group.
>
> There is no denying that a ~100 TeV VLHC brings a lot to the table
> (including likely the best place for Higgs self-coupling) and we
> should say this, but with the caveats that Graham clearly points out.
> I do like Ashutosh's suggested wording encouraging a conceptual design
> report which is what would be needed to come to more solid
> conclusion. We could preface his encouraging statement with "Although
> beyond the 20-year timeline of this report, further investigations of
> the physics and technical issues would be opportune at this time..."
> (and indeed the same holds true for TLEP).
>
> Regards,
> Rick
>
>
--
Graham W. Wilson
Associate Professor
Dept. of Physics and Astronomy
University of Kansas
Lawrence, KS 66045
Office Tel. 785-864-5231
Web: http://heplx3.phsx.ku.edu/~graham/
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