Hi Chip,
I will be unable to attend the phone meeting today, so let me give my input to HE1.
The basic assumption of this question is that there is some gap in measurement precision between the LHC and the ILC and the size of that gap drives the motivation for the ILC. This kind of argument ignores the basic physics of precision search and is counterproductive since we, of course, always want the LHC to push forward with new innovations to increase their measurement precision. The actual situation is that with the LHC data alone, there is no strong constraint below 10% on the total width and the theory error on the contributions to the total width are limited by the Hbb at about 3%. There can be no precision program (beyond the ration of gamma gamma to ZZ - which the ILC can't do anyhow) unless one launches a precision electroweak program that gives order of magnitude improvement on electroweak observables, alphas, and the W and top masses - needed in part to improve theory predictions for the Higgs sector. And we need
a high precision measurement of Hbb to eventually supersede the theory uncertainty limitations and/or total width measurements at the accuracy of 1%. The current proposals fail to provide direct 1% total width measurements, so I think they need to e rethought with more statistics on the recoil mass method and when possible more direct line shape scan sensitivity.
Also, the question should be reworded in terms of a Higgs Factory and not name the ILC directly - as all possible approaches to a new facility with a comprehensive precision electroweak and Higgs production capabilities are being considered - not just ILC.
In summary, a dedicated Higgs factory with a precision electroweak program creates the possibility of a high precision Higgs program - it is not created by an apparent gap between the LHC and Higgs factory. Once the input and constraints on the Higgs sector are tightened, one can go back to the LHC measurements (which should continue in some form to reach better and better sensitivity) and have a more accurate theory comparison where now one might be able to detect evidence for new physics.
There are other areas like spin which may be wrapped up at the LHC, and I think Andrei and Heather will be at the meeting to comment.
Best,
Chris
Sent from my iPhone
On Apr 24, 2013, at 4:54 PM, Chip Brock <[log in to unmask]> wrote:
> Hello EF Conveners,
>
> We will have our first weekly EF Convener's phone call tomorrow, Thursday.
>
> Energy Frontier Conveners' meeting
>
> April 25: 11:00 PDT / 2:00 EDT
> Contact information:
>
> You call: domestic... (877)287-0283
> international...(303)433-0165
>
> participant code: 290-043
>
> We will start the meeting promptly and end promptly after 1 hour.
>
> Agenda items
>
> 1. How did Vidyo work for you at Brookhaven? What do you require from the Seattle organizers?
>
> 2. We need to propose sessions of general interest for the parallel-session days at Minnesota. Michael started a list below. Please add to it. We've attached the first-pass block schedule discussed in the Snowmass conveners' meeting last week.
>
> 3. We need to propose questions to the other frontiers. These should in particular address issues that were not covered by the Cosmic Frontier's list. Some examples are given below. Please add more. We'll read them and briefly discuss them.
>
> 4. And, in turn we will devote time in these meetings to discussing how we will respond to the questions to us from Cosmic Frontier and others. Today, we will discuss the two questions below. For the moment, it would be good to know if we are on track to answer these questions or, if not, what studies are needed.
>
> Thank you,
>
> Chip and Michael
>
> -----------------------------------------------------------------------
>
> Titles for Sessions of General Interest at Minnesota:
>
> 1. Dark Matter -- attempt a perspective including all detection methods including direct searches, and comparison of their reach (needs to be organized with CF)
>
> 2. Lepton Flavor Violation -- what new physics models are accessed by mu-e conversion, mu-> e gamma, and tau-> ell gamma experiments now being planned? How are these compared to direct search capabilities? Can we see lepton flavor violation at colliders? (needs to be organized with IF)
>
> 3. Future of the Higgs -- To what extent have we already ruled out models of the Higgs field beyond the simple Standard Model. What are examples of models that require precision measurements at different levels? What should be the goal in precision Higgs measurement?
>
> 4. Instrumentation for High-Luminosity Hadron Colliders -- what are the emerging technologies for confronting the problems of triggering, heavy flavor ID, and precision measurement with high pileup? (needs to be organized with Inst. F.)
>
> -----------------------------------------------------------------------------
>
> Pump-priming questions to other frontiers:
>
> EF-IF1: We would like to understand the increase in sensitivity to new particles in loops as a function of time for the g-2, mu-e conversion, tau -> ell gamma, and EDM experiments. Can we plot this evolution along with the evolution in sensitivity predicted for direct searches for new particles at the LHC?
>
> EF-InstF1: High luminosity running will depend on efficient triggering in a difficult environment. Isolation requirements will likely be compromised which may place a premium on tracking for lepton triggering. What are the few most promising enabling technologies for electron/photon/tau triggers in an environment, considering luminosities up to 10^{35} cm^{-2}s^{-1}? What are likely R&D paths to realizing these technologies?
>
> EF-CF1: If dark matter has no SM interactions stronger than gravitational, are there any prospects for discovering its particle nature?
>
>
> [Daniel Whiteson also proposed the question:
>
> EF-EF!: What is our best guess at the probability that a 33 TeV (100 TeV) pp machine will discover nothing new? [ note: this may be unanswerable, but it's sort of the big elephant in the room ]
>
> We think that this must be discussed in some way in our reports. Another way to ask the question is, if there is no BSM physics at the HL-LHC, what is the motivation to go to higher energy? ]
>
> -------------------------------------------------------------------------------
>
> 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?
>
> "HE2": • How much do we gain from searches for e.g. triple-gauge-couplings in light of precision electroweak data? Is there any kind of theory where we expect to naturally have SM-like precision measurements, but large deviations in the TGCs?
>
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