Dear Colleagues,

I apologize that, in the final editorial process, a couple of our questions
relevant to Computing Frontier were omitted from our list.  Please find
attached to this email the definitive version of the questions from the Energy
Frontier conveners.  The attachment is a plain text (txt) file.

Ian Shipsey sent an email to this group adding some questions of his own
(one of which was not actually a question).   I hope that Jon or someone else
will put together the final list of questions from all frontiers. 

And, I agree with Bob Bernstein that a number of questions from the final 
list will be excellent topics for public discussion at the Minnesota meeting.
The Energy Frontier conveners are making a list of joint sessions with other 
frontiers that we would like to see scheduled in Minnesota.  Many of these 
questions -- and the complementary information from our side -- will be 
covered.   We will also address the most important questions from the Cosmic
Frontier list.  Actually, we have already been discussing our response to these in 
our weekly meetings.

On the other hand, most of our questions require analytic 
answers which cannot be fully explained in the short talks appropriate to 
a panel discussion.  For the panels at Minnesota, we will need very 
high-level questions.

Best wishes,

Michael 

-------------------------------------------------------------------------------------------
  Michael E. Peskin                           [log in to unmask]
  HEP Theory Group, MS 81                       -------
  SLAC National Accelerator Lab.        phone: 1-(650)-926-3250
  2575 Sand Hill Road                       fax:     1-(650)-926-2525
  Menlo Park, CA 94025 USA              www.slac.stanford.edu/~mpeskin/
---------------------------------------------------------------------------------------------
________________________________________
From: Jonathan L. Rosner [[log in to unmask]]
Sent: Saturday, May 11, 2013 11:39 AM
To: Peskin, Michael E.
Cc: Jonathan L. Rosner; CSS2013 Conveners -- [log in to unmask]; chip brock; Chris Quigg; Daniel Cronin-Hennessy; Howard Nicholson; Jennifer Seivwright; Hewett, JoAnne L.; Jonathan Feng; Lothar Bauerdick; Marcel Demarteau; Marge Bardeen; Michael Dine; Murdock Gilchriese; Patricia McBride; Pierre Ramond; Ritz, Steven M.; Robert H Bernstein; Ronald J. Lipton; Shipsey, Ian P.; Steven Gottlieb; Weerts, Harry; Nick Hadley
Subject: RE: Snowmass EF questions

The list of questions Michael has sent is excellent and extensive.  Other
Frontiers are invited to comment on them, in the same way we have
commented on the questions from the CF.  We also need a similar list
from the Intensity Frontier.

I see these lists as serving three purposes:

    (1) After we agree on wording, we should post them as a separate
link from the Snowmass Wiki page.

    (2) They should serve as a guide to the inter-frontier discussions
which we want to set up in Minneapolis during the interim days
July 30 - August 4 (mornings and early afternoons).

    (3) They may be guides to the subjects of the Panel Discussions
during the late afternoons of July 30-31 and August 1, 3.

I did not get a chance to discuss this except very briefly during our
teleconference on Thursday, but I would like the Cosmic, Energy, and
Intensity Frontiers to take the lead in setting up the inter-frontier
discussion sessions by estimating required room sizes and schedules and
communicating them to Yuichi Kubota ([log in to unmask]).  The sooner
such schedules get posted on the Minnesota meeting web page, the better
idea the community will have of what the meeting is about.

Regards,
Jon
--      Jonathan L. Rosner
         Enrico Fermi Inst., U. Chicago   Phone: 773-702-7694
         5620 S. Ellis Avenue             Fax:   773-702-8038
         Chicago, IL 60637 USA           [log in to unmask]

########################################################################
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



==================================================

Questions from the Energy Frontier group to other Frontiers:


EF-IF:  It is especially interesting in studies of rare processes for a discovery of a new physics effect beyond the Standard Model to point to a mass scale that would be the basis for a future accelerator search for new particles.   What are the most important rare processes that have the potential to point to a specific mass scale, and how specific can their information be?

EF-IF: Describe 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. There should be separate estimates for SUSY models, in which the flavor-changing effects come from loops, and from models in which the flavor-change comes from a tree-level effective operator. This will facilitate plotting this evolution along with the evolution in sensitivity predicted for direct searches for new particles at the LHC.

EF-IF:  Describe the increase in sensitivity to new particles in loops as a function of time coming from improved measurements of b->s gamma, B and Bs -> mu mu, and related observables. There should be separate estimates for SUSY models, in which the flavor-changing effects come from loops, and from models in which the flavor-change comes from a tree-level effective operator. This will facilitate plotting this evolution along with the evolution in sensitivity predicted for direct searches for new particles at the LHC.

EF-IF:  What is the impact of higher precision measurements processes that determine the CKM angles, such as sin 2beta, sin 2 beta_s, and V_{ub}.  Is it realistic that tensions between these parameters can be sufficiently strong to signal the presence of new physics?

EF-IF:  What is the impact of measurements of direct CP violation in charm decay on the search for new physics?   In what processes is the Standard Model prediction sufficiently well understood, including perturbative and nonperturbative effects, to allow a strong conclusion of a deviation from the Standard Model?

EF-IF:  Improvements in the muon g-2 meausurement need to be accompanied with improvements in the Standard Model prediction for the term involving the hadronic vacuum polarization.  What are the prospects for improvement of the current estimate?  To reach the parts per billion level in the error, the contribution from light-by-light scattering must also be improved with input from low-energy data. How can this be done?

EF-IF:  The best current limits on the electron EDM come from experiments using polar molecules such as YbF in which atomic physics effects enhance the influence of an electron EDM. How can we check or calibrate the atomic physics calculations that go into the interpretation of these experiments?

EF-IF:  With a grand unification scale at 10^16 GeV as predicted by SUSY-GUTs, the lifetime of the proton to K nu is naively expected to be below 10^33 yr.  What are we testing as we push the limits to 10^35 yr ?  What are the crucial parameters of GUTs that allow the proton lifetime to be longer?  Is the sensitivity to these parameters quartic, as for m_GUT, or, more optimistically, quadratic ?  Is the expectation for the proton lifetime increased if superpartner masses are heavier than expected, and what is the relation between these quantities?

EF-IF: Imagine that one measures the CP violating phase in the neutrino sector to be 85 degrees (for example). What does this imply for the hypothesis that the matter-anti-matter asymmetry is due to leptogenesis?  What is the next measurement that one should make to clarify this relation?

EF-InstF: High luminosity running at a hadron collider will depend on efficient triggering in a difficult environment. Isolation requirements will likely be compromised, and, as a result, triggering on leptons may need to depend heavily on tracking. What are the most promising enabling technologies for electron/photon/tau triggers in this environment, considering luminosities up to 10^{35} cm^{-2}s^{-1}? What are likely R&D paths to realizing these technologies?

EF-InstF:  In the context of proposals of large tunnels that could host both pp and e+e- colliders, it is interesting to ask whether it is possible to design 4 pi detectors that can be used both for pp and e+e- experiments (perhaps with some interchangable inner tracking layers).  Is there an optimal design of such a multi-purpose detector?  What are the most important compromises required?

EF-InstF:  In a hadron collider environment, the ability to recognized displaced vertices and to trigger on them at level 1 would be a transformative technology.   Can this be realized?

EF-InstF:  In some studies for ILC and CLIC, the sophistication of particle flow calorimetry approaches the ability to resolve single hadrons.  At what point does the evolution of particle flow calorimetry give a qualitative, rather than just a quantitative, boost to experimental capabilities?   Can we realistically reach this point?

EF-Computing:  To what extent is high-energy physics still generating the world's largest randomly-accessed databases?  Can we claim to be a world leader in data science?  Along what dimensions?

EF-Computing:  The Grid was commissioned along with the LHC detectors.  ESnet traffic has increased 10x every four years throughout the LHC lifetime. Will improvements in networking infrastructure, QoS, monitoring, etc continue to keep up with LHC demands for distributed computing? In what directions are new enabling technologies required and when must they mature to again keep up with the LHC machine and detector upgrades?

EF-Computing: How do the different physics frontiers--and associated theory and physics simulation--differ in their needs for future computing technology evolution.  In what respects can they benefit from common computing technology evolution?

EF-Computing:   Proposed very high statistics experiments at the Z resonance require large rates -- many kHz -- at which data is written to storage.  What are the limits?

EF-CF: If dark matter has no SM interactions stronger than gravitational, are there any prospects for discovering its particle nature? 

EF-CF: If the dark matter particle is detected through non-collider experiments, what can we learn about its properties?  (e.g., can we learn its spin?)  Would we be able to learn whether it interacts with SM matter only through the "Higgs portal"?

EF-CF: Suppose there is a 10 GeV WIMP or a 100 GeV WIMP with direct detection cross section just below current limits.  This is the best case for understanding the particle nature of the dark matter.  What is the full set of measurements that we are likely to make on such a particle from Cosmic Frontier probes alone?

EF-CF:  If there is more than one type of dark matter particle, how can we discover this in Cosmic Frontier experiments?   Can we measure the dark matter fraction from different sources?

EF-CF:  In indirect detection of dark matter, it is notoriously difficult to rule out all hypotheses that a signal is of astrophysical origin.  But perhaps other knowledge from particle physics can help.  Would it be helpful, for example, to know the mass of a dark matter candidate?  What accuracy is needed?  Can direct detection provide sufficient accuracy?

EF-CF:  For a long time, there have been indications that the number of light degrees of freedom required in cosmology is greater than 3.  However, recent measurements from the CMB and other sources have given more precise information on this question.  What are the prospects for establishing that this number of degrees of freedom is indeed greater than 3, or, alternatively, for providing an upper bound well below 4?


===================================================================================


########################################################################
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