I like Markus' write up. In the summary, what does "planned future accelerators" refer to? HL-LHC (ILC?, 100 TeV?) If it also includes 100 TeV (or around similar energies), perhaps we should use a world somewhat stronger than "potentially", since I think 100 TeV can cover a lot of ground in the model space (and significantly more than others). Liantao On Fri, Oct 11, 2013 at 12:57 AM, Markus A. Luty <[log in to unmask]> wrote: > The first installment of my homework: here is my suggestion for what is now > lines 31-41 of the 5-page summary. It is longer than what is there now, but > I think these may be the most important lines in the document. > > The discovery of the Higgs particle establishes that the masses of > elementary > particles arise dominantly from interactions with the Higgs field that is > turned > on throughout the universe. We now have for the first time in the history of > particle physics a theory all of whose ingredients have been experimentally > verified, and that can be consistently extrapolated to energy scales many > orders > of magnitude above the energy scale of collider experiments. This historic > achievement is not an end, but a beginning, because the standard model of > particle physics leaves many fundamental questions unanswered. In the > tradition > of bold theoretical ideas such as the Higgs mechanism (recognized by this > years' > Nobel prize) particle physicists have proposed compelling ideas that address > these important questions, and that have their crucial test at the TeV > scale: > > * The fact that the observed Higgs particle is a scalar particle makes it > very > difficult to understand why its mass scale is smaller than much-larger > fundamental mass scales such as the Planck scale. Addressing this problem > requires significant additional structure: either supersymmetry (an > extension of > Einstein's spacetime symmetry), Higgs compositeness, or extra dimensions of > space. All of these ideas predict a rich spectrum of particles at the TeV > mass scale, > typically including a larger Higgs sector. > > * The standard model does not account for the dark matter that makes up most > of > the matter of the universe. A stable particle at the Higgs mass scale with > weak > interactions with ordinary matter (a WIMP) is one of the simplest and > compelling > theories of dark matter. If dark matter is a WIMP it may be possible to > study > dark matter under controlled laboratory conditions in collider experiments. > > To summarize: \emph{Compelling ideas about fundamental physics predict new > particles at the TeV energy scale that are potentially accessible to present > and > planned future accelerators. These experiments are the crucial tests of > these ideas. > Furthermore, if such particles are discovered, they can be studied in detail > to > determine their properties, leading to the establishment of new fundamental > laws of > nature.} > > The past successes of particle physics clearly call for us to continue and > extend a three-pronged program of research in collider experiments: > > First, we must study the Higgs boson itself in as much detail as possible, > searching for signs of a larger Higgs sector and the effects of new heavy > particles. > > Second, we must search for small deviations in the standard model > predictions > for the couplings of the Higgs, W, Z, and top quark from new particles. > > Finally, we must directly search for new particles with TeV masses that can > address important problems in fundamental physics. > > Markus Luty > > ============================================ > Physics Department > University of California, Davis > One Shields Avenue > Davis, CA 95616 > > Phone: +1 530 554 1280 > Skype: markus_luty > > > > On Thu, Oct 10, 2013 at 1:57 PM, Ashutosh Kotwal <[log in to unmask]> > wrote: >> >> On Oct 10, 2013, at 4:03 PM, "Peskin, Michael E." >> <[log in to unmask]> wrote: >> >> > minutes of the EF phone meeting 10/8 >> > >> > attending: Chip, Michael, Sally, Daniel, LianTao, Ashutosh, Cecilia, >> > Reinhard, Markus, Andy White >> > >> > There are many items in these minutes that all of you need act on more >> > or less immediately. Please read these minutes carefully. We summary the >> > action items at the end. >> > >> > Our reports are overdue. We would like to send our reports to the >> > Snowmass conveners on Tuesday, October 15. >> > >> > All line numbers refer to the 10-3 versions sent out last Friday. >> > >> > 1. From the group on the phone, and from the emails that we have >> > received, you seem to be happy with the reports that we put together except >> > for some specific points discussed below. Michael emphasized that, if you >> > are not happy, you must speak up now. This is best done by sending email to >> > snowmass-ef. Urgently, please. >> > >> > 2. Many of the people on the phone were uncomfortable with the language >> > on likes 40-41 of the short report: "These puzzles imply that new particles >> > with masses of the order of 1 TeV which resolve these questions will be >> > found -- and will be accessible to existing and planned accelerators." >> > They felt that "imply" was too strong and that the implication of 1 TeV >> > rather than, say, 5 TeV was made in this sentence. >> >> >> what about replacing >> >> "…masses of the order of 1 TeV" >> >> by >> >> "...masses below about 10 TeV" >> >> just as an example, ATLAS studies have shown sensitivity to KK gluons -> >> ttbar in the 5 TeV range >> >> ------ >> >> as far as the word "imply" goes, it seems to me that "imply" has a >> built-in caveat that it is an implication on the basis of a certain logic. >> In this case, the logic is that nature will avoid too much fine tuning. The >> 10 TeV number would make the fine tuning about 0.01% >> and the logic is that this is very uncomfortable amount of fine tuning >> >> So, I think we are protected in the legalistic sense if we do use the >> word "imply" >> >> Also, to me, the scale of how "strong" the language is, is no longer set >> by the "strength" of "there must be some new physics to explain massive >> gauge bosons…" which worked very well for SSC and LHC motivation. I don't >> think we have to normalize to that any more. I think we have to normalize to >> the "strongest" language we could use for ANY new physics, in the post-Higgs >> discovery, post-theta13, post-Planck…etc… world we live in now. >> >> regards, >> Ashutosh >> ######################################################################## >> 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 > > > > ________________________________ > > 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 ######################################################################## 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