The SPSC has automatized the submission procedure as indicated here: https://cds.cern.ch/submit?doctype=SPSC2&ln=en Richard: ======= Better within five years, it gives an upper limit while hinting at the fact that it may be less with some improvements. For this to be clear, we could also add afterwards "assuming the same fraction of the SPS beam time as CNGS". This leaves all other parameters open (even the location, in case they want to propose a different site for the experiment). > On 3/10/13 9:16 AM, Richard Jacobsson wrote: > we arrived to the conclusion >that the wording "few years" is too strong, as I also said in the previous >mail, but on the other hand we should insist that 4.5E19 pots can be delivered >in parallel to the other NA operation and LHC. We should either find a >different word which sounds more than 2-3, or say "up to five years". Without >saying it, our formulation in the EoI should be such that we show that we are >sufficiently confident about our physics case to assume that this project >receives high priority in beam time (full CNGS time slot) and that the >necessary RD is undertaken to make sure we can double the pots to NA as >compared to 2007. It's definitely within realistic borders. > Richard There are also two minor comments from a native English: * throughout, there is some 'oscillation' between the use of "the baryon asymmetry of the Universe", and "the baryon asymmetry" and "the observed baryon asymmetry" (and maybe even just "baryon asymmetry". I think it's good to maybe use "the observed baryon asymmetry of the Universe" the first one or two times, then use "the observed baryon asymmetry" thereafter, but "the baryon asymmetry" should definitely be dropped. * page 6, section 4, would it make sense to replace "...a combination of a target and a hadron absorber [], which are..." with "...a combination of target and hadron absorber [], which is..." L204: I was advised to be specific since we can, not to give the impression that we are hiding some uncertainty:"and consequently a reduction of about 10% of the number of protons on target." L228: This sentence was so (too) strong that it triggered a few to be very concerned about the vacuum required in the beam dilution drift space. In this case we should specify the required beam vacuum. When you add the sentence, Jaap, I believe this is not what we wanted to say. It is just to say that we should not have beams scraping in aperture, which in fact is very easy in our beam line.... Can you rephrase this, please. L230: Change sentence for (interlocking is easier from one point of view but may be more difficult from another point of view so this sentence drops the impression that slow extraction makes it simpler, to be battled later): "The use of a slow extraction would further contribute to simplifying the target design. The beam extraction would need to be interlocked with the magnet currents in the dedicated transfer line, to prevent damage to the target in case of failure of the beam defocusing or beam sweeper." Line 216-217 "Such a dilution may also allow the use of water cooling for the target." - It is not strictly true that it is only the dilution that allows water cooling, so this is too strong. Clearly the reasoning here is that the heat transfer is slow so by distributing the heat deposit in time and space, it's possible to have a larger contact "surface" (area X time)? And, the amont of energy that a quantity of water can take is limited not to create violent expansions. However, there are several ways to achieve this so, while dilution of some sort is for sure needed for the reasons given earlier, we just change the wording of the sentence above to something like: "The extraction of the deposited beam energy in the proposed configuration of the target and hadron absorber may be achieved by water cooling". Call me if you have some questions/objections. HANS: ===== Title: "Proposal to search for Heavy Neutral Leptons at the SPS" Expression of Interest 10: we talk about "sensitivity" in combination with 4-orders, which is what we avoided in Section 6. But I have no alternative but to reduce to 2-orders. Maybe leave it, a little white lie for PR? 38-46: Very strange in this place. We have not yet given any details on HNL production/decay, but here we give a lot of details on other exotics. Two possibilities: 1) remove most of this text, i.e. just keep the first sentence (38-39), and then: see ref [9-12] for more detailed discussions. 2) Or we should displace this section way back "again". Such detail in this place distracts the attention of the reader to what we are really interested in. Also: we actually have not done the associated work to see if we have any sensitivity (improvement) at all. Also: we argue that HNLs solve outstanding problem, and that the SM does not require an extra mass-scale etc.. Here we talk about stuff which we actually argue nature does not need at all. Fig.6 Y-axis "pot", first mention of this abbreviation, not defined. Should in fact be pp Pythia events, which is defined in the caption. 324: Remove "used as a" 326: "The charged... interactions" Incorrect, not only for the upstream decay volume, but for both. Replace sentence by: These stations could also serve to detect neutrino interactions in the material upstream of the decay vessels. 327: "The veto ... detector" Also incorrect, since we now changed Fig.9 to have a separate Muon-ID station after each muon-filter. Let the referees come up with the suggestion to combine this . Remove, and add after "muon detector" in line 325: "which consists of an iron wall followed by a tracking station" 426,429: As suggested by Daniel, we now added tau for every U^2. But, this \tau is last used/defined in Fig.2, which is longgg ago. Suggest to add in line 421, after HNLs: "with lifetime $\tau$ 475: Note that we also need to interest other labs/institutes, this actually sounds as if we do not need anybody. Replace "The det .. years", with "A more ambitious aperture would improve the sensitivity." 475-477: I find the balance between experiment/beamline lopsided. It reads as if we can design/built the experiment in an afternoon, while we need a new CERN department for the beam-line. I suggest to down-scale the beam stuff, hence replace it all by: "The beam extraction and beam target, as well as the radiological aspects, are being actively discussed with machine experts." 488, add: Thanks go to E.~van~Herwijnen for setting up our web site\cite{http://snoopy.web.cern.ch/snoopy/}. Cheers, Hans. PS. I contatced "my" institutes, i.e. Antonio/Nikhef, Mariusz/Krakow, Gary Barker/Warwick They promised to get back to me next week, and 2 already made appointments with the director of their institutes to give their statement more weight. WALTER: ======= If I add \usepackage{hyperref} the whole thing breaks. (latex goes into error) I don't know the workaround for this. Jaap On 3/10/13 3:12 PM, Walter Bonivento wrote: > HI > I can help. yes > but what I propose is just to make sure that when you click [13] in the > text you are brought to the line in the references section which contain > the reference. > I am not proposing to link the papers as we do in LHCb. > I think it is much easier (i did it some time ago but I forgot how) > w Nico ==== line 14: "The proposed detector will reconstruct exclusive HNL decays and, in contrast to previous experiments, will be able to measure the HNL mass." As far as I understand this is strictly speaking not entirely correct, as some experiments ( peak searches) had a potential to measure the mass of HNL ( below K mass although). We could rephrase as : "The proposed detector will reconstruct exclusive HNL decays and, in contrast to previous fixed target experiments, will be able to measure the HNL mass." line 24: "This discovery implies that the Landau pole in the Higgs self-interaction is well above the quantum gravity scale MPl %@ 1019 GeV (see, e.g. Ref. [4])." It might be that not everybody in the SPSC committee knows what is Landau pole. Proposal: "This discovery implies that the Standard model is well defined till the quantum gravity scale ( the Landau pole in the Higgs self-interaction is located well above MPl 1019 GeV, see, e.g. Ref. [4])." line 96: "mass difference" is mentioned before for active neutrinos, here might be confusing for people not familiar with the model. I suggest to say just "any masses" line 98: "the most interesting" may sound subjective. What about : " From several points of view, the most interesting variant of this model is the †íMSM, that allows to explain all three beyond the SM phenomena (neutrinos masses, baryon asymmetry and Dark matter) at the same time and preserving the property of the Standard model" line 102: "the reduced number of parameters ..." might be not clear. How about reshuffling the sentences in the following way: In this model, the lightest singlet fermion, N1, has a very weak mixing with the other leptons and can be sufficiently stable to be a dark matter candidate. This particle could be detected by searching for a narrow line in the X-ray spectrum coming from radiative decays N1 ‘¡ú †í†ã (for a review see Ref. [26]). The lightest singlet N1 then does not play any significant role in active-neutrino mass generation. This results in the further requirement that N2,3 be almost degenerate in mass to enhance CP violation to the level sufficient to explain the baryon asymmetry. line 471: It was pointed out to me that "new weakly interacting particles" might be confused with electro-weak or with other kind of dark matter searched by LHC for instance. As far as I understand sometimes the phrasing "feeble interacting" or "extremely feeble interactions" is used to mean interacting weaker than neutrinos. Here are some extra comments from Oleg, Alexey and myself (see also related comments from Nico): 13: achievable in a few years of data taking -> take it away or replace by: achievable in 3-5 years of data taking 14: take away " in contrast to previous experiments", or see Nico 121: sterile -> HNL (we have to take away the word "sterile" everywhere except eV scale N!) 471: weakly -> very weakly, or feeble, in order not to confuse with standard weak interactions , or see Nico p.1 Title ... Search for heavy neutral leptons ---> Search for heavy neutral leptons at CERN or Search for heavy neutral leptons with SPS [Why no signs of SNOOPY ?] p.2, third paragraph. Dima: the search for which is the focus of the present proposal. --- > the search for which is the focus of the present proposal. The recent theory developments provide a guideline for a required experimental sensitivity [44]. The experimental signatures of the existence of these particles and estimates of power, position and scale of the experiment of beam-target type required to fully investigate the model parameter space for relevant for this proposal heavy leptons lighter than D-mesons were done in Ref.,\cite{original-proposal}. \bibitem{original-proposal} D.~Gorbunov and M.~Shaposhnikov, ``Search for GeV-scale sterile neutrinos responsible for active neutrino masses and baryon asymmetry of the Universe'', Proposal submitted to European Strategy Group, 2012; %\bibitem{Gninenko:2013tk} S.~N.~Gninenko, D.~S.~Gorbunov and M.~E.~Shaposhnikov, %``Search for GeV-scale sterile neutrinos responsible for active neutrino oscillations and baryon asymmetry of the Universe,'' Adv.\ High Energy Phys.\ {\bf 2012} (2012) 718259 [arXiv:1301.5516 [hep-ph]]. %%CITATION = ARXIV:1301.5516;%% Dima with slight modification (MS): the search for which is the focus of the present proposal. --- > the search for which is the focus of the present proposal. The recent theory developments provide a guideline for a required experimental sensitivity [44]. The preliminary studies of the experimental signatures of the existence of these particles and estimates of power, position and scale of the experiment of beam-target type required to fully investigate the model parameter space for relevant for this proposal heavy leptons lighter than D-mesons were done in Ref.,\cite{original-proposal}. \bibitem{original-proposal} D.~Gorbunov and M.~Shaposhnikov, ``Search for GeV-scale sterile neutrinos responsible for active neutrino masses and baryon asymmetry of the Universe'', Proposal submitted to European Strategy Group, 2012; %\bibitem{Gninenko:2013tk} S.~N.~Gninenko, D.~S.~Gorbunov and M.~E.~Shaposhnikov, %``Search for GeV-scale sterile neutrinos responsible for active neutrino oscillations and baryon asymmetry of the Universe,'' Adv.\ High Energy Phys.\ {\bf 2012} (2012) 718259 [arXiv:1301.5516 [hep-ph]]. %%CITATION = ARXIV:1301.5516;%% p.2 fourth paragraph ``In one generic class of these models [9], the exotic particle is created in flavour changing neutral-current processes, D ! ?X, followed by a decay to a pair of leptons, X ! l+l’¡Ý. Examples of such exotic particles are R-parity violating neutralinos [10], bulk singlet neutrinos in extra-dimension models [11] and Unparticles [12]. In models with non-universal couplings to the quarks, the production will not suffer from GIM suppression and the sensitivity (if mX < mD, where mD is the D-meson mass) will be much better than that obtained from B ! Kl+l’¡Ý decays. `` To make this correct from the theory point, this should be replaced by: ---> Examples of such exotic particles are light massive paraphotons [9], light sgoldstinos \cite{Gorbunov:2000th} and R-parity violating neutralinos [10] in supersymmetric models, bulk singlet neutrinos in models with extra-dimensions [11], singlet neutrinos with dipole transition moments \cite{Gninenko:2009ks}, unparticles [12], etc. [I don't insist on light inflaton] %\cite{Gorbunov:2000th} \bibitem{Gorbunov:2000th} D.~S.~Gorbunov, %``Light sgoldstino: Precision measurements versus collider searches,'' Nucl.\ Phys.\ B {\bf 602} (2001) 213 [hep-ph/0007325]. %%CITATION = HEP-PH/0007325;%% %\cite{Gninenko:2009ks} \bibitem{Gninenko:2009ks} S.~N.~Gninenko, %``The MiniBooNE anomaly and heavy neutrino decay,'' Phys.\ Rev.\ Lett.\ {\bf 103} (2009) 241802 [arXiv:0902.3802 [hep-ph]], %%CITATION = ARXIV:0902.3802;%% S.~N.~Gninenko and D.~S.~Gorbunov, %``The MiniBooNE anomaly, the decay $D^{+}_{s} \to \mu^{+}\nu_{\mu}$ and heavy sterile neutrino,'' Phys.\ Rev.\ D {\bf 81} (2010) 075013 [arXiv:0907.4666 [hep-ph]]; %%CITATION = ARXIV:0907.4666;%%