User Tools

Site Tools


====== John Beacom Comments ON VERSION 3.1====== {{:annie_whitepaper_v3.1.pdf|WHITEPAPER VER 3.1}}\\ [[wpedits|< Back to white paper edits page]] Overall, the white paper is shaping up well. Here I provide some comments for your consideration. Use, change, or ignore these as you see fit; no explanations are needed. I first mention an article about proposals that I have found helpful. There are three key arguments that need to be tightly written and prominently placed and repeatedly stressed. These are Importance (why must this question be answered?), Feasibility (why can it be answered?), and Efficiency (why is this the best way to answer it?). In this case, here are some points that come to mind. There are surely more. You probably want to check for what I missed and then ask if a person picking up the proposal for the first time would immediately find your main points on a quick skim (obviously, they have to read it to get the details). Importance: Needed for proton decay, not well measured, expected yield is low enough that uncertainty matters. Feasibility: Can detect neutrons, can measure event energy, can contain neutrons (???), can control backgrounds. Efficiency: Can't rely on theory, must be done with an accelerator beam at this energy, must use a water target. ========================================================================================== Points are labeled by approximate line number. 1 It would be more logical to make the "A" stand for "Accelerator," because you aren't doing the experiment with atmospheric neutrinos like SK did. You aren't measuring anything _about_ atmospheric neutrinos; you are measuring a fundamental neutrino-nucleus interaction. 4 By funny coincidence, Eric Oberla grew up a house 50 m from where I live. I know his parents and got to know him that way. We talk a few times a year about physics he could do with the LAPPDs. It would be amusing to be a co-author with him, and it sounds like he is close to being involved. 26 The Executive Summary is pretty tight, but check the points about Importance, Feasibility, and Efficiency. A related point is that the neutrino-oxygen cross section _has never been measured_. The neutron yield has never been measured well, as you note later. 61 What really matters is separating neutrino-oxygen events from inverse beta events. Neutrino-electron events are easily separable by direction. The neutrino-oxygen events are much harder, and much more valuable. You should cite a paper on that topic. 65 I always say gadolinium-loaded; gadolinium-doped sounds negative. 132 I would leave out discussion of liquid scintillator detectors, as it just confuses your points. Neutrino-carbon cross sections have been measured, and so have neutron yields. Gadolinium in oil is old news; gadolinium in water is not. Your proposal is all about water. An oil-based detector could not do the job you need. 136 arises 141 water, not liquid 144 More precisely, neutrons undergo radiative capture. Gamma ray(s) are released because the final nucleus is more tightly bound than the initial state. The final states are usually stable. 175 If you show the SK figure, you have to highlight its shortcomings. Those error bars are small, so why is ANNIE needed? You have to highlight how big the systematic uncertainties are. I would probably put that in the figure as a vertical up-down arrow showing a factor of a few or whatever it is. You also have to quantify what uncertainty you need to improve proton decay measurements given the expected number of neutrons per event. 176 This is an absolutely key section to strengthen. I think you would do well to have a figure that shows something about the future of proton decay without or with your measurement. Maybe skip the SK figure entirely. One of your fundamental points is what to do if no neutrons are observed in a candidate proton-decay event. Maybe base a new figure around that, say something like probability of an event being background versus the expected number of neutrons per event. You can use the SK measurement to indicate that we know that this number is ~ 1 but that it is uncertain by a factor of a few or whatever; the reader could then see how much that matters. Probably you can make a better figure than what I described. You want something that makes it clear that: (A) we are wasting our time on HK, etc. unless we measure this yield, and (B) ANNIE can measure it well enough. 305 You should cite my DSNB review here. Ref. [9] has only a few sentences about the DSNB. 328 Again, what matters is separating neutrino-nucleus, not neutrino-electron. See the paper noted above. 382 Several misspellings of multiplicity near here. 483 Early on, it would be good to have a diagram of how detection works. Show a beam neutrino entering the detector, what is produced, and how it is detected. Also show the same for the difficulties, like neutron escape, backgrounds, etc. 504 Missing figure number. 522 Not clear how Table 2 differs from Table 1. 548 Missing table number. 745 In this section, provide some citations to the work done. 786 Use `` to get left-hand quotes. 917 Missing section number.

john_beacom_comments.txt · Last modified: 2014/12/18 23:00 by Matt Wetstein