<div dir="ltr"><p style="margin:0px;font-size:12px;line-height:normal;font-family:helvetica">Yo peeps,</p>
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<p style="margin:0px;font-size:12px;line-height:normal;font-family:helvetica">A week from now, we will congregate to go over the paper: “Search for Majorana neutrinos near the inverted mass hierarchy region with KamLAND-Zen”</p>
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<p style="margin:0px;font-size:12px;line-height:normal;font-family:helvetica"><a href="http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.117.082503">http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.117.082503</a></p>
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<p style="margin:0px;font-size:12px;line-height:normal;font-family:helvetica"><span style="text-decoration:underline"><b>Some questions to consider are</b></span></p>
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<p style="margin:0px;font-size:12px;line-height:normal;font-family:helvetica">1) How can a detector measure a process with a half-life supposedly many orders of magnitude longer than the age of the universe?</p>
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<p style="margin:0px;font-size:12px;line-height:normal;font-family:helvetica">2) And why should we care about the neutrinoless double-beta decay (0vBB) half-life anyways?</p>
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<p style="margin:0px;font-size:12px;line-height:normal;font-family:helvetica">3) True or False - a positive measurement of 0vBB would necessarily confirm that: a) the neutrino is its own anti-particle, b) the neutrino is Majorana, c) lepton number is violated via physics beyond the standard model?</p>
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<p style="margin:0px;font-size:12px;line-height:normal;font-family:helvetica">4) What’s the significance of KamLAND-Zen probing into the edge of the “quasidegenerate” mass region?</p>
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<p style="margin:0px;font-size:12px;line-height:normal;font-family:helvetica">5) How do they distinguish potential 0vBB events from other events, such as: 2vBB, contamination/background, other exotic processes, etc?</p>
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<p style="margin:0px;font-size:12px;line-height:normal;font-family:helvetica"><span style="text-decoration:underline"><b>And some more specific discussion questions will be</b></span></p>
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<p style="margin:0px;font-size:12px;line-height:normal;font-family:helvetica">6) The authors speculate that “much of [the Ag-110m contaminant] settled to the bottom of the IB” (end of page 3), how could they test this hypothesis? Is splitting the phase 2 data into two periods, as defined by the Ag-110m lifetime, helpful to this analysis in that respect?</p>
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<p style="margin:0px;font-size:12px;line-height:normal;font-family:helvetica">7) Overall, with these results and the planned upgrades (mentioned in the conclusions), is it fair to conclude that KamLAND-Zen will be a competitive detector with a demonstrated ability to measure the hypothetical 0vBB?</p>
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<p style="margin:0px;font-size:12px;line-height:normal;font-family:helvetica">8) And if so, how does the conclusion of zero events measured (and hence only having <i>constraints</i> on the 0vBB half-life) fair for the outlook of future 0vBB work, in particular with respect to the quasidegenerate mass region and beyond.</p>
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<p style="margin:0px;font-size:12px;line-height:normal;font-family:helvetica"><span style="text-decoration:underline"><b>Also some jargon to help with your reading is</b></span> #PRLengthLimits</p>
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<p style="margin:0px;font-size:12px;line-height:normal;font-family:helvetica">* Ag-110m = a nuclear isomer (a metastable nuclear state in excitation - hence the “m”) of silver</p>
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<p style="margin:0px;font-size:12px;line-height:normal;font-family:helvetica">* quasidegenerate neutrino mass region = from neutrino oscillation experiments we can tell there must be a non-zero relative mass scale of the three neutrino mass eigenstates, and these fit into two hierarchies (the normal (NH) and inverted (IH)) which overlap at certain points referred to as quasidegenerate, where said 0vBB data would find NH and IH indistinguishable, see FIG 3 for a nice diagram of the current situation</p>
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<p style="margin:0px;font-size:12px;line-height:normal;font-family:helvetica">* nuclear matrix elements = theoretical calculations of the underlying nuclear physics of a process, for example using ab-initio many-body theory; which can predict half-lifes, given the masses of the constituents of said process are known, or visa versa (wink wink, nudge nudge, say no more)</p>
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<p style="margin:0px;font-size:12px;line-height:normal;font-family:helvetica">* spallation = the process of being broken apart into pieces upon impact, for example nuclear matter being spalled by high energy muons bouncing around</p>
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<p style="margin:0px;font-size:12px;line-height:normal;font-family:helvetica">See you then (another reminder will be sent)!</p><div><div class="gmail_signature"><div dir="ltr"><div><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div><br></div><div><br></div><div><br></div><div><span style="color:rgb(0,0,255);font-family:monospace,monospace;font-size:small">Charlie Payne</span><br></div><div dir="ltr"><p style="margin:0px"><font face="monospace, monospace" color="#0000ff" size="2">--------------------------------</font></p><p style="margin:0px"><font face="monospace, monospace" color="#0000ff" size="2">TRIUMF Office: MOB 115-4</font></p><p style="margin:0px"><font face="monospace, monospace" color="#0000ff" size="2">TRIUMF Phone: 604-222-1047x6166</font></p><p style="margin:0px"><font face="monospace, monospace" color="#0000ff" size="2">--------------------------------</font></p><p style="margin:0px"><font face="monospace, monospace" color="#0000ff" size="2">UBC Office: Hebb 1F-2</font></p><p style="margin:0px"><font face="monospace, monospace" color="#0000ff" size="2">UBC ID: 85886159</font></p><p style="margin:0px"><font face="monospace, monospace" color="#0000ff" size="2">--------------------------------</font><span style="color:rgb(0,0,255);font-family:monospace,monospace;font-size:small">---------------------------------</span></p><p style="margin:0px"><font face="monospace, monospace" color="#0000ff" size="2">Candidate: M.Sc. Physics, University of British Columbia</font></p><p style="margin:0px;min-height:14px"><font face="monospace, monospace" color="#0000ff" size="2">Awarded: B.Sc. Mathematical Physics, University of Waterloo</font></p></div></div></div></div></div></div></div></div></div></div></div></div></div></div></div>
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