I appreciate reading your idea of building a detector that is transportable to locations. As an individual who has been involved in the LBNE for the LAr near detector work, I do appreciate the challenges in bringing the known technology up another level.
The ICARUS 300 ton modules were made transportable on truck beds. The 300 ton modules can be the limit or closed to the limit of what we can build to be transportable on surface roads. There will be then as many as 20 of these standalone modules to have the 6 kton mass. On the other hand, if one were to build a single 6 kton or more unit on a site, there will not be any reason to move it again.
If then we explore the idea of a water or sea vessel as the detector, we can imagine the difficulties and the cost of operating in the very different environment. But some studies will be helpful extending this idea further.
To be able to build and have the detector operational in a few years is also important to everyone in the field.
I agree with most of Jenny’s observations, mainly that it would be premature to decide definitively on the LBNE beam, at least until we know theta13 much better than we do now. However, I disagree with her statement “by augmenting NOvA with 10 kT of LAr, we would know the Mass Hierarchy”. The Mass Hierarchy is very difficult at 735 kilometers. In my note for the LBNE physics working group, LBNE-docDB 3751-v3, I compare the NuMI beam, at both Ash River and Soudan, with LBNE/DUSEL. What is shown is that these two sites are comparable to DUSEL for nu oscillation measurements, except for Mass Hierarchy. Similar considerations suggest that it is also premature to make a decision between water Cerenkov and LAr detectors at this time.
Jack is right that in the unlucky case that the dCP effects and matter effects cancel a single narrow-band experiment at intermediate baseline has difficulty resolving the neutrino mass hierarchy. This can be mitigated, however, by an additional experiment operating at the first oscillation maximum with considerably shorter baseline and hence less matter effect. This is an experimental setup we are close to realizing with the combination of NOvA and T2K and its reasonable to ask how far that existing program can be pushed.
I appreciate reading your idea of building a detector that is transportable to locations. As an individual who has been involved in the LBNE for the LAr near detector work, I do appreciate the challenges in bringing the known technology up another level.
The ICARUS 300 ton modules were made transportable on truck beds. The 300 ton modules can be the limit or closed to the limit of what we can build to be transportable on surface roads. There will be then as many as 20 of these standalone modules to have the 6 kton mass. On the other hand, if one were to build a single 6 kton or more unit on a site, there will not be any reason to move it again.
If then we explore the idea of a water or sea vessel as the detector, we can imagine the difficulties and the cost of operating in the very different environment. But some studies will be helpful extending this idea further.
To be able to build and have the detector operational in a few years is also important to everyone in the field.
I agree with most of Jenny’s observations, mainly that it would be premature to decide definitively on the LBNE beam, at least until we know theta13 much better than we do now. However, I disagree with her statement “by augmenting NOvA with 10 kT of LAr, we would know the Mass Hierarchy”. The Mass Hierarchy is very difficult at 735 kilometers. In my note for the LBNE physics working group, LBNE-docDB 3751-v3, I compare the NuMI beam, at both Ash River and Soudan, with LBNE/DUSEL. What is shown is that these two sites are comparable to DUSEL for nu oscillation measurements, except for Mass Hierarchy. Similar considerations suggest that it is also premature to make a decision between water Cerenkov and LAr detectors at this time.
Jack is right that in the unlucky case that the dCP effects and matter effects cancel a single narrow-band experiment at intermediate baseline has difficulty resolving the neutrino mass hierarchy. This can be mitigated, however, by an additional experiment operating at the first oscillation maximum with considerably shorter baseline and hence less matter effect. This is an experimental setup we are close to realizing with the combination of NOvA and T2K and its reasonable to ask how far that existing program can be pushed.