G4 does not generate hits inside my sensitive volume

Dear Geant4 forum,

I need your help!

I’m gone mad,
because I’ve tried plenty of variations why G4 might not generate any hit inside my sensitive volume. It seems like undefined behaviour from G4’s side. So, the G4 is integrated with my experiment’s official software framework and there I’ve already built my detector’s full geometry. My detector based on multi-gap resistive plate chambers, meaning that it consists a lot of layers and between them there are tiny gaps filled with gas. In the following I’m describing the hierarchy of my detector:

  1. I have a large aluminium box filled with gas mixture and consists of 18 detectors based on mRPC. It’s mother volume is worldVolume which is the experimental hall of NA61 experiment.
  2. Then there is also large box but the material of this is gas mixture and it’s mother volume is aluminium box.
  3. Then there are 18 detectors “virtual”, material is also gas mixture, I made them up because in this way it would be easier to calculate the positions of strips (inside these mRPCs) relative to the detector’s coordinate system, rather than relative to box’s coordinate system. 6 out of 18 are large in size and the rest are small. The mother volumes of these “virtual” detectors is box described in section 2.
  4. Inside these “virtual” detectors there are plenty of layers and more importantly, in the center of “virtual” detector there are 48 strips which basically are sensitive volumes of my entire detector system. So, these layers and strips’s mother volumes is “virtual” detector.

In total, there are 864 strips, each of them is sensitive. I precisely need to collect hits from these strips.

I’ve tried to set the box described in section 2 as a sensitive volume (set its thickness exactly as strips and same material) with default production cut. In this case, I see plenty of hits inside my detector. So in this way, it turns out that the thickness of the sensitive volume, material of the sensitive volume, production cut value, physics list are not problem at all.

The mother-daughter volume philosophy is strictly respected in my code.

I have no idea what’s wrong ?! Any help and suggestions would be very appreciated!

I’m attaching my Geant4 code. There are bit of ShineOffline (experiment’s official framework) interface methods, other than that, the rest of the code is classic G4 code which builds the geometry.

The code compiles and runs successfully.
G4MRPC.cc (14.2 KB)