Difference between Score and SensitiveDetector

Dear Geant4 experts,
When I statistic the deposited energy of alpha particle in water, I find there is different between “SensitiveDetector” and “Socre” methods.
In SensitiveDetector::ProcessHits(G4Step* step, G4TouchableHistory*)

Run* fRun = static_cast<Run*>(G4RunManager::GetRunManager()->GetNonConstCurrentRun());
    G4ThreeVector position = step->GetPreStepPoint()->GetPosition();
    G4double posZ = position.getZ();
    G4double edep = step->GetTotalEnergyDeposit();
    G4double weight = step->GetTrack()->GetWeight();
    fRun->AddEdep(posZ, edep*weight);
    return true;

In run.mac with score methods

/score/create/boxMesh mesh 
/score/mesh/boxSize 25 25 25 um  
/score/mesh/nBin 1 1 50
/score/mesh/translate/xyz 0 0 25 um  
/score/quantity/energyDeposit doseDep
/score/close 
...
/score/dumpAllQuantitiesToFile mesh edep.txt

The result is print here.


The result of ‘score’ methods is a smooth cure. Whlie there is a peak in the ‘sensitive’ methods.

Regards
Max