Searching Peaks from histogram; not detecting all the peaks


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Hello
I am trying to find all the peaks from the histogram, which should return at least 3 peaks. However the code i wrote only returns 2. Here is the code:

void analysis(int run)
{
    
TH1F *QzHst = new TH1F("PedHst","",4096,0,4096);
TH1F *LYSOHst = new TH1F("PedHst","",4096,0,4096);

TFile *f = new TFile(Form("run_%d.root",run),"READ");
TTree *t=(TTree*)f->Get("dataTree");

Int_t nentries=(Int_t)t->GetEntries();
cout<<nentries<<endl;

Int_t Event;
Int_t QuartzChn;
Int_t TrRightChn;
Int_t TrLeftChn;
Int_t LYSOChn;
Float_t t1;
Int_t t2;
Int_t OR;

unsigned short_t i;
 t->Show(10);
 t->SetBranchAddress("Event",&Event);
 t->SetBranchAddress("QuartzChn",&QuartzChn); 
 t->SetBranchAddress("TrRightChn",&TrRightChn);
 t->SetBranchAddress("TrLeftChn",&TrLeftChn); 
 t->SetBranchAddress("LYSOChn",&LYSOChn);
 t->SetBranchAddress("t1",&t1); 
 t->SetBranchAddress("t2",&t2);
 t->SetBranchAddress("OR",&OR);

 for (i=0;i<nentries;i++){
   t->GetEntry(i);
   QzHst->Fill(QuartzChn);
   LYSOHst->Fill(LYSOChn);
}

TCanvas *c1 = new TCanvas();
 QzHst->SetLineColor(2);//red
  QzHst->Draw();
  c1->SetLogy();
  c1->SaveAs("testgraph1.jpg");

TCanvas *c2 = new TCanvas(); 
 LYSOHst->SetLineColor(4);//blue
 // LYSOHst->Fit("gaus","","M",0,500);
  // LYSOHst->Draw("SAME");
  LYSOHst->Draw();
  c2->SetLogy();
  c2->SaveAs("testgraph2.jpg");

  //Search for peaks
   TSpectrum *s=new TSpectrum();
   Int_t nfound=s->Search(LYSOHst);
   cout<<nfound<<endl;
   TH1 *hb= s->Background(LYSOHst);
   if(hb) c2->Update();
  c2->SaveAs("testgraph22.jpg");


}

what could i do to detect more peaks?
Thank you for reading.

You can try to play around with TSpectrum::Search parameters, sigma and threshold:
https://root.cern.ch/root/html534/TSpectrum.html#TSpectrum:Search

There is example here:

https://root.cern/doc/master/peaks_8C.html

https://root.cern/doc/master/peaks2_8C.html

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