3.6.3_DSSD_Multiplicity

分类：¶

只考虑x/y侧不大于4重的事件; xx和yy互换的事件计入同一类。即将如下两类事件视为一类2.b

(xe[0]+xe[1]=ye[0] && |xx[0]-xx[1]|=1); xe[2]=ye[1]
(ye[0]+ye[1]=xe[0] && |yy[0]-yy[1]|=1); ye[2]=xe[1]
2.a: xe[0]=ye[0]; xe[1]=ye[1]
- 47, 78, 102, 123, 161, 255, 277, 284, 293, 343, 362, 367, 382,
- 613, 639, 687, 720, 789, 858, 891, 902, 904, 964,
2.b: (xe[0]+xe[1]=ye[0] && |xx[0]-xx[1]|=1); xe[2]=ye[1]
- 42, 130, 171, 265, 425, 429, 593, 610, 695, 739, 912
2.c: (xe[0]+xe[1]=ye[0] && |xx[0]-xx[1]|$\neq$1)
- 718
2.d: (xe[0]+xe[1]=ye[0] && |xx[0]-xx[1]|=1); (xe[2]+xe[3]=ye[1] && |xx[2]-xx[3]|=1)
- 670
2.e: (xe[0]+xe[1]=ye[0]+ye[1] && |xx[0]-xx[1]|$\neq$1 && |yy[0]-yy[1]|=1)
- 864,
3.a: xe[0]=ye[0]; xe[1]=ye[1]; xe[2]=ye[2]
- 115, 175, 188, 376, 539, 684, 728, 982, 388, 419, 519,
3.b: xe[0]=ye[0]; xe[1]=ye[1]; (xe[2]+xe[3]=ye[2] && |xx[2]-xx[3]|=1)
- 187, 994,
4.a: xe[0]=ye[0]; xe[1]=ye[1]; xe[2]=ye[2]; xe[3]=ye[3]
- 517,

代码思路：¶

优先将x-y两侧能量匹配的位置考虑为一个粒子入射。
- 剩余事件类型：
  - 1. (xe[0]+xe[1]=ye[0] && |xx[0]-xx[1]|=1)
  - 1. (xe[0]+xe[1]=ye[0] && |xx[0]-xx[1]|=1); (xe[2]+xe[3]=ye[1] && |xx[2]-xx[3]|=1)
  - 1. (xe[0]+xe[1]=ye[0] && |xx[0]-xx[1]|$\neq$1)
  - 1. (xe[0]+xe[1]=ye[0]+ye[1] && |xx[0]-xx[1]|$\neq$1 && |yy[0]-yy[1]|=1)
处理剩余事件
- 有能量共享的相邻条(i,i+1)的位置记录为(i+0.5)

多重性处理代码¶

前期处理
- 修正幅度偏置，将x-y能量的关联范围内的多粒子事件存入文件。

输入文件事件结构

Int_t  dx1hit;      //multiplicity
Int_t  dx1[dx1hit];  //Strip 
Double_t  dx1e[x1hit]; //energy

Int_t  dy1hit;
Int_t  dy1[dy1hit];
Double_t  dy1e[dy1hit];

处理代码

...

//variables for TTree Branch
Int_t hit1;
Double_t e1[hit1];
Double_t x1[hit1]; 
Double_t y1[hit1];
Long64_t entry;  //for consistency check.


//new root file & new tree
TFile *fout = new TFile("event_DSSD.root","recreate");
TTree *tout = new TTree("tree","tree");
...

//event loops in input tree.
for(Long64_t jentry=0; jentry<nentries; jentry++) {
    tree->GetEntry(jentry);

    if(d1xhit>4 || d1yhit>4) continue;
    entry = jentry;

    //unmatched events
    map<int,double> mxe, mye;    //strip, energy
    //matched events
    vector<double> vx,vy;
    vector<double> ve;

    //dssd1
    for(int i=0; i<d1xhit; i++) {
        for(int j=0; j<d1yhit; j++) {
            double de = (dx1e[i]-dy1e[j]);
            //unmatched events
            if( de < -20 || de > 22+0.004*dx1e[i]) {
                mxe.insert(make_pair(dx1[i],dx1e[i]));
                mye.insert(make_pair(dy1[j],dy1e[j]));
             }
            //mathed events
             else {
                vx.push_back(dx1[i]);
                vy.push_back(dy1[i]);
                ve.push_back(dx1e[i]);
                break;
             }
        }
    }

  // Handle events that have not been matched yet
  // mxe,mye -> vx,vy,ve
    ...


   hit1 = vx.size();
   for(int i=0; i<hit1; i++) {
       x1[i] = vx[i];
       y1[i] = vy[i];
       e1[i] = ve[i];
   }
   //dssd2
    ...
   //dssd3
   ...
   tout->Fill();
}
tout->Write();
fout->Close();

3.6.3 DSSD多重性事件分析代码¶

分类：¶

代码思路：¶

多重性处理代码¶