namespace Smear {…}

1. namespace Smear {…} Michael Savastio

2. Tree Format 1 to 1 1 to 1 1 to 1 Currently ParticleS stores E, p, theta, phi, pz, pTONLY!

3. The Device Class Smears exactly 1 particle-wise variable (E,p,theta,phi,pz,pT) using up to 2 of these variables to parametrize the smearing. Each device has it’s own “acceptance” in (E,p,theta,phi) space. Particles passing through here will have smeared p and theta Particles passing through here will have smeared E only E p p P Theta These particles will be smeared only by “innermost” (last added) device IP EventS E Will output only 1 EventS with only 1 instance of each particle. phi

4. Building a “Detector” (1) DeviceEMCal_front; EMCal_front.SetGenre(1); //this detects photons/leptons EMCal_front.SetSmearedKinematics(kE); //set kinematics to be smeared by device EMCal_front.SetParametrization("0.18*sqrt(E)"); //set parametrization EMCal_front.Accept.SetTheta(0.,pi/4.); //set acceptance in theta //similarly, you can do SetAcceptPhi(min,max), SetAcceptE(min,max) and SetAcceptP(min,max) DeviceEMCal_back; EMCal_back.SetGenre(1); EMCal_back.SetSmearedKinematics(kE); EMCal_back.SetParametrization("0.25*sqrt(E)"); EMCal_back.Accept.SetTheta(3.*pi/4.,pi); //set acceptance in theta DeviceHCal; HCal.SetGenre(2); //this detects hadrons HCal.SetSmearedKinematics(kE); HCal.SetParametrization("0.35*sqrt(E)");

5. Building a “Detector” (2) DeviceThetaD; //by default devices don't care whether hadron/lepton/gauge boson ThetaD.SetSmearedKinematics(kTheta); ThetaD.SetParametrization(”sqrt(9.e-8+pow(9.e-4/P,2))/sqrt(sin(theta))"); //can use 2d parametrizations Device Tracker; Tracker.SetSmearedKinematics(kP); Tracker.SetParametrization("0.0085*P+0.0025*P*P"); Detector Test; Test.AddDevice(EMCal_front); //add the EMCal to the detector Test.AddDevice(EMCal_back); Test.AddDevice(HCal); Test.AddDevice(ThetaD); Test.AddDevice(Tracker); Test.SetPID(true); //turn on PID (still limited but works!) Test.SetEventKinematicsCalculator("NM JB DA"); //set how to calculate event kinematcs. Can use scattered electron (null momentum approximation NM), Jacquet-Blondel or Double Angle. Now in root: gSystem->Load(“BuildTree.so”); .L MyDetector.cxx SmearTree(MyDetector(),”filename”) To view in interpreter, for example: TTree t; t.AddFriend(“EICTree”,”originaltree.root”) t.AddFriend(“Smeared”,”smearedtree.smear.root”) t.Draw(“EICTree.x:Smeared.x”,”EICTree.QSquared>10”)

6. Currently Available Smear::Detector Setups All with default 4*pi acceptance.

7. E Pythia 20x250 ZEUS ZEUS STAR STAR

8. p Pythia 20x250 ZEUS ZEUS STAR STAR

9. θ Pythia 20x250 ZEUS ZEUS STAR STAR

10. Event-Wise Kinematics Pythia 20x250 ZEUS STAR Methods Available: NM (using scattered electron in the Null Momentum approximation) JB (Jacquet-Blondel, using hadronic system) DA (Double Angle, using hadronic system)

11. Particle ID π+ π- PID not Generated: Momentum outside range of validity p+ K+ K- unidentified Based on HERMES RICH P-matrices (shown on grid above)

12. TO DO • Thoroughly test event-wise kinematics (NM, JB and DA). Determine appropriate phasespace cuts. • Fix anomalous (but very minor) stability issues. These may be CINT memory management issues. • Overhaul PID to be far more flexible. Currently based on HERMES RICH format. Software-wise, this is the most labor intensive remaining task. • Improvements and testing for exception handling (especially with limited acceptance). Make more educated decisions about default conventions. • Gather parametrizations (help welcome!). • Electron bremsstrahlung

13. UPDATE • Event Kinematics are fixed, all methods now work reliably (using scattered electron, or hadronic system). • Improved exception handling, especially for event kinematics. • Particle ID has been completely rewritten and is now much more versatile. • Specialized “Devices” (tracking, calorimetry). • Arbitrary acceptance cuts. • Acceptance of specific particles. • Smearing of arbitrary functions of particle kinematics. • Many improvements to make scripting simpler.

14. Building a “Detector” (Update,1) EMCalorimeterEMCal(0.18); EMCal.Accept.SetTheta(0.,pi/4.); //set acceptance in theta EMCal.Accept.AddZone(); EMCal.Accept.SetTheta(3.*pi/4.,pi,1); //similarly, you can do Accept.SetPhi(min,max), Accept.SetE(min,max) and Accept.SetP(min,max) HCalorimeterHCal(0.35); //this has parametrization “0.35*sqrt(E)” DeviceThetaD(kTheta,”sqrt(9.e-8+pow(9.e-4/P,2))/sqrt(sin(theta))”); Device Tracking(kP,”0.001*P+0.001*P*P”); ParticleIDIdent(“Pmatrixfile.dat”); Ident.GetAcceptanceFromDevice(EMCal); //ParticleID is now declared like a device, and has its own acceptance. You can use arbitrarily many. Detector Example; Example = Example << EMCal << HCal << ThetaD << Tracking << Ident; Example = Example << “NM JB DA”; //use all 3 event methods

15. Some New Features Devious Arbitrary(“1./P”,”0.0085*P+0.0025*P*P”); //the Devious class allows you to smear a function of kinematics. This smears 1/p Arbitrary.Accept.SetPt(0.,50.); //this cut requires p_{T}\in[0,50] GeV Arbitrary.Accept.AddCustomAcceptance(“P*sin(theta)”,0.,50.); //equivalent to the above Arbitrary.Accept.AddParticle(321); //now this accepts K^+ ONLY Arbitrary.Accept.AddParticle(-321); //now it accepts K^+ and K^- only Tracker Track; Track.SetRadii(0.01,3.); //this is a tracker with inner radius 1cm, outer radius 3m Track.SetLength(6.); //and length 6m Track.SetDimensions(0.01,2.,6.); //this is equivalent to the above two lines Device CrazyExample(kE,”0.01*E”); CrazyExample.SetDistribution("pow(sin([1]*x+[0]),2)"); //smears according to arbitrary distribution. [0] is original value of E and [1] is given by parametrization. Example = Example << Arbitrary << Track; Now with extensive documentation: https://wiki.bnl.gov/eic/index.php/Namespace_Smear

16. Event Kinematics: Proof of Concept

17. x STAR 20x100

18. Q2 STAR 20x100

19. Why it’s so screwed up STAR 20x100 Smearing goes as p2

20. What Now? • Where does Smearing end and GEANT begin? • What can Smear be used for, what can it not be used for? • From now on, code will be maintained by Thomas Burton.