DalitzGUI Visual Tool ===================== 0) Compilation: ############### In PandaRoot ------------ The tool is built/installed with PandaRoot. The executable is placed at your build or install directory ````:: /bin/DalitzGUI and the configuration & example files are at:: /share/DalitzGui Standalone ---------- Alternatively one can compile it standalone. ROOT has to be installed and setup properly (including ROOTSYS and LD_LIBRARY_PATH). Compile in the DalitzGui source directory with:: . ./compile.sh Run the tool with the executable:: ./DalitzGUI 1) User interface ################# Startup ------- A window will open witht the plots and interface. Use the ``File`` menu point to load or save a configuration file. Example configurations can be found in folder ``examples``. If compilation does not work try a newer ROOT version. For initialisation the file ``DalitzGUI.ini`` is read in, which contains the particle lists of final state particles and resonances. The file can be extended with more particles. If old saved configurations should be still working properly, the ID number of the particles have to be retained. Plots: ------ (going from top left to bottom right) .. image:: Images/DalitzGuiDemo.png Left: Depends of the choice of 'Plot' in the user interface; default = Dalitz Plot Choices are:: Dalitz : The Dalitz plot. Dalitz (scat) : The Dalitz plot as scatter plot (number of bins has impact on density). Dalitz In : Dalitz plot with incoherent sum of resonances (demonstrates interference). Dalitz Diff : Difference between incoherent and coherent sum (demonstrates interference). Dalitz Ph : exactly 2 active resonances, Relative phase between amplitudes. Else: Complex phase of tal amplitude. Proj s23 : Projection to m_23^2. Proj s31 : Projection to m_31^2. Proj s12 : Projection to m_12^2 (random generation from Dalitz plot). Mass m23 : Invariant mass distribution m_23; (random generation from projection s1). Mass m31 : Invariant mass distribution m_31; (random generation from projection s2). Mass m12 : Invariant mass distribution m_12; (random generation from projection s3). Phase s23 : Total/relative phase along coordinate s23 (for broades s31 slice of Dalitz plot). Phase s31 : Total/relative phase along coordinate s31 (for broades s23 slice of Dalitz plot). Right: The 3 projections of the Dalitz Plot and the incoherent sum of the amplitudes. Interface: ---------- :: File->Open/Save as : Load or save a configuration. Example configurations in folder 'examples'. File->Save canvas as : Save complete canvas as image (.gif, .png, .jpg) / pdf (.pdf) / root file(.ot) / root macro (.C) etc. File->Create Animated Gif : Allows to create an animated GIF of current plot by looping through one riable (M, A_i, or ph_i). Configuration: 'Loop over' variable, 'Range' to loop through, number of teps', 'time' between frames in units of 10ms, 'Main plot only' or full canvas. File->Exit : Quit program. M : Total energy sqrt(s) = M of the system; can be adjusted with slider or with text input. Auto : When checked all plots are resized automatically when M ist changed. m1, m2, m3 : The three final state masses (=particles) of the system. Plot : Plot to be shown in the big canvas (top left). Bins : Number of bins; higher = better but slower; max = 500. Color : Color or greyscale palette for 2D plots (for Dalitz Ph a special fixed palette is used). Log : Log scale switch (log z for 2D, log y for 1D; exceptions: 'Dalitz (scat)', 'Dalitz Ph'). Occ : Occupancy of random generated plots (Proj s12, Mass mxy, Dalitz (scat)). Default: 200; Range: 10 - 1000; Total number of random events filled in is bins*Occ. Configuration of the resonances R23, R13, R12 (two possible per coordinate):: R23, R13, R12 : Resonance(s). On : Switch on or off resonance. A : Amplitude A of complex coefficient A*exp(i*phi). ph : Phase phi of complex coefficient. **NOTE 1:** The resonances are not normalized according to their integral (width and angular distribution), just scaled by 1/sqrt(Gamma_0). I.e. usually broad resonances with spin 0 dominate narrow resonances with higher spins. When a resonance is switched on but is not visible, try to reduce the amplitudes (A) for broader resonances. **NOTE 2:** If the Dalitz plot turns completely emtpy for a certain configuration, the value sqtr(s) = M has to be increased. In case that only the phase space border appears, one of the chosen resonances cannot decay into the assigned final states. Either switch of that resonance or chose one with higher mass. Available resonances:: rho(770) omega(782) K*(892) f0(980) phi(1020) f2(1270) f0(1370) K0(1430) K2(1430) f0(1500) f2(1525) f0(1710) f2(1710) X(3872) Z(3900) Z(4430) Available final states:: gamma pi pi0 K K0 eta eta' J/psi chi_c1 hc psi' 1) Some example configurations ############################## Predefined configurations in the directory ``examples``:: default.cfg : The default initial configuration. demo.cfg : Some fancy looking (artificial) demo configuration. example_a.cfg ... example_e.cfg : Didactic set of examples; see below. rho_omega1.cfg : The rho-omega interference in pi+ pi- rho_omega2.cgf : Hypothetical configuration with non-destructive interference. z3900_rho_f980.cfg : Hypothetical scenario of pbarp-> J/psi pi+ pi- @ 5.5 GeV with contributions from Z(3900)+- -> J/psi pi+- and rho(770)/f0(980) -> pi+ pi- 4) Learning Curve ################# In the following are some interesting and didactic things to try to get started with the tool. a) Shape of accessible phasespace --------------------------------- (example_a.cfg) - Switch off all resonances - Enter different combinations of M (with slider) and m_i -> look, how the phasespace changes, from triangular, if all m_i = m_gamma, to almost circular, if M close to Sum(m_i) b) Angular distributions of resonances -------------------------------------- (example_b.cfg) - Set M=4. (large!), m_i = pi - Switch all resonances off except one: R23(s1) = K*(892) -> Take a look to Proj_s2: angular dirstribution of a J=1 resonance -> Try the same for J=0 (e.g. f0(1370)) and J=2 (e.g. f2(1270)) resonances c) Interference and projections ------------------------------- (example_c1.cfg, example_c2.cfg, example_c3.cfg) - Set M = 2. GeV - Resonances in R23: K*(892) and f0(1370), A(K*)=0.1, ph(K*)=0, A(f0)=1.0, ph(f0)=0.25 -> Look at proj_s1: two clearly visible peaks (example_c1.cfg) -> Look at proj_s2: four visible peaks; none of them corresponds to a resonance pole mass (reflections!) - Set ph(f2) slider to roughly 0.68 -> K*disappears completely (example_c2.cfg) -> even if you switch off the K*, almost no difference is visible -> K* only disappears in projection, in Dalitz plot the band is still visible (example_c3.cfg) - Move ph(f2) slider slowly between 0.0 ... 0.7 -> See the K* peak in proj_s2 moving. The peak position isn't strictly located at m_0 of the resonance d) Projections / fake peaks --------------------------- (example_d.cfg) - Set M = 2.66, m1 = m2 = m3 = pi - Resonance in R23 : f_2(1270), A=0.15, ph=0.15 ; f_2(1710), A=0.2, ph=0.2 - Resonance in R31 : f_0(1500), A=0.3, ph=0.6 - Resonance in R12 : f_2(1525), A=0.1, ph=0.1 -> Look at Proj s31: Six peaks are visible, where actually only one *dip* corresponds to a resonance in m31 (-> f0(1500)) e) Try to imitate D0 -> K+ pi- pi0 ---------------------------------- (example_e.cfg) - Set M = 1.85, m1 = pi, m2 = K, m3 = pi0 - Resonances in R23 : K*(892) (A=0.15/ph=0.4), K0(1430) (0.1/0.2) - Resonances in R31 : rho(770) (0.25/0.0) - Resonances in R12 : K*(892) (A=0.15/ph=0.9), K0(1430) (0.1/0.4) -> Look at 'Dalitz (scat)' (Occ = 0.15) -> Plot looks similar to the one in