Addition and convolution: decay function pdfs with optional B physics effects (mixing and CP violation) that can be analytically convolved with e.g. Gaussian resolution functions
pdf1 = decay(t,tau) (x) delta(t)
pdf2 = decay(t,tau) (x) gauss(t,m,s)
pdf3 = decay(t,tau) (x) (f*gauss1(t,m1,s1) + (1-f)*gauss2(t,m1,s1))
Author: Clemens Lange, Wouter Verkerke (C++ version)
This notebook tutorial was automatically generated with ROOTBOOK-izer from the macro found in the ROOT repository on Tuesday, March 19, 2024 at 07:15 PM.
import ROOT
Variables of decay pdf
dt = ROOT.RooRealVar("dt", "dt", -10, 10)
tau = ROOT.RooRealVar("tau", "tau", 1.548)
Build a truth resolution model (delta function)
tm = ROOT.RooTruthModel("tm", "truth model", dt)
Construct decay(t) (x) delta(t)
decay_tm = ROOT.RooDecay("decay_tm", "decay", dt, tau, tm, type="DoubleSided")
Plot pdf (dashed)
frame = dt.frame(Title="Bdecay (x) resolution")
decay_tm.plotOn(frame, LineStyle="--")
<cppyy.gbl.RooPlot object at 0x92f03a0>
Build a gaussian resolution model
bias1 = ROOT.RooRealVar("bias1", "bias1", 0)
sigma1 = ROOT.RooRealVar("sigma1", "sigma1", 1)
gm1 = ROOT.RooGaussModel("gm1", "gauss model 1", dt, bias1, sigma1)
Construct decay(t) (x) gauss1(t)
decay_gm1 = ROOT.RooDecay("decay_gm1", "decay", dt, tau, gm1, type="DoubleSided")
Plot pdf
decay_gm1.plotOn(frame)
<cppyy.gbl.RooPlot object at 0x92f03a0>
Build another gaussian resolution model
bias2 = ROOT.RooRealVar("bias2", "bias2", 0)
sigma2 = ROOT.RooRealVar("sigma2", "sigma2", 5)
gm2 = ROOT.RooGaussModel("gm2", "gauss model 2", dt, bias2, sigma2)
Build a composite resolution model fgm1+(1-f)gm2
gm1frac = ROOT.RooRealVar("gm1frac", "fraction of gm1", 0.5)
gmsum = ROOT.RooAddModel("gmsum", "sum of gm1 and gm2", [gm1, gm2], [gm1frac])
Construct decay(t) (x) (fgm1 + (1-f)gm2)
decay_gmsum = ROOT.RooDecay("decay_gmsum", "decay", dt, tau, gmsum, ROOT.RooDecay.DoubleSided)
Plot pdf (red)
decay_gmsum.plotOn(frame, LineColor="r")
<cppyy.gbl.RooPlot object at 0x92f03a0>
Draw all frames on canvas
c = ROOT.TCanvas("rf209_anaconv", "rf209_anaconv", 600, 600)
ROOT.gPad.SetLeftMargin(0.15)
frame.GetYaxis().SetTitleOffset(1.6)
frame.Draw()
c.SaveAs("rf209_anaconv.png")
Info in <TCanvas::Print>: png file rf209_anaconv.png has been created
Draw all canvases
from ROOT import gROOT
gROOT.GetListOfCanvases().Draw()