def neut_eta():
#neutron pseudorapidity
etabin = 0.05
etamin = -20
etamax = 20
hEta = ut.prepare_TH1D("hEta", etabin, etamin, etamax)
can = ut.box_canvas()
particles = TClonesArray("TParticle", 200)
tree.SetBranchAddress("particles", particles)
nev = tree.GetEntriesFast()
#nev = 24
for iev in xrange(nev):
tree.GetEntry(iev)
for imc in xrange(particles.GetEntriesFast()):
part = particles.At(imc)
if part.GetPdgCode() != 2112: continue
hEta.Fill(part.Eta())
ut.put_yx_tit(hEta, "Events", "#eta", 1.4, 1.2)
hEta.Draw()
gPad.SetGrid()
gPad.SetLogy()
ut.invert_col(rt.gPad)
can.SaveAs("01fig.pdf")
def neut_en():
#neutron energy
ebin = 0.5
emin = 50
#emax = 200
emax = 1000
#ebin = 10
#emin = 500
#emax = 3000
hE = ut.prepare_TH1D("hE", ebin, emin, emax)
can = ut.box_canvas()
particles = TClonesArray("TParticle", 200)
tree.SetBranchAddress("particles", particles)
nev = tree.GetEntriesFast()
#nev = 24
for iev in xrange(nev):
tree.GetEntry(iev)
esum = 0.
for imc in xrange(particles.GetEntriesFast()):
part = particles.At(imc)
if part.GetPdgCode() != 2112: continue
esum += part.Energy()
hE.Fill(esum)
ut.put_yx_tit(hE, "Events", "E (GeV)", 1.4, 1.2)
hE.Draw()
gPad.SetGrid()
gPad.SetLogy()
ut.invert_col(rt.gPad)
can.SaveAs("01fig.pdf")
def neut_abs_eta():
#neutron absolute pseudorapidity
etabin = 0.05
etamin = 5
etamax = 20
hEta = ut.prepare_TH1D("hEta", etabin, etamin, etamax)
can = ut.box_canvas()
particles = TClonesArray("TParticle", 200)
tree.SetBranchAddress("particles", particles)
nev = tree.GetEntriesFast()
#nev = 24
for iev in xrange(nev):
tree.GetEntry(iev)
for imc in xrange(particles.GetEntriesFast()):
part = particles.At(imc)
if part.GetPdgCode() != 2112: continue
#hEta.Fill( TMath.Abs(part.Eta()) )
hEta.Fill(abs(part.Eta()))
ytit = "Events / {0:.2f}".format(etabin)
ut.put_yx_tit(hEta, ytit, "Neutron |#kern[0.3]{#eta}|", 1.4, 1.2)
ut.set_H1D_col(hEta, rt.kRed)
ut.set_margin_lbtr(gPad, 0.1, 0.09, 0.01, 0.02)
hEta.Draw()
gPad.SetGrid()
gPad.SetLogy()
ut.invert_col(rt.gPad)
can.SaveAs("01fig.pdf")
def read_particles():
#particles clones array
#tree.Print()
particles = TClonesArray("TParticle", 200)
tree.SetBranchAddress("particles", particles)
#nev = tree.GetEntriesFast()
nev = 12
for iev in xrange(nev):
tree.GetEntry(iev)
print iev
nmc = particles.GetEntriesFast()
for imc in xrange(nmc):
part = particles.At(imc)
print " ", imc, part.GetPdgCode(), part.Px(), part.Py(), part.Pz(
), part.Energy()
class STnOOnRead:
#_____________________________________________________________________________
def __init__(self, infile):
#energy in event at positive and negative rapidity
self.epos = 0.
self.eneg = 0.
#number of neutrons at positive and negative rapidity
self.npos = 0
self.nneg = 0
#flag for XnXn event
self.is_XnXn = False
#flag for central event
self.is_Cen = False
#J/psi kinematics
self.pT = 0.
self.y = 0.
self.m = 0.
#absolute eta for electron and positron
self.aeta_max = 1.
#minimal electron and positron for central trigger
#self.p_min = 1.014
#open the input
self.inp = TFile.Open(infile)
self.tree = self.inp.Get("slight_tree")
#connect the input tree
self.particles = TClonesArray("TParticle", 200)
self.tree.SetBranchAddress("particles", self.particles)
#number of events in input tree
self.nev = self.tree.GetEntriesFast()
#__init__
#_____________________________________________________________________________
def read(self, iev):
#read a given event
if iev >= self.nev: return False
self.tree.GetEntry(iev)
#initialize event variables
self.epos = 0.
self.eneg = 0.
self.npos = 0
self.nneg = 0
self.is_XnXn = False
self.is_Cen = True
vec = TLorentzVector()
#particle loop
for imc in xrange(self.particles.GetEntriesFast()):
part = self.particles.At(imc)
#central electron and positron
if TMath.Abs(part.GetPdgCode()) == 11:
if TMath.Abs(part.Eta()) > self.aeta_max: self.is_Cen = False
#if part.P() < self.p_min: self.is_Cen = False
pv = TLorentzVector()
part.Momentum(pv)
vec += pv
#select the neutrons
if part.GetPdgCode() != 2112: continue
#energy at positive and negative rapidity
if part.Eta() > 0:
self.epos += part.Energy()
self.npos += 1
else:
self.eneg += part.Energy()
self.nneg += 1
#particle loop
#flag for XnXn event
if self.npos > 0 and self.nneg > 0: self.is_XnXn = True
#J/psi kinematics
self.pT = vec.Pt()
self.y = vec.Rapidity()
self.m = vec.M()
return True
def neut_en_pn():
#neutron energy and positive and negative rapidity
#plot range
ebin = 3
#emin = 1
emin = 30
#emax = 1400
emax = 710
#analysis cuts
eta_max = 6.6 # absolute eta
en_max = 1250 # energy
en_min = 20
hE = ut.prepare_TH2D("hE", ebin, emin, emax, ebin, emin, emax)
can = ut.box_canvas()
particles = TClonesArray("TParticle", 200)
tree.SetBranchAddress("particles", particles)
nev = tree.GetEntriesFast()
#nev = int(1e4)
nall = 0.
nsel = 0.
for iev in xrange(nev):
tree.GetEntry(iev)
epos = 0.
eneg = 0.
for imc in xrange(particles.GetEntriesFast()):
part = particles.At(imc)
if part.GetPdgCode() != 2112: continue
#ZDC eta
if abs(part.Eta()) < eta_max: continue
if part.Eta() > 0:
epos += part.Energy()
else:
eneg += part.Energy()
if epos < en_min or eneg < en_min: continue
nall += 1.
if epos > en_max or eneg > en_max: continue
#if epos < en_min or epos > en_max: continue
#if eneg < en_min or eneg > en_max: continue
nsel += 1.
hE.Fill(eneg, epos)
print nall, nsel, nsel / nall
ut.put_yx_tit(hE, "#it{E}_{#it{n}} (GeV), #it{#eta} > 0",
"#it{E}_{#it{n}} (GeV), #it{#eta} < 0", 1.7, 1.2)
ut.set_margin_lbtr(gPad, 0.12, 0.09, 0.02, 0.11)
hE.SetMinimum(0.98)
hE.SetContour(300)
hE.Draw()
gPad.SetGrid()
gPad.SetLogz()
#ut.invert_col(rt.gPad)
can.SaveAs("01fig.pdf")