Mattione Update 07092012

Y(2175) Study

Reaction

• γ p → Y(2175), p
  • Y(2175) → π⁺, π^-, φ
    • φ → K⁺, K^-
• Final State: p, π⁺, π^-, K⁺, K^-
• ~530,000 Events Generated using genr8 with: 9 GeV Photons, Γ_Y(2175) = 61 MeV/c², t-slope = 5.0, 50.0 < Vertex-Z (cm) < 80.0

Background Channel

• γ p → f₁(1285), p
  • f₁(1285) → π⁺, π^-, π⁺, π^-
• NOTE: had to trick genr8 by having the f₁(1285) decay to η, η, and then each decaying to π⁺, π^-
• Final State: p, π⁺, π^-, π⁺, π^-
• ~530,000 Events Generated using genr8 with: 9 GeV Photons, Γf₁(1285) = 24 MeV/c², t-slope = 5.0, 50.0 < Vertex-Z (cm) < 80.0

Pythia

• Generated entire photon energy region

Thrown Track Parameters

• Thrown Track Parameters

Track	Y(2175)	f1(1285)	Pythia
γ	350px	350px
K+	350px	350px
K-	350px	350px
π+	350px
π-	350px
p	350px

Initial Mass Peaks

• Initial Mass Peaks

Mass Peak	Y(2175)	f1(1285)	Pythia
φ
p
Y(2175)

Kinematic Fitting

• Confidence Level

Fit Constraint	Y(2175)	f1(1285)	Pythia
(p)