Run 1b and 630 GeV Photon Cross Sections

Contact Person: Dana Partos, Steve Kuhlmann

Date Blessed: April 20, 2001

CDF Notes: 4910, 5457, 5085, 5219

Abstract

We have measured the 1b and 630 GeV prompt photon cross section after modifying the CPR efficiencies to agree with the measured efficiencies of the $\pi^{0}$ from the decay $\rho^{pm} \rightarrow \pi^{\pm} \pi^{0} \rightarrow \pi^{\pm} \gamma \gamma$. The 1b cross section is consistent with the 1a measurement. The 1b and 630 GeV cross sections are consistent with each other when plotted as a function of photon $P_T$, but there is a large discrepancy when the two cross sections are shown as a function of photon $x_T$ (=2$P_T/\sqrt{s}$).

Plots

rho_plot.ps Rho sample used to calculate efficiencies.

rho_cpr_ces_eff_mass.ps Measured $\pi^{0}$ CPR and CES efficiency in the $\rho$ peak

def_lin_fit.ps Comparison of CES and CPR cross sections after efficiency recalibration

cpr_sys.ps CPR systematic errors from changes to the signal and background efficiencies in the cprweighting routine, backscattering, and changing the background mixture.

phofrac_1a1b.eps Run 1a and Run 1b photon fractions.

phofrac_630_1b.eps Run 1b and 630 GeV photon fractions.

phoeff1b_630.eps Fractions of photon candidates with a CPR hit from both the 630 and Run 1b data sets.

log_4m.ps Comparison of Run 1a and Run 1b cross sections to CTEQ4M

lin_2m_ow_upt_1a.ps (Data-Theory)/Theory comparison of 1a and 1b cross section with CTEQ2M (Owens et al)

owens_evol.ps Evolution of theoretical predictions by Owens et al.

lin_4m_vo_ow_comp.ps Comparison of theoretical predictions by Owens et al. and Vogelsang et al.

log_630_1800.eps Comparison of Run 1b and 630 GeV cross sections to CTEQ5M

log_630_1800_ua2_d0.ps Comparison of CDF Run 1b and 630 GeV cross sections and the UA2 and D0 results to CTEQ5M.

lin_4m_ow_upt.ps (Data-Theory)/Theory comparison of 1b cross section with CTEQ4M (Owens et al)

lin_4m_data_vo_comp.ps (Data-Theory)/Theory comparison of 1b cross section with CTEQ4M (Vogelsang et al)

lin_pdf_comp_color.ps (Data-Theory)/Theory comparison of 1b cross section with different PDF's (Vogelsang et al)

lin_pt.eps (Data-Theory)/Theory comparison of the Run 1b and 630 GeV cross sections as a funtion of photon pt with CTEQ5M (Vogelsang et al)

lin_xt.eps (Data-Theory)/Theory comparison of the Run 1b and 630 GeV cross sections as a function of photon xt with CTEQ5M (Vogelsang et al)

lin_pt_d0.eps (Data-Theory)/Theory comparison of the CDF and D0 Run 1b cross sections as a function of photon pt with CTEQ5M (Vogelsang et al).

lin_pt_ua2.eps (Data-Theory)/Theory comparison of the CDF and UA2 630 GeV cross sections as a function of photon pt with CTEQ5M (Vogelsang et al).

lin_630_xt_ua2.ps (Data-Theory)/Theory comparison of the CDF and UA2 630 GeV cross sections as a function of photon xt with CTEQ5M (Vogelsang et al).

lin_xt_ua2.ps (Data-Theory)/Theory comparison of the CDF 630 and 1800 GeV cross sections and the UA2 630 GeV cross section as a function of photon xt with CTEQ5M (Vogelsang et al).

lin_xt_ua2_d0.ps (Data-Theory)/Theory comparison of the CDF Run 1b, CDF 630 GeV, D0 Run 1b, and UA2 630 GeV cross sections as a function of photon xt with CTEQ5M (Vogelsang et al).

prllin_kt.ps (Data-Theory)/Theory comparison of the CDF Run 1b cross section as a function of photon pt with CTEQ5M (Vogelsang et al) and Kt corrections. Note that the data has been shifted up by 25% in order to make shape comparisons to the different kt corrections.

kt630gev.ps (Data-Theory)/Theory comparison of the CDF Run 1b cross section as a function of photon pt with CTEQ5M (Vogelsang et al) and Kt corrections.

Dana Partos
Last modified: Thu Aug 30 11:18:41 CDT 2001