==============Top Mass Measurements at CDF in Run II======================

-----------------LEPTON+JETS----------------------------------------------
CDF has been exploring several different techniques for the top mass
measurement. The best single number is from a mass template technique
in the lepton+jets channel (ttbar-> lvbqqb).  The top
quark mass and hadronic W boson mass distributions reconstructed in
data are compared to Monte Carlo expectations to determine
simultaneously the top quark mass and the jet energy scale.

We use 680 pb-1 of Run II data (March 2002-September 2005) to measure

173.4 +1.7 (stat) +/- 2.2 (jet energy+syst) GeV/c2

This constitutes the best measurement of the top quark mass to date and 
is better than the previous world average!

The jet energy systematic is dominated by the modeling of the calorimeter
response (new forward calorimeter, extra material in new tracking
system).  The first use of an in-situ calibration,  
where the jet energy scale is determined from the W->jj reconstructed 
invariant mass in the same data lepton+jets events, has reduced this systematic uncertainty 
by about 40%.

-----------------DILEPTON-------------------------------------------------
CDF has developed the first matrix element technique to measure the top mass
in this channel.  Even using all possible kinematic constraints (equal top masses,
equal W masses, conservation of momentum in the transverse direction), the lack of information on
the two neutrinos  means that one needs to extra information to reconstruct the final state.
CDF computes a posterior probability for the top quark mass from the 
per-event differential cross section for ttbar.  This allows all possible lepton-jet combinations to be considered,
weighted by their probability.  CDF also computes the differential cross section for various background processes,
which mitigates the impact of background on this measurement.

We use 760 pb-1 of Run II data (March 2002-September 2005!) to measure

CDF Run II preliminary
164.5 +- 4.5 (stat) +- 2.6 (jet energy) +/- 1.7 (syst) GeV/c2


------------CDF+D0 combination------------------------------------------------
Last updated in March 2006 - See Tevatron link and hep-ex/0603039 for all the details.

Run I+II CDF+D0 dilepton + lepton+jets + all-hadronic

172.5 +- 2.3 GeV/c2

where the uncertainty is 1.3 GeV/c2 statistical and 1.9 GeV/c2 systematic.


-----------FUTURE----------------------------------------------------------
The future projections show the CDF+D0 combined uncertainty 
	   from lepton+jets channel only, 
with jet energy scale constrained by in situ W->jj only.

A rather conservative assumption is made that other systematics do not decrease
from the summer 2005 estimate of 1.3 GeV for CDF.  

In 2006, with completion of analyses on already collected 1 fb-1 of data, 
CDF+D0 should attain an uncertainty of about 2 GeV on the top quark mass.

By the end of Run II, CDF+D0 should attain an uncertainty of about 1.5 GeV on the top quark mass.

-------------PAST-----------------------------------------------
For comparison, the best single result from the lepton+jets channel,
with about 110 pb-1 of Run I data (1994-1995), is

CDF Run I result 176.1 +- 5.1 (stat) +- 5.3 (syst) GeV/c2
D0  Run I result 180.1 +- 3.6 (stat) +- 3.9 (syst) GeV/c2

World average 	 178.0 +- 4.3 GeV/c2 (hep-ex/0404010)
(Run I only)