Measurement of the Top Quark mass

using data from CDF experimentat Tevatron

Fedor Prokoshin

Particles our world is made of

Neutrino

Leptons and quarks

Top Quark

Top QuarkmassMtop = 173.1±1.3 GeV/c2

• twice of W±, Z0

• 2 orders b• 4 orders u, d• 5 orders e-

Why Measure the Top Quark Mass?

• mtop is a fundamental parameter of the Standard Model

• constrains the mass of the elusive Higgs Boson: 1-loop corrections to mW depend quadratically on the top quark mass mtop and logarithmically on mH. Measuring mtop and mW one can extract information on mH

22tW mm

W W

H

W

W W

t

b

HW mm log2

173.1 1.3tM GeV 2009

174 15tM GeV 1994-95

CDF199 30tM GeV DǾ

History of top mass measurements

172.1 1.4tM GeV 2008

170.9 1.8tM GeV 2007

171.4 2.1tM GeV 2006

178.0 4.3tM GeV 2004 (Data 1992-1996)

172.7 2.9tM GeV 2005

176.7 7.1tM GeV 2004

Main Injectorand Recycler

p source

Booster

DD Tevatron

• Collisions every 396 ns• Beam energy 980 GeV s = 1.96 TeV

• Inst. Lum. ~5x1032 cm-

2s-1

CDF Detector

CDF II Collaboration

BACKUP SLIDES

Gervasio Gomez/CDF Moriond EW 2005 14

Top MassMt 175 GeV Yukawa coupling 1 Special role in EWSB?

Dominant parameter in radiative corrections:

quadratic in mt , logarithmic in mH

GeV166181

),(,sin,, 2

top

WFBZZ

M

MZAM

GeV100070HiggsMHiggstop MEWM

Mt from precision EW measurements