W mass and W asymmetry at CDF Page: 4 of 10
This article is part of the collection entitled: Office of Scientific & Technical Information Technical Reports and was provided to UNT Digital Library by the UNT Libraries Government Documents Department.
Extracted Text
The following text was automatically extracted from the image on this page using optical character recognition software:
the value of the W mass on the charged lepton - missing transverse energy system. After
doing this, one found two solutions for the neutrino four-momentum. At V s = 630 GeV, the
solution which minimizes I Y w I was the right one in most cases. At the Tevatron, the Ws
have a large longitudinal boost which makes the wrong solution equally likely in the central
region of the detector. However, the W rapidity has a strong influence on the rapidity
distribution of the decay leptons, which also depends on the V - A couplings. Therefore we
investigate the lepton (pseudo) rapidity as a means to study structure functions at low x. It
is convenient to measure the charge asymmetry of the leptons as a function of rapidity:
a (i ti i) = r-N-
N+ + N‘
where N+ is taken to be the number of events with charge( lepton ) x rapidity(lepton ) > 0
and N' vice-versa3). This asymmetry is insensitive to acceptance corrections, requiring only
equal detection efficiency for both lepton charges and small corrections for background
events.
Fig. 1 shows the lepton asymmetry, A ( \t]\ ), computed at lowest order for different
sets of structure functions6>7,8,9). The effect of higher-order QCD diagrams for W production
was investigated with the Papageno Montecarlo by producing several million W events with
either 1 or 0 jets, using EHLQ1. MRS 1 and DOl structure function sets. The asymmetry in
the central region is predicted to increase with increasing the transverse momentum of the W.
For our analysis we will use low Pt Ws only. For the range of Pt(W) of interest here, we
estimate the size of this increase in asymmetry due to the non-zero Pt of the accepted W's to
be less than 0.013).
0. 10
0. OS
EHLQ2
0. 06
0FLM1-3
^ O. 04
0. 02
O. OO
-0. 02
O. 25
0. 75
77
Fig. 1 Lepton charge asymmetry in W decay obtained from several
structure functions.
Upcoming Pages
Here’s what’s next.
Search Inside
This article can be searched. Note: Results may vary based on the legibility of text within the document.
Tools / Downloads
Get a copy of this page or view the extracted text.
Citing and Sharing
Basic information for referencing this web page. We also provide extended guidance on usage rights, references, copying or embedding.
Reference the current page of this Article.
Leone, S. (Pisa Univ. (Italy) Istituto Nazionale di Fisica Nucleare, Pisa (Italy)). W mass and W asymmetry at CDF, article, May 1, 1991; Batavia, Illinois. (https://digital.library.unt.edu/ark:/67531/metadc1066022/m1/4/: accessed March 29, 2024), University of North Texas Libraries, UNT Digital Library, https://digital.library.unt.edu; crediting UNT Libraries Government Documents Department.