Selected Papers
This directory contains descriptons and links to
some of the physics that I have worked on.
CMS: Hadron Collider Physics at the LHC
The Higgs discovery was announced on July 4, 2012.
We lead one of the diphoton analyses, the Vector-Boson
Fusion. In this mode, the proton proton collision
produces Higgs particles by emitting W+W- bosons that
interact to produce a Higgs. In the Standard Model, the rates for VBF
are lower than the rates for general (glue-glue) production
of the Higgs.
However, VBF opens a window on the electroweak symmetry
breaking (why the Higgs was postulated in the first place,
decades ago).
Our VBF result, submitted to JHEP, is
here .
The 3jet resonance search we invented at CDF (see below)
was also done at CMS. The large rates at the LHC mean
that jet thresholds have to be set high, and therefore
we could not search for the top excess we saw at CDF
(UPDATE: this is being addressed with special triggers
in the 2012 run!)
The first CMS result came out with 2010 data
in PRL (Physical Review Letters).
The result with 2011 data is being prepared for publication
now, the public results are
here .
A sophisticated multilepton search for new physics we did here
at Rutgers with a large group has been
accepted by JHEP .
This analysis does not make any model-dependent selections, so
is sensitive to most models of new physics that have leptons
(Supersymmetry, 4th generation quarks, etc).
CDF: Hadron Collider Physics at the Tevatron
We invented an entirely new technique to look for multi-jet
resonances. With this technique we were able to see top
quarks decay to 3 jets, without any additional kinematic
requirements (like b-jets, W-resonance, leptons).
In other
words, if you didn't already know that there was supposed to
be a resonance at 175 GeV/c^2, this would have been one way
to find it.
The paper was published
in PRL .
Note that there was an excess of top quarks in this analysis.
We did additional studies with more data. We looked for the
signal of the W-boson within the top and found that the excess
was indeed due to top quarks, and not some other 3jet resonance
at similar mass.
Extra Plots for the multijet top excess.
On CDF we have performed one of the most sensitive searches for
the MSSM Higgs Boson, published in Physical Review Letters in 2006.
We searched for
Higgs decaying to tau leptons ,
and in the process greatly
improved the status of tau physics at CDF.
Our work was highlighted in talks by Pier Oddone, director
of Fermilab, as one of the most promising analyses being
performed at the Tevatron.
We have a
HREF="http://www-cdf.fnal.gov/physics/exotic/r2a/20050519.mssm_htt/index.htm">
website for this analysis, which includes our limit plots
(one of which is also shown in the 2006 Particle Data Book) and
plots showing expected
sensitivity with higher luminosity.
We updated this result in 2009
in this PRL
KTeV: Fixed Target Physics with Neutral Kaon Beam
The first paper published by KTeV was
on the search for the neutral SUSY hadron, the R0, consisting
of a light gluino paired with a gluon.
I performed a
more sophisticated search
presented at the International Conference
for High Energy Physics
(ICHEP' 98, or the "Rochester Conference")
in Vancouver, which was
published in early '99.
![[DIR]](/icons/folder.gif)
R0 Papers Reference papers for the KTeV light gluino search.
The rare decay K_L-> e+e-mu+mu- was
finally seen with high enough statistics. This decay is important
for determining the CKM matrix element V_td (from K_L->mu+mu-)
This paper is also now published.
We also made a measurement of
the
radiative widths on excited kaons
(including several states
never before measured).
Simply put, the radiative
width gives the likelihood of an excited state decaying by emitting
a photon. In other words, we find out well the picture of the neutral
kaon as a hydrogen-atom-like structure (albeit with strange and
down quarks instead of electron and proton) holds up.
SLD: Polarized electron-positron collisions at the Z pole
My thesis was on the SLD measurement of ALR, and the
1996
publication of this measurement , as well as a previous
(1994) paper (my thesis) ,
are available.
A paper on all the polarized asymmetries
is also available.
Langacker and Erler have interpreted this and other precision electroweak
data as limits on Standard Model Higgs.
(UPDATE: The Higgs was found! See CMS section above. The mass was well
inside the window predicted 17 years earlier by electroweak precision measurements
like this one).
The ALR measurement depended on the Compton Polarimeter,
which was cross-checked with a Moller Polarimeter. An
interesting effect (Levchuk effect)
due to atomic electron effects was seen to bias Moller
Polarimetry.
Amit &
Last modified: Wed Jul 11 18:44:21 EDT 2012