CERN particle accelerator_311.
(photo credit: reuters)
Weizmann Institute of Science astrophysicists have been prominent in the
experiments that have shown “promising signs” of the existence of the Higgs
boson – the “God particle” – that provides a framework for all of the subatomic
particles in nature and has been sought for decades.
Scientists at the
Large Hadron Collider (LHC) and the CERN research center in Switzerland said in
an excited announcement on Tuesday that it found some evidence in its
experiments of the existence of the elementary particle.
Physicist doubts CERN experiment will disprove Einstein
It was suggested
in 1964 by six physicists, including University of Edinburgh physicist Peter
Higgs whom it was named after, as a way to explain mass.
particle called Higgs is the one piece of the Standard Model of Particle Physics
that has not been proven to exist, and some scientists believe that the model
will have to be rethought if the Higgs is not found.
Mikenberg of the Rehovot institute was the ATLAS Muon Project leader for many
years and now heads the Israeli LHC team.
Prof. Ehud Duchovni heads the
Weizmann Atlas group, as well as a small group looking for SUSY signals. Prof
Eilam Gross is currently the ATLAS Higgs physics group convener.
members of the Weizmann Institute’s Particle Physics and Astrophysics
Department, and they have been part of the effort to find the Higgs since
ATLAS and its sister experiment in the LHC, CMS, have been
searching for the Higgs boson together.
“In 2011, the LHC particle
accelerator in Geneva collided over 300 trillion protons,” said Gross. “All of
that enormous energy – seven-trillion electron volts – went into the effort to
produce the Higgs boson.
But in each collision, other similar particles
are created, and there is no way to foresee what we will find. The chances of a
collision producing a Higgs boson are so small that only about 100 are expected
to be observed over the course of a year.”
Finding possible signs of a
Higgs involved looking for statistical anomalies in the data (compared to what
the results would look like if there were no Higgs) in the expected mass
The problem is that once these anomalies appear, the scientists
had to rule out statistical flukes. But several weeks ago, it was noticed that
“extra” events in the probable Higgs range had accumulated in the experimental
results during 2011.
“We couldn’t believe our eyes – we looked at the
screen for ages before we started to digest what we were seeing,” Gross
“In the past three weeks, the entire Higgs search team in the
ATLAS experiment have checked and rechecked the results from every possible
angle. We checked for errors… for bugs in the program.”
The ATLAS results
suggest that there could be a Higgs boson with a mass of around 126 GeV, and
that there is just a 1 in 5,000 chance that the extra events they observed in
this particular mass are the result of a statistical fluke, and not the creation
of a Higgs boson.
Such fluctuations might still disappear, so the proof
is still not at all conclusive, but scientists believe that it bodes well for
the next round of LHC collisions, which are due to begin in April 2012.