Nav: Home

Evidence of the Higgs particle's decay in quarks

July 19, 2017

As part of the ATLAS collaboration, the Freiburg research group led by Prof. Dr. Karl Jakobs and Dr. Christian Weiser has contributed to finding strong evidence that, among other things, the Higgs particle decays into quarks. The researchers analyzed data sets that were recorded in 2015 and 2016 with the ATLAS detector at the world's largest particle accelerator, the Large Hadron Collider (LHC) at the European Organization for Nuclear Research (CERN) in Geneva, Switzerland. "The strong evidence that the Higgs particle, as predicted by theory, decays into quarks provides yet another essential piece to the puzzle about this particle," says Weiser, who leads the research activity in Freiburg. "The goal now is to prove the decay exists beyond a shadow of a doubt and, based on this knowledge, to measure the Higgs particle's properties more accurately." As a result, measuring the decay is extremely important for the researchers in order to explain the short lifespan of the Higgs particle. Measurable deviations from standard theory's predictions could point to so-called new physics, which reaches beyond the Standard Model.

The discovery of the Higgs particle through the ATLAS and CMS experiments at the LHC accelerator in CERN in 2012 presented a milestone in physics even as the particle's existence had been predicted nearly 50 years prior to that. It is a most short-lived particle that decays into other particles nearly the moment it is produced.

The rate with which decays into various particles occur can be computed within the framework of the underlying theory. Up to now, researchers have been able to fully prove the decay into other particles - so-called W and Z bosons, photons and tau leptons. But they had not been able to observe the Higgs particle's decay into a couple of b-quarks that is expected to occur with the largest rate of around 60 percent probability. The reason is that a number of other processes exist that are hard to differentiate from the Higgs particle's decay in b-quarks and that occur at a much higher rate. But now they have discovered new evidence: The probability that the observed signal is feigned solely by other processes is only 0.018 percent. The presentation of these findings was one of the highlights of the conference run by the European Physical Society (EPS) that was held July 5-12, 2017 in Venice, Italy.
-end-
Further information: http://press.cern/update/2017/07/lhc-experiments-delve-deeper-precision
https://atlas.cern/updates/atlas-news/atlas-highlights-eps-hep-2017

University of Freiburg

Related Physics Articles:

Diamonds coupled using quantum physics
Researchers at TU Wien have succeeded in coupling the specific defects in two such diamonds with one another.
The physics of wealth inequality
A Duke engineering professor has proposed an explanation for why the income disparity in America between the rich and poor continues to grow.
Physics can predict wealth inequality
The 2016 election year highlighted the growing problem of wealth inequality and finding ways to help the people who are falling behind.
Physics: Toward a practical nuclear pendulum
Researchers from Ludwig-Maximilians-Universitaet (LMU) Munich have, for the first time, measured the lifetime of an excited state in the nucleus of an unstable element.
Flowers use physics to attract pollinators
A new review indicates that flowers may be able to manipulate the laws of physics, by playing with light, using mechanical tricks, and harnessing electrostatic forces to attract pollinators.
More Physics News and Physics Current Events

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Teaching For Better Humans
More than test scores or good grades — what do kids need to prepare them for the future? This hour, guest host Manoush Zomorodi and TED speakers explore how to help children grow into better humans, in and out of the classroom. Guests include educators Olympia Della Flora and Liz Kleinrock, psychologist Thomas Curran, and writer Jacqueline Woodson.
Now Playing: Science for the People

#535 Superior
Apologies for the delay getting this week's episode out! A technical glitch slowed us down, but all is once again well. This week, we look at the often troubling intertwining of science and race: its long history, its ability to persist even during periods of disrepute, and the current forms it takes as it resurfaces, leveraging the internet and nationalism to buoy itself. We speak with Angela Saini, independent journalist and author of the new book "Superior: The Return of Race Science", about where race science went and how it's coming back.