The Higgs boson, a mysterious particle that has captivated scientists and researchers for over a decade, has become a crucial element in the quest to understand the fundamental nature of the universe. Recently, the ATLAS collaboration announced a groundbreaking achievement in measuring the mass of the Higgs boson, surpassing all previous measurements in precision. This advancement holds significant implications for our understanding of particle physics and the universe as a whole.
Unlike other particles, the mass of the Higgs boson cannot be predicted by the Standard Model, the most comprehensive theory in particle physics. Therefore, experimental measurements are required to determine its mass. The Higgs boson’s mass dictates the strength of its interactions with other particles and itself, making it a crucial parameter for theoretical calculations. By comparing these measurements with predictions from the Standard Model, physicists can identify potential deviations that may indicate the presence of new phenomena yet to be explained. Additionally, the mass of the Higgs boson plays a significant role in the stability and evolution of the universe’s vacuum.
Over the years, the ATLAS and CMS collaborations have continuously improved the precision of their measurements of the Higgs boson’s mass since its discovery. The latest breakthrough from the ATLAS collaboration combines two significant measurements: one based on the Higgs boson’s decay into two high-energy photons (the “diphoton channel”) and another involving its decay into four leptons (the “four-lepton channel”).
Unprecedented Precision in the Diphoton Channel
The new measurement in the diphoton channel utilizes the complete ATLAS data sets from Runs 1 and 2 of the Large Hadron Collider (LHC). This cutting-edge measurement resulted in a Higgs boson mass of 125.22 GeV with an uncertainty of only 0.14 GeV. With a precision of 0.11%, this diphoton-channel result stands as the most accurate measurement to date of the Higgs boson’s mass from a single decay channel.
Compared to the previous ATLAS measurement in this channel, the latest result benefits from the use of the full ATLAS Run 2 data set, reducing the statistical uncertainty by a factor of two. Additionally, significant improvements in photon energy measurement calibration have reduced the systematic uncertainty to 0.09 GeV—a remarkable four-fold decrease.
By combining the new mass measurement in the diphoton channel with the previous measurement in the four-lepton channel, the ATLAS researchers obtained a Higgs boson mass of 125.11 GeV with an uncertainty of 0.11 GeV. This combined measurement represents the most accurate determination of this fundamental parameter to date, with a precision of 0.09%.
ATLAS spokesperson, Andreas Hoecker, emphasizes the tireless dedication of the ATLAS collaboration in improving their understanding of the data. He highlights the importance of powerful reconstruction algorithms and precise calibrations in achieving such precise measurements. The collaboration’s efforts have contributed to the increasingly detailed map of this critical new sector in particle physics.
The ATLAS collaboration has made remarkable strides in measuring the mass of the Higgs boson, reaching an unprecedented level of precision. This achievement not only solidifies the crucial role of the Higgs boson in unraveling the structure of the universe but also showcases the relentless pursuit of knowledge by scientists in their quest to unravel the mysteries of the cosmos. These advancements open new doors for further exploration and could potentially lead to groundbreaking discoveries in particle physics. The future looks promising as scientists continue to push the boundaries of our understanding of the fundamental building blocks of the universe.