atlas records precise bᴼ meson lifetime lhc

Pioneering Precision: Scientists Record Electrically Neutral Beauty Meson Lifetime

New High-Precision Measurement of Bᴼ Meson Lifetime by ATLAS Collaboration

Researchers from the ATLAS collaboration at the Large Hadron Collider (LHC) have unveiled a new high-precision measurement of the electrically neutral beauty (Bᴼ) meson's lifetime, a hadron made up of a bottom antiquark and a down quark.

Understanding Beauty Mesons and Their Significance

Beauty (B) mesons consist of two qarks, including a bottom quark. For decades, their study has allowed physicists to probe rare, well-predicted phenomena, offering insights into weak force-mediated interactions and the dynamics of heavy-quark bound states. Accurate determination of the Bᴼ meson lifetime, the interval before its decay, remains crucial in this research domain.

ATLAS Collaboration's Latest Study on Bᴼ Meson Decay

The ATLAS collaboration's latest study on the Bᴼ meson focuses on its decay into an excited neutral kaon (K ͯ ᴼ) and a J/ψ meson. The J/ψ meson subsequently decays into two muons, while the k K ͯ ᴼ meson is analyzed through its decay into a charged pion and a charged kaon. This analysis leverages a substantial data set of 140 inverse femtobarns collected from proton-proton collisions during LHC Run 2 (2015-2018).

Measurement of Bᴼ Meson Lifetime

The ATLAS team reported a measurement of the Bᴼ meson lifetime at 1.5053 picoseconds (1 ps = 10⁻¹² seconds), with statistical and systematic uncertainties of 0.0012 ps and 0.0035 ps, respectively. This is the most precise determination to date, marking a significant enhancement over previous results, including prior ATLAS findings.

Overcoming Experimental Challenges

To achieve these precise measurements, researchers had to surmount various experimental challenges, such as systematic uncertainty minimization, advanced modeling, and refined detector alignment.

Decay Width Measurement and Its Implications

Beyond measuring the Bᴼ meson lifetime, the ATLAS team also determined its decay width, a fundamental property of unstable with finite lifetime. According to Heisenberg's uncertainty principle, shorter lifetime correspond to broader decay widths. The Bᴼ meson's decay width was measured as 0.664 inverse picoseconds (ps⁻¹), with a total uncertainty of 0.004 ps⁻¹.

Comparison with Bsᴼ Meson Decay Width

The researchers subsequently compared their result with an earlier measurement of the decay width of the Bsᴼ meson, which consists of a bottom quark and a strange quark. The ratio of the decay widths was found to be consistent with unity, indicating similar values for both measurements. These findings align with the predictions of the heavy-quark model and provide valuable data for refining these predictions.

Impact on Our Understanding of Weak-Force-Mediated Decays

The latest ATLAS precision measurements significantly deepen our understanding of weak-force-mediated decays within the Standard Model and offer crucial data for advancing future theoretical research.

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