Guillaume Pietrzyk
@willpietrak.bsky.social
Particle Physicist. Postdoc at IJClab, in collaboration with the LHCb Experiment at CERN. Former PhD student at EPFL.
Reposted by Guillaume Pietrzyk
Finally the rumours become public: The CEPC Chinese collider project is on hold.
cerncourier.com/a/cepc-matur...
cerncourier.com/a/cepc-matur...
October 26, 2025 at 12:39 PM
Finally the rumours become public: The CEPC Chinese collider project is on hold.
cerncourier.com/a/cepc-matur...
cerncourier.com/a/cepc-matur...
Reposted by Guillaume Pietrzyk
Today LHCb presented a new measurement of the decay of a B meson into a K* and a μ+ μ- pair
Previous results disagreed with the Standard Model prediction for the branching fraction and angular distribution
The new measurement has almost twice as much data and still disagrees!
🧵1/6
Previous results disagreed with the Standard Model prediction for the branching fraction and angular distribution
The new measurement has almost twice as much data and still disagrees!
🧵1/6
September 9, 2025 at 6:48 PM
Today LHCb presented a new measurement of the decay of a B meson into a K* and a μ+ μ- pair
Previous results disagreed with the Standard Model prediction for the branching fraction and angular distribution
The new measurement has almost twice as much data and still disagrees!
🧵1/6
Previous results disagreed with the Standard Model prediction for the branching fraction and angular distribution
The new measurement has almost twice as much data and still disagrees!
🧵1/6
Reposted by Guillaume Pietrzyk
An unexpected surprise. The 2025 Breakthrough Prize in Fundamental Physics honors over 13,000 researchers whose labors have led to the precise description the Higgs mechanism, … breakthroughprize.org/News/91 @CERN
April 5, 2025 at 11:24 PM
An unexpected surprise. The 2025 Breakthrough Prize in Fundamental Physics honors over 13,000 researchers whose labors have led to the precise description the Higgs mechanism, … breakthroughprize.org/News/91 @CERN
Reposted by Guillaume Pietrzyk
American science and medicine has been thrown into chaos and uncertainty over the past week. Here are some stories to get up to speed. 1/12
January 28, 2025 at 3:58 AM
American science and medicine has been thrown into chaos and uncertainty over the past week. Here are some stories to get up to speed. 1/12
After 8 incredible years as part of the LHCb collaboration at CERN, it is time for me to explore new horizons. I am very happy to announce that I am now a contractor for SII, working as a software developer for clients in the parisian area.
November 28, 2024 at 11:56 AM
After 8 incredible years as part of the LHCb collaboration at CERN, it is time for me to explore new horizons. I am very happy to announce that I am now a contractor for SII, working as a software developer for clients in the parisian area.
Reposted by Guillaume Pietrzyk
Determination of short- and long-distance contributions in B⁰→K*⁰μ⁺μ⁻ decays arxiv.org/abs/2312.09102 - The overall level of compatibility with the Standard Model is evaluated to be between 1.8 and 1.9 standard deviations when looking at the C9 Wilson coefficient alone.
December 15, 2023 at 12:14 PM
Determination of short- and long-distance contributions in B⁰→K*⁰μ⁺μ⁻ decays arxiv.org/abs/2312.09102 - The overall level of compatibility with the Standard Model is evaluated to be between 1.8 and 1.9 standard deviations when looking at the C9 Wilson coefficient alone.
Reposted by Guillaume Pietrzyk
Le titre de professeur honoraire est décerné par l'@epfl aux professeurs Tatsuya Nakada, Aurelio Bay et Mikhail Shaposhnikov. 👏👏👏
November 6, 2023 at 7:24 PM
Le titre de professeur honoraire est décerné par l'@epfl aux professeurs Tatsuya Nakada, Aurelio Bay et Mikhail Shaposhnikov. 👏👏👏
Hello Bluesky!
October 11, 2023 at 2:55 PM
Hello Bluesky!