Freya Blekman
@freyablekman.bsky.social
Particle physicist at @CMSExperiment at @CERN - Lead Scientist DESY & Professor of Physics University of Hamburg - World citizen ➡🇳🇱🇺🇸 🇬🇧🇨🇭🇧🇪🇩🇪
Posts: #physics #SciComm + academia/tech stuff + my opinions + summaries of #CMSpapers
Posts: #physics #SciComm + academia/tech stuff + my opinions + summaries of #CMSpapers
Our summer students (and friends) are right: particle physics summer student programs are among the bucket-list activities for physics students. Registration for next summer opens now, and typically closes late January.
For your convenience, here are some links for the programs world-wide:
For your convenience, here are some links for the programs world-wide:
November 21, 2025 at 3:05 PM
Our summer students (and friends) are right: particle physics summer student programs are among the bucket-list activities for physics students. Registration for next summer opens now, and typically closes late January.
For your convenience, here are some links for the programs world-wide:
For your convenience, here are some links for the programs world-wide:
Are there invisible (and long-lived) undiscovered particles produced in the decays of B mesons? Those would be super rare, so we use a huge dataset of B mesons with dedicated data taking techniques. We didn't see any new particles though, this #CMSPaper is a #nullresult arxiv.org/abs/2508.06363
November 21, 2025 at 1:03 PM
Are there invisible (and long-lived) undiscovered particles produced in the decays of B mesons? Those would be super rare, so we use a huge dataset of B mesons with dedicated data taking techniques. We didn't see any new particles though, this #CMSPaper is a #nullresult arxiv.org/abs/2508.06363
If you need a reference model of what an extension of the standard model with many new particles would look like, Supersymmetry is a good benchmark. This #CMSPaper shows a general search in many standard signatures, looking for deviations spread over different signatures arxiv.org/abs/2508.13900
November 21, 2025 at 11:27 AM
If you need a reference model of what an extension of the standard model with many new particles would look like, Supersymmetry is a good benchmark. This #CMSPaper shows a general search in many standard signatures, looking for deviations spread over different signatures arxiv.org/abs/2508.13900
Every year in november, I make a little video summarising our group in Hamburg. We do such awesome stuff!
Enjoy this year's video 📽️ 💪 🤩 🤓
Enjoy this year's video 📽️ 💪 🤩 🤓
November 20, 2025 at 1:03 PM
Every year in november, I make a little video summarising our group in Hamburg. We do such awesome stuff!
Enjoy this year's video 📽️ 💪 🤩 🤓
Enjoy this year's video 📽️ 💪 🤩 🤓
Also it is sad to see that Amsterdam has given in to boring clothing. Things have changed #vertrutting
November 17, 2025 at 2:37 PM
Also it is sad to see that Amsterdam has given in to boring clothing. Things have changed #vertrutting
And off to The Hague for a talk on particle physics!
November 17, 2025 at 2:25 PM
And off to The Hague for a talk on particle physics!
We don't see the decay of the Higgs boson to charm quarks (yet!), but it is also possible to measure the interaction of the Higgs boson with charm by studying those particles being produced together. This #CMSPaper studies that Higgs+charm signature (we don't see it yet): arxiv.org/abs/2508.14988
November 9, 2025 at 6:22 PM
We don't see the decay of the Higgs boson to charm quarks (yet!), but it is also possible to measure the interaction of the Higgs boson with charm by studying those particles being produced together. This #CMSPaper studies that Higgs+charm signature (we don't see it yet): arxiv.org/abs/2508.14988
This #CMSpaper looks again at a non-significant (but intriguing!) excess in signatures consistent with two unstable, unknown particles from a heavier source. This paper further compares to theory predictions explaining these four-jet events
arxiv.org/abs/2507.17884
arxiv.org/abs/2507.17884
November 9, 2025 at 1:03 PM
This #CMSpaper looks again at a non-significant (but intriguing!) excess in signatures consistent with two unstable, unknown particles from a heavier source. This paper further compares to theory predictions explaining these four-jet events
arxiv.org/abs/2507.17884
arxiv.org/abs/2507.17884
This #CMSPaper explores the excitation of three particles with a B quark and other quark, examining how they store extra energy beyond the ground state. It marks the first simultaneous measurement of these particles. This improves knowledge of particles that contain quarks arxiv.org/abs/2508.05820
November 8, 2025 at 6:22 PM
This #CMSPaper explores the excitation of three particles with a B quark and other quark, examining how they store extra energy beyond the ground state. It marks the first simultaneous measurement of these particles. This improves knowledge of particles that contain quarks arxiv.org/abs/2508.05820
Are there undiscovered particles that decay to a Higgs boson and something else? This #CMSPaper describes how we scanned the invariant mass spectrum, but did not find any signs (in very very few events, and this should be rare. We will do this again when we have more data) arxiv.org/abs/2508.11494
November 8, 2025 at 1:03 PM
Are there undiscovered particles that decay to a Higgs boson and something else? This #CMSPaper describes how we scanned the invariant mass spectrum, but did not find any signs (in very very few events, and this should be rare. We will do this again when we have more data) arxiv.org/abs/2508.11494
The LHC produces a large number of Z bosons. So it is worthwhile checking if some of them behave inconsistently with the standard model. This #CMSPaper measured that the chance that Z bosons decay to two different kinds of leptons is smaller than one in 10 million arxiv.org/abs/2508.07512
November 7, 2025 at 1:03 PM
The LHC produces a large number of Z bosons. So it is worthwhile checking if some of them behave inconsistently with the standard model. This #CMSPaper measured that the chance that Z bosons decay to two different kinds of leptons is smaller than one in 10 million arxiv.org/abs/2508.07512
Are there undiscovered particles (that are very light for LHC standard) produced in Higgs boson decays? This #CMSPaper describes how we look for them, but did not see any arxiv.org/abs/2508.06947
November 7, 2025 at 11:27 AM
Are there undiscovered particles (that are very light for LHC standard) produced in Higgs boson decays? This #CMSPaper describes how we look for them, but did not see any arxiv.org/abs/2508.06947
Are there invisible (and long-lived) undiscovered particles produced in the decays of B mesons? Those would be super rare, so we use a huge dataset of B mesons with dedicated data taking techniques. We didn't see any new particles though, this #CMSPaper is a #nullresult arxiv.org/abs/2508.06363
November 6, 2025 at 6:22 PM
Are there invisible (and long-lived) undiscovered particles produced in the decays of B mesons? Those would be super rare, so we use a huge dataset of B mesons with dedicated data taking techniques. We didn't see any new particles though, this #CMSPaper is a #nullresult arxiv.org/abs/2508.06363
If you need a reference model of what an extension of the standard model with many new particles would look like, Supersymmetry is a good benchmark. This #CMSPaper shows a general search in many standard signatures, looking for deviations spread over different signatures arxiv.org/abs/2508.13900
November 6, 2025 at 1:03 PM
If you need a reference model of what an extension of the standard model with many new particles would look like, Supersymmetry is a good benchmark. This #CMSPaper shows a general search in many standard signatures, looking for deviations spread over different signatures arxiv.org/abs/2508.13900
I learnt a lot today and so did the audience. Lifelong learning for everyone. On science for peace, and the power of big questions to achieve the impossible at cern 😇🤩
November 5, 2025 at 11:04 PM
I learnt a lot today and so did the audience. Lifelong learning for everyone. On science for peace, and the power of big questions to achieve the impossible at cern 😇🤩
I learnt a lot today and so did the audience. Lifelong learning for everyone. On science for peace, and the power of big questions to achieve the impossible at cern 😇🤩
November 5, 2025 at 11:01 PM
I learnt a lot today and so did the audience. Lifelong learning for everyone. On science for peace, and the power of big questions to achieve the impossible at cern 😇🤩
The production of the Higgs boson along with an undiscovered hypothetical particle is an important signature for detecting physics beyond the standard model. This #CMSPaper looks for the "Higgs boson+jet not consistent with the standard model" signature (we didn't see any): arxiv.org/abs/2509.13635
November 5, 2025 at 6:22 PM
The production of the Higgs boson along with an undiscovered hypothetical particle is an important signature for detecting physics beyond the standard model. This #CMSPaper looks for the "Higgs boson+jet not consistent with the standard model" signature (we didn't see any): arxiv.org/abs/2509.13635
The production of top quark pairs together with a W boson is a great way to test the quality of standard model predictions. This #CMSPaper measures provides boundaries on things like the difference between ttW+/- production, a very sensitive quantity to test the predictions arxiv.org/abs/2509.13512
November 4, 2025 at 1:03 PM
The production of top quark pairs together with a W boson is a great way to test the quality of standard model predictions. This #CMSPaper measures provides boundaries on things like the difference between ttW+/- production, a very sensitive quantity to test the predictions arxiv.org/abs/2509.13512
The LHC recently collided oxygen ions, and this #CMSPaper shows that we see charged particle suppression , a telltale sign that these collisions are creating the quark gluon plasma: arxiv.org/abs/2510.09864
November 4, 2025 at 11:27 AM
The LHC recently collided oxygen ions, and this #CMSPaper shows that we see charged particle suppression , a telltale sign that these collisions are creating the quark gluon plasma: arxiv.org/abs/2510.09864
You may have noticed that I stopped numbering the #CMSPapers I posted about. This is mostly because the numbering is kind of ambiguous. But we have published over 1400 papers (of which 1380+ on LHC data) since 2009 already!
check them all out (searchable) here: cms-results-search.web.cern.ch
check them all out (searchable) here: cms-results-search.web.cern.ch
October 31, 2025 at 1:04 PM
You may have noticed that I stopped numbering the #CMSPapers I posted about. This is mostly because the numbering is kind of ambiguous. But we have published over 1400 papers (of which 1380+ on LHC data) since 2009 already!
check them all out (searchable) here: cms-results-search.web.cern.ch
check them all out (searchable) here: cms-results-search.web.cern.ch
We are hiring! Well, my DESY colleague Katerina Lipka is hiring. She does precision measurements of the standard model, trying to find the cracks. Do you want to help identify where the standard model starts breaking down? Then this is the PhD for you: inspirehep.net/jobs/3065448
October 31, 2025 at 11:27 AM
We are hiring! Well, my DESY colleague Katerina Lipka is hiring. She does precision measurements of the standard model, trying to find the cracks. Do you want to help identify where the standard model starts breaking down? Then this is the PhD for you: inspirehep.net/jobs/3065448
We don't see the decay of the Higgs boson to charm quarks (yet!), but it is also possible to measure the interaction of the Higgs boson with charm by studying those particles being produced together. This #CMSPaper studies that Higgs+charm signature (we don't see it yet): arxiv.org/abs/2508.14988
October 30, 2025 at 6:22 PM
We don't see the decay of the Higgs boson to charm quarks (yet!), but it is also possible to measure the interaction of the Higgs boson with charm by studying those particles being produced together. This #CMSPaper studies that Higgs+charm signature (we don't see it yet): arxiv.org/abs/2508.14988
This #CMSpaper looks again at a non-significant (but intriguing!) excess in signatures consistent with two unstable, unknown particles from a heavier source. This paper further compares to theory predictions explaining these four-jet events
arxiv.org/abs/2507.17884
arxiv.org/abs/2507.17884
October 30, 2025 at 1:04 PM
This #CMSpaper looks again at a non-significant (but intriguing!) excess in signatures consistent with two unstable, unknown particles from a heavier source. This paper further compares to theory predictions explaining these four-jet events
arxiv.org/abs/2507.17884
arxiv.org/abs/2507.17884
This #CMSPaper explores the excitation of three particles with a B quark and other quark, examining how they store extra energy beyond the ground state. It marks the first simultaneous measurement of these particles. This improves knowledge of particles that contain quarks arxiv.org/abs/2508.05820
October 29, 2025 at 6:22 PM
This #CMSPaper explores the excitation of three particles with a B quark and other quark, examining how they store extra energy beyond the ground state. It marks the first simultaneous measurement of these particles. This improves knowledge of particles that contain quarks arxiv.org/abs/2508.05820
Are there undiscovered particles that decay to a Higgs boson and something else? This #CMSPaper describes how we scanned the invariant mass spectrum, but did not find any signs (in very very few events, and this should be rare. We will do this again when we have more data) arxiv.org/abs/2508.11494
October 29, 2025 at 1:06 PM
Are there undiscovered particles that decay to a Higgs boson and something else? This #CMSPaper describes how we scanned the invariant mass spectrum, but did not find any signs (in very very few events, and this should be rare. We will do this again when we have more data) arxiv.org/abs/2508.11494