LHCb Experiment at CERN

The LHCb collaboration is happy to announce the first observation of muonic Dalitz decays of χb mesons!
Read: https://lhcb-outreach.web.cern.ch/2024/08/12/first-observation-of-muonic-dalitz-decays-of-%cf%87b-mesons/

LHCb Experiment at CERN investigates the properties of one of physics’ most puzzling particles

The particle, known as χc1(3872), has fascinated physicists for years. Now, the LHCb collaboration is closer to finding out what it is made up of.

Find out more: https://home.cern/news/news/physics/lhcb-investigates-properties-one-physics-most-puzzling-particles

At the ICHEP conference in Prague, the LHCb collaboration reported a measurement of the effective leptonic weak mixing angle, a parameter involved in the unification of the electromagnetic and weak forces.

Read our public news:

Measurement of the effective leptonic weak mixing angle Today, at the 42nd International Conference on High Energy Physics, ICHEP, Prague, Czech Republic, the LHCb collaboration reported a measurement of the effective leptonic weak mixing angle, sin2θleff, the parameter which is involved in the unification of the electromagnetic and weak forces. The res...

At the ICHEP conference, the LHCb experiment reported an improved determination of the CKM angle γ with a precision better than 3°.

Read our public page news:

Improved determination of the CKM angle γ Today, at the 42nd International Conference on High Energy Physics, ICHEP, Prague, Czech Republic, the LHCb collaboration reported an improved determination of the CKM angle γ with a precision better than 3°. This result was obtained by a simultaneous combination of measurements sensitive to the C...

Today, at the "Rencontres de Moriond QCD", LHCb announced the observation of the rare decay of a J/ψ particle to 4 muons!

The J/ψ particle is very famous in the particle physics community because its discovery in 1974 revolutionized the field! The J/ψ is made of a charm and an anticharm particle.
The proton-proton collisions of the LHC produce a big amount of J/ψ particles and the LHCb detector is perfectly suited to study them. One of the most probable decays of the J/ψ is to two leptons (electrons or muons). However, the decay of a J/ψ to 4 leptons (such as 4 muons) has only been observed for the first time two weeks ago by . LHCb is able to observe a very clear peak (shown on the first image), indicating the presence of 450 J/ψ->μμμμ decays. This result is compatible with Standard Model expectations.

Read more here: https://lhcb-outreach.web.cern.ch/2024/04/02/lhcb-observes-the-rare-decay-j-%cf%88%e2%86%92%ce%bc%ce%bc-%ce%bc%ce%bc/

Yesterday, at a dedicated CERN seminar, the LHCb collaboration announced some important updates on the matter-antimatter oscillations of "charm" particles.

Check out our public page to learn more: https://lhcb-outreach.web.cern.ch/2024/03/26/measurement-of-d0-%e2%88%92-d0-mixing-and-cp-violation-in-d0%e2%86%92k%cf%80-decays/

Have you ever conducted an experiment? Something like finding out how likely it is to get a 2 when throwing a dice?
If you throw 10 times, you can have a good guess, if you throw 1000 times, even better.
More data means your guess becomes more reliable, or in other words: the uncertainty on your guess becomes smaller.

What we do in science is very similar: we look at the same process over and over and over again so that we can deduce properties of particles.
Many of LHCb’s measurements from the past years have shown that the Standard Model (our current theory of particle behaviour) works very well.
For some of the measurements however, we cannot make a clear statement because the uncertainties are yet too large.
During Run 3, we want to collect more data with a new and better detector.
Our future measurements may be the final piece of the puzzle to better understand the behaviour of beauty quarks.

If you wander why we are so interested in the beauty quark, read our previous post about it in the DID YOU KNOW series of post! ;)

Today the LHCb collaboration completes the release of data collected in 2011 and 2012 from proton-proton collisions.
All scientific results from the LHCb collaboration are already made publicly accessible in open-access papers. Starting from today, not only are the results available, but also the data used by the researchers to produce these results are accessible.

LHCb releases the entire Run I dataset Today the LHCb collaboration complete the release of data collected throughout the Run I of the Large Hadron Collider at CERN. The sample made available amounts to approximately 800 terabytes (TB) of data. These data, collected by the LHCb experiment in 2011 and 2012, contain information obtained fr...

The LHCb collaboration is delighted to submit its 700th publication!
It studies the production of two important particles made of a charm-anticharm quark pair: the J/ψ and the ψ(2S). The physicists analysed the production of these particles directly at the proton-proton collision point, or following the decay of a Beauty particle.
This result provides important information to improve calculations of the strong force, one of the fundamental forces known in Nature.
We cannot wait for our 800th publication! 🎉

Read our public news: https://lhcb-outreach.web.cern.ch/2023/12/13/lhcb-s-700th-publication-reports-interesting-studies-of-quantum-chromodynamics/

Today, for   /  , we join our friends and colleagues around the world to celebrate the presence and important contributions of LGBTQ+ people across the Science, Technology, Engineering and Mathematics (STEM) disciplines!

Beauty physics 🥰

Sounds like a typo? It's not! Physics is BEAUTIful and today we tell you all about beauty quarks.

At LHCb, we are dedicated to these little particles. Beauty quarks are interesting because they can decay via the weak interaction and we suspect that new interesting stuff hides in weak interactions! For example, the weak interaction is CP violating. This means that the decay of a particle and its antiparticle do not happen in the same way. (Have a look at our older posts where we explain how we measure CP violation.)

If particles and antiparticles always behaved in exactly the same way, they would cancel, and therefore no matter that makes up us humans and our planet could exist. The only problem is: until now we don't really know why there is so much matter and almost no antimatter. That's why we keep searching for more CP violation with the help of our little beauty quarks! 🕵️

This week marks the end of the 2023 LHCb data taking! This year LHCb started taking data on April 14 with proton-proton collisions and ended on Monday with the last lead beams used for heavy ion collisions. This was the longest run with lead ions in the LHC and it was also the first one after five years.
Lead ions are large nuclei composed of substantial number of protons and neutrons. When they collide at the LHC energy, a huge amount of energy density is involved. This energy may be sufficient to create the so-called quark-gluon plasma, i.e., a state of matter in which quarks and gluons can move freely instead of being bound inside hadrons. Physicists are convinced that the Universe was in such a state shortly after the Big Bang. The study of quark-gluon plasma is therefore important for understanding not only quark-gluon interactions in quantum chromodynamics (QCD), but also the evolution of the Universe.

Now it is time for LHCb to take a winter break! The LHCb collaboration is very much looking forward to taking data next year!

Read our public news: https://lhcb-outreach.web.cern.ch/2023/10/30/heavy-ion-collisions-ended-2023-data-taking-period/

This week, the LHC is not colliding protons inside its ring, but lead ions. This marks the first heavy-ion collision campaign in 5 years!

The primary goal of having heavy ion collisions is to create an extremely hot elusive state of matter known as quark-gluon plasma, which consists of a soup of free quarks (constituants making particles such as protons and neutrons) and gluons (the force carriers of the strong force). This state is believed to have filled the Universe up to a millionth of a second after the Big Bang.

The LHCb collaboration is currently recording lead-lead collisions inside its detector. The first image is an event display of the LHCb detector, showing the numerous particles produced by lead-lead collisions and passing through our various subdetectors.
The second image shows some of the LHCb physicsts taking part in this important period of data taking.

Stay tuned for more!

You may remember that the nuclei of atoms are made of protons and neutrons. The Hydrogen nucleus consists of a single proton and is therefore the lightest, most simple, and also most abundant nucleus in the Universe. By gluing two neutrons to the proton, we can build a rarer version of Hydrogen, called Tritium. In very extreme conditions however, such as the proton-proton collisions at the LHC, we can produce other even more exotic nuclei. The LHCb Experiment recently observed an exotic version of Tritium, consisting of a proton, a neutron, and a Λ baryon. This new state is called Hypertriton. Contrary to neutrons (which we find in the Tritium and all other nuclei), Λ baryons are unstable and decay to a proton and a pion. This implies that our Hypertriton transforms themselves into Helium 3 (two protons and a neutron) and a pion.
LHCb physicists managed to detect Hypertriton by reconstructing the Helium and the pion. This observation exploits novel techniques to detect Helium tracks with our detector.

The peak of the first image shows the reconstructed mass of the Hypertriton nucleus, obtained from around 100 nuclei. In the second image you can see a sketch of the Hypertriton decay. Studying the production of Helium as well as Antihelium with collider experiments, such as LHCb, will improve our understanding of the nuclear force. It can also provide information about how these nuclei may be created in outer space. Moreover, hypernuclei, such as the Hypertriton, have significant implications for the understanding of dense astrophysical objects. Indeed, astrophysicists speculate that the core of neutron stars consist of Hypertriton coming from supernova explosions of massive stars!

Read our public news: https://lhcb-outreach.web.cern.ch/2023/08/23/new-observation-of-hypertriton-and-antihypertriton-production-in-lhc-proton-proton-collisions/

The LHCb experiment was designed to look at the physics of "b"eauty quark decays at the "L"arge "H"adron "C"ollider. Beauty quarks are produced in the collissions at the LHC together with all sorts of other particles. Many of these particles fly away into all possible directions. Our beauty quarks however mostly fly along the beam direction and stay within the blue cones illustrated in the second image. That's why our detector looks so different from other big particle physics experiments which want to see everything produced in the collision. This is for example the case for the that fully encloses the collision point. As we mainly want to see beauty quarks, we can focus on the region close to the beam pipe on one side of the interaction point.
In principle, we could have another identical detector on the other side of the interaction point, but this would mean higher cost and would require more space. Thanks to this arm only we collected and we keep collecting enough data to be able to study the physics behind the beauty - and the charm - quark!

The LHCb collaboration welcomes a new spokesperson and two new deputy-spokespersons: Vincenzo Vagnoni, Patrick Robbe and Ulrich Uwer.
Thanks a lot to Chris Parkes and Matteo Palutan, members of the previous LHCb management.
Read our news: https://lhcb-outreach.web.cern.ch/2023/06/30/vincenzo-vagnoni-patrick-robbe-and-ulrich-uwer-new-management-for-the-lhcb-collaboration/

LHCb presented today a precise measurement of the CP-violating phase φs, an important parameter to understand the matter-antimatter asymmetry of the Universe and to look for physics beyond the Standard Model.
Read our news: https://lhcb-outreach.web.cern.ch/2023/06/13/precise-measurement-of-the-cp-violating-phase-%cf%86s/

Today, LHCb presented an important precise measurement of the unitarity triangle angle β, an important parameter to study the matter-antimatter asymmetry in the Universe.
Read our news: https://lhcb-outreach.web.cern.ch/2023/06/13/precise-measurement-of-the-unitarity-triangle-angle-%ce%b2/