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Taking a closer look at LHC

 

  "If there's one thing to do, it's to engage in education".

 George Charpak (Nobel Prize in Physics in 1992).

 


CERN celebrates 70 years of scientific discovery and innovation.




Large Hadron Collider is the world’s highest energy particle accelerator. LHC (situated in the northwest suburbs of Geneva on the Franco–Swiss border) generates the greatest amount of information that has ever been produced in an experiment before. It is aimed to reveling some of the most fundamental secrets of nature.

Despite the enormous amount of information available about this topic, it is not easy for non-specialists to know where the data come from.

Basically, the purpose of this Website is to help introducing and informing the wider public about the LHC experiment, and some simple physical calculations which take place in all particle accelerators. They can also be used in secondary school classrooms, and, to a lesser extent, to primary school pupils and teachers. in order to stimulate the curiosity of the students, help them understand the physical concepts of LHC, and they can also be used as an example of the relationship between the cold equations of Physics on the blackboard and the exciting scientific research.

Through several sections and many sub-sections (CERN, LHC, PHYSICS at the LHC, Detectors, Standard Model, Education, Links, News ... ) we approach the contents that we believe should be known by non-specialists who are interested in Particle Physics, CERN and the LHC.

It is important to point out that the calculations that appear on this website are adapted to secondary school level, and in most cases, although they may be useful, they are simply approximations of the correct results.

We also present below some of the most recent news items (which we believe to be relevant to the purpose of our website) that feature CERN, and the LHC in particular. In the News section  section you will find news from previous years.

This Website has received the permissión of CERN to use informations, data, texts and images from CERN websites. The use on this Website of the various materials from publications produced by CERN is strictly in accordance with CERN's terms of use.

The rest of images, graphs, etc., not belonging to the authors of this website, have been taken as "fair use" qualification, but, please, let us know if that is not the case, and they will be removed immediately.


LHC live


We show below some facts that are of special relevance, appearing in the different Sections of this website the development of the concepts and contents that we consider to be of interest. 

If you are not familiar with the basic concepts of particle physics, we recommend that you first visit the different sections of the general menu of our website.

In the Referencias Section you can find many articles and books dealing with different aspects of Particle Physics, CERN and the LHC. In addition, in this other Section you can consult the articles that the authors of this website have published on these issues with an essentially outreaching intention.

We also present below some of the most recent news items (which we believe to be relevant to the purpose of our website) that feature CERN, and the LHC in particular. In the More News  section you will find news from previous years.



 

CERN highlights en 2024                   

 

Tomado de CERN WEBSITE

 

Run 3            

Year 2022, starts LHC Run 3 after a vast programme of works completed during Long Shutdown 2 (LS2). Protons collide at higher energies (13.6 TeV compared to 13 TeV) and with higher luminosities (containing up to 1.8 × 1011 protons per bunch compared to 1.3–1.4 × 1011 ) than in Run 2.

This third experimental phase runs until the end of 2025.

A few weeks after the start of Run3, several records were already reached.

Some of these are:

.- energy with Pb ions: 6.8 Z TeV (or 2.76 TeV/nucleon)

.- peak luminosity: 2.5·1034

.- pile-up (almost simultaneous collision points) > 100

.- stored energy per beam: ~ 400 MJ


Current schedule foresees Long Shutdown 3 (LS3) to start in 2026, one year later than in the previous schedule, and to last for three instead of 2.5 years (taken from CERN Courier).


Energy               

In 2012  protons at LHC were running with a beam energy of 4 TeV per proton (8 TeV in collision). At the beginning of 2013, the LHC collided protons with lead ions before going into a long maintenance stop (LS1) until the end of 2014. Running was resumed in 2015 with increased collision 6,5 TeV per proton (13 TeV in collision) and another increase in luminosity. Its maximum total energy of 14 TeV is very close, and after the Long Shutdown 2 (LS2) (2019-2022), in Run 3,  an energy of  6,8 TeV per proton (13,6 TeV in collision) has been already reached (very close to the designed maximum initial energy, 7 TeV per proton)


Higgs Boson                   

One of its main goal has already been achieved in the first phase of operation: to find the Higgs boson

The Nobel prize in Physics 2013 was awarded to François Englert and Peter W. Higgs "for the theoretical discovery of a mechanism that contributes to our understanding of the origin of mass of subatomic particles, and which recently was confirmed through the discovery of the predicted fundamental particle, by the ATLAS and CMS experiments at CERN's Large Hadron Collider."

The ATLAS and CMS collaborations announced their discovery of the particle at CERN on 4 July 2012. This result was further elucidated in 2013.

Candidate Higgs Decay to four muons recorded by ATLAS in 2012 (Image: ATLAS/CERN).

Interesting articles about the Higgs Boson on the tenth anniversary of its discovery are the following:

https://arxiv.org/abs/2207.00043

https://www.nature.com/articles/d41586-022-01819-4



R E C E N T   N E W S


We present here some of the most recent and interesting news, according to our criteria, about Particle Physics that have CERN (and the LHC, in particular) as a protagonist.

Other news from earlier times here...



CERN Public Events 2025.

Jan, 2025

To celebrate the International Year of Quantum Science and Technology, CERN invites you take part in its public conferences, which will showcase quantum through five distinct events, each representing a type of art.

Image CERN

 More here...



Clocking nature’s heaviest elementary particle.

Jan, 2025

In a first measurement of its kind at the LHC, the CMS experiment tests whether top quarks adhere to Einstein’s special theory of relativity, and improves the bounds on noncompliance by up to a factor of one hundred with respect to previous results.
Special relativity has stood the test of time. However, some theories, for instance particular models of string theory, predict that at very high energies, special relativity will no longer work. In particular, experimental observations could become dependent on the orientation of the experiment in space-time.That could be observable at lower energies, such as at the energies of the LHC.

(Image CERN)

More precisely, since the earth is rotating around its axis, the LHC beam and the average direction of top quarks produced in collisions at the center of the CMS detector also changes depending on the time of the day.
The new CMS result, which is based on data from the second run of the LHC, agrees with a constant rate, meaning that Lorentz symmetry is not broken and Einstein’s special relativity remains valid.

More here...



The most precise measurement of the lifetime of the electrically neutral B meson.

Dec, 2024

The ATLAS collaboration has released a new high-precision measurement of the lifetime of the electrically neutral beauty (B0) meson – a hadron composed of a bottom antiquark and a down quark.

The new ATLAS precision measurements enhance the understanding of weak-force-mediated decays in the Standard Model and provide valuable data for future theoretical developments.

More here...




LHCb sheds light on two pieces of the matter–antimatter puzzle.

Dec, 2024

The collaboration LHCb has found evidence of CP violation in decays of baryons and in decays of beauty hadrons into charmonium particles.

(CERN Image)

In two new articles, the LHCb collaboration reports seeing evidence of CP violation in decays of baryons and in decays of beauty hadrons into charmonium particles.

The two studies mark significant steps towards establishing whether or not CP violation exists in these types of decays. Data from the third run of the LHC and from the collider’s planned upgrade, the High-Luminosity LHC, are set to shed further light on these and other pieces of the matter–antimatter puzzle.

More here…



ALICE finds first ever evidence of the antimatter partner of hyperhelium-4.

Dec, 2024

The ALICE measurement is based on lead–lead collision data taken in 2018 at an energy of 5.02 teraelectronvolts (TeV) for each colliding pair of nucleons (protons and neutrons). Using a machine-learning technique that outperforms conventional hypernuclei search techniques, the ALICE researchers looked at the data for signals of hyperhydrogen-4, hyperhelium-4 and their antimatter partners. Candidates for (anti)hyperhydrogen-4 were identified by looking for the (anti)helium-4 nucleus and the charged pion into which it decays, whereas candidates for (anti)hyperhelium-4 were identified via its decay into an (anti)helium-3 nucleus, an (anti)proton and a charged pion.

(CERN Image)

Hypernuclei are exotic nuclei formed by a mix of protons, neutrons and hyperons, the latter being unstable particles containing one or more quarks of the strange type.

More here…



Particle accelerator conducting real scientific research in CERN Science Gateway.

Dec, 2024

After years of development, the proton accelerator ELISA (Experimental Linac for Surface Analysis) is now being used for archaeological research at Science Gateway, CERN’s education and outreach centre.

This marks the first time a proton accelerator of this kind has been used for research as a part of a museum exhibition

More here...


More news...




... and to know what is coming see HL-LHC: High Luminosity and also The Future Circular Collider.


Professor Mark Thomson selected as the new Director-General of CERN from 2026.

Nov, 2024

The CERN selected British physicist Mark Thomson as the Organization’s next Director-General. The appointment will be formalised at the December session of the Council and Professor Thomson’s five-year mandate will begin on 1 January 2026.

 

Professor Thomson is currently the Executive Chair of the Science and Technology Facilities Council (STFC) in the United Kingdom and a Professor of Experimental Particle Physics at the University of Cambridge. He has dedicated much of his career to CERN, where he initially contributed to precision measurements of the W and Z bosons in the 1990s, as part of the OPAL experiment at CERN’s Large Electron–Positron Collider. At CERN’s Large Hadron Collider (LHC), he has been a member of the ATLAS collaboration.

More here...


Fabiola Gianotti, CERN Director General until the end of 2025.

At its 195th Session (Nov 2019), the CERN Council selected Fabiola Gianotti, as the Organization’s next Director-General, for her second term of office. Gianotti’s new five-year term of office goes from 1 January 2021 to Decembrer 2025.

(Image CERN)

This is the first time in CERN’s history that a Director-General has been appointed for a full second term.


IMPORTANT NOTICE           

For the bibliography used when writing each Section in this Website please go to the References Section

We reiterate that the calculations that you will be finding in this Website are adapted from the Physics of Secondary School and in most cases they are just very simple approaches to the correct results.

Besides the Sections of this Website, it may be interesting to take a look at other documents or websites which give simple description of Particle PhysicsFor exampleAn Introduction To Particle Physics or A brief introduction to Particle Physics or other ones that you can find in the section Education of this website. Please note that some of these documents or websites are not up to date, but we believe that they still provide good information to get started in particle physics.

We insist that this Website has received the permissión of CERN to use informations, data, texts and images from CERN websites. The use on this Website of the various materials from publications produced by CERN is strictly in accordance with CERN's terms of use.

The rest of images, graphs, etc., not belonging to the authors of this website, have been taken as "fair use" qualification, but, please, let us know if that is not the case, and they will be removed immediately.

 

Glossary with an alphabetical list of particle physics terms is included in the last section of this website.


 

AUTHORS


Xabier Cid Vidal, PhD in experimental Particle Physics for Santiago University (USC). Research Fellow in experimental Particle Physics at CERN from January 2013 to Decembre 2015. He was until 2022 linked to the Department of Particle Physics of the USC as a "Juan de La Cierva", "Ramon y Cajal" fellow (Spanish Postdoctoral Senior Grants), and Associate Professor. Since 2023 is Senior Lecturer in that Department.(ORCID).

Ramon Cid Manzano, until his retirement in 2020 was secondary school Physics Teacher at IES de SAR (Santiago - Spain), and part-time Lecturer (Profesor Asociado) in Faculty of Education at the University of Santiago (Spain). He has a Degree in Physics and a Degree in Chemistry, and he is PhD for Santiago University (USC) (ORCID).

CERN


CERN WEBSITE

CERN Directory

CERN Experimental Program

Theoretical physics (TH)

CERN Experimental Physics Department

CERN Scientific Committees

CERN Structure

CERN and the Environment

LHC


LHC

Detector CMS

Detector ATLAS

Detector ALICE

Detector LHCb

Detector TOTEM

Detector LHCf

Detector MoEDAL

Detector FASER

Detector SND@LHC

 


 IMPORTANT NOTICE

 For the bibliography used when writing this Section please go to the References Section


© Xabier Cid Vidal & Ramon Cid - rcid@lhc-closer.es  | SANTIAGO (SPAIN) |

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