Nobel Laureate Abel Laureate Advisory Board Member USERN President USERN Policy Making Council USERN Manager USERN Deputy Junior Ambassador

Major: Physics

Field: Particle and nuclear physics

Alberto Ruiz Jimeno


Field: particle physics

I am a  researcher at the Institute of Physics of Cantabria (CSIC-University of Cantabria). Area of specialisation, High Energy Physics.

Professor Emeritus of the University of Cantabria, from 1-9-2022.

Professor of Atomic, Molecular and Nuclear Physics at the University of Cantabria from 1991 to 2022.

Scientific Associate at CERN, since 1982.

Visiting Scientist at Fermi National Laboratory, Fermilab, since 1999.

Founder of the High Energy Group of the Institute of Physics of Cantabria, 1995.

Coordinator of the Spanish Network of Future Colliders, since 2005.

Spanish delegate to the International Particle Physics Outreach Group (IPPOG), since 2006.

Acknowledgements and awards:

- 2022 Silver Medal of the University of Cantabria

- 2016, member of the Science Selection of the Spanish National Research Council (CSIC) and the journal QUO, 2016.

- Research Award of the Social Council of the University of Cantabria 2007.


- Founder of the first Doctoral School in Spain, at the University of Cantabria, in 2010.

- Director of several doctoral theses on topics of great relevance in experimental particle physics.

- Member of the Award Thesis Committee of the large CMS collaboration at the European Particle Physics Laboratory, CERN, since 2013.

- President of the Cantabria Local Section of the Royal Spanish Physics Society, RSEF, 2010-2020.

- Member of the Board of Directors of the Spanish Association for the Advancement of Science (AEAC), since 2021 and Founding Director and Physics coordinator of the Gadea Foundation.

Vice-Rector for Doctoral Studies and Institutional Relations of the University of Cantabria, 2016-2020.

I have participated in several particle accelerator experiments: DELPHI at CERN's Large Electron and Positron Collider (LEP), CDF at Fermilab's Tevatron collider, and CMS at CERN's Large Hadron Collider (LHC). I am also a member of the Physics and Speakers Board of the ILD collaboration for the future collider, Higgs factories projects.

I have signed more than 2000 scientific papers. The main scientific contributions in which I have participated are the following:

- The discovery of the Higgs boson, by CMS at the LHC, 2012.

- Evidence of Higgs boson production decaying to a bottom-antibottom quark pair in the Tevatron CDF experiment, Fermilab, in 2012, through the production associated with the W boson.

- Major advances in b-quark physics at the CDF experiment at the Tevatron (Fermilab, USA), particularly concerning the so-called CP violation and the oscillations between matter and antimatter in hadrons with bottom content. One of the major discoveries in I  was directly involved was the observation of the Bs(0)/antiBs(0) oscillations and, later, the more precise determination of the ratio of the fundamental parameters of the Cabibbo-Kobayashi-Maskawa matrix, |Vtd/Vts| .

- In the context of the top quark, I have  contributed, in the CDF experiment, to very precise measurements of its mass and its production cross section. Another important result, the subject of a thesis work led by myself, was the discovery of the electroweak production of the top quark, the single-top, providing the best measurement of another of the fundamental Cabibbo-Kobayashi-Maskawa parameters, the Vtb,

- The precise measurement of the mass and width of the Z0 boson, in the DELPHI experiment at LEP (CERN) in 1991. I was the coordinator at DELPHI of the physics of the tau lepton.

- The number of light neutrino families in the DELPHI experiment at LEP (CERN) in 1991. From the results of the decay width of the Z boson, it was possible to determine with high precision the number of neutrino families with a mass less than half the Z mass.

- The precise properties of the tau lepton in the DELPHI experiment at LEP (CERN) between 1989 and 2000.

-  I was involved in the study of the physics of heavy, second and third generation quarks, in particular charm and bottom quarks. Charm-anticharm photoproduction experiments WA34, WA45 and WA58, using fixed targets of nuclear emulsions and high-energy photon beams, at CERN's Omega facility, from 1977 to 1984. In these experiments, the associated charm-anticharm photoproduction was photographed for the first time and very precise measurements of the charm quark decay time were made, thanks to the 1-micron sensitivity of the nuclear emulsions.

- I was also involved in the study of the nuclear interactions of hadrons with emulsion nuclei, in order to understand the collective and individual mechanisms of the collisions of the target and beam hadron components.  This was carried out in collaboration with physicists from Lund (Sweden) and others using proton and pion collisions on emulsion, based on data from the LBL (Berkeley, USA) and Fermilab experiments, between 1975 and 1980.

As for the infrastructure for high-energy physics and transfer I was involved in:

- At the CDF (Tevatron, Fermilab, USA), design and construction of a time-of-flight detector with a precision of one hundred picoseconds.

- Leadership of the Cantabria node, in 1985-1991, one of the few nodes of the Faenet network (integrated in the HEPnet network), which was the germ of the current Spanish academic communication network, "Red Iris".

- Contribution to the development of the World Wide Web, particularly in Spain,where the first web page was built at the Cantabria node in 1994. Also, under the direction of A. Camacho's doctoral thesis, in 1990, on the communication environment for the DELPHI experiment, in collaboration with Tim Berners-Lee for the development of a hyper-language for communication contributing to the research towards the then future www.

- I  was the principal investigator of a European network called "Technical development for LEP detectors", involving groups from LAL (Orsay, France), RAL (UK), CERN, and Padova (Italy).

- I collaborated with some of the pioneers of silicon detectors, Drs. E. Heijne and P. Jarron, at CERN on the WA71 experiment at CERN for bottom photoproduction in nuclear emulsion combined with silicon microstrip detectors.

- Development of new detection techniques by automating microscopes for emulsion measurements, from 1977 to 1982 in collaboration with the CNRS research centre in Strasbourg.

- I have been involved in R&D for Future Accelerators, as coordinator of the Spanish Future Colliders Network which includes experimental groups (CIEMAT-Madrid, IFCA-Santander and IFIC-Valencia), technology centres and departments (UB-Barcelona, US-Seville, ITAINNOVA-Aragon, ITAINNOVA-Aragon and ITAINNOVA-Aragon), ITAINNOVA-Aragon, NTC-Valencia, INTA-Madrid and CNM-IMB-Barcelona), accelerator groups (ALBA-Barcelona, CIEMAT and IFIC), and theoretical groups (UGR-Granada, IFT-Madrid, IFCA-Santander, IFIC-Valencia), as well as the Spanish Science Industry Association, INEUSTAR.



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