Large Apparatus studying Grand Unification and Neutrino Astrophysics or LAGUNA is or was a

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a subcontinent of Eurasia and it is located entirel ...

an project aimed to develop the next-generation, very large volume underground

neutrino A neutrino ( ; denoted by the Greek letter ) is a fermion (an elementary particle with spin of ) that interacts only via the weak interaction and gravity. The neutrino is so named because it is electrically neutral and because its rest mass ...

observatory. The detector should be much bigger and more sensitive than any previous detector, and make new discoveries in the field of particle and astroparticle physics. The project involves 21 European institutions in 10 European countries, and brings together over 100 scientists. As of 2011, the project was assessing the feasibility of developing the observatory-infrastructure and the observatory particle detectors themselves, as well as looking for a deployment site (seven candidates) in

. There have also been propositions of merging the project with similar international projects, like DUSEL. In June 2011, the LAGUNA collaboration finished the Feasibility Studies of building the proposed neutrino detectors. The studies were paid for by the EU (€1.7 million). No further activity is known. As of 2016, the LAGUNA project seems to be defunct. No further development has happened, and it is unclear if any development will happen. Also the similar DUSEL-project in the United States was cancelled. However, the neutrino-component of the DUSEL-project (the Long Baseline Neutrino Experiment, LBNE) was rebooted as the DUNE project. The construction of DUNE started in 2017 in Sanford Lab in

South Dakota South Dakota (; Sioux: , ) is a U.S. state in the North Central region of the United States. It is also part of the Great Plains. South Dakota is named after the Lakota and Dakota Sioux Native American tribes, who comprise a large porti ...

, USA with expected completion 2027. It is expected that, with DUNE under construction, the LAGUNA-project will not be constructed, especially because the DUNE-project was enlarged from a USA-only project into an international project that now comprises many of the researchers worldwide (especially American and European researchers) who work on the topic, thus making the case for LAGUNA construction weaker.

Detectors

There were three possible detector technologies being studied, the MEMPHYS, GLACIER and LENA detectors, MEMPHYS being a water-based detector, GLACIER being liquid argon and LENA liquid scintillator-based. All the detectors work by observing the faint light and electric charge produced when a neutrino particle interacts with a nucleus of the liquid inside the detector. The detectors will be based deep underground (even 1.4 km deep) to filter the noise that is developed by the atmospheric and cosmic particles that bombard everything at the surface of the Earth. These noise particles do not penetrate the Earth at that depth, but the neutrinos that interact only weakly with normal matter do. The detectors will be huge in size, with the liquid target mass being of order 100 000 – 1 000 000 tons.

LENA

LENA (Low Energy Neutrino Astronomy) is a liquid scintillation detector with a mass about 50 kton. Its cylindrical shaped tank with about 100 meters height and 30 meters diameter. The actual scintillation volume is surrounded by nylon barrier and buffer volume. Additionally the buffer volume is surrounded by a pure water volume. The detection mechanism of LENA will be the photomultiplier tubes, which are designed to cover partly the walls between buffer volume and water volume. The scintillation light produced in scintillation volume will be detected with those photomultiplier tubes. LENA's aim is to study low energy neutrinos originated by supernova explosions, Sun and Earth's interior.

Scientific goals

The goals of the project were to: study the unification of all forces by observing

proton decay In particle physics, proton decay is a hypothetical form of particle decay in which the proton decays into lighter subatomic particles, such as a neutral pion and a positron. The proton decay hypothesis was first formulated by Andrei Sakharov ...

(a very rare phenomenon expected to occur according to some

Grand Unified Theory A Grand Unified Theory (GUT) is a model in particle physics in which, at high energies, the three gauge interactions of the Standard Model comprising the electromagnetic, weak, and strong forces are merged into a single force. Although this ...

(GUT) models but never observed), study the galactic supernovae through neutrino-observations, study

terrestrial Terrestrial refers to things related to land or the planet Earth. Terrestrial may also refer to: * Terrestrial animal, an animal that lives on land opposed to living in water, or sometimes an animal that lives on or near the ground, as opposed to ...

and solar neutrinos (neutrinos are formed in nuclear processes), study the excess of matter over antimatter in the universe through observing neutrino oscillations in collaboration with CERN (that provides the neutrino-beams for the experiment; neutrinos are made in the CERN and the sent as underground beam for hundreds of kilometers through the

Earth Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surfa ...

to the detectors).

Sites

The candidate sites for the observatory were: * Callio at Pyhäsalmi Mine (

Finland Finland ( fi, Suomi ; sv, Finland ), officially the Republic of Finland (; ), is a Nordic country in Northern Europe. It shares land borders with Sweden to the northwest, Norway to the north, and Russia to the east, with the Gulf of B ...

) *

Fréjus Road Tunnel The Fréjus Road Tunnel is a tunnel that connects France and Italy. It runs under Col du Fréjus in the Cottian Alps between Modane in France and Bardonecchia in Italy. It is one of the major trans-Alpine transport routes between France and Ital ...

(

France France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of overseas regions and territories in the Americas and the Atlantic, Pacific and Indian Oceans. Its metropolitan area ...

) * Boulby Mine (

United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the European mainland, continental mainland. It comprises England, Scotlan ...

) *

Umbria it, Umbro (man) it, Umbra (woman) , population_note = , population_blank1_title = , population_blank1 = , demographics_type1 = , demographics1_footnotes = , demographics1_title1 = , demographics1_info1 = , ...

(this site requires a new cavern to be excavated, as in contrast to the other sites, this site is not an old mine) (

Italy Italy ( it, Italia ), officially the Italian Republic, ) or the Republic of Italy, is a country in Southern Europe. It is located in the middle of the Mediterranean Sea, and its territory largely coincides with the homonymous geographical ...

) * SUNLAB (Sieroszowice UNderground LABoratory) in Polkowice-Sieroszowice mine (

Poland Poland, officially the Republic of Poland, is a country in Central Europe. It is divided into 16 administrative provinces called voivodeships, covering an area of . Poland has a population of over 38 million and is the fifth-most populou ...

) * Unirea mine in Slănic (

Romania Romania ( ; ro, România ) is a country located at the crossroads of Central, Eastern, and Southeastern Europe. It borders Bulgaria to the south, Ukraine to the north, Hungary to the west, Serbia to the southwest, Moldova to the east, and ...

) * Canfranc Underground Laboratory (

Spain , image_flag = Bandera de España.svg , image_coat = Escudo de España (mazonado).svg , national_motto = ''Plus ultra'' (Latin)(English: "Further Beyond") , national_anthem = (English: "Royal March") , i ...

) From these candidates, the observatory location is chosen (See the project website Laguna sites
/ref> for more information about the sites).

References

External links

{{neutrino detectors Neutrino experiments International science experiments