Future directions in High Energy Physics

Nekrasov M. Dmitriy

Kyungpook National University

2003.

The future of high energy physics lies in the questions that are being posed in particle physics and astrophysics.

For the last 50 years , particle physics and high energy physics have been almost synonymous.

We should made progress in understanding the structure of matter and energy by building accelerators with ever high energy

What is “LHC”?

The Large Hadron Collider (LHC)

is a particle accelerator which will

probe deeper into matter than

ever before. Due to switch on in

2007, it will ultimately collide

beams of protons at an energy of

14 TeV . Beams of lead nuclei will

be also accelerated, smashing

together with a collision energy of

1150 TeV.

How does the “LHC” work?

By using superconductivity. To keep the LHC's beams on track needsstronger magnetic fields than have ever been used before in a CERNaccelerator. Superconductivity makes such fields possible, but a superconductinginstallation as large as the LHC has never before been built. Intensive R&D withEuropean industry has shown that it can be done. At the end of 1994, an importantmilestone was reached with the first operation of an entire prototype section of theaccelerator.. The LHC will operate at about 300 degrees below room temperature,even colder than outer space. With its 27 km circumference, the accelerator will be thelargest superconducting installation in the world. Because the LHC will accelerate twobeams moving in opposite directions, it is really two accelerators in one. To keep themachine as compact and economical as possible, the magnets for both will be built into asingle 2-in-1 housing.The LHC will be built in the same tunnel as CERN's LargeElectron Positron collider, LEP, and so will cost much less than a similar machine on agreen field site. Proton beams will be prepared by CERN's existing accelerator chainbefore being injected into the LHC.

“TESLA”"TESLA" A new large-scale facility is currently beingplanned and developed by an internationalcollaboration at the Deutsches ElektronenSynchrotron DESY in Hamburg, Germany.TESLA - the acronym stands for:

• T era Electron Volt• E nergy• S uperconducting• L inear• A ccelerator

opens up new possibilities for both research anda broad range of applications in a variety of fields.Characterized by an unusual degree of versatility,the new facility is ideally suited to form the heartof an innovative, interdisciplinary research anddevelopment center.

• some facts...• total length 33 km

• two linear accelerators with 15 km each

• accelerator tunnel with approx. 5 m diameter

• collision energy of 500 Giga Electron Volt X-ray wavelength of 5 to 0.05 nanometer superconducting accelerating structures approx. 20 000 accelerating structures operating temperature of 2 K, i.e. -271 deg Celsius

Fermilab• With recent discoveries that neutrinos carry a tiny bit

of mass, physicists are avidly pursuing detailed studies of these ghostly particles. Thus two experiments under construction at Fermi lab are poised to make important contributions. Beginning in 2002, the MiniBooNE experiment will attempt to confirm whether muon neutrinos are indeed "oscillating" into electron neutrinos, as suggested by a Los Alamos experiment. If so, MiniBooNE researchers will obtain many more examples of this conversion process, which would indicate the existence of a strange new type of neutrino beyond the three known kinds.

• Another Fermi lab experiment called MINOS will observe how muon neutrinos convert into tau neutrinos. Assembly of its major detector, deep underground in the Soudan mine in northern Minnesota, began in July 2001, and should be completed in 2003. This summer a portion of the detector will begin observing neutrinos produced in the atmosphere by cosmic rays. The full detector will eventually examine a neutrino beam coming from Fermilab, 450 miles away.

NiniBooNe phototubes wil detect light produced by electron-neutrino interactions

Minos• Physicists have recently detected ultrahigh-energy

cosmic rays hitting the earth's atmosphere with energies above 100 billion GeV — 100 million times that of protons accelerated at Fermilab. When these cosmic rays interact in the atmosphere, they generate enormous showers of subatomic particles, covering many square miles at ground level. An international collaboration of 250 physicists from 18 countries, supported in part by DOE and the National Science Foundation, is now constructing the world's largest experiment, the Pierre Auger Observatory, to study these stupendously energetic particles and trace them back to their violent astrophysical origins. They will deploy two arrays, each with more than 1,600 detectors spread out over 1,000 square miles, in Utah and Argentina. During 2001, a prototype 40-detector array began operations in Argentina and has already recorded several extensive cosmic-ray showers. The physicists will continue collecting data as more detectors are added between now and 2004.

Two detectors in the Argentina array guarded by the Andes Mountains.

Summary four questions…

1. What is the source of electroweak symmetry breaking?

2. Why is there a preponderance of matter in our part of the universe ,when the lows of physics that seem to govern the subatomic universe put matter and antimatter on the same footing?

3. What is the cause of the unexpected and unexplained deficit of electron neutrinos emerging from the sun , and the cause of the unexplained ratio of electron neutrinos produced when cosmic rays slam into the upper atmosphere?

4. What is the universe made of?

References

http://tesla.desy.de

http://www.sc.doe.gov

http://public.web.cern.ch