Origin of Mass in the Universe. Thomas Ry*ov Harvard University DIAS Public lecture Odense

Transcription

1 Origin of Mass in the Universe Thomas Ry*ov Harvard University DIAS Public lecture Odense

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3 Seeking answers to big puzzles in the Universe

4 Seeking answers to big puzzles in the Universe I am a theorist very interested in the LHC

5 Seeking answers to big puzzles in the Universe I am a theorist very interested in the LHC I will tell you about what we know, what we don t know and what we hope to learn

6 Seeking answers to big puzzles in the Universe I am a theorist very interested in the LHC I will tell you about what we know, what we don t know and what we hope to learn People have been wainng 40 years for this

7 Seeking answers to big puzzles in the Universe I am a theorist very interested in the LHC I will tell you about what we know, what we don t know and what we hope to learn People have been wainng 40 years for this What s the fuzz all about? Let s get started!

8 Large 27 km circular tunnel the biggest in the world Hadron parncles made from quarks e.g. protons and neutrons Hadros means fat in Greek Collider accelerator with two beams of parncles colliding at prescribed locanons Long standing quesnons are being addressed as we speek The Standard Model The Higgs Mechanism What lies beyond the Standard Model?

9 Why do we build such a machine? Fact sheet: The worlds most powerful microscope. There are profound mysteries in the Universe we want to find an explananon to. Max energy of a proton = 7 TeV. KineNc energy of mosquito = 1 TeV. In fact, we only know very li*le about the Universe. Only about 4% of its consntuents... Energy per beam = 1 billion million mosquitos = 1 DSB intercity train.

10 We are all made of Nny elementary parncles: quarks and leptons.

11 6 types of quarks and leptons. Nobody knows why. They vary in mass. Nobody knows why. Only few of these are used as building blocks.

12 How do these parncles talk together? How do they bind together to form structures? Protons/neutrons, atomic nuclei, atoms, molecule, etc. They are bound together by fundamental forces/interacnons in the Universe.

13 All known forces can be classified as: γ, Photon ElectromagneNc interacnon e.g. atomic structure q q Strong (nuclear) interacnon e.g. nuclear structure, protons/neutrons q g, Gluon q Weak (nuclear) interacnon e.g. radioacnvity q W +,W -,Z bosons q GravitaNonal interacnon e.g. galaxies, stars, planetary systems q G, Graviton q

14 Distance scales where the forces become important: ElectromagneNc interacnon (atomic scale) Atom radius m. [ ] Strong (nuclear) interacnon Proton size m. [ ] Weak (nuclear) interacnon Higgs mechanism m. [1930- present] GravitaNonal interacnon Quantum space- Nme m. [2150??]

15 Distance scales where the forces become important: ElectromagneNc interacnon (atomic scale) Atom radius m. [ ] Strong (nuclear) interacnon Proton size m. [ ] Weak (nuclear) interacnon Higgs mechanism m. [1930- present] GravitaNonal interacnon Quantum space- Nme m. [2150??]

16 Once upon a Nme Two long range (massless) forces. Weak Isospin and Hypercharge W 1,W 2,W 3 Y

17 Once upon a Nme Two long range (massless) forces. Weak Isospin and Hypercharge W 1,W 2,W 3 Y Higgs Mechanism Rearranges the forces Massive W +,W -,Z. Weak interacnons Massless photon. ElectromagneNc interacnons W +,W -,Z γ Higgs mechanism also gives masses to the ma*er parncles.

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19 Data Hints at Elusive ParNcle, but the Wait ConNnues New York Times Forskere Nærmer sig Løsningen på Universets Gåde Svaret er 126 PoliNken Berlingske

20 One single parncle can do the job The Higgs parncle ParNcles move through the Higgs soup Problem: TheoreNcal

21 We live in 3+1 dimensions If parncles move through the 5th dimesion in the right way the forces also can be rearranged

22 Why add new parncles? TheoreNcal problems are alleviated TheoreNcally very beaunful.

23 The strong force already rearranges the forces a li*le but. But not enough. Need to make a small detour to understand this.

24 Empty space is not really empty!! It is filled with virtual parncle pairs popping in and out of the empty space.

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27 Electric charges become weaker with distance. -

28 Electric charges become weaker with distance. - Color (strong) charges become stronger with distance.

29 At small distances the quarks are free At larger distances the quarks combine to form a soup similar to the Higgs soup. Therefore the strong interacnons rearranges the forces but at the wrong distance scale.

30 Dilaton Has been seen at the LHC?

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32 Outer stars move faster than expected. 1 Modify gravity 2 Existence of Dark Ma*er Dark ma*er consntute about 21% of the mass- energy density of the Universe. Different theories provide different dark ma*er parncles. It might be possible to study it at the LHC.

33 Universe is expanding at an acceleranng rate Dark Energy Unfortunately LHC is not going to tell us what it is.

34 Universe is composed of ma*er - not ann- ma*er. They seem to be produced almost equally. Hopefully LHC will shed light on this.

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