¿ de qué está hecho el universo - projects.ift.uam...

Carlos Muñoz

Residencia de Estudiantes, Madrid, 6 Noviembre 2014

¿ De qué está hecho el Universo ?de las partículas elementales a la materia oscura

Carlos Muñoz

IFT UAM-CSIC

¿De qué está hecho el Universo? 2

RESUMEN

1. Solo entenderemos la composición del Universo si conocemos las

partículas elementales que lo constituyen y las fuerzas que se ejercen

entre ellas

• Describiremos todas las partículas y las interacciones conocidas

3. Supersimetría, Supercuerdas, ...

• ¿De qué está hecha la materia oscura?

2. Después especularemos

• ¿Hacen falta más partículas en nuestra lista?

Carlos Muñoz

IFT UAM-CSIC


Esta charla, al ser la primera, espero que sirva de introducción a otras

charlas posteriors de este ciclo donde se desarrollarán de forma mucho más

extensa temas que aquí solo se introducen:

Higgs, quarks y gluones, cuerdas, cosmología, etc.

What is the Universe made of? 4

finalized in 1948 whenFeynman, Schwinger, Tomonagashowed it was renormalizable(Nobel Prize in 1965)

The mess at the beginning of the 20th century:Heat, magnetism, electricity, light, X-rays, ultraviolet rays, …

QED is a quantum field theory, wherethe particles are excitations of the fields

What is the Universe made of? 5Carlos Muñoz

IFT UAM-CSIC


IFT UAM-CSIC

Carlos Muñoz What is the Universe made of?

Gell-Mann (Nobel Prize in 1969)Zweig 1964, proposed quarks

Friedman, Kendall & Taylordiscovered the quarks in 1967-73 at SLAC (Nobel Prize in 1990)

QCD was finalized in 1973 when Gross & Wilczek, Politzerproposed asymptotic freedom(Nobel Prize in 2004)

What is the Universe made of?8

m = 1/7 mp


IFT UAM-CSIC

¿De qué está hecho el Universo? 10Carlos Muñoz

IFT UAM-CSIC

(-1/3)

(+2/3)

(-1)

Glashow, Weinberg, Salam,proposed the electroweak theorySU(2)XU(1) in 1960’s(Nobel Prize in 1979)

Rubia, Van der Meer,discovered W, Z in 1983 at CERN(Nobel Prize in 1984)

‘t Hooft, Veltman,showed it was renormalizablethanks to the Higgs mechanismin early 1970’s(Nobel Prize in 1999)

La emission de neutrinos está asociada a la desintegración beta. Parecía que este procesono conservaba la energía y eso llevó a Pauli a postular la existencia de una partícula nueva (el neutrino)

25 años más tarde, Reines lo descubrió(Nobel Prize in 1995)

la carga está relacionada con el estado de

movimiento y no con el tipo de partícula

(aquellas con espín anti-paralelo a la

dirección del movimiento poseen carga débil)

Carlos Muñoz

IFT UAM-CSIC


IFT UAM-CSIC

~0.00000001


IFT UAM-CSIC

~0.00000001

Mendeleiev, 1869

~1970’s

15

Kobayashi & Maskawa,predicted in 1972 a third familiy of quarks(Nobel Prize in 2008)

b and t discovered in 1977 and 1995 at Fermilab

Mendeleiev, 1869

~0.00000001

~1970’s

H~125000

And, in addition, the Higgs boson exists!

16

Glashow, Iliopoulos & Maiani,predicted in 1970 the quark c

Richter at SLAC, Ting at BNLdiscovered it in 1974 (Nobel Prize in 1976)

The Higgs is not just another elementary particle

Englert & Brout,proposed this mechanism in 1964.Higgs also the particle associated(Nobel Prize in 2013) Almost 50 years later, LHC discovered it

It has a huge mass = 125 mp . Only the top quark is heavierIt’s a scalar. The first known elementary particle with spin=0

The Higgs (field) defines the vacuum. Since <0|H|0>=v≠0, wecan imagine the quantum vacuum as a sea full of the Higgs field(rather like the concept of the ether of one century ago!)

All particles interact with the Higgs field, getting their unique masses.


IFT UAM-CSIC


Besides, the standard model providesthe fundaments of the early Universe cosmology

Carlos Muñoz

IFT UAM-CSIC


History

Symmetries are crucial in physics

The laws of modern physics are invariant under certain symmetries:

Lorentz transformations [special relativity] Local gauge transformations [SU(3)CxSU(2)LxU(1)Y]

Supersymmetry (SUSY) was proposed in the early 1970’s:Golfand, Likhtman, 1971

Volkov, Akulov, 1972Wess, Zumino, 1974

SPECULATION: Do other particles exist still undetected ?

Carlos Muñoz

IFT UAM-CSIC


Boson Fermion

Fermion Boson

But known bosons and fermions are not married up in this fashion

Quarks (u,d)ElectronNeutrino

GluonsW, Z

Photon

Instead, every known particle should have a (super) partner Fayet, 1976

The spectrum of elementary particles is doubled ! With masses 1000

QuarksElectronNeutrino

SquarksSelectronSneutrino

GluonsPhoton

W, Z

GluinoPhotinoWino, Zino

An invariance of the theory under interchange of fermions and bosons

L (bosons, fermions) L (fermions, bosons) = L (bosons, fermions)

mp

Carlos Muñoz

IFT UAM-CSIC


~0.00000001

H~125000

spin 0 particle

Carlos Muñoz

IFT UAM-CSIC


~0.00000001

Hu , Hd

~125000

spin 0 particles

Hu , Hd

spin 1/2 particle

~ ~

Carlos Muñoz

IFT UAM-CSIC


( 1000 mp )( 100 mp )

msusy 1000 mp

.

Carlos Muñoz

IFT UAM-CSIC

LEP LHC

28

E.g., in 2012 with a luminosity of 20 fb-1 and a QCD jet production cross sectionof 106 pb, 2x1010 events of this kind were produced. These are just background events, but they have to be analyzed!! in order to find the new physics

But no more than 2x106 events of this kind can be produced!!

Detection of the Higgs

In spite of the huge backgrounds, ATLAS and CMS detectors at the LHC were able to observe the Higgs in 2012.

(gg H) 10 pb H clean decay

¿De qué está hecho el Universo?38

Carlos MuñozIFT UAM-CSIC

…perhaps it is one of the Higgses also predicted by models beyond the standard model…

already ~ 1 million Higgses produced at LHC

http://www.google.es/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&docid=syMraJJZ7ZrmiM&tbnid=akCxQfIg1zf_FM:&ved=0CAUQjRw&url=http://kjende.web.cern.ch/kjende/en/zpath_hevents.htm&ei=6B7sUYGvGabF0QW31oGADg&bvm=bv.49478099,d.ZGU&psig=AFQjCNHIhMHwUQJBYai3jUKY8YXFvwAe_g&ust=1374515271674639

http://www.google.es/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&docid=syMraJJZ7ZrmiM&tbnid=akCxQfIg1zf_FM:&ved=0CAUQjRw&url=http://kjende.web.cern.ch/kjende/en/zpath_hevents.htm&ei=6B7sUYGvGabF0QW31oGADg&bvm=bv.49478099,d.ZGU&psig=AFQjCNHIhMHwUQJBYai3jUKY8YXFvwAe_g&ust=1374515271674639

¿De qué está hecho el Universo?38

Carlos MuñozIFT UAM-CSIC

Englert, Higgs, Nobel Prize in 2013

Be prepared for more Nobel Prizes thanks to the LHC

Particle physics is living a historical moment:

-Years before the LHC, too early to test any model or theory

-Years later, too late, the unknown will already be known


MORE SPECULATIONS: What about gravity?

Carlos Muñoz

IFT UAM-CSIC


Might be finite

Carlos Muñoz

IFT UAM-CSIC

Schwarz, Scherk, 1974Green, Schwarz, 1984

Carlos Muñoz Metaphysics 36


~0.00000001

Hu , Hd

~125000

spin 0 particles

Hu , Hd

spin 1/2 particle

~ ~

All this zoo is unifiedin an unique fundamental object

Carlos Muñoz

IFT UAM-CSIC

38¿De qué está hecho el Universo?Carlos Muñoz

IFT UAM-CSIC

Materia Oscura 46

Summarizing: Apart from speculations, everything in the Universe is made of quarks and leptons,

exchanging photons, W, Z, gluons (also gravitons?) in the Higgs vacuum

EVERYTHING ?

One of the great enigmas still unsolved is the existence of dark matter

Carlos Muñoz

IFT UAM-CSIC

giant galaxy cluster CL0025+1654, about 1000 Mpc away

The analysis reveals that the cluster's dark matter (shown in blue) is not evenly distributed, but follows the clumps of luminous matter closely

Carlos Muñoz Materia Oscura 50

A SOLUTION

To assume that there is non-luminous matterin and around the Galaxies

It has gravitational interaction but no electromagnetic interaction

Zwicky, 1933

This hypothesis is not so odd if we remember that the existence of Neptunewas suggested on the basis of the irregular motion of Uranus

85% of the matter in the Universe is dark

As often remarked, this impliesanother Copernican revolution:

We are not the center of the Universe

+

We are not made of what most of the Universe is made of !

Carlos Muñoz

IFT UAM-CSIC

Materia Oscura 76

BUT…also Dark Energy !!

Perlmutter, Schmidt, Ries,discovered in 1998 the acceleratingexpansión of the Universe(Nobel Prize in 2011)

Carlos Muñoz

IFT UAM-CSIC

Materia Oscura 77

http://www.google.es/url?sa=i&rct=j&q=planck+results&source=images&cd=&cad=rja&docid=ssIUhldXVl-mTM&tbnid=J8QNwd9SqFBcBM:&ved=0CAUQjRw&url=http://blogs.discovermagazine.com/outthere/2013/03/22/four-surprises-in-plancks-new-map-of-the-cosmos/&ei=UdyPUeGZA4aG0AXisoHIBA&bvm=bv.46340616,d.ZGU&psig=AFQjCNFhrK95RyXfFg1f4FeagZfCjeXoLQ&ust=1368468918871780

http://www.google.es/url?sa=i&rct=j&q=planck+results&source=images&cd=&cad=rja&docid=ssIUhldXVl-mTM&tbnid=J8QNwd9SqFBcBM:&ved=0CAUQjRw&url=http://blogs.discovermagazine.com/outthere/2013/03/22/four-surprises-in-plancks-new-map-of-the-cosmos/&ei=UdyPUeGZA4aG0AXisoHIBA&bvm=bv.46340616,d.ZGU&psig=AFQjCNFhrK95RyXfFg1f4FeagZfCjeXoLQ&ust=1368468918871780

Thus to decipher the nature of the dark matter is one of the great enigmas still unsolved

Materia Oscura 56

Within the Standard Model of particle physics there are no candidates

This is a clear indication that we need to go

beyond the standard model of particle physics

PARTICLE CANDIDATES

Carlos Muñoz

IFT UAM-CSIC

i.e. we need to speculate

We need a new particle with the following properties:

Stable or long-lived

Neutral Otherwise it would bind to nuclei and would be excluded from unsuccessful searches for exotic heavy isotopes

Produced after the Big Bang and still present today

Reproduce the observed amount of dark matter

Could this new particle be a supersymmetric particle?

Carlos Muñoz

IFT UAM-CSIC

photino, sneutrino, gravitino

the question now is: Can we detect it in experiments ?

Let us then assume that this kind of particles existand that any of them is the dark matter

Materia Oscura 55

DETECTION

The LHC could detect a new kind of particle

…but how can we be sure it is stable on cosmological scales?

58Carlos Muñoz

IFT UAM-CSIC

A complete confirmation can only arise from experimentswhere the particle is detected as part of the galactic halo

DETECTION

Since the detection will be on the Earth or on satellites, we only needto know the properties of the Galactic halo near the Earth

For m ~ 100 mp these imply

J ~ 100,000 particles/cm2 s,

and therefore direct detection through elasticscattering with nuclei in a detector is possible

Goodman, Witten, 85Wasserman, 86

Carlos Muñoz Materia Oscura 62

experiment: Installing the detectors

inside the copper box and shield

View of some detectors

in the copper box in

progress of installation

Annihilation of dark matter particles in the galactic halo will produce gamma rays, antimatter, neutrinos

and these can be measuredin space–based detectors:Fermi (gammas), PAMELA, AMS (antimatter)

or Cherenkov telescopesMAGIC, HESS, VERITAS, CANGAROO (gammas)

INDIRECT DETECTION

Materia Oscura 63Carlos Muñoz

IFT UAM-CSIC

63

Dark matter can accumulate in the Sun or the Earth. Its annihilation willproduce neutrinos which can be detected in neutrino telescopes, speciallythrough the muons produced by their interactions in the rock

Underwater experiments(ANTARES with a size of 104

m2. In the future KM3NeTwith a size of 106 m2 )

Under-ice experiments(IceCube witha size 106 m2 )


CONCLUSIONS

Supersymmetry, that predicts that every known particle should have a partner, has candidates for dark matter, which could be tested in the LHC and in direct and indirect detection experiments

However, one of the great enigmas still unsolved is the existence of dark matter

Within the standard model there are no possible candidates, thus we need to assume the existence of new particles

The standard model of particle physics “almost” answers the question: What is the Universe made of?

Supersymmetry is not sufficient to unify gravity with the otherinteractions in Nature, but perhaps string theory allow us to achive thisgoal

Carlos Muñoz

IFT UAM-CSIC

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