# Presentation: 181187

_**COSMO-02**_

## Quarks to the Cosmos

**Quarks to the Cosmos**

**how remarkable!**

## physics is not an onion!

**tears of the antireductionists**

**physics on the tiniest scales**
**informs us about physics on**
**the very largest scales, and**
**vice-versa.**

**physics is not an onion!**

## a puzzle:

**a puzzle:**

##  gravity is weird

**because of two remarkable facts:**

** ****gravity is weird**

** ****the universe is weird**

## gravity is weird

**effective field theory says that high energy physics**
**is ****irrelevant**** for low energy physics – it can be replaced**
**by matching conditions + operators suppressed by**
**powers of ****(low momenta)/(big mass scales)**

**by this argument, gravity should be irrelevant**
**for large scale physics!**

## gravity is weird

**but in fact gravity is a long-range force**
**with no screening **
**so on large scales it actually dominates.**

## the universe is weird

**because the universe is**
**large, homogeneous,**
**transparent, ... we**
**can reconstruct its**
**history**

## particle accelerators

**the program for this decade**

**five main activities in HEP:**

**all of them important for cosmological questions**

** ****energy frontier colliders**
** ****heavy quark factories**
** ****neutrino beams**
** ****rare processes**
** ****precision measurements**

## energy frontier colliders

**energy frontier colliders**

**Fermilab Tevatron Collider**

**CERN Large Hadron Collider (2007)**

**explore the TeV energy scale**

**what are we looking for?**

## supersymmetry

**susy is not a model**
**susy is a spontaneously broken spacetime symmetry**

## supersymmetry

**Tevatron mass reach:   400 – 600 GeV for gluinos,**
**                                        ****150 – 250 GeV for charginos and **
**                                                                  ****neutralinos**
**                                        ****200 – 300 GeV for stops and sbottoms**

**LHC reach:   1 – 3 TeV for almost all sparticles**
**                               **

**If  susy has anything to do with generating the**
**electroweak scale, we will discover sparticles soon.**

## extra dimensions 

**Tevatron reach:**
**M* ~ 1 – 2 TeV**
**LHC reach:**
**M* ~ 5 – 7 TeV**

**look for graviton production**
**with M* suppressed couplings**

## heavy quark factories

**BaBar, Belle, CLEO, CDF, D0, LHC-b, BTeV,...**

**big question: what are the sources of CP violation?**

## neutrino beams

- MiniBooNE neutrino beam

**neutrino beams**

**MiniBooNE, NUMI/Minos, CNGS, JHF, ...**

- high intensity, high purity, known composition

## precision measurements

**precision measurements**

**the anomalous magnetic moment of the muon can be**
**measured very precisely; it is sensitive, through**
**loop effects, to new particles like smuons and charginos **

**The Brookhaven**
**g-2 experiment**
**has reported**
**surprising results:**

## if this is new physics, it is probably susy, and the Tevatron will confirm it.

**if this is new physics, it is probably susy, and the Tevatron will confirm it.**

**if it is not new physics, it constrains susy models significantly**

## particle accelerators

**the program for this decade**

**cosmology questions that we attack ****directly:**

** ****what is the dark matter?**

** ****what is going on with baryo/lepto genesis?**

**  ****are there effects of extra dimensions**
** ****at accessible scales?**

## Dark Matter

**CDM candidates that can be**
**produced and identified at colliders:**

** ****neutralinos**
** ****sneutrinos**
** ****gravitinos**

** ****4****th**** generation neutrinos**
** ****mirror partners**
** ****messenger particles**
** ****lightest Kaluza-Klein particles**

## neutralino dark matter

**we are closing in fast on either discovery or exclusion!**

**there is a great degree of complementarity**
**between direct, indirect, and collider searches**

**J. Feng et al, L. Roszkowski et al, P. Nath et al, ...**

## 

************

************

**J. Feng, K. Matchev, F. Wilczek**

## How do we detect neutralino DM at colliders?

**look at missing energy signatures:**
**QCD jets + missing energy**
**like-sign dileptons + missing energy**
**trileptons + missing energy**
**leptons + photons + missing energy**
**b quarks + missing energy**
**etc.**

## CDF 300 GeV gluino candidate:

**CDF 300 GeV gluino candidate:**
**gluino pair strongly produced,**
**decays to quarks + neutralinos**

## how likely are we to discover neutralinos

**sooner rather than later?**

## good news for

**good news for**
**the Tevatron**

## good news for

**good news for**
**direct searches, too!**

## sneutrino dark matter

**if sneutrinos are the LSP, they are dark matter**
**but there are problems:**

**LEP measurement of the invisible width of the Z boson**
**implies M_sneutrino > 45 GeV**
**but then expect low abundance due to rapid annihilation**
**via s-channel Z and t-channel neutralino/chargino exchange.**

## sneutrino dark matter

**L. Hall et al (1997): susy with lepton flavor violation can split**
**the sneutrino mass eigenstates by  ~> 5 GeV, enough**
**to suppress the annihilation processes**

**however, the same interaction seems to induce at**
**least one neutrino mass ~> 5 MeV.**

**this is now excluded completely by SuperK + SNO +**
**tritium beta decay.**
**it appears that sneutrinos are ruled out as the**
**dominant component of CDM**

## gravitino dark matter

**Large classes of susy models, i.e. gauge-mediated and**
**other low-scale susy breaking schemes, produce light**
**(keV) gravitinos that overclose the universe.**

**Fujii and Yanagida have found a class of**
**“****direct” gauge mediation models where the decays**
**of light messenger particles naturally dilutes the**
**gravitino density to just the right amount!**

**Such models have distinctive collider signatures**

## Kaluza-Klein dark matter

**See talk by Tim Tait**

**If we live in the bulk of the extra dimensions,**
**then Kaluza-Klein parity (i.e. KK momentum)**
**is conserved.**
**So the lightest massive KK particle (LKP) is stable**

**Could be a KK neutrino, bino, or photon**

## How heavy is the LKP?

**Current data requires ****M****LKP ****~> 300 GeV**

**LKP as CDM requires ****M****LKP ****~ 650 –850 GeV**** **

**the LHC collider experiments will certainly see this!**

## furthermore, we should have signals from

**furthermore, we should have signals from**
**direct searches, including positrons for AMS**

**H-C Cheng, J. Feng, K. Matchev**

## colliders and baryogenesis

**see talk by Mark Trodden**

**Baryogenesis requires new sources of CP violation**
**besides the CKM phase of the Standard Model**
**(or, perhaps, CPT violation).**

**B physics experiments look for new CP violation**
**by over-constraining the unitarity triangle**

**Susy models are a promising source for extra phases**

## electroweak baryogenesis

**since colliders will thoroughly explore the**
**electroweak scale, we ought to be able to reach**
**definite conclusions about EW baryogenesis**

**EW baryogenesis in susy appears very constrained,**
**requiring a Higgs mass less than 120 GeV, and a**
**stop lighter than the top quark**

**M Carena et al**

## such a light stop will be seen at the Tevatron

**such a light stop will be seen at the Tevatron**

## (high luminosity) is essential 

**At Fermilab we can also search for higgs bosons with mass**
**up to 190 GeV, i.e. the preferred range from precision data,**
**and are very likely to discover an MSSM higgs.**

**Superb performance of the accelerator and detectors**
**(high luminosity) is essential**** **

**But it will not be easy**

## where

**where**

**in warped extra dimensions models, modifications**
**of the Friedmann equation can help electroweak**
**baryogenesis:**

**see talk by G. Servant**

## Summary

**There is an excellent chance to discover the identity**
**of dark matter in the next few years**

**There is an excellent chance for enlightenment**
**about baryogenesis, especially EW baryogenesis,**
**in the next few years**

**A discovery of either supersymmetry or extra**
**dimensions (or both) at the TeV scale, will**
**have profound consequences for cosmology**