# Presentation: 685579

## I. Partonic Equation of State in High-Energy Nuclear Collisions II. Neutrino PropertiesNu XuNuclear Science DivisionLawrence Berkeley National LaboratoryEmail: NXu@lbl.gov      Webpage: http://www-rnc.lbl.gov/~nxuOffice: (510)495-2951      Cell Phone: (510)384-5112

## “Standard” Model

- “Standard” Model

**Weak Interaction: **is one of the four fundamental forces of nature. It is most commonly seen in beta decay and the associated radioactivity. The weak nuclear force affects all *leptons* and *quarks*. It is the only force affecting *neutrinos*. It is about 1013 time weaker than the strong force.

## The masses

- Higgs mass: electro-weak symmetry breaking. (current quark mass)
- QCD mass: Chiral symmetry breaking. (constituent quark mass)
-   Strong interactions do not affect heavy-quark mass.

- Muller:
- nucl-th/0404015

## Outline

** ****Search for Quark Gluon Plasma (QGP)**
-      - History of the high-energy nuclear collisions
-      - Equation of state with partonic degrees of freedom
-      - Recent progress in STAR at RHIC
** ****Neutrino properties**
-      - Neutrino-less double beta decay
-      - The CUORE experiment at Gran Sasso

## QCD confinement potential

**QCD confinement potential**

- T < T conf

- T > T conf

- constant potential

- linear potential

- r

- V(r,T)

- The potential between quarks is a
- function of distance. It also depends on the temperature.
- 1) At low temperature, the potential
- increases linearly with the distance
- between quarks
-  quarks are confined;
- 2) At high temperature, the confinement potential is ‘melted’
-  quarks are ‘free’ (larger than that from p+p collisions);
- 3) LGT calculation predicted a fast-cross over temperature
-  TC = 160 - 170 MeV.

##  Phase diagram of strongly interacting matter

- CERN-SPS, RHIC, LHC:  high temperature, low baryon density
- AGS, GSI (SIS200):      moderate temperature, high baryon density

## Lattice QCD - the Equation of State 

- (1) Large increase of degrees of freedom at Tc seen in quick change in
-    energy density and pressure
- (2) Pressure gradient, d**p**/d**e** generates collective flow
*                                                     **F. Karsch and E. Laerman,  hep-lat/0305025*

## Equation of State

- _Equation of state_:
-  **EOS I **:  relativistic ideal gas: *p* = /3
-  **EOS H**:  resonance gas: *p* ~ /6
-  **EOS Q**:  Maxwell construction:
- 	*T*crit= 165 MeV, *B*1/4 = 0.23 GeV
- 	**lat=1.15 GeV/fm3
-                *P. Kolb et al., Phys. Rev.*_*** C62***_*, 054909 (2000).*

-  EOS - the system response to the changes of the thermal condition - is fixed by its ***p*** and ***T ***(********)**.

## Physics goals at RHIC

**Identify and study the properties of matter with partonic degrees of freedom.**
-     _***Penetrating probes***_	         _***Bulk probes***_
-       - direct photons, leptons	           - spectra, v1, v2 ...
-       - “jets” and heavy flavor	           - partonic collectivity
- 				           - fluctuations
-         _jets_            - observed high pT hadrons (at RHIC, pT(min) > 3 GeV/c)
-          _collectivity_  - collective motion of observed hadrons, not necessarily reached
-                              thermalization among them.

## RHIC @ Brookhaven National Laboratory 

**RHIC @ Brookhaven National Laboratory**

**h**

**STAR**

**PHENIX**

**PHOBOS**

**BRAHMS**

***STAR Collaboration***

## STAR Detector

**TPC dE/dx PID:**
- pion/kaon: pT ~ 0.6 GeV/c; proton pT ~ 1.2 GeV/c

## Au + Au Collisions at RHIC

***Au + Au Collisions at RHIC***

**Central**** Event**

**(real-time Level 3)**

## Collective Flow 

-                                           Central Collisions: transverse radial flow, b~0
-                                           -  Integrates pressure history over complete
-                                              expansion phase

-                                           Elliptic flow (v2) , hexadecupole flow (v4) , v6,...
-                                           caused by anisotropic initial overlap region
-                                            - More weight towards early stage of expansion

-                                            Directed flow (v1) , sensitive to earliest
-                                              collision stage (b > 0)
-                                            - Large effect at forward rapidity, at mid-rapidity
-                                              perhaps different origin

## Hadron Spectra from RHICmid-rapidity, p+p and Au+Au collisions at 200 GeV

*centrality*

- 5%
- 10-20%
- 20-40%
- 40-60%
- 60-80%

*Results from BRAHMS, PHENIX, and STAR experiments*

## Thermal model fit

- Source is assumed to be:
- Local thermal equilibrated  random motion
- Radial boosted                   collective motion

- random

- boosted

*E.Schnedermann, J.Sollfrank, and U.Heinz, Phys. Rev. ****C48****, 2462(1993)*

## Fit results: Tfo vs. <   >

- 1) **, *K*, and *p* change
-    smoothly from peripheral
-    to central collisions.
- 2)  At the most central
-     collisions, <T> reaches
-    0.6c.
- 3) Multi-strange particles ,
-      are found at higher T
-     and lower <T>
** ******** ****Sensitive to early partonic stage!**
** ******** ****How about v****2****?**
- STAR: NP_**A715**_, 458c(03);  *PRL *_***92***_*, 112301(04); *_***92***_*, 182301(04).*

**200GeV Au + Au collisions**

## Anisotropy parameter v2

- y

- x

- py

- px

- coordinate-space-anisotropy              momentum-space-anisotropy

- Anisotropy parameter v2

**Initial/final conditions, EoS, degrees of freedom**

## Collectivity, deconfinement at RHIC

-  -  v2, spectra of light hadrons
-     and multi-strange hadrons
-  -  scaling of the number of
-     constituent quarks
-  At RHIC, I believe we have
-  achieved:
****** ****Partonic Collectivity **
****** ****Deconfinement***** ***
*PHENIX**: PRL*_***91***_*, 182301(03)      *
*STAR**: PRL*_***92***_*, 052302(04)*
*S. Voloshin, NPA715, 379(03)*
*Models: Greco et al, PR*_***C68***_*, 034904(03)*
*X. Dong, et al., Phys. Lett. *_***B597***_*, 328(04).*
*...**.*

**200GeV Au + Au collisions**

## Summary I

-  - Flavor equilibration - necessary for QGP
-  - Jet energy loss - ***QCD*** at work
-  - Collectivity - pressure gradient **∂*****P******QCD****	*
-        Deconfinement and Partonic collectivity
-  - **Next step:** demonstrate the status of possible thermalization (***T***) in Au+Au collisions at RHIC
**      ******** ** heavy-flavors (c- & b-quarks) collectivity

## II. Neutrino-less double beta decay

## 1930 - W. Pauli and 

-  Public letter to the group of the Radioactives at the district society meeting in Tübingen:
-  Physikalisches Institut
-  der Eidg. Technischen Hochschule
-  Gloriastr.
-  Zürich						Zürich, 4 December 1930
- “As the bearer of these lines, to whom I graciously ask to listen, will explain to you in more detail, how because of the ‘wrong’ statistics of the N and 6Li nuclei and the continuous beta-spectrum. I have hit upon a desperate remedy to save the ‘exchange theorem’ of statistics and the law of conservation of energy. ***Namely, the possibility that there could exist in the nuclei electrically neutral particles, that I wish to call neutrons, which have the spin 1/2 and obey the exclusion principle and which further differ from light quanta in that they do not travel with the velocity of light. The mass of the neutrons should be of the same order of magnitude as the electron mass and in any event not larger that 0.01 proton masses.*** - The continuous beta-spectrum would then become understandable by the assumption that in beta-decay, a neutron is emitted in addition to the electron such that the sum of the energies of the neutron and electron is constant. ....
- I admit that on a first look my way out might seem to be quite unlikely, since one would certainly have seen the neutrons by now if they existed. But nothing ventured nothing gained, and the seriousness of the matter with the continuous beta-spectrum is illustrated by a quotation of my honored predecessor in office. Mr. Debye, who recently told me in Brussels: ‘Oh,  it is best not to think about it, like the new taxes.’ Therefore one should earnestly discuss each way of salvation. - So, dear Radioactives, examine and judge it. - Unfortunately I cannot appear in Tübingen personally, since I am indispensable here in Zurich because of a ball on the night of 6/7 December. - With my best regards to you, and also Mr. Back, your humble servant.”
- 					  		            W.  Pauli

## 1956,       discovered 

- Twenty six years later, in 1956,  Reines and Cowan first observed the electron anti-.
- Today, after seventy five years of Pauli’s prediction, fundamental properties of neutrino remain to be mysteries:
-  - neutrino and its anti-particle
-  - neutrino mass
-  - in SM, the knowledge of our understand of the Nature, m = 0
- Consequences:
-  - Inside: the structure and symmetry of elementary particles
-  - Outside: the beginning and evolution of our universe

## -oscillation results  

- Solar:		Homestake, Kamiokande, SAGE
- 				GALLEX/GNO, SK, SNO
- 2) 	Atmospheric:		SK, SNO
- 3)	Reactor: 		KamLAND

*F. Feruglio, A. Strumia, and F. Vissani, Nucl. Phys. *_***B637***_*, 345(02); *_***B659***_*, 359(03)*

## -oscillation results

*- B. Pontecorvo, Zh. Eksp., Teor. Fiz. *_***33***_*, 54(57); *_***34***_*, 247(1958)*
*- Z. Maki, M. Nakagawa, and S. Sakata, Prog. Theor. Phys., *_***28***_*, 870 (1962)*

## Double beta decay

***u***

***d***

***d***

***e***

**-**

***u***

**2********2******** decay**

**0********2******** decay**

***d***

***d***

***u***

***u***

-  Dirac type                        Majorana type

## Neutrino’s nature ?

- Experiment:    neutrino-less double beta decay
-                        neutrino - neutrino interferometry* (?)

## Double beta decay

## Experimental methodsFermi’s golden rule

- Measurements

- Phase space integral

- Neutrino mass

- Nuclear decay matrix elements
- Large model uncertainties

## CUORE/CUORICINO

*CUORE starts data taking in 2009*
*http://crio.mib.infn.it/wig/Cuorepage/CUORE.php*

- Details see: Tom Gutierrez et al. talk

## Laboratori Nazionali Del Gran Sasso (LNGS)

- Hall B

- Hall A

- Hall C

- CNGS

*- World largest underground Lab.*
*- 2 hours drive from airport at Rome*

## Next generation 02 experiments

*F. Feruglio, A. Strumia, and F. Vissani, Nucl. Phys. *_***B637***_*, 345(02); *_***B659***_*, 359(03)*

*Majorana **76**Ge**enr*

*CUORE **130**Te**nat*

- Inverted Hierarchy

- Normal Hierarchy

## Summary II

- Next generation 02 experiments potentials:
- Rule out inverted hierarchy scenario, based on today’s model limit.
- Discover neutrino nature.
- Determine neutrino mass.

## “Standard” Model

- “Standard” Model

**Weak Interaction: **is one of the four fundamental forces of nature. It is most commonly seen in beta decay and the associated radioactivity. The weak nuclear force affects all *leptons* and *quarks*. It is the only force affecting *neutrinos*. It is about 1013 time weaker than the strong force.

## The fate of Spinosaurid ...

- P.C. Sereno *et al*. **Science**, Nov. 13, 1298(1998).
-                                                    (Spinosaurid)

- For about 50 years Spinosaurid has been vegetarian, now it is a carnivore.
***Imagine*** what will it be in the next 50 years, 100 years, ...?

## What can you do? 

_**High-Energy Nuclear Collisions:**_**   **(RHIC at BNL, Long Island,  NY)
- Analyze data from 200 GeV Au+Au collisions;
- Simulations, construction new detector - heavy flavor tracker
- ...
-  SoftHadron Group: 3.5 Staffs,   3 postdocs, 5 Ph.D students
-                                 _[http://www-rnc.lbl.gov/~nxu/group/starhadron.html](http://www-rnc.lbl.gov/~nxu/group/starhadron.html)_

_**Neutrino-less Double Beta Decay:**_**  **(CUORE at Gran Sasso, Italy)
- Analyze data from CUORICINO;
- Simulations, proposal for construction new detector CUORE
- ...
-  CUORE group: 2.5 staffs,  1.5 postdocs,  1 Ph.D student (?)
-                           _[http://www-rnc.lbl.gov/~nxu/cuore/cuore_lbnl.html](http://www-rnc.lbl.gov/~nxu/cuore/cuore_lbnl.html)_
-                A new group, needs more students!

## Acknowledgements 

- X. Dong*, H. Huang,  P. Jacobs, H.G. Ritter, K. Schweda*, A. Tai, Z. Xu
*E.L. Bratkovskaya,*** **L. Grandchamp, J. Raufeisen, R. Vogt, X.N. Wang

- I. Bandac, C. Bucci, S. Freeman, P. Gorla, T. Gutierrez*, J. Thomas, F. Vassani