Solar Neutrinos, Neutrino Cross Sections, and NUSEL Developments A.B. Balantekin ORNL SNS Workshop August 28, 2003

Puzzles where neutrinos may play a role What is the Dark Matter made of? What is Dark Energy? How much neutrinos contribute and why? (what is  ?) What happened to all the anti-matter?

Solar Energy Generation 4 p  alpha particle + 2 positrons MeV 97% is emitted as photons, 3% as neutrinos

Where does the Energy of the Sun come from? 1854 von Helmholtz gravitational 1920 Eddington nuclear fusion “We do not argue with the critic who urges that the stars are not hot enough for this process; we tell him to go and find a hotter place.” 1938 Bethe and Critchfield p+p  2 H +e + + e 1946 Pontecorvo the idea of using chlorine as detec t or 1964 Davis chlorine detector at Homestake Bahcall Standard Solar Model “..to see into the interior of a star and thus verify directly the hypothesis of nuclear energy generation..”

Neutrinos from the Sun

The Homestake Experiment 2002 Nobel Prize in Physics

Sudbury Neutrino Observatory

SNO e + d  p + p + e - CC e + e  e + e ES x + d  x + p + n NC

Results from SNO Fluxes (10 6 cm -2 s -1 ) e : 1.76(11) ,  : 3.41(66) TOTAL :5.09(64) SSM :5.05

Physics Potential of Solar Neutrino Experiments Neutrino Physics - Neutrino masses and mixings, A.B. Balantekin and H. Yuksel, JPG 29, 665 (2003) (hep-ph/ ). Solar Physics - Solar temperature and density. A.B. Balantekin and H. Yuksel, PRD 68, (2003) (hep-ph/ ). Nuclear Physics - Axial two-body current. A.B. Balantekin and H. Yuksel, (hep- ph/ ).

A global analysis of the solar neutrino data Balantekin & Yuksel hep-ph/

KamLAND e + p  n + e +

Solar + KamLAND Global Analysis

3 parameter Global Fits to Solar Neutrino Experiments And KamLAND for different values of  13 Balantekin and Yuksel, hep- ph/

Effective Field Theories Goal: to integrate the undesired degrees of freedom  But ~  Hence introduce counter-terms consistent with the symmetries of the theory to cancel the infinities.

EFT applied to neutrino capture Deuteron break-up : e + d  e - + p + p x + d  x + p + n 3 S 1  3 S 0 transition dominates and one only needs the coefficient of the two-body counter term, L 1A. (Butler and Chen)  p + p  d + e + e + ”Calibrating the Sun”

Balantekin and Yuksel, 2003

National Underground Science and Engineering Laboratory

Science Underground Solar Neutrinos Double  -decay Dark Matter Nucleon Decay Atmospheric neutrinos Long-baseline neutrino oscillation experiments Supernova ’s Nuclear astrophysics Geoscience Materials Development and Technology Monitoring nuclear tests. Microbiology

Where do we stand? A perspective

Fundamental discoveries are recently made SNO, 2002: Discovery of the non-electron neutrino component of the solar flux (  neutrino oscillations); measurement of the total solar neutrino flux. SuperK, 1998:Discovery of atmospheric neutrino flux variations (  neutrino oscillations). Baksan, Kamioka, IMB, 1987: Detection of neutrinos from Supernova 1987A (neutrino flux consistent with neutron star binding energy, cooling time is near that expected). Irvine, 1987: Detection of two-neutrino double-beta decay. MSW, 1986: Recognition that matter enhances neutrino oscillations.

.. that broadly impact physics, astronomy, and cosmology Massive neutrinos: Beyond the Standard Model of elementary particles. Neutrino mixing angles are close to maximal: Impacts on leptogenesis; explosion mechanism and nucleosynthesis in core-collapse supernovae. Total solar neutrino flux is measured: The theory of main sequence stellar evolution is verified. Direct neutrino mass measurements: Neutrino component of dark matter. Sloan DDS analysis requires a knowledge of neutrino mass at ≈ 0.3 eV

Neutrino Astrophysics and Cosmology

Open questions in neutrino physics What is the absolute scale of neutrino masses? Direct mass measurements. Why are the mixing angles so large? What is  13 ? Is CP violated in the neutrino sector? Is this the origin of the CP violation needed to explain the baryon asymmetry of the universe? Real-time solar neutrino experiments, very-long baseline experiments. Do sterile neutrinos exist?

Open questions… What is the behavior of neutrinos under charge-conjugation (Dirac vs. Majorana)? Is neutrino its own antiparticle? Double beta decay experiments What is the role of neutrinos in core- collapse supernovae? SN neutrino detectors, MiniBooNE Is CPT violated?

Open questions… Can we do astrophysics with neutrinos? Measure solar properties? Learn about the interior of the supernovae?

Neutrino-nucleus cross- sections A rich physics program, only - C is reasonably well-known. Detector response 16 O, Ga, Mo, Xe, Pb Input into supernova modeling, Fe peak Fundamental physics, strangeness content of the proton Tests of effective field theories, e + d  p + p (related to p + p  d + e “calibrating the Sun”)

Direct Measurements of the Neutrino Mass KATRIN proposal

Double Beta Decay Probes the charge-conjugation properties of neutrino: (A,Z)  (A,Z+2) + e + + e - + e + e Is lepton number-violating:  m Maj  =  i U ei 2 m i

Why go deep?

Depth requirements are driven by improvements in experimental sensitivity

NUSL Overview (cross-section) Oro Hondo Exhaust Ellison Exhaust No.5 Shaft Air Intake No. 4 Shaft No. 3 Shaft No. 7 Shaft Service Shaft 8000’ 7400’ 6800’ 6200’ 4850’ No. 6 Shaft Ross Shaft and Complex Mining and Operations Yates Shaft and Complex Science Operations Proposed Yates Shaft Ext. 7400’ Laboratory Area

Neutrinos in Cosmology  = 1 (Inflation) Primordial neutrinos as one component of the dark matter : 3 H beta decay   closure ≤  ≤ 0.20  closure

Neutrinos from core- collapse supernovae M prog ≥ 8 M Sun  E ≈ ergs ≈ MeV 99% of the energy is carried away by neutrinos and antineutrinos with 10 ≤ E ≤ 30 MeV Neutrinos!

Why do we have a baryon excess over antibaryons in the Universe? Baryogenesis conditions (Sakharov): 1. Baryon number non-conservation 2. CP-violation 3. Non-equilibrium conditions Is the CP-violation necessary for this hidden in the neutrino sector?

CP-violation in neutrino oscillations

Very Long Baseline Experiments