what atomic physics can do for neutrino and direct dark matter detection? jiunn-wei chen national...
Post on 20-Jan-2016
222 Views
Preview:
TRANSCRIPT
What Atomic Physics Can Do for Neutrino and Direct Dark
Matter Detection?
Jiunn-Wei Chen
National Taiwan U.
Collaborators:
Chih-Liang Wu, Chih-Pang Wu (NTU) Chen-Pang Liu, Hsin-Chang Chih (NDHU) Keh-Ning Huang, Hao-Tse Shiao, Hao-Bin Li, Henry T. Wong, Lakhwinder Singh (AS)
Neutrino and Dark Matter are Portals to New Physics
Neutrino: Challenges and Opportunities
• Mass: hierarchy and absolute values• Dirac or Majorana?• CP phase(s)• Sterile neutrinos? • Electromagnetic properties: magnetic moments? Charge
Radius?...
Those are probes of new physics!
5
How neutrino magnetic moment arises in SM?
ii jj
ll
WW
ii jj
ll
WW
Neutrino Magnetic Moment (NMM)
Flavor changing MMFlavor changing MM Flavor unchanging MMFlavor unchanging MM
DiracDirac
MajoranaMajorana ×× (forbiden by CTP)(forbiden by CTP)
○ ○
○
eV 110 19 m
B
A probe of new physics!
Dark Matter (DM)
• Bigger density than the visible Universe• Its existence hints that there might be a dark
sector
Portals to the Dark Sector
• Other dark matter candidates include MACHOs: MAssive Compact Halo Objects WIMPs: Weakly Interacting Massive Particles
Why Atomic Physics?• Energy scales: Atomic (~ eV) Reactor neutrino (~ MeV) WIMP (~ GeV)• Neutrino: NNM atomic ionization signal larger at lower energy
scattering (current Ge detector threshold 0.1 keV) • DM: direct detection, velocity slow (~ 1/1000), max energy 1 keV for
mass 1 GeV DM. • Opportunity: Applying atomic physics at keV (low for nuclear physics
but high for atomic physics)
Neutrino Atomic Ionization
• The complete set of neutrino electromagnetic form factor is can be constrained:
scattering
2/1sin2
2/1
wv
A
g
g
Weak InteractionWeak Interaction
Magnetic momentMagnetic moment
ETme
112
22
eνeν Xe
Should go for low T (energy transfered)!
Two Approximations ---IEquivalent Photon Approx.
• proposed by Henry Wong et al. ( PRL 105 061801)
• photon q2 ～ 0 : relativistic beam or soft photons qμ ～ 0
• several orders of magnitude enhancement
→ tighen the μν constraint with the same set of data
Two Approximations --- II
Free Electron Approx.
• revisited by Voloshin et al. ( PRL 105 201801)
• sum rule and Hydrogen-like calculation
• FEA works well at sub-keV regime
Toy: ν-H atomic ionization, exact result obtained (1307.2857)
Toy: ν-H atomic ionization, exact result obtained (1307.2857)
Two Approximations
Free Electron Approx.
(revisited by Voloshin et.al)Equivalent Photon Approx.
binding momentum of hydrogen: αme↓
18
Ge atomic ionization: ab initio MCRRPA Theory
• MCRRPA: multiconfiguration relativistic random phase approx.
Reducing the N-body problem to a 1-body problem by solving the 1-body effective potential self consistently.
Hartree-Fock :
RPA:
RRPA:
MCRRPA:
↓Including 2 particle 2 hole excitations
↓Correcting the relativistic effect
↓More than one configurations in Hartree-Fock; Important for open shell system like Ge where the energy gap is smaller than the closed shell case
MCRRPA Theory
( ) ( )t H V t HN-electron relativistic Hamiltonian
↓
Dirac Hamiltonian +Coulomb interaction The rest of EM interaction
Solve initial wavefucntion of atom Solve final wavefunction by time evolution
↓ ↓
Benchmark: Ge Photoionization
Exp. data: Ge solid
Theory: Ge atom (gas)
Above 100 eV error under 5%.
JWC et. al. arXiv: 1311.5294
Ge atomic ionization withab initio MCRRPA Theory
JWC et. al. arXiv: 1311.5294
Ge atomic ionization withab initio MCRRPA Theory
JWC et. al. arXiv: 1311.5294
Ge atomic ionization withab initio MCRRPA Theory
JWC et. al. 1411.0574
JWC et. al. arXiv: 1411.0574
Direct Dark Matter Detection
RPP 2014
What Can Atomic Physics Contribute?
• Light dark matter detection:
• Electron recoil background from solar neutrinos for a LXe detector
• Large LXe detectors can be used as a neutrino/axion detectors as well (measuring NNM w/ a source nearby)
Electron Recoil Background for DARWIN (Lxe)
L. Baudis et al 1309.7024
Summary
• Neutrinos and dark matter particles are portals to new physics
• Ab initio calculations of Ge neutrino atomic ionization performed with 5-10% estimated error. Xe can be done as well.
• Ongoing: dark matter atomic ionization
Searching for the QCD Critical End Point
Jiunn-Wei Chen
National Taiwan U.
JWC, Jian Deng, Lance Labun
1410.5454
Universality• In the scaling region, physics is the same
within the same universality class---an effective field theory argument.
• QCD near CEP ~ Ising model
(Stephanov)
4th momentCPOD 2014
3rd momentCPOD 2014
When the Imaginary is a Real Alternative
Jiunn-Wei Chen
National Taiwan U.
Phys.Rev.Lett. 110 (2013) 262301Collaborators: Jens Braun, Jian Deng, Joaquin E. Drut, Bengt Friman, Chen-Te Ma, Yu-Dai Tsai
From the hottest to the coolest, and back?
When Mr. Berry Meets Mr. Wigner
Jiunn-Wei Chen
National Taiwan U.
JWC, Shi Pu, Qun Wang, Xin-Nian Wang
Phys.Rev.Lett. 110 (2013) 262301
Flavor Structure of the Nucleon Sea from Lattice QCD
Jiunn-Wei Chen
National Taiwan U.
arXiv:1402.1462 [hep-ph]
Collaborators: Huey-Wen Lin, Saul D. Cohen, Xiangdong Ji
Backup slides
Solar Neutrino Flux
40
Case study: NMM• Reactor antineutrino ( )
GEMMA : Ge detector with threshold 1.5keV
TEXONO: Ge detector with threshold 5keV
• Solar neutrino
Borexino
• Astrophysical limit (model dependent)
ee
Be
11109.2
Be
11104.7
B11104.5
B1311 10 to10 from
41
scattering
ee
eνeν Xe
Weak InteractionWeak Interaction Magnetic momentMagnetic moment
How low is low enough?Be
1010•
Now sub-keV Ge detector is available!
Parton Physics on a Euclidean LatticeX. Ji, PRL, 2013
Schematic QCD Phase Diagram
The location of the critical point (CEP)is still unknown.Th: Difficult to apply LQCD to the low T / high chemical potential region.
Our Contribution JWC, Jian Deng, Lance Labun,1410.5454
• Work out the mapping in a simple model: 1+1dim Gross-Neveu model in the large N limit. Not in the same universality class---different critical exponents but behavior similar.
• More diagrams not included are also important in the power counting:
top related