Laser Irradiated Enhancement of Atomic Electron Capture Rate For New Physics SearchTakashi Shimomura (Saitama Univ.)In Collaboration withJoe Sato and Takaaki Nomura(Saitama Univ.)hep-ph 0605031 Prog. Theor. Phys. 117
1. Introduction1. Majorana nature of neutrinos2. Lepton Flavor Violations3. Mono energetic neutrino beamM. Rolinec and J. Sato, hep-ph/0612148 J. Sato, Phys.Rev.Lett.95:131804,2005. Electron capture processes have a potential Power to Search New Physics !Ikeda, Nakano, Sakuda, Tanaka and Yoshimura, hep-ph/0506062 M. Yoshimura, hep-ph/0611362 , hep-ph/0507248
To obtain a high statisticsElectron capture processes are attractive ! The capture rate is generally low LFV and LNV are rare eventsEnhance the capture processes !But
How to enhance the capture processes?An interesting way isLASER irradiation to an atomM. Yoshimura, hep-ph/0507248 another Enhance mechanism by a LASER We found Laser Power is Laser Energy several eV Resonance
Key point of our workAmplitude of capture process with a free electronElectron Capture RateWave function of the electronMake the electron effectively heavier !
Change of the momentum Change of the de Broglie wave lengthNave explanation of our mechanismWave pictureUnder the laser irradiationChange of the energy
2. Non-Relativistic Equation with LASER filedDirac equationCoulomb potentialVector potentialThe two identical lasers are irradiated from the both sidesAverage photon number density
Effective massDiagonalized by U
The wave length of the laser is much larger than the size of the atom. the oscillation period of the laser is longer than the time interval which we consider. Ignore the position dependence of U, meffIgnore the time dependence of U, meffassumptions
Non-Relativistic LimitTake the direction of to zSeparate the time dependenceVirial theorem
3. Wave FunctionsSolve the non-relativistic equation perturbatively0th orderIn the following, we consider 1s state.
2nd order1st orderOnly l=even and m=0 states appear
Probability density is determined by the 0th order
4. Enhancement of Atomic Electron Capture RateCapture RateEnhancement rateIncrease function of
Intensity DependenceEnhancement RateEnhancement rate
Enhancement RateEnergy DependenceEnhancement rate
5. SummaryWe have investigated a mechanism to enhance atomic electron capture decay by a laser irradiationThe mass of electron becomes effectively heavier under the laser irradiation.The non-relativistic equation with effective mass was derived.The lower energy beam is better when the intensity is the same.The order of magnitude enhancement can be theoretically achieved.
We considered the short time intervalWe have to consider the time dependence of the laser for more realistic situations.We replaced the vector potential by its time averageWe have to calculate the time average of for longer time period.
In the followingEnergy,Intensity,Static assumption is validTime average
4. Competitive IonizationsTunnel IonizationMulti-photon Absorption IonizationtunnelingPotential of the laserprobabilityCoulomb electric fieldLaser electric fieldCross section0Vector potentialLarge!LHuillier, et al. Phys.Rev.A, 1989Ammosov, et al. Zh. Eksp. Teor. Fiz, 1986
Intensity Dependence
Electron Capture Ratedetermined by the fundamental physicscan enhance ?
Table of TalkIntroductionNon-Relativistic Equation with Laser FieldProbability DensityCompetitive IonizationsEnhancement of Atomic Electron Capture RateSummary and Future Work
