119171754
Embedding the Pentagon
The Pentagon Model is an explicit supersymmetric extension of the Standard Model, which involves a new strongly-interacting SU(5) gauge theory at TeV-scale energies. We show that the Pentagon can be embedded into an SU(5) × SU(5) × SU(5) gauge group at the GUT scale. The doublet-triplet splitting problem, and proton decay compatible with experimental bounds, can be successfully addressed in this context. The simplest approach fails to provide masses for the lighter two generations of quarks and leptons; however, this problem can be solved by the addition of a pair of antisymmetric tensor fields and an axion.
125302371
Cosmological SUSY Breaking and the Pyramid Scheme
124138605
String theory, holography and Quantum Gravity
118356346
HOLOGRAPHIC SPACE–TIME AND ITS PHENOMENOLOGICAL IMPLICATIONS
I briefly review the theory of holographic space–time and its relation to the cosmological constant problem, and the breaking of supersymmetry (SUSY). When combined with some simple phenomenological requirements, these ideas lead to a fairly unique model for Tera-scale physics, which implies direct gauge mediation of SUSY breaking and a model for dark matter as a hidden sector baryon, with nonzero magnetic dipole moment.
119283684
Holographic Space-time and Newton's Law
We derive Newton's Law from the formalism of Holographic Space-Time (HST). More precisely, we show that for a large class of Hamiltonians of the type proposed previously for the HST description of a geodesic in Minkowski space, the eikonal for scattering of two massless particles at large impact parameter scales as expected with the impact parameter and the energies of the particles in the center of mass (CM) frame. We also discuss the criteria for black hole production in this collision, and find an estimate, purely within the HST framework, for the impact parameter at which it sets in, which coincides with the estimate based on general relativity.
116990186
Essay: Supersymmetry, the Cosmological Constant, and a Theory of Quantum Gravity in Our Universe
There are many theories of quantum gravity, depending on asymptotic boundary conditions, and the amount of supersymmetry. The cosmological constant is one of the fundamental parameters that characterizes different theories. If it is positive, supersymmetry must be broken. A heuristic calculation shows that a cosmological constant of the observed size predicts superpartners in the TeV range. This mechanism for SUSY breaking also puts important constraints on low energy particle physics models.
73646575
Initial performance of the CUORE-0 experiment
CUORE-0 is a cryogenic detector that uses an array of tellurium dioxide bolometers to search for neutrinoless double-beta decay of $$\mathrm {^{130}Te}$$130Te. We present the first data analysis with $$7.1 \,\mathrm {kg\cdot y}$$7.1kg·y of total $$\mathrm {TeO_2}$$TeO2 exposure focusing on background measurements and energy resolution. The background rates in the neutrinoless double-beta decay region of interest (2.47 to $$2.57 \,\mathrm {MeV}$$2.57MeV) and in the $$\alpha $$α background-dominated region (2.70 to $$3.90\,\mathrm {MeV}$$3.90MeV) have been measured to be $${0.071\pm 0.011}$$0.071±0.011 and $${0.019\pm 0.002}\,\mathrm {counts/(keV\cdot kg\cdot y)}$$0.019±0.002counts/(keV·kg·y), respectively. The latter result represents a factor of 6 improvement from a predecessor experiment, Cuoricino. The results verify our understanding of the background sources in CUORE-0, which is the basis of extrapolations to the full CUORE detector. The obtained energy resolution (full width at half maximum) in the region of interest is $$5.7\,\mathrm {keV}$$5.7keV. Based on the measured background rate and energy resolution in the region of interest, CUORE-0 half-life sensitivity is expected to surpass the observed lower bound of Cuoricino with one year of live time.
3255120
Improved measurement of the positive-muon lifetime and determination of the Fermi constant.
The mean life of the positive muon has been measured to a precision of 11 ppm using a low-energy, pulsed muon beam stopped in a ferromagnetic target, which was surrounded by a scintillator detector array. The result, tau(micro)=2.197 013(24) micros, is in excellent agreement with the previous world average. The new world average tau(micro)=2.197 019(21) micros determines the Fermi constant G(F)=1.166 371(6)x10(-5) GeV-2 (5 ppm). Additionally, the precision measurement of the positive-muon lifetime is needed to determine the nucleon pseudoscalar coupling g(P).
119144377
A circulating hydrogen ultra-high purification system for the MuCap experiment
Abstract The MuCap experiment is a high-precision measurement of the rate for the basic electroweak process of muon capture, μ − +p→n+ ν μ . The experimental approach is based on an active target consisting of a time projection chamber (TPC) operating with pure hydrogen gas. The hydrogen has to be kept extremely pure and at a stable pressure. A Circulating Hydrogen Ultra-high Purification System was designed at the Petersburg Nuclear Physics Institute (PNPI) to continuously clean the hydrogen from impurities. The system is based on an adsorption cryo pump to stimulate the hydrogen flow and on a cold adsorbent for the hydrogen cleaning. It was installed at the Paul Scherrer Institute (PSI) in 2004 and performed reliably during three experiment runs. During several months long operating periods the system maintained the hydrogen purity in the detector on the level of 20 ppb for moisture, which is the main contaminant, and of better than 7 and 5 ppb for nitrogen and oxygen, respectively. The pressure inside the TPC was stabilized to within 0.024% of 10 bar at a hydrogen flow rate of three standard liters per minute.
41701681
Measurement of the 8B solar neutrino flux with the KamLAND liquid scintillator detector
We report a measurement of the neutrino-electron elastic scattering rate from ^8B solar neutrinos based on a 123 kton-day exposure of KamLAND. The background-subtracted electron recoil rate, above a 5.5-MeV analysis threshold is 1.49 ± 0.14(stat) ± 0.17(syst) events per kton-day. Interpreted as due to a pure electron flavor flux with a ^8B neutrino spectrum, this corresponds to a spectrum integrated flux of 2.77 ± 0.26(stat) ± 0.32(syst) ×10^6 cm^(−2_s^(−1). The analysis threshold is driven by ^(208)Tl present in the liquid scintillator, and the main source of systematic uncertainty is due to background from cosmogenic ^(11)Be. The measured rate is consistent with existing measurements and with standard solar model predictions which include matter-enhanced neutrino oscillation.
1645909
Partial radiogenic heat model for Earth revealed by geoneutrino measurements
The Earth has cooled since its formation, yet the decay of radiogenic isotopes, and in particular uranium, thorium and 
potassium, in the planet’s interior provides a continuing heat source. The current total heat flux from the Earth to space is 44:2±1.0 TW, but the relative contributions from residual primordial heat and radiogenic decay remain uncertain. However, radiogenic decay can be estimated from the flux of geoneutrinos, electrically neutral particles that are emitted during radioactive decay and can pass through the Earth virtually unaffected. Here we combine precise measurements of the geoneutrino flux from the Kamioka Liquid-Scintillator Antineutrino Detector, Japan, with existing measurements from the Borexino detector, Italy.We find that decay of uranium-238 and thorium-232 together contribute 20.0^(+8.8)_(-8.6)TW to Earth’s heat 
flux. The neutrinos emitted from the decay of potassium-40 are below the limits of detection in our experiments, but are known to contribute 4TW. Taken together, our observations indicate that heat from radioactive decay contributes about half of Earth’s total heat flux. We therefore conclude that Earth’s primordial heat supply has not yet been exhausted.