42385898
Production of Radioactive Isotopes through Cosmic Muon Spallation in KamLAND
Radioactive isotopes produced through cosmic muon spallation are a background for rare-event detection in ν detectors, double-β-decay experiments, and dark-matter searches. Understanding the nature of cosmogenic backgrounds is particularly important for future experiments aiming to determine the pep and CNO solar neutrino fluxes, for which the background is dominated by the spallation production of ^(11)C. Data from the Kamioka liquid-scintillator antineutrino detector (KamLAND) provides valuable information for better understanding these backgrounds, especially in liquid scintillators, and for checking estimates from current simulations based upon MUSIC, FLUKA, and GEANT4. Using the time correlation between detected muons and neutron captures, the neutron production yield in the KamLAND liquid scintillator is measured to be Y_n=(2.8±0.3)×10^(-4) μ^(-1) g^(-1) cm^2. For other isotopes, the production yield is determined from the observed time correlation related to known isotope lifetimes. We find some yields are inconsistent with extrapolations based on an accelerator muon beam experiment.
55697871
Search for 14.4 keV solar axions from M1 transition of Fe-57 with CUORE crystals
We report the results of a search for axions from the 14.4 keV M1 transition from Fe-57 in the core of the sun using the axio-electric effect in TeO2 bolometers. The detectors are 5x5x5 cm(3) crystals operated at about 10 mK in a facility used to test bolometers for the CUORE experiment at the Laboratori Nazionali del Gran Sasso in Italy. An analysis of 43.65 kg.d of data was made using a newly developed low energy trigger which was optimized to reduce the energy threshold of the detector. An upper limit of 0.58 c.kg(-1).d(-1) is established at 95% C.L., which translates into lower bounds f(A) >= 3.12 x 10(5) GeV 95% C.L. (DFSZ model) and f(A) >= 2.41 x 10(4) GeV 95% C.L. (KSVZ model) on the Peccei-Quinn symmetry-breaking scale, for a value of S = 0.5 of the flavor-singlet axial vector matrix element. These bounds can be expressed in terms of axion masses as m(A) <= 19.2 eV and m(A) <= 250 eV at 95% C.L. in the DFSZ and KSVZ models respectively. Bounds are given also for the interval 0.35 <= S <= 0.55.
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.
55546545
Validation of techniques to mitigate copper surface contamination in CUORE
In this article we describe the background challenges for the CUORE experiment posed by surface contamination of inert detector materials such as copper, and present three techniques explored to mitigate these backgrounds. Using data from a dedicated test apparatus constructed to validate and compare these techniques we demonstrate that copper surface contamination levels better than 10(-7)- 10(-8) Bq/cm(2) are achieved for U-238 and Th-232. If these levels are reproduced in the final CUORE apparatus the projected 90% C.L. upper limit on the number of background counts in the region of interest is 0.02-0.03 counts/keV/kg/y depending on the adopted mitigation technique. (C) 2013 Elsevier B.V. All rights reserved.
55856903
Sensitivity of CUORE to Neutrinoless Double-Beta Decay
Sensitivity of CUORE to Neutrinoless Double-Beta Decay b c,:L d e f F . Alessandria , E . A n d r e o t t i ' , R. A r d i t o , C. Arnaboldi , F . T. Avignone IIP , M . B a l a t a , I. Bandac , T. I. Banks ' ' , G . B a r f , J . Beeman , F . Bellini ' , A . Bersani , M . Biassoni ' , T. Bloxham , C. Brofferio ' , A . Bryant , C. B u c c i , X . Z. C a i , L . C a n o n i c a , S. C a p e l l i , L . Carbone , L . Cardani ' , M . Carrettoni , N . Casali ' , N . Chott , M . Clemenza ' , C. Cosmelli ' , O. Cremonesi , R. J . Creswick , I. Dafinei , A . Dally , A . De B i a s i , M . R Decowski ' ' , M . M . Deninno , A . de Waard , S. D i D o m i z i o ' , L . Ejzak '*, R. Faccini ' , D. Q. Fang , H . A . Farach , E . Ferri '°, F . Ferroni , E . F i o r i n i , L . F o g g e t t a ' ° , M . A . Franceschi*, S. J . Freedman G . Frossati , B . K . Fujikawa , A . Giachero , L . Gironi '°, A . Giuliani , P. G o r l a , C. G o t t i , E . Guardincerri , T. D . Gutierrez , E . E . H a l l e r ' , K . Han , K . M . Heeger , H . Z. Huang*', K . Ichimura , R. KadeP, K . K a z k a z , G . KeppeT, L . Kogler ' , Y u . G . Kolomensky ' , S. K r a f t ' , D . Lenz , Y . L . L i , X . L i # , E . Longo ' , Y . G . M a . C. M a i a n o ' , G . M a i e r , M . M a i n o ' , C. Mancini ' , C. Martinez , M . M a r t i n e z , R. H . M a r u y a m a , N . Moggi , S. Morganti , T. Napolitano*, S. Newman ' , S. N i s i , C. N o n e s ' ' , E . B . N o r m a n ' , A . N u c c i o t t i ' , F . O r i o , D. O r l a n d i , J . L . Ouellet ' , M . Pallavicini ' , V . Palmieri , L . Pattavina , M . P a v a n ' , M . P e d r e t t i , G . Pessina , S. P i r r o , E . P r e v i t a l i , V . Rampazzo , F . R i m o n d i J , C. Rosenfeld , C. Rusconi , C. S a l v i o n i , S. Sangiorgio '*, D . Schaeffer ' , N . D . Scielzo , M . S i s t i ' , A . R. S m i t h , F . Stivanello , L . Taffarello , G . Terenziani , W . D . T i a n , C. Tornei , S. Trentalange*', G . V e n t u r a ' , M . Vignati ' , B . S. W a n g ' , H . W . W a n g , C. A . Whitten J r . - \ T. Wise . A . Woodcraft , N . X u , L . Z a n o t t i ' , C. Zarra , B . X . Zhu*', S. Zucchelli J k e j w k x c c e , c b e c ab ah c (CUORE e a a c a c j e c c m aa c b,c aa,q af e a c q a a f ae a8 c ad, aa aa c e c n v e f p d e,c b c e e e c f c e s e e,c c f p,n f v ad Collaboration) a INFN - Sezione di Milano, Milano 1-20133 - Italy di Fisica e Matematica, Universita dell'Insubria, Como 1-22100 - Italy INFN - Sezione di Milano Bicocca, Milano 1-20126 - Italy Dipartimento di Ingegneria Strutturale, Politecnico di Milano, Milano 1-20133 - Italy Dipartimento di Fisica, Universita di Milano-Bicocca, Milano 1-20126 - Italy fDepartment of Physics and Astronomy, University of South Carolina, Columbia, SC 29208 - USA INFN - Laboratori Nazionali del Gran Sasso, Assergi (L'Aquila) 1-67010 - Italy Department of Physics, University of California, Berkeley, CA 94720 - USA 'Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94-720 - USA UN FN - Sezione di Bologna, Bologna 1-40127 - Italy Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 - USA 'Dipartimento di Fisica, Sapienza Universita di Roma, Roma 1-00185 - Italy INFN - Sezione di Roma, Roma 1-00185 - Italy INFN - Sezione di Genova, Genova 1-16146 - Italy Shanghai Institute of Applied Physics (Chinese Academy of Sciences), Shanghai 201800 - China Dipartimento di Fisica, Universita di Genova, Genova I-I6I46 - Italy Department of Physics, University of Wisconsin, Madison, WI 53706 - USA INFN - Laboratori Nazionali di Legnaro, Legnaro (Padova) 1-35020 - Italy Kamerlingh Onnes Laboratorium, Leiden University, Leiden, RA 2300 - The Netherlands INFN - Laboratori Nazionali di Frascati, Frascati (Roma) 1-00044 - Italy Centre de Spectrometrie Nucleaire et de Spectrometrie de Masse, 914-05 Orsay Campus - France b Dipartimento C d g h k M p q r f INFN - Sezione di Roma Tor Vergata, Roma 1-00133 - Italy ' 'Physics Department, California Polytechnic State University, San Luis Obispo, CA 934-07 - USA ^Department of Materials Science and Engineering, University of California, Berkeley, CA 94-720 - USA Department of Physics and Astronoma, University of California, Los Angeles, CA 90095 - USA Physics Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94-720 - USA Lawrence Livermore National Laboratory, Livermore, CA 94-550 - USA Laboratorio de Fisica Nuclear y Astroparticulas, Universidad de Zaragoza, Zaragoza 50009 - Spain Department of Nuclear Engineering, University of California, Berkeley, CA 94-720 - USA Dipartimento di Fisica, Universita di Bologna, Bologna 1-4-0127 - Italy EH&S Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94-720 - USA flNFN - Sezione di Padova, Padova 1-35131 - Italy Dipartimento di Fisica, Universita di Firenze, Firenze 1-50125 - Italy INFN - Sezione di Firenze, Firenze 1-50125 - Italy SUPA, Institute for Astronoma, University of Edinburgh, Blackford Hill, Edinburgh EH9 3HJ - UK v aa ab ac ad ae a ag ah al * C o r r e s p o n d i n g author Email addresses: e j z a k 8 w i s c . e d u ( L . E j z a k ) , s a n g i o r g i o l 8 1 1 n l . g o v (S. Sangiorgio) Presently at: Joint Research Center, Institute for Reference M a t e r i a l s and Measurements, 2440 Geel - B e l g i u m P r e s e n t l y at: Nikhef, 1098 X G A m s t e r d a m - T h e Netherlands P r e s e n t l y at: L o s A l a m o s N a t i o n a l L a b o r a t o r y , L o s A l a m o s , N M 87545 - U S A P r e s e n t l y at: C E A / Saclay, 91191 G i f - s u r - Y v e t t e - France Deceased Preprint submitted to Astroparticle Physics December
9940369
de Sitter vacua, renormalization, and locality
We analyze the renormalization properties of quantum field theories in de Sitter space and show that only two of the maximally invariant vacuum states of free fields lead to consistent perturbation expansions. One is the Euclidean vacuum, and the other can be viewed as an analytic continuation of Euclidean functional integrals on $RP^d$. The corresponding Lorentzian manifold is the future half of global de Sitter space with boundary conditions on fields at the origin of time. We argue that the perturbation series in this case has divergences at the origin, which render the future evolution of the system indeterminate without a better understanding of high energy physics.
125302371
Cosmological SUSY Breaking and the Pyramid Scheme
117855940
The Top $10^{500}$ Reasons Not to Believe in the Landscape
The String Landscape is a fantasy. We actually have a plausible landscape of minimally supersymmetric $AdS_4$ solutions of supergravity modified by an exponential superpotential. None of these solutions is accessible to world sheet perturbation theory. If they exist as models of quantum gravity, they are defined by conformal field theories, and each is an independent quantum system, which makes no transitions to any of the others. This landscape has nothing to do with CDL tunneling or eternal inflation. 
A proper understanding of CDL transitions in QFT on a fixed background dS space, shows that the EI picture of this system is not justified within the approximation of low energy effective field theory. The cutoff independent physics, defined by the Euclidean functional integral over the 4-sphere admits only a finite number of instantons. Plausible extensions of these ideas to a quantum theory of gravity obeying the holographic principle explain all of the actual facts about CDL transitions in dS space, and lead to a picture radically different from eternal inflation. 
Theories of Eternal Inflation (EI) have to rely too heavily on the anthropic principle to be consistent with experiment. Given the vast array of effective low energy field theories that could be produced by the conventional picture of the string landscape one is forced to conclude that the most numerous anthropically allowed theories will disagree with experiment violently.
15542424
Recurrent nightmares? Measurement theory in de Sitter space
The idea that asymptotic de Sitter space can be described by a finite Hilbert Space implies that any quantum measurement has an irreducible innacuracy. We argue that this prevents any measurement from verifying the existence of the Poincare recurrences that occur in the mathematical formulation of quantum de Sitter (dS) space. It also implies that the mathematical quantum theory of dS space is not unique. There will be many different hamiltonians, which give the same results, within the uncertainty in all possible measurements.
17779961
Holographic cosmology 3.0
We present a new version of holographic cosmology, which is compatible with present observations. A primordial p = ρ phase of the universe is followed by a brief matter dominated era and a brief period of inflation, whose termination heats the universe. The flatness and horizon problems are solved by the p = ρ dynamics. The model is characterized by two parameters, which should be calculated in a more fundamental approach to the theory. For a large range in the phenomenologically allowed parameter space, the observed fluctuations in the cosmic microwave background were generated during the p = ρ era, and are exactly scale invariant. The scale invariant spectrum cuts off sharply at both upper and lower ends, and this may have observational consequences. We argue that the amplitude of fluctuations is small but cannot yet calculate it precisely.