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).
118695560
First results from the MuLan and MuCap experiments
MuLan and MuCap are ongoing experiments at the Paul Scherrer Institut, Switzerland, that use the muon lifetime to determine fundamental weak interaction parameters. The goal of MuLan is a 1 ppm measurement of the positive muon lifetime τμ+ to determine the Fermi constant GF to 0.5 ppm. The goal of MuCap is to make a 1% determination of the rate ΛS of the process of nuclear muon capture by the proton, μp→nν, by measuring the μ− disappearance rate in hydrogen gas to 10 ppm and subtracting the world average for the μ+ decay rate. A 1% determination of the capture rate ΛS is of interest because it would enable a 7% determination of gP, the induced pseudoscalar coupling of the nucleon. In 2007, both experiments published first results based upon data collected by each in 2004. MuLan reported an 11 ppm μ+ lifetime measurement, τμ+ = 2.197 013(24) μs, resulting in a new, 9.6 ppm world average, τμ+ = 2.197 019(21) μs, which determines the Fermi constant, GF = 1.166 371(6)×10−5 GeV−2, to 5 ppm. MuCap reported a 3%...
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.
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
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.
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.
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.
120087716
Anharmonic Oscillator with Polynomial Self‐Interaction
A quantum anharmonic oscillator with a polynomial self‐interaction is defined in coordinate space by a Hamiltonian of the form H = −d2/dx2 + ¼x2 + g[(½x2)N + a(½x2)N−1 + b(½x2)N−2 + ⋯]. Using WKB techniques we derive a secular equation which determines the eigenvalues of H for small |g|. We find that the qualitative analytic structure of these eigenvalues as functions of complex g remains unchanged for all fixed values of a, b,…, including a = b = ⋯ = 0. The secular equation also implies an elegant theorem which predicts how the a,b,⋯ terms in H affect the large‐order growth of perturbation theory. We use this theorem to compare the perturbative behavior of non‐Wick‐ordered and Wick‐ordered field theories in one‐dimensional space‐time. In particular, we show that the perturbation series ∑Angn and ∑Bngn for the energy levels of the (gψ2N)1 and (:gψ2N:)1 field theories differ in large order by an over‐all multiplicative constant limn→∞An/Bn = exp[N(2N − 1)/(2N − 2)].
15932069
Cosmological Supersymmetry Breaking and the Power of the Pentagon: A Model of Low Energy Particle Physics
I present a low energy Lagrangian implementing the idea of Cosmological SUSY breaking (CSB). The model predicts ${\rm tan}\beta \sim 1$, and incorporates a new mechanism for breaking of $SU(2)\times U(1)$. The Higgs mass is determined by new physics and can evade the bounds of the MSSM. The model resolves the CP and flavor problems of SUSY. The up quark mass is non-vanishing. An axion-like particle, with TeV scale decay constant, appears inevitably. Such a particle is experimentally ruled out if it has conventional QCD axion couplings. The problem {\it may} be avoided by adding dimension 5 operators, which explicitly break the axial symmetry, but this probably introduces a strong CP problem.
119133202
Two Point Pade Approximants and Duality
We propose the use of two point Pade approximants to find expressions valid uniformly in coupling constant for theories with both weak and strong coupling expansions. In particular, one can use these approximants in models with a strong/weak duality, when the symmetries do not determine exact expressions for some quantity.
119046412
Some Thoughts on the Quantum Theory of Stable de Sitter Space
I review and update ideas about the quantum theory of de Sitter space. New results include a quantum relation between energy and entropy of states in the causal patch, which is satisfied by small dS black holes. I also discuss the preliminaries of a quantum theory in global coordinates, which is invariant under a q-deformed version of the de Sitter supergroup. In this context I outline an algebraic derivation of the CSB scaling relation between Poincare SUSY breaking and the dS radius. I also review recent work on infra-red divergences in dS/CFT, as well as the phenomenology of CSB. I show that a coincidence been two scales in the phenomenological model is explained by insisting on the existence of galaxies.