For 3-dimensional field theories with N = 2 supersymmetry the Euclidean path integrals on the three-sphere can be calculated using the method of localization; they reduce to certain matrix integrals that depend on the R-charges of the matter fields. We solve a number of such large N matrix models and calculate the free energy F as a function of the trial R-charges consistent with the marginality of the superpotential. In all our N = 2 superconformal examples, the local maximization of F yields answers that scale as N 3/2 and agree with the dual M-theory backgrounds AdS 4 × Y , where Y are 7-dimensional Sasaki-Einstein spaces. We also find in toric examples that local F -maximization is equivalent to the minimization of the volume of Y over the space of Sasakian metrics, a procedure also referred to as Z-minimization. Moreover, we find that the functions F and Z are related for any trial R-charges. In the models we study F is positive and decreases along RG flows. We therefore propose the "F -theorem" that we hope applies to all 3-d field theories: the finite part of the free energy on the three-sphere decreases along RG trajectories and is stationary at RG fixed points. We also show that in an infinite class of Chern-Simons-matter gauge theories where the Chern-Simons levels do not sum to zero, the free energy grows as N 5/3 at large 7.3.4 Q 1,1,1

Measurements of the jet energy calibration and transverse momentum resolution in CMS are presented, performed with a data sample collected in proton-proton collisions at a centreof-mass energy of 7 TeV, corresponding to an integrated luminosity of 36 pb −1. The transverse momentum balance in dijet and γ/Z+jets events is used to measure the jet energy response in the CMS detector, as well as the transverse momentum resolution. The results are presented for three different methods to reconstruct jets: a calorimeter-based approach, the "Jet-Plus-Track" approach, which improves the measurement of calorimeter jets by exploiting the associated tracks, and the "Particle Flow" approach, which attempts to reconstruct individually each particle in the event, prior to the jet clustering, based on information from all relevant subdetectors. KEYWORDS: Si microstrip and pad detectors; Calorimeter methods; Detector modelling and simulations I (interaction of radiation with matter, interaction of photons with matter, interaction of hadrons with matter, etc) ARXIV EPRINT: 1107.4277

The conjectured F -theorem for three-dimensional field theories states that the finite part of the free energy on S 3 decreases along RG trajectories and is stationary at the fixed points. In previous work various successful tests of this proposal were carried out for theories with N = 2 supersymmetry. In this paper we perform more general tests that do not rely on supersymmetry. We study perturbatively the RG flows produced by weakly relevant operators and show that the free energy decreases monotonically. We also consider large N field theories perturbed by relevant double trace operators, free massive field theories, and some Chern-Simons gauge theories. In all cases the free energy in the IR is smaller than in the UV, consistent with the F -theorem. We discuss other odd-dimensional Euclidean theories on S d and provide evidence that (−1) (d−1)/2 log |Z| decreases along RG flow; in the particular case d = 1 this is the well-known g-theorem.arXiv:1105.4598v4 [hep-th]

When ultralight axion dark matter encounters a static magnetic field, it sources an effective electric current that follows the magnetic field lines and oscillates at the axion Compton frequency. We propose a new experiment to detect this axion effective current. In the presence of axion dark matter, a large toroidal magnet will act like an oscillating current ring, whose induced magnetic flux can be measured by an external pickup loop inductively coupled to a SQUID magnetometer. We consider both resonant and broadband readout circuits and show that a broadband approach has advantages at small axion masses. We estimate the reach of this design, taking into account the irreducible sources of noise, and demonstrate potential sensitivity to axionlike dark matter with masses in the range of 10 −14 -10 −6 eV. In particular, both the broadband and resonant strategies can probe the QCD axion with a GUT-scale decay constant. DOI: 10.1103/PhysRevLett.117.141801 A broad class of well-motivated dark matter (DM) models consists of light pseudoscalar particles a coupled weakly to electromagnetism [1][2][3]. The most famous example is the QCD axion [4][5][6][7], which was originally proposed to solve the strong CP problem. More generally, string compactifications often predict a large number of axionlike particles (ALPs) [8], with Planck-suppressed couplings to electric (E) and magnetic (B) fields of the form aE · B. Unlike QCD axions, generic ALPs do not necessarily couple to the QCD operator GG, where G is the QCD field strength. The masses and couplings of ALP DM candidates are relatively unconstrained by theory or experiment (see Refs. [9-11] for reviews). It is therefore important to develop search strategies that cover many orders of magnitude in the axion parameter space.The ADMX experiment [12][13][14] has already placed stringent constraints on axion DM in a narrow mass range around m a ∼ few × 10 −6 eV. However, ADMX is only sensitive to axion DM whose Compton wavelength is comparable to the size of the resonant cavity. For the QCD axion, the axion mass m a is related to the PecceiQuinn (PQ) symmetry-breaking scale f a viawhere m π ≈ 140 MeV (f π ≈ 92 MeV) is the pion mass (decay constant). Lighter QCD axion masses therefore correspond to higher-scale axion decay constants f a . The GUT scale (f a ∼ 10 16 GeV, m a ∼ 10 −9 eV) is particularly well motivated, but well beyond the reach of ADMX as such small m a would require much larger cavities. More general ALPs can also have lighter masses and larger couplings than in the QCD case.In this Letter, we propose a new experimental design for axion DM detection that targets the mass range m a ∈ ½10 −14 ; 10 −6 eV. Like ADMX, this design exploits the fact that axion DM, in the presence of a static magnetic field, produces response electromagnetic fields that oscillate at the axion Compton frequency. Whereas ADMX is based on resonant detection of a cavity excitation, our design is based on either broadband or resonant detection of an oscillating magnetic flux with sensit...

We present a new method to characterize unresolved point sources (PSs) generalizing traditional template fits to account for non-Poissonian photon statistics. We apply this method to Fermi Large Area Telescope γ-ray data to characterize PS populations at high latitudes and in the Inner Galaxy. We find that PSs (resolved and unresolved) account for ∼50% of the total extragalactic γ-ray background in the energy range ∼1.9 to 11.9 GeV. Within 10°of the Galactic Center with jbj ≥ 2°, we find that ∼5%-10% of the flux can be accounted for by a population of unresolved PSs distributed consistently with the observed ∼GeV γ-ray excess in this region. The excess is fully absorbed by such a population, in preference to dark-matter annihilation. The inferred source population is dominated by near-threshold sources, which may be detectable in future searches.