124078930
Muon Capture in Hydrogen
Abstract : An experiment to measure the muon capture rate in liquid hydrogen was carried out using scintillation counter techniques. The experiment tests muon-electron universality in interaction with a proton at a momentum transfer of 100 MeV/c. The use of ultra-pure liquid hydrogen, a purified muon beam, neutron-gamma ray discriminating detectors and oscilloscope photography made possible the detection of the 5.2 MeV neutron from the relatively improbable capture reaction (mu + p yields n + nu). The muon molecular formation rate was measured in an independent experiment, but the present result is relatively insensitive to it. The stability of the muon molecular ortho state against transitions to the para ground state for times comparable to the free muon life-time is confirmed. The experimental result of the capture rate measurement, 464 + or - 42 per second is compared with 562 + or - 60 per second, the rate expected on the basis of the conserved vector current theory, muon-electron universality and the accepted value of the "induced pseudo scalar" coupling constant.
125174279
Design and performance of the multiparticle argo spectrometer system
Abstract The Multiparticle Argo Spectrometer System, MASS, consists of a magnetic vertex spectrometer, two external trigger spectrometers, an on-line monitoring system and an off-line data analysis chain. The performance of MASS has been evaluated from physics data taken in a study of 28.5 GeV/ c pp collisions covering a large range of transverse momentum.
120381541
Experimental study of pi- p ---> pi- n* at 8 and 16 gev/c
121141376
Charged Multiplicity Associated with Transverse Momentum of a Leading Proton in pp at 28.5 GEV/C
We have measured the mean charged multiplicity nCH as a function of transverse momentum p⊥ of the forward proton in the reaction p + p ⇒ p + MM for five intervals of missing mass MM using our Multiparticle Argo Spectrometer System. We observe an increase of nCH for p⊥ > 1 GeV/c.
139640917
Effects of Channel Failure Rates on the Jet Reconstruction Efficiencies an Resolutions in an Fe HF Calorimeter
121981552
Observation and study of centrally produced pion clusters in 28. 5-GeV/c p-p interactions
A double-arm spectrometer is used to identify a pion cluster produced in central p-p collisions at 28.5 GeV/c. Cluster properties studied are angular momentum, quantum statistics, multiplicity, and effective mass. There is some speculation on the production mechanism. (AIP)
119244537
Quantum cosmological relational model of shape and scale in 1D
Relational particle models are useful toy models for quantum cosmology and the problem of time in quantum general relativity. This paper shows how to extend existing work on concrete examples of relational particle models in 1D to include a notion of scale. This is useful as regards forming a tight analogy with quantum cosmology and the emergent semiclassical time and hidden time approaches to the problem of time. This paper shows furthermore that the correspondence between relational particle models and classical and quantum cosmology can be strengthened using judicious choices of the mechanical potential. This gives relational particle mechanics models with analogues of spatial curvature, cosmological constant, dust and radiation terms. A number of these models are then tractable at the quantum level. These models can be used to study important issues (1) in canonical quantum gravity: the problem of time, the semiclassical approach to it and timeless approaches to it (such as the naive Schr?dinger interpretation and records theory) and (2) in quantum cosmology, such as in the investigation of uniform states, robustness and the qualitative understanding of the origin of structure formation.
119158624
Block Diagonalization using SRG Flow Equations
Here s is a flow parameter and the flow operator Gs specifies the type of SRG [4]. Decoupling between low-energy and high-energy matrix elements is naturally achieved in a momentum basis by choosing a momentum-diagonal flow operator such as the kinetic energy Trel or the diagonal of Hs; either drives the Hamiltonian toward banddiagonal form. This decoupling leads to dramatically improved variational convergence in few-body nuclear systems compared to unevolved phenomenological or chiral EFT potentials [5, 6]. Renormalization Group (RG) methods that evolve NN interactions with a sharp or smooth cutoff in relative momentum, known generically as Vlow k, rely on the invariance of the two-nucleon T matrix [7, 8]. These approaches achieve a block-diagonal form characterized by a cutoff Λ (see left plots in Figs. 1 and 2). As usually implemented they set the high-momentum matrix elements to zero but this is not required. Block-diagonal decoupling of the sharp Vlow k form can
32865960
Recent advances in low level counting techniques.
Problems involving low level counting techniques are encountered in many diverse fields including biological and chemical tracer studies, archaeo­ logical and geological dating (I), investigations of natural and induced radio­ activities, and the study of fundamental particles. Such a host of methods and variations on methods have been reported that an exhaustive catalog would constitute little more than an annotated bibliography. We have, there­ fore, limited our attention to a few selected examples which seem to be of special interest because of their versatility or their extreme sensitivity. We prefer to organize our discussion around specific problems rather than around types of detectors since this permits a comparison of alternative methods and provides practical examples of various techniques in actual operation. Alpha counting is arbitrarily excluded. For a discussion of photographic methods (radioautographs) the reader is referred to Norris & Woodruff (2) and refer­ ences cited therein. We will discuss the methods developed for the measure­ ment of natural radiocarbon and tritium, cosmic ray produced Be7, and the K(O content of the human body. DOUble-beta decay experiments are consid­ ered since they seem to constitute one of the most difficult of the outstanding problems and because of their importance from the viewpoint of theoretical nuclear physics. Finally, an account is given of recent attempts to detect the neutrino, probably the most difficult low level counting problem of all and one which seems finally on the verge of successful solution. Principles.-The fundamental principles of low level counting are simple: maximize the number of detected events of the desired kind (signal) and minimize all others (background). The number of detected events is, of course, the product of sample size, over-all counting efficiency, and counting time. However, the striking importance of the net sample counting rate is not always fully appreciated. It can be shown (3) from elementary counting statistics, that if the sample rate is small compared with background (which is usually the case in a truly low level problem) and if counting statistics is the limiting source of error (also usually true), then the proper parameter for the comparison of counting methods is S2/B, the ratio of the square of the net sample rate to the background rate. (Any sample strength can be used in making the comparison so long as the same strength is used in testing all methods.) The method giving the maximum value of S2/B will yield the
124543914
The Production and Distribution of Natural Radiocarbon
14761899
Leibniz--Mach foundations for GR and fundamental physics
Consider the configuration space Q for some physical system, and a continuous group of transformations G whose action on the configurations is declared to be physically irrelevant. Implement G indirectly by adjoining 1 auxiliary g per independent generator of G to Q, by writing the system's action in an arbitrary G-frame (G-AF), and then passing to the quotient Q/G thanks to the constraints encoded by g-variation. I show that this G-AF principle supercedes (and indeed leads to a derivation of) the Barbour--Bertotti (BB) best matching principle. My other consideration is that absolute external time is meaningless for the universe as a whole. For various choices of Q and G, these lead to BB's proposed absolute structure free replacement of Newtoninan mechanics, to Gauge Theory and to the 3-space approach (TSA) formulation of GR. For the latter with matter fields, I discuss the SR postulates, Principle of Equivalence (POE) and simplicity postulates. I explain how a full enough set of fundamental matter fields to describe nature can be accommodated in the TSA, and compare the TSA with the `split spacetime formulation' of Kuchar. I explain the emergence of broken and unbroken Gauge Theories as a consequence of the POE. I also consider as further examples of the G-AF principle the further quotienting out of conformal transformations (CT) or volume preserving CT. Depending on which choices are made, this leads to York's initial value formulation (IVF) of GR, new alternative foundations for it, or alternative theories of gravity built out of similar conformal mathematics which nevertheless admit no GR-like spacetime interpretation.