37383185
JOINT PROBABILITIES REPRODUCING THREE EPR EXPERIMENTS ON TWO QUBITS
An eight-parameter family of the most general non-negative quadruple probabilities is constructed for EPR–Bohm–Aharonov experiments when only three pairs of analyser settings are used. It is a simultaneous representation of three different Bohr-incompatible experimental configurations involving mutually noncommuting observables valid for arbitrary quantum states.
120093834
Rigorous sum rules and bounds on pion-pion scattering amplitudes with positivity
We derive the complete set of crossing symmetric forward pion-pion amplitudes with non-negative absorptive parts obeying twice-subtracted dispersion relations. We give a method to eliminate subtraction constants for these amplitudes by making a simultaneous use of subtracted dispersion relations for the amplitude and its inverse, and unitarity. We thus deduce from axiomatic field theory (i) lower bounds on forward real parts in terms of physical forward amplitudes, (ii) lower bounds on S- and P-wave scattering lengths in terms of forward amplitudes in any part of the physical region, (iii) sum rules on scattering lengths in terms of physical forward amplitudes which provide a complete test of forward dispersion relations, (iv) upper bounds on scattering lengths in terms of total cross sections and (v) absolute sum rule inequalities on total and forward differential cross sections in terms of the pion mass alone which provide new tests of dispersion relations not involving scattering lengths.
123580858
Unitarity upper bound on the absorptive parts of elastic scattering amplitudes
We derive a unitarity upper bound on the absorptive part A(s, t) of the elastic-scattering amplitude in the physical region. In the diffraction peak region the bound on A(s, t)/A(s, 0) is a function only of the parameter σ tot 2 (−t)/4πσ el . Assuming the diffraction scattering to be purely absorptive and spin independent we find the pp, pp, and π ± p data to lie a little below the theoretical upper bound. Further the experimental curve of X(t)/X(0) vs −4tX(0)/σ el , where X(t)≡dσ/dt, seems "universal."
123264743
Rigorous sum rules and bounds on pion-pion scattering lengths
Abstract We deduce from axiomatic field theory rigorous sum rules, and upper and lower bounds on S-and P-wave ππ scattering lenghts in terms of physical region forward ππ amplitudes, and also absolute sum rule inequalities on those amplitudes involving pion mass alone.
119834941
Analytic continued fraction theory for a class of confinement potentials
We study a general class of confinement potentials in Schrödinger theory using the analytic theory of continued fractions. We construct an infinite continued fraction representation for the Green's function and study its convergence, its analytic properties in the major coupling constant and its relation to the perturbation series. We prove the existence of normalizable confined state eigensolutions with equally spaced energy levels if certain constraints on the coupling constants of the theory are satisfied: we also show that under a separate set of constraints neither bound nor confined states exist.
118649782
Unitarity restrictions on meson-nucleon helicity-flip amplitudes and slope of the diffraction peak
SummaryWe generalize the MacDowell-Martin bound on the slope parameterbA for the spinless case to the case of spin-0-spin-1/2 elastic scattering with parity conservation. We give the optimal answer for all energies as well as the simpler (slightly weaker) bound

$$cb^A \geqslant \frac{{\sigma _{tot}^2 }}{{36\pi \sigma _{el} }}\left[ {\sqrt {1 + \frac{{9\pi \sigma _{el} }}{{4k^2 \sigma _{tot}^2 }}} + 1} \right] - \frac{1}{{4k^2 }} (k = c.m. momentum).$$

 Here the superscript A refers to the absorptive-part contribution. We also obtain unitarity restrictions on the helicity-flip amplitude

$$cf_{ + - }^A (t)/\sqrt { - t} |_{t = 0} $$

 in terms ofσtot,σel, andbA(s).RiassuntoSi generalizza il limite di McDowell- Martin sul parametro di inclinazionebA per il caso privo di spin fino al caso dello seattering elastico tra spin nullo e spin 1/2 con conservazione della parità. Si dà una risposta ottimale per tutte le energie così come per il limite più semplice (leggermente più debole)

$$cb^A \geqslant \frac{{\sigma _{tot}^2 }}{{36\pi \sigma _{el} }}\left[ {\sqrt {1 + \frac{{9\pi \sigma _{el} }}{{4k^2 \sigma _{tot}^2 }}} + 1} \right] - \frac{1}{{4k^2 }}(k = impulso del centro di massa).$$

 L'esponente A si riferisce al contributo della parte assorbente. Si ottengono restrizioni di unitarietà sull'ampiezza dell'elicità-flip

$$cf_{ + - }^A (t)/\sqrt { - t} |_{t = 0} $$

 in termini diσtot,σel, ebA(S).РезюмеМы обобщаем гранипу МкДовелла-Мартина для параметра наклонаbA для бесспинового случая на случай упругого рассеяния спина 0 на спине 1/2 с сохранением четности. Мы приводим онтимальный ответ для всех энергий, а также более простую гранипу гдеk—импульс в системе центра масс. Здесь индекс Ν относится к абсорбционному вкладу. Мы также получаем ограничения на амплитуду с изменением спиральности

$$cf_{ + - }^A (t)/\sqrt { - t} |_{t = 0} $$

 в терминахσполн,σупр иbA(S).
118562891
Constraints on Non-Commutative Physics Scale with Neutrino-Electron Scattering
Neutrino-electron scatterings ($\ensuremath{\nu}\ensuremath{-}e$) are purely leptonic processes with robust standard model predictions. Their measurements can therefore provide constraints to physics beyond the standard model. Noncommutative (NC) field theories modify space-time commutation relations, and allow neutrino electromagnetic couplings at the tree level. Their contribution to the neutrino-electron scattering cross section was derived. Constraints were placed on the NC scale parameter ${\ensuremath{\Lambda}}_{\mathrm{NC}}$ from $\ensuremath{\nu}\ensuremath{-}e$ experiments with reactor and accelerator neutrinos. The most stringent limit of ${\ensuremath{\Lambda}}_{\mathrm{NC}}g3.3\text{ }\text{ }\mathrm{TeV}$ at 95% confidence level improves over the direct bounds from collider experiments.
119234381
Suzaku X-ray spectral study of the Compton-thick Seyfert galaxy NGC 5135
We present the 0.5–50 keV Suzaku broad-band X-ray spectral study of the Compton-thick active galactic nucleus (AGN) in NGC 5135. The Suzaku observation provides the first detection of NGC 5135 above 10 keV that allowed us, for the first time, to estimate the absorbing column density, the intrinsic X-ray luminosity, the strength of the reflection component and the viewing angle of the torus for this AGN. The 0.5–10 keV spectrum of NGC 5135 is characterized by the standard components for a Compton-thick source: a scattered continuum, a prominent Fe Kα emission line [equivalent width (EW) ∼ 2.1 keV] and a soft excess. At higher energies (E > 10 keV), the intrinsic AGN continuum shows up, implying an absorbing column density of the order of ∼2.5 × 1024 cm−2 and the intrinsic 2.0–10 keV X-ray luminosity of ∼1.8 × 1043 erg s−1. Assuming a toroidal geometry of the reprocessing material, we show that an edge-on view of the obscuring torus is preferred in this source.
119187939
Two source emission behaviour of alpha fragments of projectile having energy around 1 GeV per nucleon
84 Kr interactions with nuclei of the nuclear emulsion detector composition at relativistic energy below 2 GeV per nucleon. The angular distribution of projectile fragments alpha in terms of transverse momentum could not be explained by a straight and clean-cut collision geometry hypothesis of Participant – Spectator (PS) Model. Therefore, it is assumed that projectile fragments alpha were produced from two separate sources that belong to the projectile spectator region differing drastically in their temperatures. It has been clearly observed that the emission of projectile fragments alpha are from two different sources. The contribution of projectile fragments alpha from contact layer or hot source is a few percent of the total emission of projectile fragments alphas. Most of the projectile fragments alphas are emitted from the cold source. It has been noticed that the temperature of hot and cold regions are dependent on the projectile mass number. Nuclear fragmentation is an important experimental phenomenon in nucleus – nucleus collisions at relativistic high energy and heavy ion [1]. The PS Model is a simple and basic model for the study of the high energy nucleus – nucleus collisions. The emission of projectile fragments alpha has been studied in lots of high energy heavy ion experiments having energy more than a GeV per nucleon and the general consensus was that they are coming out from the projectile spectator part in the context of a PS Model [2]. According to the PS Model, the interacting system in high energy nucleus – nucleus collisions can be clearly divided into three regions such as target and projectile spectators and a participant region. The overlapping region of the two colliding nuclei is called the participant region and the other regions are called the target and the projectile spectators, respectively. Data from lighter projectiles has been successfully explained with the help of PS Model but data from heavy ion interactions pointed finger towards the PS Model because experiments observed many projectile fragments alpha having larger emission angle that could not be explained by the straight and clean-cut collision geometry picture of the PS Model. Therefore, this large angle scattering indicated the failure of the PS Model and forced us to rethink and modify this model according to the physics requirements and the idea of multiple sources i.e. emission of projectile fragments alpha from different sources having different temperature has been introduced [3]. In this paper, we analyzed the transverse momentum distributions of projectile fragments alpha produced in 84 Kr interactions with the nuclei of the Nuclear Emulsion Detector’s (NED) target at around 1 GeV per nucleon kinetic energy [4]. Experimental techniques are briefly
119305151
Characteristics of compound multiplicity in 84Kr36 with various light and heavy targets at 1 GeV per nucleon
Interactions of 84Kr36 having kinetic energy around 1 GeV per nucleon with NIKFI BR-2 nuclear emulsion detector’s target reveal some of the important features of compound multiplicity. Present article shows that width of compound multiplicity distributions and value of mean compound multiplicity have linear relationship with mass number of the projectile colliding system.
122493550
Feynman path-integral approach to the Aharonov-Bohm effect
The Aharonov-Bohm effect is investigated in the Feynman path-integral formulation of quantum mechanics. We consider an idealized situation with an electron moving in a magnetic-field-free region outside a solenoid whose radius to length ratio is very small. The nonvanishing vector potential term in the Lagrangian is written as an angular-velocity-dependent potential. In order to account for a singularity due to the presence of the solenoid itself, a periodic constraint is imposed on the path integral. The propagator can then be evaluated using the polar-coordinate methods of Peak and Inomata. It is found that the propagator has the general form $K({\stackrel{\ensuremath{\rightarrow}}{\mathrm{r}}}^{\ensuremath{'}\ensuremath{'}},{\stackrel{\ensuremath{\rightarrow}}{\mathrm{r}}}^{\ensuremath{'}};\ensuremath{\tau})=\ensuremath{\Sigma}{n}^{}{\ensuremath{\chi}}_{n}{K}_{n}({\stackrel{\ensuremath{\rightarrow}}{\mathrm{r}}}^{\ensuremath{'}\ensuremath{'}},{\stackrel{\ensuremath{\rightarrow}}{\mathrm{r}}}^{\ensuremath{'}};\ensuremath{\tau})$ where the sum is taken over all classes of homotopic paths and the ${\ensuremath{\chi}}_{n}$ are a one-dimensional representation of the homotopy group. This is the form of the propagator as conjectured by Schulman.