Belle Results Research Articles

The characteristics of the mechanical and acoustic bronze cu20sn as traditional bell material

This study is aimed to find out the mechanical and acoustic characteristics of casting traditional bell's result using metal mold and sand mold. The mechanical and acoustic characteristics of casting traditional bell's result are compared between metal molded and sand molded casting. The bronze alloy was smelted in a crucible furnace at the casting temperatures of 1000, 1050, and 1100 °C. The melted alloy is poured into a sand mold and a preheated metal mold at a temperature of 200 °C. Specimens were formed into bell and billet. The bell form was for acoustic testing. The Billet casted was cut into a few parts and were manufactured as a specimen for hardness test. This study has showed that mechanical characteristic specifically the hardness of metal molded casting is better than sand molded casting. The Acoustic properties of particular damping characteristicsis depended on the porosity of casting’s result. The bell’s tone isn’t produced by the mono frequency but it’s generated by more than one frequency domain. Similarly, the subjective test of acoustic characteristic didn’t show a significant obvious difference.

Improved description of dilepton production in τ−→ντP− decays

Recently, the Belle collaboration reported the first measurements of the $\tau^- \to\nu_{\tau}\pi^-e^+e^-$ branching fraction and the spectrum of the pion-dielectron system. In an analysis previous to Belle's results, we evaluated this branching fraction which turned out to be compatible with that reported by Belle, although with a large uncertainty. This is the motivation to seek for improvements on our previous evaluation of $\tau^- \to \nu_{\tau}\pi^-\ell^+\ell^-$ decays ($\ell=e,\,\mu$). In this paper we improve our calculation of the $WP^-\gamma^*$ vertex by including flavour symmetry breaking effects in the framework of the Resonance Chiral Theory. We impose QCD short-distance behaviour to constrain most parameters and data on the $\pi^-e^+e^-$ spectrum reported by Belle to fix the remaining free ones. As a result, improved predictions for the branching ratios and hadronic/leptonic spectra are reported, in good agreement with observations. Analogous calculations for the strangeness-changing $\tau^- \to \nu_{\tau}K^-\ell^+\ell^-$ transitions are reported for the first time. Albeit one expects the $m_{\pi\mu^+\mu^-}$ spectrum to be measured in Belle-II and the observables with $\ell=e$ can be improved, it is rather unlikely that the $K$ channels can be measured due to the suppression factor $|V_{ud}/V_{us}|^2=0.05$.

Bell, Bohm, and qubit: EPR remixed

This article reviews the predictions of quantum mechanics (QM) for one- and two-particle Stern–Gerlach experiments and then frames Bell's results, which rule out hidden-variable alternatives to QM, as attempts by a skeptical Eve to fool Alice and Bob with (first example) classical probability mixtures of non-entangled quantum states and (second example) a classical hidden-variable theory. With hidden variables, Eve can succeed when Alice and Bob limit themselves to two Stern–Gerlach directions, but always fails for some choices of three directions. For three random directions, hidden-variable theories are impossible (we show) exactly 2/3 of the time. All the calculations in this article are available in Mathematica and Python files in the supplementary material, allowing readers to experiment with their own variants.

R(D(⁎)) in a general two Higgs doublet model

Motivated by an anomaly in R(D(⁎))=BR(B¯→D(⁎)τ−ν¯)/BR(B¯→D(⁎)l−ν¯) reported by BaBar, Belle and LHCb, we study R(D(⁎)) in a general two Higgs doublet model (2HDM). Although it has been suggested that it is difficult for the 2HDM to explain the current world average for R(D(⁎)), it would be important to clarify how large deviations from the standard model predictions for R(D(⁎)) are possible in the 2HDM. We investigate possible corrections to R(D(⁎)) in the 2HDM by taking into account various flavor physics constraints (such as Bc−→τ−ν¯, b→sγ, b→sl+l−, ΔmBd,s, Bs→μ+μ− and τ+τ−, and B−→τ−ν¯), and find that it would be possible (impossible) to accommodate the 1σ region suggested by the Belle's result when we adopt a constraint BR(Bc−→τ−ν¯)≤30% (BR(Bc−→τ−ν¯)≤10%). We also study productions and decays of heavy neutral and charged Higgs bosons at the Large Hadron Collider (LHC) experiment and discuss the constraints and implications at the LHC. We show that in addition to well-studied production modes bg→tH− and gg→H/A, exotic productions of heavy Higgs bosons such as cg→bH+,t+H/A and cb¯→H+ would be significantly large, and the search for their exotic decay modes such as H/A→tc¯+ct¯, μ±τ∓ and H+→cb¯ as well as H/A→τ+τ− and H+→τ+ν would be important to probe the interesting parameter regions for R(D(⁎)).

An Analysis of Professor J.F. Bell's Research on the Finite Twist and Extension of Thin-walled Polycrystalline Cylindrical Tubes

Professor J.F. Bell's empirical result regarding the rotation factor in the polar decomposition of the deformation gradient for the finite twist–extension of a thin-walled polycrystalline cylindrical metal tube is examined. The correct expression for the rotation is derived and used to show how Bell's result should be interpreted. Some implications for his incremental plasticity equations are also discussed. In particular, they are shown to satisfy appropriate invariance requirements when cast in terms of the variables actually measured by Bell in his experiments. Further consequences of his equations consistent with his data are also derived. Finally, it is shown that his theory furnishes a consistent constitutive statement about the response of isotropic solids provided that the Cauchy stress is constrained to be symmetric.

Non-local Hidden Variable Theories and Bell's Inequality

The conceptually puzzling features of quantum mechanics as a statistical theory all have their source in the impossibility of relating the probability assignments defined by the quantum state to distributions over determinate values of the physical magnitudes. While some interpretations of quantum mechanics, as well as “hidden variable” modifications of the theory, have proposed several constructions for assigning values to magnitudes (beyond the value assignments defined by the quantum state alone), a variety of theorems exist which impose severe restrictions on such theoretical constructions.This note will deal with Bell's proof (in [2]), that any hidden variable theory satisfying a physically reasonable locality condition is characterized by an inequality which is inconsistent with the quantum statistics. Bell's result has initiated a series of experiments designed to refute the entire class of local hidden variable theories. We show that Bell's inequality actually characterizes a feature of hidden variable theories which is much weaker than locality in the sense considered physically motivated.

Are superluminal connections necessary?

The following theorem is proved: If the statistical predictions of quantum theory are true in general and if the macroscopic world is not radically different from what is observed, then what happens macroscopically in one space-time region must in some cases depend on variables that are controlled by experimenters in far-away, space-like-separated regions. By what happens macroscopically in one space-time region is meant specifically the occurrence or nonoccurrence of a macroscopic event, such as the detection and recording of a particle by some macroscopic device. By a variable controlled by an experimenter in a certain space-time region is meant specifically the experimental setting in that region of some macroscopic device, in which this setting is controlled by an experimenter acting within that region. The theorem pertains specifically to experimental situations in which there are two far-apart, spacelike-separated regions in each of which there is a device that can be set at either of two alternative settings by an experimenter acting within that region. There is also a long sequence of experimental results (i.e. events) in each of the two regions. The theorem asserts that, for some such cases, it is mathematically impossible, within the manifold of all conceivable results compatible with the statistical predictions of quantum theory (to within a generous limit of, for example, 1000 standard deviations), that what happens in each region be independent of the experimental setting of the device in the far-away region. In short, there are situations in which it is mathematically impossible to meet both the statistical requirements of quantum theory and also the locality requirement that what happens in each region be independent of the setting made in the far-away, spacelike separated region. This result is a sharpening of a result due to Bell. Bell's result was formulated in terms of unspecified local hidden variables, and claimed merely to rule out the notion of local hidden variables, which was believed by hardly anyone anyway. The present theorem is formulated directly in terms of specified macroscopic quantities, and within the philosophic framework of contemporary quantum theory. The aim of this work is to discuss the significance of this theorem and its possible uses.

Hidden variables and locality

Bell's problem of the possibility of a local hidden variable theory of quantum phenomena is considered in the context of the general problem of representing the statistical states of a quantum mechanical system by measures on a classical probability space, and Bell's result is presented as a generalization of Maczynski's theorem for maximal magnitudes. The proof of this generalization is shown to depend on the impossibility of recovering the quantum statistics for sequential probabilities in a classical representation without introducing a randomization process for the hidden variables. Hidden variable theories that exclude such a randomization process are termed “strict,” and it is shown that the class of local hidden variable theories is included in the class of strict theories. A counterargument by Freedman and Wigner is evaluated with reference to Clauser's extension of a hidden variable model proposed by Bell.

Note on an Abstract Inversion Principle

In a recent paper [1] of Bell, an abstract inversion principle has been formulated for inverting a type of finite series by employing operators. Bell's result involves Baker's general principle of cross-classification [2], Dedekind-Möbius inversion, L.C.M. inversion and some known generalisations. The purpose of this note is to introduce operators of negative degree and to formulate an inversion principle which covers more cases than Bell's.