Gluon Research Articles

Accumulation of cesium in glue balls of spiders' orb webs

Spiders capture prey by applying sticky coating substances to the spiral line of their orb webs. The main constituents of these sticky substances are glycoproteins and salts. This sticky substance is an intelligent material. Salt plays a key role regarding the properties of the sticky substance. Spiders typically weave a new orb webs by recycling used orb webs, and salts, typically salts of the alkali metals sodium and potassium, were therefore assumed to be recycled in this process. Here, we fed cesium (Cs) carbonate (which is an alkali metal salt) to spiders (Araneus ventricosus) to test this hypothesis. After feeding, we mapped the sticky substance in the spiders' orb web using an in‐house time‐of‐flight secondary ion mass spectrometer with high lateral resolution. The results showed that Cs ion was ingested and integrated into the sticky substance, and it showed properties similar to those of sodium ion and potassium ion.

Measurement of the cross section for $\text{t}\bar{\text{t}}$ production with additional jets and b jets in pp collisions at $\sqrt{s}=$ 13 TeV

Measurements of the cross section for the production of top quark pairs in association with a pair of jets from bottom quarks $ \left({\sigma}_{\mathrm{t}\overline{\mathrm{t}}\mathrm{b}\overline{\mathrm{b}}}\right) $ and in association with a pair of jets from quarks of any flavor or gluons $ \left({\sigma}_{\mathrm{t}\overline{\mathrm{t}}\mathrm{jj}}\right) $ and their ratio are presented. The data were collected in proton-proton collisions at a center-of-mass energy of 13 TeV by the CMS experiment at the LHC in 2016 and correspond to an integrated luminosity of 35.9 fb$^{−1}$. The measurements are performed in a fiducial phase space and extrapolated to the full phase space, separately for the dilepton and lepton+jets channels, where lepton corresponds to either an electron or a muon. The results of the measurements in the fiducial phase space for the dilepton and lepton+jets channels, respectively, are $ {\sigma}_{\mathrm{t}\overline{\mathrm{t}}\mathrm{jj}} $ = 2.36±0.02 (stat)±0.20 (syst) pb and 31.0±0.2 (stat)±2.9 (syst) pb, and for the cross section ratio 0.017 ± 0.001 (stat) ± 0.001 (syst) and 0.020 ± 0.001 (stat) ± 0.001 (syst). The values of $ {\sigma}_{\mathrm{t}\overline{\mathrm{t}}\mathrm{b}\overline{\mathrm{b}}} $ are determined from the product of the $ {\sigma}_{\mathrm{t}\overline{\mathrm{t}}\mathrm{jj}} $ and the cross section ratio, obtaining, respectively, 0.040±0.002 (stat)±0.005 (syst) pb and 0.62±0.03 (stat)±0.07 (syst) pb. These measurements are the most precise to date and are consistent, within the uncertainties, with the standard model expectations obtained using a matrix element calculation at next-to-leading order in quantum chromodynamics matched to a parton shower.[graphic not available: see fulltext]

Loss of Phosphate Determines the Versatility of a Spider Orb-web Glue Ball

Spiders capture their prey by weaving an "invisible" orb-web that has both adhesive and fixed properties. Different types of silk in the orb-web have different functions, wherein the key to capturing a prey is the ball-like glue (glue ball), which coats the silk strands. This glue ball has highly versatile properties, but the mechanisms leading to its versatility remain unclear. The salts found in the web have been previously suggested to play an important role in terms of viscosity, not water. However, the distribution of salt and water in the glue ball has not yet been directly observed. Here, we mapped the salts in different states using a homemade time-of-flight secondary ion mass spectrometer (TOF-SIMS) with a high lateral resolution. To our surprise, the glue ball was found to contain little water. The functional transformation of the glue ball from a viscous glycoprotein (capturing prey) to a hardened protein (retaining prey) relies solely on the stimulation of mechanical forces. The phosphate is a key factor for its versatility.

Changes of Calcium Distribution in Glue Ball of Spider's Orb-web under Low-temperature Stress

Changes of Calcium Distribution in Glue Ball of Spider's Orb-web under Low-temperature Stress

M-theory exotic scalar glueball decays to mesons at finite coupling

Using the pull-back of the perturbed type IIA metric corresponding to the perturbation of [1]’s M-theory uplift of [2]’s UV-complete top-down type IIB holographic dual of large-N thermal QCD, at finite coupling, we obtain the interaction Lagrangian corresponding to exotic scalar glueball(GE)-ρ/π-meson interaction, linear in the exotic scalar glueball and up to quartic order in the π mesons. In the Lagrangian the coupling constants are determined as (radial integrals of) [1]’s M-theory uplift’s metric components and six radial functions appearing in the M-theory metric perturbations. Assuming MG> 2Mρ, we then compute ρ → 2π, GE → 2π, 2ρ, ρ + 2π decay widths as well as the direct and indirect (mediated via ρ mesons) GE → 4π decays. For numerics, we choose f 0[1710] and compare with previous calculations. We emphasize that our results can be made to match PDG data (and improvements thereof) exactly by appropriate tuning of some constants of integration appearing in the solution of the M-theory metric perturbations and the ρ and π meson radial profile functions — a flexibility that our calculations permits.

Glueballs' of pure force must exist – will we ever find them?

Want to make a lightsaber? Easy! Just find bundles of gluons – particles made entirely of force – to unleash your inner Skywalker

Research on parton distributions in nucleon

We present the parton distributions at leading order(LO) coming from GJR,MSTW and CTEQ parton sets and compare them at different momentum scales.Obvious differences exist in their gluon and sea quark distributions at small x region.Itindicates that people have not known the nucleon parton distributions very well.We analysze the influence of higher twist effects,i.e.,the shadowing effects and anti-shadowing effects,on parton distributions.Because of the shadowing effects,the twist-4 gluon and sea quark distributions are smaller than the twist-2 distributions at small and middle x region,while,the anti-shadowing effects make the twist-4 gluon and sea quark distributions larger than the twist-2 distributions at x≥2 region.Finally,we present a detailed analysis of how the proton's momentum is shared among various parton flavors at different Q~2 for different parton sets.With the numerical calculation,we show that the MD-DGLAP equations are momentum conservation.

We Can Unify Quantum Mechanics And Gravity Only By ToE i.e MIND

A Theory of Everything would unify all the fundamental interactions of nature: gravitation , strong interaction , weak interaction , and electromagnetism . Because the weak interaction can transform elementary particles from one kind into another, the ToE should also yield a deep understanding of the various different kinds of possible particles. The usual assumed path of theories is given in the following graph, where each unification step leads one level up In Unification physics where four fundamental forces are tried to unify . It means Four natural forces which are mediated by four particles ( photon, vector boson , gluons and gravitons) are created from one particle . It is called super unification. GUT means three forces ( Photon, vector bosons, and GLUON ) could be unified as these are made up of one type of fundamental particle called energy basic building blocks .

Study of Charmed and Bottom Baryons in a Variational Approach and Chiral Interactions

Models have been widely used to study charmed and bottom baryons. In this work using the confining, one gluon exchange and Goldstone boson exchange terms as inter-quark interactions, we study the heavy flavour baryon spectrum in the framework of the constituent quark model. We use a variational method to solve the non-relativistic three-body problem for baryons in the hypercentral approach. The masses of heavy baryons containing one, two, and three heavy flavour quarks are found to be in accordance with the existing experimental values or with other theoretical predictions. The magnetic moments of single heavy baryons with J^p=3/2^+ are also obtained.

Meson Spectra in p + p Collisions at LHC

The p + p (proton + proton) collisions are important to understand particle production mechanism in partonic collisions and are also used as baseline for heavy ion collisions. We present systematic study of meson spectra in p + p collisions at LHC energies (√s = 0.9, 2.76 and 7.0 TeV). We also studied the transverse mass (m T ) spectra of pion and kaon for p + p collisions at all above mentioned energies. In an earlier study [1], it was shown that all the mesons produced in p + p and d + Au collisions at √s NN = 200 GeV follow m T scaling while in Au + Au collisions at same energy the mesons with strange and charm quark contents do not follow m T scaling which can be attributed to medium modifications. Here we fit all pion spectra with Hagedorn distribution and extract all the output parameters from the fitting. Then we fit kaon spectra using m T scaling with the help of those extracted fitting parameters along with a normalizing factor. We observed that m T scaling in case of kaon is valid in p + p collisions at LHC energies. The normalizing factor of kaon with respect to pion (K/π) is almost constant in all energies . This study is important for the observation of strangeness enhancement in heavy ion collisions, which is an important probe of quark gluon plasma (QGP). It is also used as a baseline for the study of medium modifications in heavy ion collisions. Kaon spectra provides a unique opportunity to identify new flavor and CP violating interactions beyond the Standard Model (SM).

Evolution of singularities in unequal time correlator in thermalization of quark gluon plasma

We studied thermalization of strongly coupled gauge theory using a gravitational collapse model. In particular, we studied unequal time correlator for the glue ball operator. We found singularities of the correlator for zero momentum sector is consistent with a geometric optics picture in the gravitational theory. The singularities of the correlator indicates strong temporal correlation, thus the time after which the singularities disappear provides a measure of the temporal decoherence in the thermalization process.

Detection of Heterogeneous Peptides in Tryptic Digests of Ajiao by UPLC -QTOF and RRLC-IT

Donkey-hide gelatin (Ajiao in Chinese) is a gelatin drug, which is the dry glue pieces made from the hide of Equus asinus L. (family Equidae), and used to tone the blood, arrest bleeding, nourish yin and prevent dryness. After a series of processes of the hide: washing, soaking, plucking, rinsing and stewing, the collagen of the donkey hide was hydrolyzed into a mixture of polypeptides. It is used unprepared, or stir-baked with oyster shell powder or cat-tail pollenpowder into small glue balls for use. In China, bovine and porcine hides are also used as the gelatin drug. The similarity between different gelatins makes it difficult to trace their species origin[1].

Gluon-propagator functional form in the Landau gauge in SU(3) lattice QCD: Yukawa-type gluon propagator and anomalous gluon spectral function

We study the gluon propagator ${D}_{\ensuremath{\mu}\ensuremath{\nu}}^{ab}(x)$ in the Landau gauge in SU(3) lattice QCD at $\ensuremath{\beta}=5.7$, 5.8, and 6.0 at the quenched level. The effective gluon mass is estimated as $400--600\text{ }\text{ }\mathrm{MeV}$ for $r\ensuremath{\equiv}({x}_{\ensuremath{\alpha}}{x}_{\ensuremath{\alpha}}{)}^{1/2}=0.5--1.0\text{ }\text{ }\mathrm{fm}$. Through the functional-form analysis of ${D}_{\ensuremath{\mu}\ensuremath{\nu}}^{ab}(x)$ obtained in lattice QCD, we find that the Landau-gauge gluon propagator ${D}_{\ensuremath{\mu}\ensuremath{\mu}}^{aa}(r)$ is well described by the Yukawa-type function ${e}^{\ensuremath{-}mr}/r$ with $m\ensuremath{\simeq}600\text{ }\text{ }\mathrm{MeV}$ for $r=0.1--1.0\text{ }\text{ }\mathrm{fm}$ in the four-dimensional Euclidean space-time. In the momentum space, the gluon propagator ${\stackrel{\texttildelow{}}{D}}_{\ensuremath{\mu}\ensuremath{\mu}}^{aa}({p}^{2})$ with $({p}^{2}{)}^{1/2}=0.5--3\text{ }\text{ }\mathrm{GeV}$ is found to be well approximated with a new-type propagator of $({p}^{2}+{m}^{2}{)}^{\ensuremath{-}3/2}$, which corresponds to the four-dimensional Yukawa-type propagator. Associated with the Yukawa-type gluon propagator, we derive analytical expressions for the zero-spatial-momentum propagator ${D}_{0}(t)$, the effective mass ${M}_{\mathrm{eff}}(t)$, and the spectral function $\ensuremath{\rho}(\ensuremath{\omega})$ of the gluon field. The mass parameter $m$ turns out to be the effective gluon mass in the infrared region of $\ensuremath{\sim}1\text{ }\text{ }\mathrm{fm}$. As a remarkable fact, the obtained gluon spectral function $\ensuremath{\rho}(\ensuremath{\omega})$ is almost negative definite for $\ensuremath{\omega}gm$, except for a positive $\ensuremath{\delta}$-functional peak at $\ensuremath{\omega}=m$.

Shape-Controllable Synthesis and Electrochemical Properties of Nanostructured Manganese Oxides

Several nanostructured manganese oxides with novel shapes were controllably synthesized from the same precursor Na−BirMO via a facile, direct hydrothermal or surging method. The synthesis parameters for nanostructured manganese oxides were investigated, along with their influences on structure, morphology, composition, and electrochemical properties on glass carbon electrode. XRD diffraction showed that the prepared nanostructured manganese oxides belonged to different polymorphs. SEM, TEM, and HRTEM revealed that they had a variety of morphologies, including 0-dimension microspheres, 1-dimension distinct tetragonous and semi-tubular structures, nanorolls, and spindly nanowire bundles. Basis on the experimental results, a rolling rice glue ball formation mechanism for manganese oxide microspheres was proposed. Electrochemical properties were studied on glass carbon electrode (GCE) using cyclic voltammetry (CV). The results showed the electrochemical properties depended on the shape, size and crystal structure of the prepared nanostructured manganese oxides.

Cooling of quark stars in the colour superconductive phase: effect of photons from glueball decay

The cooling history of a quark star in the colour superconductive phase is investigated. Here we specifically focus on the two-flavour colour (2SC) phase where the novel process of photon generation via glueball (GLB) decay has already been investigated. The picture we present here can, in principle, be generalized to quark stars entering a superconductive phase where similar photon generation mechanisms are at play. As much as 10 45 ‐10 47 erg of energy is provided by the GLB decay in the 2SC phase. The generated photons slowly diffuse out of the quark star, keeping it hot and radiating as a blackbody (with possibly a Wien spectrum in gamma-rays) for millions of years. We discuss hot radio-quiet isolated neutron stars in our picture (such as RX J185635‐3754 and RX J0720.4‐3125) and argue that their nearly blackbody spectra (with a few broad features) and their remarkably tiny hydrogen atmosphere are indications that these might be quark stars in the colour superconductive phase where some sort of photon generation mechanism (reminiscent of the GLB decay) has taken place. Fits to observed data of cooling compact stars favour models with superconductive gaps of � 2SC ∼ 15‐35 MeV and densities ρ 2SC = (2.5‐3.0) × ρ N (ρ N being the nuclear matter saturation density) for quark matter in the 2SC phase. If correct, our model combined with more observations of isolated compact stars could provide vital information to studies of quark matter and its exotic phases.

Synthesis and luminescent properties of novel RENbO4:Ln3+ (RE = Y, Gd, Lu; Ln = Eu, Tb) micro-crystalline phosphors

Using rare earth coordination polymers with aromatic carboxylic acids as the precursors of rare earth oxide components, with polyethylene glycol (PEG) as the dispersing media, micro-crystalline phosphors RENbO4:Ln3+ (RE=Y,Gd,Lu; Ln=Eu,Tb) have been synthesized by an in situ co-precipitation method. Both X-ray diffraction and scanning electron microscopy have shown that the resultant samples present are crystalline with ‘rice glue ball’ micro-morphology and crystalline grain sizes in the range of 1–2μm. The luminescent properties of these phosphors have been studied, which show that the best photoluminescent performance is achieved for GdNbO4:Tb3+ or Eu3+. This was because Gd3+ plays an important role to enhance the luminescence of Tb3+ or Eu3+ in an energy transfer process. In addition, the influence of the doping concentration on the fluorescence behaviors has been examined. With increase of the doping concentration from 1mol% to 5mol%, both the red emission intensity of Eu3+ and the green emission intensity of Tb3+ increase.

NMHV amplitudes in simple electroweak processes

The author applied extended BCF/BCFW rules with fermions to a set of simple electroweak processes in colliders. In such processes, there are two electroweak channels, one with a photon and the other with aZ as the internal particle. Some qualifications are needed. Compact results were obtained for tree-level NMHV amplitudes which include a quark-anti-quark pair andn gluons of the same helicity except one in the final state. In this work, we present a brief review of the BCF/BCFW rules and extensions, and list the NMHV amplitudes.

The static quark potential and scaling behavior of SU(3) lattice Yang-Mills theory

The potential between a static quark and antiquark in pure SU(3) Yang-Mills theory is evaluated non-perturbatively through computations on the lattice in the region from short to intermediate distances (0.05 fm < r < 0.8 fm). In the high energy regime the results are compared with the parameter-free prediction of perturbation theory obtained by solving the Renormalization Group equation at two and three loops. The choice of the renormalization scheme to define a running coupling turns out to be important for the accuracy of the perturbative prediction: by obtaining the running coupling through the force, perturbation theory is applicable up to alpha ~ 0.3, while from the static potential only up to alpha ~ 0.15. In the region where perturbation is supposed to be reliable, no large unexpected non-perturbative term is observed. In the second part of this work, universality and scaling behavior of different formulations of Yang-Mills theory on the lattice are discussed, in particular the Iwasaki and DBW2 actions. The deconfinement temperature T_c*r0 and the glueball masses (m_0++)*r0, (m_2++)*r0 are analyzed. Particular attention is dedicated to the violation of physical positivity which occur in these actions and the consequences in the extraction of physical quantities from Euclidean correlation functions.

Possible hints and search for glueballs in charmless rare B decays

We suggest possibility for glueball search in 3-body charmless B decays, and compare hints in these channels with other possibilities, such as p p annihilation, pp central production, and ϒ decay.

Enhancement of φ meson production in p-p and Pb-Pb collisions at SPS energy

The φ meson yield, rapidity and transverse mass distributions in p-p and Pb-Pb collisions at 158 A GeV were studied by the hadron-string cascade model, LUCIAE. By adjusting the width parameter in q\(\bar q\) Gaussian like transverse momentum distribution in string fragmentation to fit the NA49 data of φ meson transverse mass distribution in p-p collisions, the obtained φ meson rapidity distribution in p-p collisions, the rapidity and transverse mass distributions in Pb-Pb collisions, and the φ meson enhancement factor in Pb-Pb relative to p-p collisions were compatible with corresponding NA49 data, which might be attributed to the collective effect in gluon emission of string and the reduction of strange quark suppression mechanisms involved in the LUCIAE model