scholarly journals Recent Hadronic Cross Section Measurements from BABAR

2019 ◽  
Vol 218 ◽  
pp. 02003
Author(s):  
Konrad Griessinger
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Hadronic Cross Section ◽  
Babar Experiment

New hadronic cross sections measured by the BABAR experiment are presented: e+e−→ π+π−π0π0, e+ e−→ π+π−η, and the kaonic channels e+e−→ KS KLπ0 , KS KLπ0π0 , KS KLη, KS K±π+π0 , KS K±π+η.

scholarly journals Hadronic Cross Section Measurements at Belle and perspectives for BELLE-II

2019 ◽  
Vol 218 ◽  
pp. 02011
Author(s):  
B. Shwartz
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Large Data ◽  
Hadronic Cross Section ◽  
Belle Detector ◽  
Belle Ii ◽  
Integrated Luminosity

Large data amount, about 1 ab−1 of integrated luminosity, collected in experiments with the Belle detector provided a good possibilities for precise measurements of the hadronic cross sections in e+e− annihilation. Main results obtained in this field with the Belle detector as well as perspectives of the new experiments with the Belle II detector at the SuperKEKB collider is discussed in this report.

The effect of Higgs boson radiation from TeV black holes on the hadronic cross section at the LHC

2012 ◽  
Vol 90 (1) ◽  
pp. 25-37 ◽  
Author(s):  
A. Sepehri ◽  
M.E. Zomorrodian ◽  
A. Moradi Marjaneh ◽  
P. Eslami ◽  
S. Shoorvazi
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Higgs Boson ◽  
Cross Section ◽  
Cross Sections ◽  
Unruh Effect ◽  
Leading Order ◽  
Hadronic Cross Section ◽  
The Cross ◽  
Mini Black Holes

In curved space–time near TeV black holes many gluons and quarks produced by the Unruh effect interact with each other and create Higgs bosons. We study the Unruh effect and show that, for gluons and quarks, the internal stationary state of a Schwarzschild black hole can be represented by a maximally entangled two-mode squeezed state of outgoing and infalling Hawking radiation. We consider different channels for Higgs boson production near event horizons of mini black holes at the Large Hadron Collider (LHC) and obtain the cross section in each channel. We observe that the cross section of a Higgs boson produced via gluon fusion near a single black hole is much larger for smaller black hole masses. This is because the temperature of the black hole becomes larger as the mass becomes smaller and the thermal radiation of the gluons is enhanced. At lower mass, MBH < 4 TeV, the black hole will not be able to emit Higgs, but will still be able to produce a quark; for MBH < 3 TeV the black hole can only emit massless gluons. We show that as the black hole mass at the LHC increases (4 TeV < MBH < 8 TeV) most of the Higgs boson production is due to the Unruh effect near the event horizon of the black hole. Comparing these Higgs boson cross sections with Higgs boson cross sections in perturbative quantum chromodynamics, we find that micro black holes can be a source of Higgs production at the LHC. Finally, we calculate the effects of Higgs boson radiation due to mini black holes on the hadronic cross section at the LHC. We observe that as the order of perturbation theory increases this effect becomes systematically more significant because at higher orders there exist more channels for Higgs production and, in our calculations, Higgs decay into massive quark–antiquark pairs. At smaller masses, MBH < 2 TeV, the hadronic cross section at leading order is large while the cross sections at next-to-leading order and at next-to-next-to-leading order are rising at MBH ∼ 2 and 3 TeV, respectively, and exhibit a turn-over at moderate values of black hole mass.

HADRONIC CROSS SECTION MEASUREMENT AT BES-III

2014 ◽  
Vol 35 ◽  
pp. 1460408
Author(s):  
SVEN SCHUMANN ◽  
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Structure Constant ◽  
Fine Structure Constant ◽  
Initial State ◽  
Section Data ◽  
Hadronic Cross Section ◽  
Section Measurement ◽  
R Ratio ◽  
State Radiation

Measurements of the R ratio are closely related to two pre quantities, the anomalous magnetic moment of the muon (g - 2), and the value of the electromagnetic fine structure constant [Formula: see text]. Hadronic contributions to both quantities can be derived via dispersion integrals, using experimental R data as input. For the phenomenological evaluations of these contributions, different energy ranges of hadronic cross section data are required. At BES-III, Initial State Radiation (ISR) from an existing Ψ(3770) dataset will be used for measurements of hadronic cross sections below [Formula: see text], while for higher energies a dedicated energy scan program will be performed up to [Formula: see text].

scholarly journals New results on low energy exclusive hadronic final states from BABAR

2018 ◽  
Vol 172 ◽  
pp. 04002
Author(s):  
J. William Gary
Keyword(s):  
Standard Deviation ◽  
Cross Section ◽  
Cross Sections ◽  
Particle Physics ◽  
Low Energy ◽  
Final States ◽  
Muon Anomalous Magnetic Moment ◽  
The Standard Model ◽  
Babar Experiment ◽  
Hadronic Final States

The 3.6 standard deviation discrepancy between the standard model (SM) prediction for the muon anomalous magnetic moment gμ - 2 and the corresponding experimental measurement is one of the most persistent and intriguing potential signals in particle physics for physics beyond the SM. The largest uncertainty in the SM prediction for gμ - 2 arises from the uncertainty in the measured low energy inclusive e+e- → hadrons cross section. New results from the BABAR experiment at SLAC for the e+e- → π+ π- π0 π0 and e+e- → KK ππ cross sections are presented that significantly reduce this uncertainty. New BABAR results for other low energy exclusive hadronic processes are also discussed.

scholarly journals Overview of SND hadronic cross section measurements

2019 ◽  
Vol 218 ◽  
pp. 02002
Author(s):  
T.V. Dimova ◽  
M.N. Achasov ◽  
V.M. Aulchenko ◽  
A.Yu. Barnyakov ◽  
K.I. Beloborodov ◽  
...  
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Hadronic Cross Section

At the end of 2016 the SND detector resumed data taking at the upgraded VEPP-2000 e+e− collider. The analysis of data accumulated in 2010-2013 with an integrated lumonosity of 70 pb−1 is continuing. Recent results on measurements of various hadronic cross sections are presented.

Electron Irradiation Effects in Polyoxymethylene Crystals Grown Inside Trioxane Crystals

1971 ◽  
Vol 29 ◽  
pp. 78-79
Author(s):  
J. P. Colson ◽  
D. H. Reneker
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Detailed Examination ◽  
The Other ◽  
Electron Micrograph ◽  
Irradiation Effects ◽  
Threefold Axis ◽  
Typical Sample ◽  
Polymer Crystals ◽  
Chain Axis

Polyoxymethylene (POM) crystals grow inside trioxane crystals which have been irradiated and heated to a temperature slightly below their melting point. Figure 1 shows a low magnification electron micrograph of a group of such POM crystals. Detailed examination at higher magnification showed that three distinct types of POM crystals grew in a typical sample. The three types of POM crystals were distinguished by the direction that the polymer chain axis in each crystal made with respect to the threefold axis of the trioxane crystal. These polyoxymethylene crystals were described previously.At low magnifications the three types of polymer crystals appeared as slender rods. One type had a hexagonal cross section and the other two types had rectangular cross sections, that is, they were ribbonlike.

A quantitative approach to inner shell losses

1978 ◽  
Vol 36 (1) ◽  
pp. 526-527 ◽  
Author(s):  
R.D. Leapman ◽  
P. Rez ◽  
D.F. Mayers
Keyword(s):  
Energy Transfer ◽  
Cross Section ◽  
Cross Sections ◽  
Accurate Determination ◽  
Background Intensity ◽  
Core Excitation ◽  
Quantitative Basis ◽  
Cross Section Differential ◽  
Bound Electrons

Microanalysis by EELS has been developing rapidly and though the general form of the spectrum is now understood there is a need to put the technique on a more quantitative basis (1,2). Certain aspects important for microanalysis include: (i) accurate determination of the partial cross sections, σx(α,ΔE) for core excitation when scattering lies inside collection angle a and energy range ΔE above the edge, (ii) behavior of the background intensity due to excitation of less strongly bound electrons, necessary for extrapolation beneath the signal of interest, (iii) departures from the simple hydrogenic K-edge seen in L and M losses, effecting σx and complicating microanalysis. Such problems might be approached empirically but here we describe how computation can elucidate the spectrum shape.The inelastic cross section differential with respect to energy transfer E and momentum transfer q for electrons of energy E0 and velocity v can be written as

Oxygen K near edge structures studied with multiple scattering calculations

1988 ◽  
Vol 46 ◽  
pp. 504-505
Author(s):  
Xudong Weng ◽  
Peter Rez
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Partial Cross Section ◽  
Energy Window ◽  
Edge Structure ◽  
Fine Structures ◽  
Hydrogenic Model ◽  
Electron Energy Loss ◽  
Quantitative Chemical

In electron energy loss spectroscopy, quantitative chemical microanalysis is performed by comparison of the intensity under a specific inner shell edge with the corresponding partial cross section. There are two commonly used models for calculations of atomic partial cross sections, the hydrogenic model and the Hartree-Slater model. Partial cross sections could also be measured from standards of known compositions. These partial cross sections are complicated by variations in the edge shapes, such as the near edge structure (ELNES) and extended fine structures (ELEXFS). The role of these solid state effects in the partial cross sections, and the transferability of the partial cross sections from material to material, has yet to be fully explored. In this work, we consider the oxygen K edge in several oxides as oxygen is present in many materials. Since the energy window of interest is in the range of 20-100 eV, we limit ourselves to the near edge structures.

Absolute inner-shell cross section determination for EELS analysis

1988 ◽  
Vol 46 ◽  
pp. 534-535
Author(s):  
P.A. Crozier
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Absolute Cross Section ◽  
Specimen Thickness ◽  
Mass Thickness ◽  
Scattering Cross ◽  
Before And After ◽  
Estimated Error ◽  
Scattering Cross Sections ◽  
Electron Microscopist

Absolute inelastic scattering cross sections or mean free paths are often used in EELS analysis for determining elemental concentrations and specimen thickness. In most instances, theoretical values must be used because there have been few attempts to determine experimental scattering cross sections from solids under the conditions of interest to electron microscopist. In addition to providing data for spectral quantitation, absolute cross section measurements yields useful information on many of the approximations which are frequently involved in EELS analysis procedures. In this paper, experimental cross sections are presented for some inner-shell edges of Al, Cu, Ag and Au.Uniform thin films of the previously mentioned materials were prepared by vacuum evaporation onto microscope cover slips. The cover slips were weighed before and after evaporation to determine the mass thickness of the films. The estimated error in this method of determining mass thickness was ±7 x 107g/cm2. The films were floated off in water and mounted on Cu grids.

A technique for preparing semiconductor cross sections for both TEM and SEM analysis

1989 ◽  
Vol 47 ◽  
pp. 712-713
Author(s):  
Stanley J. Klepeis ◽  
J.P. Benedict ◽  
R.M Anderson
Keyword(s):  
Sample Preparation ◽  
Cross Section ◽  
Cross Sections ◽  
Sem Analysis ◽  
Preparation Technique ◽  
Ion Milling ◽  
Tem Analysis ◽  
Polished Cross Section ◽  
Area Of Interest ◽  
Polished Side

The ability to prepare a cross-section of a specific semiconductor structure for both SEM and TEM analysis is vital in characterizing the smaller, more complex devices that are now being designed and manufactured. In the past, a unique sample was prepared for either SEM or TEM analysis of a structure. In choosing to do SEM, valuable and unique information was lost to TEM analysis. An alternative, the SEM examination of thinned TEM samples, was frequently made difficult by topographical artifacts introduced by mechanical polishing and lengthy ion-milling. Thus, the need to produce a TEM sample from a unique,cross-sectioned SEM sample has produced this sample preparation technique.The technique is divided into an SEM and a TEM sample preparation phase. The first four steps in the SEM phase: bulk reduction, cleaning, gluing and trimming produces a reinforced sample with the area of interest in the center of the sample. This sample is then mounted on a special SEM stud. The stud is inserted into an L-shaped holder and this holder is attached to the Klepeis polisher (see figs. 1 and 2). An SEM cross-section of the sample is then prepared by mechanically polishing the sample to the area of interest using the Klepeis polisher. The polished cross-section is cleaned and the SEM stud with the attached sample, is removed from the L-shaped holder. The stud is then inserted into the ion-miller and the sample is briefly milled (less than 2 minutes) on the polished side. The sample on the stud may then be carbon coated and placed in the SEM for analysis.

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