scholarly journals Δ-Isobar contribution to the pion production in the reaction pp → {pp}sπ0

2019 ◽  
Vol 204 ◽  
pp. 01015
Author(s):  
Yuriy Uzikov
Keyword(s):  
Excitation Energy ◽  
Cross Section ◽  
Pion Production ◽  
Forward Direction ◽  
Dominant Contribution ◽  
Final State ◽  
Proton Pair ◽  
Order Of Magnitude ◽  
The Cross ◽  
The One

ANKE@COSY data on the cross section of the reaction pp → {pp}sπ0, where {pp}s is the proton pair in the 1S 0 state at small excitation energy Epp = 0 – 3 MeV, obtained at beam energies 0.5 - 2.0 GeV are analyzed within the one-pion exchange model. The model involves the subprocess π0 p → π0 p and accounts for the final state pp-interaction. A broad maximum observed in the cross section of the reaction pp → {pp}sπ0 at 0.5 - 1.4 GeV in the forward direction is explained by this model as a dominant contribution of the isospin $\cfrac{3}{2}$ in the π0 p-scattering. The second bump in data at 2 GeV is underpredicted within this model by one order of magnitude. An explicit excitation of the Δ(1232)-isobar using the box-diagram is also considered in the region of the first maximum.

ISOSPIN DECOMPOSITION OF pp → NNππ CROSS SECTIONS — DO WE SEE A SIGN OF Δ(1600) EXCITATION IN THE nnπ+π+ CHANNEL?

2009 ◽  
Vol 24 (02n03) ◽  
pp. 450-453
Author(s):  
◽  
T. SKORODKO ◽  
M. BASHKANOV ◽  
D. BOGOSLOWSKY ◽  
H. CALÉN ◽  
...  
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Differential Cross ◽  
Pion Production ◽  
Significant Contribution ◽  
Differential Cross Sections ◽  
Pp Collisions ◽  
Theoretical Predictions ◽  
Order Of Magnitude ◽  
The Cross

The two-pion production in pp-collisions has been investigated in exclusive measurements from threshold up to Tp = 1.36 GeV . Total and differential cross sections have been obtained for the channels pnπ+π0, ppπ+π-, ppπ0π0 and also nnπ+π+. For intermediate incident energies Tp > 1 GeV , i.e. in the region, which is beyond the Roper excitation but at the onset of ΔΔ excitation the total ppπ0π0 cross section falls behind theoretical predictions by as much as an order of magnitude near 1.2 GeV, whereas the nnπ+π+ cross section is a factor of five larger than predicted. A model-unconstrained isospin decompostion of the cross section points to a significant contribution of an isospin 3/2 resonance other than the Δ(1232). As a possible candidate the Δ(1600) is discussed.

scholarly journals Probing the Higgs sector in the nonrelativistic domain

2019 ◽  
Vol 2019 (7) ◽  
Author(s):  
Zhentao Zhang
Keyword(s):  
Pair Production ◽  
Cross Section ◽  
Higgs Sector ◽  
Threshold Region ◽  
Final State ◽  
Direct Information ◽  
The Cross ◽  
The One ◽  
Nonperturbative Contribution

AbstractAs a process that contains direct information from the Higgs self-coupling, we investigate the muon-induced Higgs pair production $\mu^-\mu^+\rightarrow HH$. We calculate the one-loop corrections to the cross section, and in the threshold region we take into account the nonperturbative contribution from the Higgs self-interactions in the final state. We point out that the Higgs pair production in the nonrelativistic domain might be a useful process for probing the Higgs sector.

UPS of a-Si:H: What is the energy of the Er 4f states?

2000 ◽  
Vol 609 ◽  
Author(s):  
Leandro R. Tessler ◽  
Cínthia Piamonteze ◽  
Ana Carola Iniguez ◽  
Abner de Siervo ◽  
Richard Landers ◽  
...  
Keyword(s):  
Binding Energy ◽  
Excitation Energy ◽  
Cross Section ◽  
Energy Gap ◽  
Valence States ◽  
Erbium Doped ◽  
Order Of Magnitude ◽  
Synchrotron Light ◽  
The Cross ◽  
Er Doped

ABSTRACTOne very important problem concerning erbium-doped silicon is the electronic structure of the Er3+ impurities. In particular, it is still not clear if the 4f levels can be treated as frozen core levels or their overlap with s and p states of their neighbors must be considered explicitly. For crystalline Si, the 4f levels have been supposed to be anywhere between 20 eV below the valence band and within the energy gap. In this paper we report on the first ultraviolet photoemission spectroscopy (UPS) measurements on Er-doped a-Si:H. Samples of a-Si:H<Er> with different Er contents (up to 1 at. % Er) were prepared by co-sputtering from a Si target partially covered with metallic Er platelets. In order to enhance the Er states relative to the Si and H states, the excitation energy was tuned between 40 and 140 eV with a synchrotron light source. At 140 eV excitation energy the cross-section of the Er 4f and 5p states is more than an order of magnitude higher than the cross section of the Si 3s or 3p states. As the Er concentration increases, a shoulder and then a peak appears at 10.0±0.5 eV binding energy. The intensity and width of this peak is well correlated with the Er concentration, and with the Er 5p and 5p½ levels at 26 and 32 eV binding energy, respectively. We attribute the peak at 10.0±0.5 eV binding energy to the Er 4f level. These are the only occupied states that can be related to the presence of Er, indicating that these levels are not valence states and consequently can be treated as frozen core levels.

scholarly journals Searching for axionlike particles with low masses in pPb and PbPb collisions

2021 ◽  
Vol 81 (6) ◽  
Author(s):  
V. P. Gonçalves ◽  
D. E. Martins ◽  
M. S. Rangel
Keyword(s):  
Detailed Analysis ◽  
Cross Section ◽  
Experimental Analysis ◽  
Mass Range ◽  
Final State ◽  
Lhcb Detector ◽  
The Cross ◽  
Photon Coupling

AbstractThe production of axionlike particles (ALPs) with small masses in ultraperipheral Pb–p and Pb–Pb collisions at the LHC is investigated. The cross section and kinematical distributions associated to the diphoton final state produced in the $$\gamma \gamma \rightarrow a \rightarrow \gamma \gamma $$ γ γ → a → γ γ subprocesses are estimated considering a realistic set of kinematical cuts. A detailed analysis of the backgrounds is performed and the expected sensitivity to the ALP production is derived. Our results demonstrate that a future experimental analysis of the exclusive diphoton production for the forward rapidities probed by the LHCb detector can improve the existing exclusion limits on the ALP–photon coupling in the mass range 2 GeV $$\le m_a \le $$ ≤ m a ≤ 5 GeV.

scholarly journals Quasielastic Lepton Scattering off Two-Component Dark Matter in Hypercolor Model

Symmetry ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 708 ◽  
Author(s):  
Vitaly Beylin ◽  
Maxim Bezuglov ◽  
Vladimir Kuksa ◽  
Egor Tretiakov
Keyword(s):  
Dark Matter ◽  
Total Cross Section ◽  
Cross Section ◽  
Strong Dependence ◽  
Cosmic Ray ◽  
High Energy ◽  
Dominant Contribution ◽  
Quasielastic Scattering ◽  
Two Component ◽  
The Cross

The interaction of high-energy leptons with components of Dark Matter in a hypercolor model is considered. The possibility of detection, using IceCube secondary neutrinos produced by quasielastic scattering of cosmic ray electrons off hidden mass particles, is investigated. The dominant contribution to the cross section results from diagrams with scalar exchanges. A strong dependence of the total cross section on the Dark Matter components mass is also found.

Static and Dynamic Analysis of Aircraft Structures by Component-Wise Approach

2013 ◽  
Author(s):  
E. Carrera ◽  
A. Pagani ◽  
M. Petrolo
Keyword(s):  
Cross Section ◽  
Three Dimensional ◽  
Aircraft Structures ◽  
Static And Dynamic Analysis ◽  
Computational Costs ◽  
Commercial Code ◽  
Wing Structures ◽  
Order Of Magnitude ◽  
The Cross ◽  
Beam Theories

This paper proposes an advanced approach to the analysis of reinforced-shell aircraft structures. This approach, denoted as Component-Wise (CW), is developed by using the Carrera Unified Formulation (CUF). CUF is a hierarchical formulation allowing for the straightforward implementation of any-order one-dimensional (1D) beam theories. Lagrange-like polynomials are used to discretize the displacement field on the cross-section of each component of the structure. Depending on the geometrical and material characteristics of the component, the capabilities of the model can be enhanced and the computational costs can be kept low through smart discretization strategies. The global mathematical model of complex structures (e.g. wings or fuselages) is obtained by assembling each component model at the cross-section level. Next, a classical 1D finite element (FE) formulation is used to develop numerical applications. It is shown that MSC/PATRAN can be used as pre- and post-processor for the CW models, whereas MSC/NASTRAN DMAP alters can be used to solve both static and dynamic problems. A number of typical aeronautical structures are analyzed and CW results are compared to classical beam theories (Euler-Bernoulli and Timoshenko), refined models and classical solid/shell FE solutions from the commercial code MSC/NASTRAN. The results highlight the enhanced capabilities of the proposed formulation. In fact, the CW approach is clearly the natural tool to analyze wing structures, since it leads to results that can be only obtained through three-dimensional elasticity (solid) elements whose computational costs are at least one-order of magnitude higher than CW models.

New Results on Double Charmonium Production in e+e- Annihilation at $\sqrt{s} \approx 10.6~{\rm GeV}$ with the Belle Detector

2005 ◽  
Vol 20 (16) ◽  
pp. 3617-3620
Author(s):  
◽  
T. Ziegler
Keyword(s):  
Cross Section ◽  
Strong Evidence ◽  
Previous Analysis ◽  
Charmonium State ◽  
Data Set ◽  
Charmonium Production ◽  
Belle Detector ◽  
Theoretical Predictions ◽  
Order Of Magnitude ◽  
The Cross

Extending a previous analysis1 the double charmonium production [Formula: see text] and [Formula: see text] has been investigated with a data set of 155 fb-1 with the Belle detector. Theoretical predictions for the cross section are one order of magnitude lower than the measured value and this discrepancy is still not understood. In a very recent update with a dataset of 285 fb-1 strong evidence for a new charmonium state at a mass of 3.940 GeV was found.

The Bakerian lecture.— On the forms of equipotential curves and surfaces and on lines of flow

1876 ◽  
Vol 24 (164-170) ◽  
pp. 1-32
Keyword(s):  
Cross Section ◽  
Outer Boundary ◽  
The Other ◽  
Curves And Surfaces ◽  
Conducting Wire ◽  
The Wire ◽  
The Cross ◽  
Current Flows ◽  
The One

When any portion of a conducting-wire which joins the two poles of a voltaic battei'y is increased in size, the resistance of the circuit is diminished and a greater current flows through the wire ; and as any increase in the cross section of any portion of the wire causes a corre­sponding increase in the current, it is clear that there is no part of the conducting-wire through which some portion of the current does not flow from the one pole to the other; and the outer boundary of such a wire will be a line of flow. A line of flow is a line drawn in a conductor which indicates at every point of it the direction of the current at that point. A portion of the conductor completely enclosed by lines of flow may be termed a tube of flow.

scholarly journals Sudakov Form Factors in Leptoproduction of Vector Mesons

1997 ◽  
Vol 12 (35) ◽  
pp. 2717-2723
Author(s):  
I. M. Dremin
Keyword(s):  
Cross Section ◽  
Form Factors ◽  
Model Parameters ◽  
Vector Mesons ◽  
Large Size ◽  
Color Dipole ◽  
Order Of Magnitude ◽  
The Cross ◽  
Qcd Inspired Model

It is shown that Sudakov form factors for a color dipole in a QCD-inspired model of leptoproduction of vector mesons reduce the value of the cross-section of the process by an order of magnitude. They suppress the large size quark–antiquark pairs and unequal sharing of energy among the components of the dipole. Some freedom in the choice of the model parameters is also discussed.

scholarly journals The Dynamic Collective Model Interpretation of the Photoneutron Cross Section of 181Ta

1973 ◽  
Vol 26 (5) ◽  
pp. 585 ◽  
Author(s):  
RS Hicks ◽  
BM Spicer
Keyword(s):  
Fine Structure ◽  
Excitation Energy ◽  
Cross Section ◽  
Neutron Detection ◽  
Collective Model ◽  
High Excitation ◽  
Absolute Value ◽  
Model Interpretation ◽  
Quadrupole Resonance ◽  
The Cross

The cross section for photoneutron production in 181Ta has been measured from threshold to 28� 8 MeV using bremsstrahlung and direct neutron detection. Integrated between these limits, the absolute value of the cross section has been determined to be 2 '47 �O' 35 MeV. b. An examination of the cross section variation with excitation energy reveals the existence of the giant quadrupole resonance lying on the high excitation edge of the dipole peak. This provides additional evidence for the validity of the dynamic collective model. The present data do not support the existence of extensive fine structure below 17 MeV, as proposed by Ishkhanov et al. (1969).

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