scholarly journals πe3Form Factorf-Near the Mass Shell

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
M. I. Krivoruchenko
Keyword(s):  
Form Factor ◽  
Mass Shell ◽  
Numerical Estimate ◽  
Mass Difference ◽  
Form Factors ◽  
Vector Current ◽  
Gauge Dependence ◽  
A Value ◽  
Model Independent ◽  
The Difference

The generalized Ward-Takahashi identity (gWTI) in the pion sector for broken isotopic symmetry is derived and used for the model-independent calculation of the longitudinal form factorf-of theπe3vector vertex. The on-shellf-is found to be proportional to the mass difference of the pions and the difference between the vector isospinT=1and scalar isospinT=2pion radii. A numerical estimate of the form factor yields a value two times higher than the previous estimate from the quark model. Off-shell form factors are known to be ambiguous because of the gauge dependence and the freedom in the parameterization of the fields. The near-mass-shellf-appears to be an exception, allowing for experimental verification of the consequences of the gWTI. We calculate the near-mass-shellf-using the gWTI and dispersion techniques. The results are discussed in the context of the conservation of vector current (CVC) hypothesis.

scholarly journals Tensor form factor for the D → π(K) transitions with Twisted Mass fermions.

2018 ◽  
Vol 175 ◽  
pp. 13022
Author(s):  
Vittorio Lubicz ◽  
Lorenzo Riggio ◽  
Giorgio Salerno ◽  
Silvano Simula ◽  
Cecilia Tarantino
Keyword(s):  
Form Factor ◽  
Matrix Element ◽  
Form Factors ◽  
Vector Current ◽  
Hadronic Matrix Element ◽  
Tensor Form ◽  
Scalar Form ◽  
Mass Collaboration ◽  
Twisted Mass ◽  
Tensor Current

We present a preliminary lattice calculation of the D → π and D → K tensor form factors fT (q2) as a function of the squared 4-momentum transfer q2. ETMC recently computed the vector and scalar form factors f+(q2) and f0(q2) describing D → π(K)lv semileptonic decays analyzing the vector current and the scalar density. The study of the weak tensor current, which is directly related to the tensor form factor, completes the set of hadronic matrix element regulating the transition between these two pseudoscalar mesons within and beyond the Standard Model where a non-zero tensor coupling is possible. Our analysis is based on the gauge configurations produced by the European Twisted Mass Collaboration with Nf = 2 + 1 + 1 flavors of dynamical quarks. We simulated at three different values of the lattice spacing and with pion masses as small as 210 MeV and with the valence heavy quark in the mass range from ≃ 0.7 mc to ≃ 1.2mc. The matrix element of the tensor current are determined for a plethora of kinematical conditions in which parent and child mesons are either moving or at rest. As for the vector and scalar form factors, Lorentz symmetry breaking due to hypercubic effects is clearly observed in the data. We will present preliminary results on the removal of such hypercubic lattice effects.

scholarly journals Endpoint relations for baryons

2021 ◽  
Vol 2021 (11) ◽  
Author(s):  
Gudrun Hiller ◽  
Roman Zwicky
Keyword(s):  
Form Factor ◽  
Explicit Form ◽  
Form Factors ◽  
New Physics ◽  
Angular Distributions ◽  
Effective Hamiltonian ◽  
Model Independent ◽  
Belle Ii

Abstract Following our earlier work we establish kinematic endpoint relations for baryon decays using the Wigner-Eckart theorem and apply them to $$ \frac{1}{2}\to \frac{1}{2} $$ 1 2 → 1 2 and $$ \frac{1}{2}\to \frac{3}{2} $$ 1 2 → 3 2 baryon transitions. We provide angular distributions at the kinematic endpoint which hold for the generic d = 6 model-independent effective Hamiltonian and comment on the behaviour in the vicinity of the endpoint. Moreover, we verify the endpoint relations, using an explicit form factor parametrisation, and clarify constraints on helicity-based form factors to evidence endpoint relations. Our results provide guidance for phenomenological parameterisations, consistency checks for theory computations and experiment. Results are applicable to ongoing and future new physics searches at LHCb, BES III and Belle II with rare semileptonic-, dineutrino-and charged-modes, which include Λb → Λ(*)ℓℓ, Λb → Λ(*)νν, Ωb → Ωℓℓ, Λc → pℓℓ, Σ → pℓℓ and Λb → $$ {\Lambda}_c^{\left(\ast \right)} $$ Λ c ∗ ℓν.

scholarly journals Pauli Radius of the Proton

2021 ◽  
Vol 38 (12) ◽  
pp. 121401
Author(s):  
Zhu-Fang Cui ◽  
Daniele Binosi ◽  
Craig D. Roberts ◽  
Sebastian M. Schmidt
Keyword(s):  
Form Factor ◽  
Form Factors ◽  
Magnetic Form Factor ◽  
Proton Scattering ◽  
Statistical Sampling ◽  
Function Form ◽  
The Difference ◽  
Factor Data ◽  
Form Factor Data ◽  
Prime 2

Using a procedure based on interpolation via continued fractions supplemented by statistical sampling, we analyze proton magnetic form factor data obtained via electron+proton scattering on Q 2 ∈ [0.027, 0.55] GeV2 with the goal of determining the proton magnetic radius. The approach avoids assumptions about the function form used for data interpolation and ensuing extrapolation onto Q 2 ≃ 0 for extraction of the form factor slope. In this way, we find r M = 0.817(27) fm. Regarding the difference between proton electric and magnetic radii calculated in this way, extant data are seen to be compatible with the possibility that the slopes of the proton Dirac and Pauli form factors, F 1,2(Q 2), are not truly independent observables; to wit, the difference F ′ 1 ( 0 ) − F ′ 2 ( 0 ) / κ p = [ 1 + κ p ] / [ 4 m p 2 ] , viz., the proton Foldy term.

scholarly journals DISPERSION THEORY METHODS FOR TRANSITION FORM FACTORS

2014 ◽  
Vol 35 ◽  
pp. 1460461
Author(s):  
SEBASTIAN P. SCHNEIDER
Keyword(s):  
Form Factor ◽  
Form Factors ◽  
Transition Form ◽  
Dispersion Theory ◽  
Stepping Stones ◽  
Independent Determination ◽  
Model Independent ◽  
Scattering Contribution ◽  
Theoretical Analyses

Dispersion-theoretical analyses of transition form factors are stepping stones to a model-independent determination of the light-by-light scattering contribution to (g - 2)μ. We extend a calculation of the conversion decays of the lightest isoscalar vector mesons, ω/ϕ → π0ℓ+ℓ-, that builds on a previous dispersive analysis of the ω/ϕ → 3π partial-wave amplitudes and the pion vector form factor as its sole ingredients. We construct a good parametrization of e+e- → 3π that, together with information on the anomalous process γπ → ππ, allows us to obtain a description of the π0 transition form factor measured in e+e- → π0γ.

scholarly journals The Water Footprint of Primary and Secondary Processing of Beef from Different Cattle Breeds: A Value Fraction Allocation Model

2021 ◽  
Vol 13 (12) ◽  
pp. 6914
Author(s):  
Frikkie Alberts Maré ◽  
Henry Jordaan
Keyword(s):  
Water Footprint ◽  
Negative Relationship ◽  
High Water ◽  
Allocation Model ◽  
Cattle Breeds ◽  
A Value ◽  
Average Production ◽  
High Water Intake ◽  
The Difference ◽  
By Products

The high water intake and wastewater discharge of slaughterhouses have been a concern for many years. One neglected factor in previous research is allocating the water footprint (WF) to beef production’s different products and by-products. The objective of this article was to estimate the WF of different cattle breeds at a slaughterhouse and cutting plant and allocate it according to the different cuts (products) and by-products of beef based on the value fraction of each. The results indicated a negative relationship between the carcass weight and the processing WF when the different breeds were compared. Regarding a specific cut of beef, a kilogram of rib eye from the heaviest breed had a processing WF of 614.57 L/kg, compared to the 919.91 L/kg for the rib eye of the lightest breed. A comparison of the different cuts indicated that high-value cuts had higher WFs than low-value cuts. The difference between a kilogram of rib eye and flank was 426.26 L/kg for the heaviest breed and 637.86 L/kg for the lightest breed. An option to reduce the processing WF of beef is to lessen the WF by slaughtering heavier animals. This will require no extra investment from the slaughterhouse. At the same time, the returns should increase as the average production inputs per kilogram of output (carcass) should reduce, as the slaughterhouse will process more kilograms.

The influence of the nuclear and atomic form factors on the muon bremsstrahlung cross section

1968 ◽  
Vol 46 (10) ◽  
pp. S377-S380 ◽  
Author(s):  
A. A. Petrukhin ◽  
V. V. Shestakov
Keyword(s):  
Form Factor ◽  
Cross Section ◽  
Born Approximation ◽  
Form Factors ◽  
Experimental Results ◽  
Simple Analytical Expression ◽  
Nuclear Form Factor ◽  
The Cross ◽  
Atomic Electrons ◽  
Bremsstrahlung Process

The cross section for the muon bremsstrahlung process is calculated as a function of the nuclear form factor in the Born approximation following the Bethe and Heitler theory. The influence of the nuclear form factor is greater than that taken by Christy and Kusaka. The simple analytical expression for the effect of the screening of the atomic electrons is found. The influence of a decrease in the cross section upon the interpretation of some experimental results is estimated.

scholarly journals Strong CP violation in spin-1/2 singly charmed baryons

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Y. Ünal ◽  
Ulf-G. Meißner
Keyword(s):  
Perturbation Theory ◽  
Dipole Moment ◽  
Form Factor ◽  
Cp Violation ◽  
Mass Shell ◽  
Chiral Expansion ◽  
Renormalization Scheme ◽  
Leading Order ◽  
Chiral Perturbation ◽  
Charmed Baryons

Abstract We report on the calculation of the CP-violating form factor F3 and the corresponding electric dipole moment for charmed baryons in the spin-1/2 sector generated by the QCD θ-term. We work in the framework of covariant baryon chiral perturbation theory within the extended-on-mass-shell renormalization scheme up to next-to-leading order in the chiral expansion.

SUBSTRUCTURE EFFECT ON ρ-ω MIXING IN CHARGE-SYMMETRY VIOLATION

1992 ◽  
Vol 07 (32) ◽  
pp. 3037-3043 ◽  
Author(s):  
T. GOLDMAN ◽  
J.A. HENDERSON ◽  
A.W. THOMAS
Keyword(s):  
Symmetry Breaking ◽  
Quark Model ◽  
Quark Mass ◽  
Mass Shell ◽  
Mass Difference ◽  
Charge Symmetry Breaking ◽  
Symmetry Violation ◽  
Charge Symmetry ◽  
A Charge ◽  
Simple Quark Model

In generating a charge-symmetry breaking potential using ρ-ω mixing it is usually assumed that the mixing amplitude is constant (at the on-mass-shell value). Since the exchanged meson is actually far off-shell one must question the validity of this assumption. By constructing a simple quark model in which the mixing is generated by the u-d quark mass difference, we find that the assumption seems to be a very poor one.

Berechnung kinetischer Isotopeneffekte für die Reaktion von Methyljodid mit Cyanid-Ion

1966 ◽  
Vol 21 (9) ◽  
pp. 1377-1384
Author(s):  
A. V. Willi
Keyword(s):  
Transition State ◽  
Secular Equation ◽  
Isotope Effects ◽  
Force Constants ◽  
Bond Breaking ◽  
Bending Force ◽  
A Value ◽  
Order Of Magnitude ◽  
Deuterium Isotope Effects ◽  
The Difference

Kinetic carbon-13 and deuterium isotope effects are calculated for the SN2 reaction of CH3I with CN-. The normal vibrational frequencies of CH3I, the transition state I · · · CH3 · · · CN, and the corresponding isotope substituted reactants and transition states are evaluated from the force constants by solving the secular equation on an IBM 7094 computer.Values for 7 force constants of the planar CH3 moiety in the transition state (with an sp2 C atom) are obtained by comparison with suitable stable molecules. The stretching force constants related to the bonds being broken or newly formed (fCC, fCC and the interaction between these two stretches, /12) are chosen in such a way that either a zero or imaginary value for νʟ≠ will result. Agreement between calculated and experimental methyl-C13 isotope effects (k12/ k13) can be obtained only in sample calculations with sufficiently large values of f12 which lead to imaginary νʟ≠ values. Furthermore, the difference between fCI and fCC must be small (in the order of 1 mdyn/Å). The bending force constants, fHCI and fHCC, exert relatively little influence on k12/k13. They are important for the D isotope effect, however. As soon as experimental data on kH/kD are available it will be possible to derive a value for fHCC in the transition state if fHCI is kept constant at 0.205 mdynA, and if fCI, fCC and f12 are held in a reasonable order of magnitude. There is no agreement between experimental and calculated cyanide-C13 isotope effects. Possible explanations are discussed. — Since fCI and fCC cannot differ much it must be concluded that the transition state is relatively “symmetric”, with approximately equal amounts of bond making and bond breaking.

Analisis Skrining Fitokimia dan Aktivitas Antioksidan Ekstrakk Biji Sangrai Kopi Robusta (Coffea canephora) dari Tanaman Hasil Pemupukan Organik dan Anorganik

2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Farah Aida Qotrun Nada ◽  
Tintrim Rahayu ◽  
Ari Hayati
Keyword(s):  
Statistical Tests ◽  
Linear Regression Analysis ◽  
Coffea Canephora ◽  
Coffee Bean ◽  
Phytochemical Screening ◽  
Robusta Coffee ◽  
A Value ◽  
Coffee Beans ◽  
Ic50 Value ◽  
The Difference

Ground coffee is coffee beans that have been roasted, ground or ground so that they have a smooth shape. The purpose of this study was to determine the content of compounds in robusta coffee roasted seed extract (Coffea canephora) from plants produced by organic and inorganic fertilization, and to know the difference in compounds between the results of organic and inorganic fertilization. The characteristics of phytochemical screening were carried out qualitatively on alkaloids, flavonoids, tannins, terpenoids and saponins and the antioxidant activity was carried out by the DPPH (1,1-dipenyl-2-picrihidrazil) method. Phytochemical screening characteristic test results show that robusta coffee bean extract extract from the results of organic and inorganic fertilization both contain flavonoids, alkaloids, tannins, and saponins, while the antioxidant test activity of robusta coffee beans extracts shows differences based on the results of statistical tests of linear regression analysis with the IC50 value the highest antioxidant content was inorganic coffee roasted bean extract only 14.0629 ppm compared to the organic roasted extract with a value of 30.6159 ppmKeywords: Robusta Coffee (Coffea canophora), Phytochemical Screening, DPPH MethodABSTRAKKopi bubuk adalah biji kopi yang telah disangrai digiling atau ditumbuk sehingga mempunyai bentuk halus. Tujuan dari penelitian ini adalah untuk mengetahui kandungan senyawa dalam ekstrak biji sangrai kopi robusta (Coffe canephora) dari tanaman hasil pemupukan organik dan anorganik, dan mengetahui perbedaan senyawa antara hasil pemupukan organik dan anorganik. Karakteristik skrining fitokimia dilakukan secara kualitatif yang dilakukan terhadap alkaloid, flavonoid, tanin, terpenoid dan saponin dan aktivitas antioksidan dilakukan dengan metode DPPH (1,1-difenil-2-pikrihidrazil). Hasil uji karakteristik skrining fitokimia menunjukkan bahwa ekstrak biji sangrai kopi robusta dari hasil pemupukan oganik dan anorganik keduanya sama mengandung senyawa flavonoid, alkaloid, tanin, dan saponin,  sedangkan pada aktifitas uji antioksidan ekstrak biji sangrai kopi robusta menunjukan perbedaan berdasarkan hasil uji statistik analisis regresi linear dengan nilai IC50 kadar antioksidan paling tinggi adalah ekstrak biji sangrai kopi anorganik hanya 14,0629 ppm dibandingkan dengan ekstrak sangrai dari organik dengan nilai 30,6159 ppm.Kata kunci : Kopi Robusta (Coffea canophera), Skrining Fitokimia, Metode DPPH

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