Form Factors for Graviton–Particle Interactions

1971 ◽  
Vol 49 (14) ◽  
pp. 1869-1873 ◽  
Author(s):  
M. G. Hare
Keyword(s):  
Form Factors ◽  
Dispersion Relations ◽  
Elementary Particles ◽  
Threshold Region ◽  
Particle Interactions ◽  
Mass Energy ◽  
Vertex Corrections

Contributions to the mass-energy form factors are calculated for the graviton–nucleon and graviton–deuteron (singlet and triplet) vertex interactions using sidewise dispersion relations. These factors are useful in astrophysics for vertex corrections to graviton–particle interactions. Electromagnetic contributions are considered for all vertices, π-meson contributions for the nucleon vertex and the two nucleon breakup for the singlet deuteron vertex. The deuterons are treated as elementary particles and the threshold region is assumed to dominate the results.

scholarly journals Measurement of the shape of the $$ {B}_s^0\to {D}_s^{\ast -}{\mu}^{+}{\nu}_{\mu } $$ differential decay rate

2020 ◽  
Vol 2020 (12) ◽  
Author(s):  
R. Aaij ◽  
◽  
C. Abellán Beteta ◽  
T. Ackernley ◽  
B. Adeva ◽  
...  
Keyword(s):  
Decay Rate ◽  
Form Factors ◽  
Proton Collision ◽  
Centre Of Mass ◽  
Mass Energy ◽  
Proton Proton ◽  
Lhcb Detector ◽  
Proton Proton Collision ◽  
Integrated Luminosity

Abstract The shape of the $$ {B}_s^0\to {D}_s^{\ast -}{\mu}^{+}{\nu}_{\mu } $$ B s 0 → D s ∗ − μ + ν μ differential decay rate is obtained as a function of the hadron recoil parameter using proton-proton collision data at a centre-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 1.7 fb−1 collected by the LHCb detector. The $$ {B}_s^0\to {D}_s^{\ast -}{\mu}^{+}{\nu}_{\mu } $$ B s 0 → D s ∗ − μ + ν μ decay is reconstructed through the decays $$ {D}_s^{\ast -}\to {D}_s^{-}\gamma $$ D s ∗ − → D s − γ and $$ {D}_s^{-}\to {K}^{-}{K}^{+}{\pi}^{-} $$ D s − → K − K + π − . The differential decay rate is fitted with the Caprini-Lellouch-Neubert (CLN) and Boyd-Grinstein-Lebed (BGL) parametrisations of the form factors, and the relevant quantities for both are extracted.

scholarly journals Variation in rms charge radii of deuteron and helium nuclei with s\sqrt s

Nukleonika ◽  
2020 ◽  
Vol 65 (4) ◽  
pp. 211-215
Author(s):  
Sarwat Zahra ◽  
Bushra Shafaq ◽  
Bushra Kanwal ◽  
Nosheen Akbar
Keyword(s):  
Center Of Mass ◽  
Form Factors ◽  
Mass Energy ◽  
Charge Radii ◽  
Center Of Mass Energy ◽  
Theoretical Predictions ◽  
Dependent Form ◽  
Energy Dependent ◽  
The Relationship ◽  
Good Agreement

AbstractBy considering energy-dependent form factors extracted from generalized Chou–Yang model, root mean square (rms) charge radii of deuteron and helium nuclei (alpha) are predicted at different values of center of mass energy which are in good agreement with theoretical predictions and experimental results. The rms radius is inversely proportional to mass of nuclei. Besides, the relationship between radii and energy are also derived.

Symmetry-breaking corrections to the form factors for heavy-to-heavy B-meson at large recoil

2019 ◽  
Vol 34 (08) ◽  
pp. 1950046
Author(s):  
Saba Shafaq ◽  
Ishtiaq Ahmed ◽  
M. Jamil Aslam
Keyword(s):  
Perturbation Theory ◽  
Symmetry Breaking ◽  
Heavy Quark ◽  
B Meson ◽  
Form Factors ◽  
Heavy Meson ◽  
Effective Theory ◽  
Vertex Corrections ◽  
Soft Collinear Effective Theory ◽  
Heavy Quark Limit

The present study investigates the decay of B to heavy meson using the soft collinear effective theory. By assigning different loop momenta, the factorization has been tested and it is found to be valid to all orders in the perturbation theory. It is noted that theory contains one hard collinear and two soft modes depending upon virtuality of different momenta. In the next step, symmetry-conserving relations (in heavy quark limits) to the form factors have been studied. These relations are then used to parametrize the form factors to get symmetry-breaking corrections. These symmetry-breaking corrections can be calculated using perturbative (vertex corrections) as well as nonperturbative (hard spectator interactions) QCD. It is found that in the heavy quark limit, these symmetry contributions do not contribute to the form factors that appear in physical observables for the case of [Formula: see text] decays which are contrary to the heavy-to-light meson decays.

scholarly journals Ghost poles in the nucleon propagator: Vertex corrections and form factors

1993 ◽  
Vol 47 (6) ◽  
pp. 2485-2491 ◽  
Author(s):  
G. Krein ◽  
M. Nielsen ◽  
R. D. Puff ◽  
L. Wilets
Keyword(s):  
Form Factors ◽  
Vertex Corrections

Dispersion relations for form factors

1958 ◽  
Vol 9 (4) ◽  
pp. 610-623 ◽  
Author(s):  
Y. Nambu
Keyword(s):  
Form Factors ◽  
Dispersion Relations
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