Bounds on the hadronic matrix element in the $$K^0 - \bar K^0 $$ transition amplitude

1984 ◽  
Vol 22 (1) ◽  
pp. 93-98 ◽  
Author(s):  
F. D. Gault ◽  
J. N. Webb
Keyword(s):  
Matrix Element ◽  
Transition Amplitude ◽  
Hadronic Matrix Element

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.

Estimate of the hadronic matrix element of B0- mixing within QCD sum rules

1988 ◽  
Vol 207 (3) ◽  
pp. 333-337 ◽  
Author(s):  
A.A. Ovchinnikov ◽  
A.A. Pivovarov
Keyword(s):  
Matrix Element ◽  
Sum Rules ◽  
Hadronic Matrix Element ◽  
Qcd Sum Rules

EVALUATION OF ELASTIC NΔ SCATTERING AMPLITUDE FROM INELASTIC pp→NΔ AMPLITUDE

1990 ◽  
Vol 05 (03) ◽  
pp. 207-214 ◽  
Author(s):  
N. HIROSHIGE ◽  
M. KAWASAKI ◽  
W. WATARI ◽  
M. YONEZAWA
Keyword(s):  
Matrix Element ◽  
Scattering Amplitudes ◽  
Partial Wave ◽  
Energy Region ◽  
Scattering Amplitude ◽  
Transition Amplitude ◽  
Channel Approximation ◽  
S Matrix

In the dibaryon energy region we have evaluated the NΔ→NΔ (5S2) partial-wave S-matrix element from recently obtained pp→NΔ transition amplitude by combining with the information on pp→pp, pp→πd, and πd→πd scattering amplitudes in the three-channel approximation. One of the two solutions allowed by the unitarity shows an anticlockwise rotating behavior.

scholarly journals Parton Distribution Functions and One-Loop Matching

2016 ◽  
Vol 40 ◽  
pp. 1660053 ◽  
Author(s):  
Xiangdong Ji ◽  
Jian-Hui Zhang ◽  
Yong Zhao
Keyword(s):  
Matrix Element ◽  
Parton Distribution ◽  
Light Cone ◽  
Matching Condition ◽  
Distribution Functions ◽  
Large Momentum ◽  
Hadronic Matrix Element ◽  
Parton Distribution Functions ◽  
Recent Developments ◽  
The One

We discuss recent developments on computing a light-cone parton distribution from the large momentum limit of the hadronic matrix element of a space-like correlator, and present the one-loop matching condition connecting these two quantities. The matching condition is useful for extracting the former quantity from the latter, which is calculable on the lattice.

Quantum mechanics

2018 ◽  
Author(s):  
Michael Kachelriess
Keyword(s):  
Field Theory ◽  
Quantum Field Theory ◽  
Quantum Mechanics ◽  
Relativistic Quantum ◽  
Transition Amplitude ◽  
External Source ◽  
Quantum Field ◽  
Damping Term ◽  
Relativistic Quantum Theory ◽  
Generating Functional

After a brief review of the operator approach to quantum mechanics, Feynmans path integral, which expresses a transition amplitude as a sum over all paths, is derived. Adding a linear coupling to an external source J and a damping term to the Lagrangian, the ground-state persistence amplitude is obtained. This quantity serves as the generating functional Z[J] for n-point Green functions which are the main target when studying quantum field theory. Then the harmonic oscillator as an example for a one-dimensional quantum field theory is discussed and the reason why a relativistic quantum theory should be based on quantum fields is explained.

scholarly journals Low Energy Antikaon-nucleon/nuclei interaction studies by AMADEUS

2019 ◽  
Vol 199 ◽  
pp. 01014
Author(s):  
K. Piscicchia ◽  
M. Bazzi ◽  
G. Belloti ◽  
A. M. Bragadireanu ◽  
D. Bosnar ◽  
...  
Keyword(s):  
Cross Sections ◽  
Transition Amplitude ◽  
Nuclear Interaction ◽  
Branching Ratios ◽  
Analysis Procedure ◽  
Low Energy ◽  
Carbon Target ◽  
Pure Carbon ◽  
Nuclear Targets ◽  
Mass Spectroscopic Study

The AMADEUS experiment at the DAΦNE collider of LNF-INFN deals with the investigation of the at-rest, or low-momentum, K− interactions in light nuclear targets, with the aim to constrain the low energy QCD models in the strangeness sector. The 0 step of the experiment consisted in the reanalysis of the 2004/2005 KLOE data, exploiting K− absorptions in H, 4He, 9Be and 12C, leading to the first invariant mass spectroscopic study with very low momentum (about 100 MeV) in-flight K− captures. With AMADEUS step 1 a dedicated pure Carbon target was implemented in the central region of the KLOE detector, providing a high statistic sample of pure at-rest K− nuclear interaction. The first measurement of the non-resonant transition amplitude $\left| {{A_{{K^ - }n \to \Lambda {\pi ^ - }}}} \right|$ at $\sqrt s = 33\,MeV$ below the K̄N threshold is presented, in relation with the Λ(1405) properties studies. The analysis procedure adopted in the serarch for K− multi-nucleon absorption cross sections and Branching Ratios will be also described.

scholarly journals K → μ+μ− as a clean probe of short-distance physics

2021 ◽  
Vol 2021 (7) ◽  
Author(s):  
Avital Dery ◽  
Mitrajyoti Ghosh ◽  
Yuval Grossman ◽  
Stefan Schacht
Keyword(s):  
Matrix Element ◽  
Standard Model ◽  
Short Distance ◽  
Time Dependent ◽  
Final States ◽  
Interference Effects ◽  
Fundamental Theory ◽  
Long Distance ◽  
Ckm Matrix ◽  
The Standard Model

Abstract The K → μ+μ− decay is often considered to be uninformative of fundamental theory parameters since the decay is polluted by long-distance hadronic effects. We demonstrate that, using very mild assumptions and utilizing time-dependent interference effects, ℬ(KS → μ+μ−)ℓ=0 can be experimentally determined without the need to separate the ℓ = 0 and ℓ = 1 final states. This quantity is very clean theoretically and can be used to test the Standard Model. In particular, it can be used to extract the CKM matrix element combination $$ \mid {V}_{ts}{V}_{td}\sin \left(\beta +{\beta}_s\right)\mid \approx \mid {A}^2{\lambda}^5\overline{\eta}\mid $$ ∣ V ts V td sin β + β s ∣ ≈ ∣ A 2 λ 5 η ¯ ∣ with hadronic uncertainties below 1%.

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