scholarly journals STRANGE SEA ASYMMETRY IN NUCLEONS

2003 ◽  
Vol 18 (08) ◽  
pp. 1403-1407
Author(s):  
XUE-QIAN LI ◽  
XIAO-BING ZHANG ◽  
BO-QIANG MA
Keyword(s):  
Weak Interaction ◽  
Strong Interaction ◽  
Short Distance ◽  
Strange Quark ◽  
Medium Effects ◽  
Long Distance ◽  
Distance Effects

We evaluate the medium effects in nucleon which can induce an asymmetry of the strange sea. The short-distance effects determined by the weak interaction can give rise to [Formula: see text] where [Formula: see text] is the medium-induced mass of strange quark by a few KeV at most, but the long-distance effects by strong interaction could be sizable.

scholarly journals NONFACTORIZABLE CONTRIBUTIONS IN NONLEPTONIC WEAK INTERACTIONS OF K MESONS

2001 ◽  
Vol 16 (09) ◽  
pp. 1605-1630 ◽  
Author(s):  
K. TERASAKI
Keyword(s):  
Short Distance ◽  
Weak Interactions ◽  
Mass Difference ◽  
Long Distance ◽  
Field Algebra ◽  
K Meson ◽  
Distance Effects ◽  
Intermediate States ◽  
Meson Pole ◽  
Existing Data

K→ππ, KL-KS mass difference (Δ mK) and KL→γγ(*) are studied systematically by decomposing their amplitude into a sum of factorizable and nonfactorizable ones. The former is calculated by using the naive factorization while the latter is assumed to be controlled by hadron dynamics. Nonfactorizable amplitudes for the K→ππ decays which are estimated by using a hard pion technique dominates the |ΔI| = ½ amplitude. It is seen that the naively factorized short distance term dominates ΔmK as usual since contributions of pseudoscalar-meson poles and ππ intermediate states as the nonfactorizable long distance effects interfere destructively with each other. The K*-meson pole survives in the KL→γγ decay and plays an important role in the present perspective in contrast with the existing theories which are restricted by the theory of field algebra. The form factor for the Dalitz decays of KL and their rates are compared with the existing data.

scholarly journals Extremal effective field theories

2021 ◽  
Vol 2021 (5) ◽  
Author(s):  
Simon Caron-Huot ◽  
Vincent Van Duong
Keyword(s):  
Scalar Field ◽  
Scattering Amplitudes ◽  
Effective Field Theories ◽  
Convex Hull ◽  
Short Distance ◽  
Large Fraction ◽  
Effective Field ◽  
Field Theories ◽  
Long Distance ◽  
Distance Effects

Abstract Effective field theories (EFT) parameterize the long-distance effects of short-distance dynamics whose details may or may not be known. Previous work showed that EFT coefficients must obey certain positivity constraints if causality and unitarity are satisfied at all scales. We explore those constraints from the perspective of 2 → 2 scattering amplitudes of a light real scalar field, using semi-definite programming to carve out the space of allowed EFT coefficients for a given mass threshold M. We point out that all EFT parameters are bounded both below and above, effectively showing that dimensional analysis scaling is a consequence of causality. This includes the coefficients of s2 + t2 + u2 and stu type interactions. We present simple 2 → 2 extremal amplitudes which realize, or “rule in”, kinks in coefficient space and whose convex hull span a large fraction of the allowed space.

$R_{e^ + e^ - } ,\,\Gamma _{had}^{Z^0 } $ AND αs: DO THE EXPERIMENTAL DATA AGREE WITH PERTURBATIVE QCD?

1991 ◽  
Vol 06 (07) ◽  
pp. 605-610 ◽  
Author(s):  
G. PREPARATA ◽  
P.G. RATCLIFFE ◽  
M. VERPELLI
Keyword(s):  
Experimental Data ◽  
Perturbative Qcd ◽  
Strong Interaction ◽  
High Energy ◽  
Long Distance ◽  
Qcd Vacuum ◽  
Energy Regime ◽  
Distance Effects ◽  
High Energy Regime

We examine the present experimental determinations of the two related quantities: [Formula: see text] and [Formula: see text] and compare their values with the predictions of perturbative QCD. Both sets of data consistently lie systematically above the theoretical values. However, they are shown to be mutually consistent with a strong-interaction correction roughly twice the magnitude of that calculated within the framework of perturbative QCD. We conclude that this seems to point to the failure of this approach to correctly account for the non-trivial structure of the QCD vacuum and thus of long-distance effects which may pervade even the high-energy regime.

STRIPES IN DOPED ANTIFERROMAGNETS: BOND-CENTERED VERSUS SITE-CENTERED

2000 ◽  
Vol 14 (29n31) ◽  
pp. 3783-3790 ◽  
Author(s):  
MARC G. ZACHER ◽  
ROBERT EDER ◽  
ENRICO ARRIGONI ◽  
WERNER HANKE
Keyword(s):  
Perturbation Theory ◽  
Green’S Function ◽  
Green's Function ◽  
Single Particle ◽  
Short Distance ◽  
Long Distance ◽  
Distance Effects ◽  
Cluster A

The single-particle Green's function for a striped t–J model is calculated using cluster a perturbation theory, where short-distance effects are accounted for by exact cluster diagonalization and long-distance effects by perturbation (in the hopping). Both site-centered and bond-centered stripe scenarios have been studied. The data for site-centered stripes quantitatively reproduce salient (ARPES-) features.

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%.

scholarly journals Prospects for disentangling long- and short-distance effects in the decays B → K∗μ+μ−

2019 ◽  
Vol 2019 (10) ◽  
Author(s):  
Marcin Chrzaszcz ◽  
Andrea Mauri ◽  
Nicola Serra ◽  
Rafael Silva Coutinho ◽  
Danny van Dyk
Keyword(s):  
Short Distance ◽  
Distance Effects

Including long-distance effects in theKL−KSmass splitting

1990 ◽  
Vol 42 (1) ◽  
pp. 118-125 ◽  
Author(s):  
B. Machet ◽  
N. F. Nasrallah ◽  
K. Schilcher
Keyword(s):  
Long Distance ◽  
Distance Effects

scholarly journals WHAT IS A MATTER PARTICLE?

2006 ◽  
Vol 15 (01) ◽  
pp. 259-272
Author(s):  
TSAN UNG CHAN
Keyword(s):  
Standard Model ◽  
Weak Interaction ◽  
Strong Interaction ◽  
Neutral Particle ◽  
Z Bosons ◽  
Baryon Number ◽  
Lepton Number ◽  
Neutral Particles ◽  
The Standard Model ◽  
The Stability

Positive baryon numbers (A>0) and positive lepton numbers (L>0) characterize matter particles while negative baryon numbers and negative lepton numbers characterize antimatter particles. Matter particles and antimatter particles belong to two distinct classes of particles. Matter neutral particles are particles characterized by both zero baryon number and zero lepton number. This third class of particles includes mesons formed by a quark and an antiquark pair (a pair of matter particle and antimatter particle) and bosons which are messengers of known interactions (photons for electromagnetism, W and Z bosons for the weak interaction, gluons for the strong interaction). The antiparticle of a matter particle belongs to the class of antimatter particles, the antiparticle of an antimatter particle belongs to the class of matter particles. The antiparticle of a matter neutral particle belongs to the same class of matter neutral particles. A truly neutral particle is a particle identical with its antiparticle; it belongs necessarily to the class of matter neutral particles. All known interactions of the Standard Model conserve baryon number and lepton number; matter cannot be created or destroyed via a reaction governed by these interactions. Conservation of baryon and lepton number parallels conservation of atoms in chemistry; the number of atoms of a particular species in the reactants must equal the number of those atoms in the products. These laws of conservation valid for interaction involving matter particles are indeed valid for any particles (matter particles characterized by positive numbers, antimatter particles characterized by negative numbers, and matter neutral particles characterized by zero). Interactions within the framework of the Standard Model which conserve both matter and charge at the microscopic level cannot explain the observed asymmetry of our Universe. The strong interaction was introduced to explain the stability of nuclei: there must exist a powerful force to compensate the electromagnetic force which tends to cause protons to fly apart. The weak interaction with laws of conservation different from electromagnetism and the strong interaction was postulated to explain beta decay. Our observed material and neutral universe would signify the existence of another interaction that did conserve charge but did not conserve matter.

scholarly journals Searching for new physics in charm radiative decays

2018 ◽  
Vol 33 (32) ◽  
pp. 1850194
Author(s):  
Aritra Biswas ◽  
Sanjoy Mandal ◽  
Nita Sinha
Keyword(s):  
Standard Model ◽  
Branching Ratio ◽  
New Physics ◽  
Radiative Decays ◽  
Symmetric Model ◽  
Leading Order ◽  
Photon Polarization ◽  
Long Distance ◽  
The Standard Model ◽  
Distance Effects

We show that for a heavy vector-like quark model with a down type isosinglet, branching ratio for [Formula: see text] decay is enhanced by more than [Formula: see text] as compared to that in the Standard model when QCD corrections to next-to-leading order are incorporated. In a left–right symmetric model (LRSM) along with a heavy vector-like fermion, enhancement of this order can be achieved at the bare (QCD uncorrected) level itself. We propose that a measurement of the photon polarization could be used to signal the presence of such new physics in spite of the large long distance effects. We find that there is a large region within the allowed parameter space of the model with a vector-like quark and an additional left–right symmetry, where, the photon polarization can be dominantly right-handed.

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