scholarly journals The study of doubly charmed pentaquark $$c c {\bar{q}}qq$$ with the SU(3) symmetry

2021 ◽  
Vol 81 (11) ◽  
Author(s):  
Ye Xing ◽  
Yuekun Niu
Keyword(s):  
Bound States ◽  
Flavor Symmetry ◽  
Stable States ◽  
Diquark Model ◽  
Decay Channels ◽  
Decay Modes ◽  
Leptonic Decays ◽  
The Masses

AbstractWe study the masses and lifetimes of doubly charmed pentaquark $$P_{cc{\bar{q}}qq}(q=u,d,s)$$ P c c q ¯ q q ( q = u , d , s ) primarily. The operation of masses carried out by the doubly heavy triquark-diquark model, whose results suggests the existence of stable states $$cc{\bar{s}} ud$$ c c s ¯ u d with the parity $$J^P=\frac{1}{2}^-$$ J P = 1 2 - . The roughly calculation about lifetimes show the short magnitudes, $$(4.65^{+0.71}_{-0.55})\times 10^{-13}s $$ ( 4 . 65 - 0.55 + 0.71 ) × 10 - 13 s for the parity $$J^P=\frac{1}{2}^-$$ J P = 1 2 - and $$(0.93^{+0.14}_{-0.11})\times 10^{-12} s $$ ( 0 . 93 - 0.11 + 0.14 ) × 10 - 12 s for $$J^P=\frac{3}{2}^-$$ J P = 3 2 - . Since the pentaquark $$cc{\bar{s}} ud$$ c c s ¯ u d is interpreted as the stable bound states against strong decays, then we will focus on the production and possible decay channels of the pentaquark in the next step, the study would be fairly valuable supports for future experiments. For completeness, we systematically studied the production from $$\Omega _{ccc}$$ Ω ccc and the decay modes in the framework SU(3) flavor symmetry, including the processes of semi-leptonic and two body non-leptonic decays. Synthetically, we make a collection of the golden channels.

scholarly journals R2-Cosmology and New Windows for Superheavy Dark Matter

Symmetry ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 877
Author(s):  
Elena Arbuzova ◽  
Alexander Dolgov ◽  
Rajnish Singh
Keyword(s):  
General Relativity ◽  
Dark Matter ◽  
Modified Gravity ◽  
Gauge Bosons ◽  
Decay Channels ◽  
Decay Modes ◽  
The Masses ◽  
Superheavy Dark Matter ◽  
The Universe

Evolution and heating of the universe in R2-modified gravity are considered. It is shown that the universe’s history can be separated into four different epochs: (1) inflation, (2) heating due to curvature oscillations (scalaron decay), (3) transition to matter dominated period, and (4) conventional cosmology governed by General Relativity. Cosmological density of dark matter (DM) particles for different decay channels of the scalaron is calculated. The bounds on the masses of DM particles are derived for the following dominant decay modes: to minimally coupled scalars, to massive fermions, and to gauge bosons.

THE NEXT STEP IN LEPTONIC DECAYS OF ETA AND KL BOUND STATES

1992 ◽  
Vol 07 (09) ◽  
pp. 1935-1951 ◽  
Author(s):  
G.A. KOZLOV
Keyword(s):  
Field Theory ◽  
Transition Form Factor ◽  
Bound States ◽  
Three Dimensional ◽  
Bound State ◽  
Quantum Field ◽  
Relative Momentum ◽  
Transition Form ◽  
Structure Transition ◽  
Leptonic Decays

A systematic discussion of the probability of eta and KL bound-state decays—[Formula: see text] and [Formula: see text](l=e, μ)—within a three-dimensional reduction to the two-body quantum field theory is presented. The bound-state vertex function depends on the relative momentum of constituent-like particles. A structure-transition form factor is defined by a confinement-type quark-antiquark wave function. The phenomenology of this kind of decays is analyzed.

scholarly journals The Resonant and Normal Auger Spectra of Ozone

Symmetry ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 516
Author(s):  
Simone Taioli ◽  
Stefano Simonucci
Keyword(s):  
Bound States ◽  
Point Group ◽  
Coulomb Repulsion ◽  
Theoretical Description ◽  
Incoming Wave ◽  
Decay Channels ◽  
Continuum States ◽  
Symmetric Molecule ◽  
Accurate Treatment ◽  
Auger Spectra

In this work, we outline a general method for calculating Auger spectra in molecules, which accounts for the underlying symmetry of the system. This theory starts from Fano’s formulation of the interaction between discrete and continuum states, and it generalizes this formalism to deal with the simultaneous presence of several intermediate quasi-bound states and several non-interacting decay channels. Our theoretical description is specifically tailored to resonant autoionization and Auger processes, and it explicitly includes the incoming wave boundary conditions for the continuum states and an accurate treatment of the Coulomb repulsion. This approach is implemented and applied to the calculation of the K−LL Auger and autoionization spectra of ozone, which is a C2v symmetric molecule, whose importance in our atmosphere to filter out radiation has been widely confirmed. We also show the effect that the molecular point group and, in particular, the localization of the core-hole in the oxygen atoms related by symmetry operations, has on the electronic structure of the Auger states and on the spectral lineshape by comparing our results with the experimental data.

scholarly journals Fermion mass and mixing in a low-scale seesaw model based on the S4 flavor symmetry

2019 ◽  
Vol 2019 (11) ◽  
Author(s):  
V V Vien ◽  
H N Long ◽  
A E Cárcamo Hernández
Keyword(s):  
Low Energy ◽  
Spontaneous Breaking ◽  
Fermion Mass ◽  
Recent Experimental Data ◽  
Neutrino Masses ◽  
Flavor Symmetry ◽  
Seesaw Model ◽  
Mixing Parameters ◽  
The Masses ◽  
Good Agreement

Abstract We construct a low-scale seesaw model to generate the masses of active neutrinos based on $S_4$ flavor symmetry supplemented by the $Z_2 \times Z_3 \times Z_4 \times Z_{14}\times U(1)_L$ group, capable of reproducing the low-energy Standard Model (SM) fermion flavor data. The masses of the SM fermions and the fermionic mixing parameters are generated from a Froggatt–Nielsen mechanism after spontaneous breaking of the $S_4\times Z_2 \times Z_3 \times Z_4 \times Z_{14}\times U(1)_L$ group. The obtained values for the physical observables of the quark and lepton sectors are in good agreement with the most recent experimental data. The leptonic Dirac CP-violating phase $\delta _\mathrm{CP}$ is predicted to be $259.579^\circ$ and the predictions for the absolute neutrino masses in the model can also saturate the recent constraints.

scholarly journals η meson physics with WASA-at-COSY

2019 ◽  
Vol 199 ◽  
pp. 01006
Author(s):  
Nils Hüsken ◽  
Kay Demmich ◽  
Alfons Khoukaz
Keyword(s):  
Beyond Standard Model ◽  
Standard Model ◽  
Bound States ◽  
Focal Point ◽  
Nucleon Nucleon ◽  
Large Datasets ◽  
Research Center ◽  
Decay Modes ◽  
Electromagnetic Interactions ◽  
Physics Programme

In recent years, the η meson has been a focal point of research for the WASA experiment at the Cooler Synchrotron COSY of the Research Center Jülich. Production experiments using nucleon-nucleon and nucleon-nucleus collisions have been performed, studying the η − N interaction in various configurations. A better understanding of this interaction is a key aspect in the ongoing search for η-nuclear bound states. In addition, the η meson itself represents an ideal laboratory for precision studies of the strong and electromagnetic interactions as well as for searches for beyond Standard Model physics. Large datasets were assembled using the WASA experiment to enable studies on rare and forbidden decay modes. An overview over recent highlights of the WASA η meson physics programme was given.

ELECTROWEAK MEASUREMENTS FROM RUN II AT THE TEVATRON

2004 ◽  
Vol 19 (06) ◽  
pp. 794-807
Author(s):  
T. R. WYATT
Keyword(s):  
Cross Section ◽  
Branching Ratio ◽  
Centre Of Mass ◽  
Mass Energy ◽  
Total Decay Width ◽  
Decay Modes ◽  
Leptonic Decays ◽  
Vector Bosons ◽  
First Time ◽  
Intermediate Vector

The CDF and DØ detectors were fully commissioned for physics running in Run II at the Tevatron [Formula: see text] collider in early 2002. Since then both experiments have collected data samples corresponding to an integrated luminosity of around ∫L=200 pb -1 at a [Formula: see text] centre-of-mass energy of [Formula: see text]. Datasets corresponding ∫L=120 pb-1 have been analyzed for physics so far. Recent electroweak measurements from Run II are reviewed. Cross section times branching ratio measurements (σ· Br ) are presented for the intermediate vector bosons (IVB's) in their leptonic decay modes: W→ℓν and Z→ℓ+ℓ-. For the first time, a combination of the σ· Br results from the CDF and DØ experiments is made; this includes using a consistent choice of the total inelastic [Formula: see text] cross section for the luminosity determinations of the two experiments. Quantities derived from these σ· Br values are also updated. These include: R ℓ the ratio of the σ· Br values for W and Z; Br (W→ℓν), the leptonic branching ratio of the W; and Γw, the total decay width of the W. Other measurements using events containing W and Z leptonic decays are presented, including studies that probe the QCD phenomenology of W/Z production and searches for events containing two intermediate vector bosons.

Searching for the doubly charged scalars in the Georgi–Machacek model via γγ collisions at the ILC

2018 ◽  
Vol 33 (11) ◽  
pp. 1841003
Author(s):  
Jun Cao ◽  
Yu-Qi Li ◽  
Yao-Bei Liu
Keyword(s):  
Cross Sections ◽  
Linear Collider ◽  
Coupling Parameter ◽  
Production Cross ◽  
International Linear Collider ◽  
Scalar Coupling ◽  
Decay Channels ◽  
Decay Modes ◽  
The Future ◽  
Doubly Charged

The Georgi–Machacek (GM) model predicts the existence of the doubly-charged scalars [Formula: see text], which can be seen the typical particles in this model and their diboson decay channels are one of the most promising ways to discover such new doubly-charged scalars. Based on the constraints of the latest combined ATLAS and CMS Higgs boson diphoton signal strength data at [Formula: see text] confidence level, we focus on the study of the triple scalar production in [Formula: see text] collisions at the future International Linear collider (ILC): [Formula: see text], where the production cross-sections are very sensitive to the triple scalar coupling parameter [Formula: see text]. Considering the typical same-sign diboson decay modes for the doubly-charged scalars, the possible final signals might be detected via this process at the future ILC experiments.

scholarly journals Compact Exotic Tetraquark Mesons in Large-Nc QCD

2018 ◽  
Vol 191 ◽  
pp. 04003
Author(s):  
Wolfgang Lucha ◽  
Dmitri Melikhov ◽  
Hagop Sazdjian
Keyword(s):  
Scattering Amplitudes ◽  
Quantum Chromodynamics ◽  
Internal Consistency ◽  
Selection Criteria ◽  
Bound States ◽  
Degrees Of Freedom ◽  
Decay Rates ◽  
Meson Decay ◽  
Decay Channels ◽  
Colour Singlet

We embark on systematic explorations of the behaviour of tetraquark mesons, i.e., colour-singlet bound states of two quarks and two antiquarks, in the (idealized) limit of a large number of colour degrees of freedom, Nc,; of quantum chromodynamics, QCD. Considering the scattering of two ordinary mesons into two ordinary mesons, we start off with formulating a set of selection criteria that should enable us to unambiguously single out precisely those contributions to all encountered scattering amplitudes that potentially will develop tetraquark poles. Assuming that tetraquark mesons do exist and, if so, emerge in the contributions compatible with our criteria at largest admissible order of Nc; we deduce, for the categories of tetraquarks that exhibit either four or only two different open quark flavours, that the decay rates of these tetraquark types are, at least, of order 1/N2c and that internal consistency requires all the members of the first species to exist pairwise, distinguishable by their favoured two-ordinary-meson decay channels.

Dynamical variables in the Bethe-Salpeter formalism

1955 ◽  
Vol 233 (1193) ◽  
pp. 248-266 ◽  
Keyword(s):  
Matrix Element ◽  
Bound States ◽  
Dynamical Variable ◽  
Wave Functions ◽  
Coupling Constant ◽  
Scattering States ◽  
The Matrix ◽  
The Masses

It is shown that a knowledge of the behaviour of the propagators around their singularities enables one to determine not only the masses of bound states, but also the matrix element of any dynamical variable between two bound states. One is thus enabled to find such a matrix element, to any order in the coupling constant, by the integration of certain expressions over the corresponding Bethe-Salpeter wave-functions. As a consequence, it is possible to find normalization and orthogonality properties of these wave-functions, which in turn lead to the condition which must be imposed on their singularities a t the origin. More light is thus shed on Goldstein’s difficulty concerning the existence of a continuous infinity of bound states. The formalism is extended to scattering states in which some of the particles may be composite—in particular, an expression for the S -matrix is obtained

INVESTIGATIONS OF THE FLAVOR SYMMETRY, RADIATIVE SEESAW MODEL AND COLD DARK MATTER

2007 ◽  
Vol 16 (05) ◽  
pp. 1541-1556
Author(s):  
HIROSHI OKADA
Keyword(s):  
Dark Matter ◽  
Cold Dark Matter ◽  
Vacuum Expectation ◽  
The Other ◽  
Type Model ◽  
Flavor Symmetry ◽  
Heavy Particles ◽  
Neutrino Sector ◽  
Seesaw Model ◽  
The Masses

It is now clear that the masses of the neutrino sector are much lighter than those of the other three sectors. Canonial seesaw model would be the most famous for the above explanation. But one must introduce heavy particles that will not be able to observed with present scientific technologies. On the other hand, there are many attempts to explain the neutrino masses radiatively by means of inert Higgses, which do not have the vacuum expectation values. Then one can discuss cold dark matter candidates, because of no needing so heavy particles. The most famous work would be the Zee model17. Recently a new type model (hep-ph/0601225)4 along this line of thought was proposed by E. Ma. We adopted this idea, and then we introduced a new flavor symmetry to constrain the Yukawa sector. So our model might be more predictive, and can be investigated at LHC. I will present how we can obserb the particular signal at LHC, and what we can predict about the neutrino sector.

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