scholarly journals A simple alternative to the relativistic Breit–Wigner distribution

2021 ◽  
Vol 57 (12) ◽  
Author(s):  
Francesco Giacosa ◽  
Anna Okopińska ◽  
Vanamali Shastry
Keyword(s):  
Experimental Data ◽  
Decay Width ◽  
Wigner Distribution ◽  
Decay Chain ◽  
Threshold Effects ◽  
Energy Distributions ◽  
Spectral Functions ◽  
Decay Channels ◽  
Simple Alternative ◽  
Wigner Energy

AbstractFirst, we discuss the conditions under which the non-relativistic and relativistic types of the Breit–Wigner energy distributions are obtained. Then, upon insisting on the correct normalization of the energy distribution, we introduce a Flatté-like relativistic distribution -denominated as Sill distribution- that (i) contains left-threshold effects, (ii) is properly normalized for any decay width, (iii) can be obtained as an appropriate limit in which the decay width is a constant, (iv) is easily generalized to the multi-channel case (v) as well as to a convoluted form in case of a decay chain and - last but not least - (vi) is simple to deal with. We compare the Sill distribution to spectral functions derived within specific QFT models and show that it fairs well in concrete examples that involve a fit to experimental data for the $$\rho $$ ρ , $$a_1(1260)$$ a 1 ( 1260 ) , and $$K^*(982)$$ K ∗ ( 982 ) mesons as well as the $$\varDelta (1232)$$ Δ ( 1232 ) baryon. We also present a study of the $$f_2(1270)$$ f 2 ( 1270 ) which has more than one possible decay channels. Finally, we discuss the limitations of the Sill distribution using the $$a_0(980)$$ a 0 ( 980 ) -$$a_0(1450)$$ a 0 ( 1450 ) and the $$K_0^*(700)$$ K 0 ∗ ( 700 ) -$$K_0^*(1430)$$ K 0 ∗ ( 1430 ) resonances as examples.

scholarly journals MASS EFFECTS IN THE QUARK–GLUON DECAYS OF HEAVY PARAQUARKONIA

1998 ◽  
Vol 13 (27) ◽  
pp. 2199-2204 ◽  
Author(s):  
A. YA. PARKHOMENKO ◽  
A. D. SMIRNOV
Keyword(s):  
Experimental Data ◽  
Energy Distribution ◽  
Decay Width ◽  
Branching Ratios ◽  
Energy Distributions ◽  
Total Decay Width ◽  
Quark Masses ◽  
Decay Widths ◽  
The Masses ◽  
Good Agreement

Quark–gluon decays of heavy paraquarkonia [Formula: see text] are investigated with account of the masses of final quarks. The decay widths and the energy distributions of the final quarks and gluons are calculated in dependence on the relative quark masses. The strong collinear enhancement of the gluon energy distribution at the end of the spectrum is shown to take place in all such decays of ηc and ηb mesons except the decay [Formula: see text]. The total decay width is shown to have an essential dependence on the final quark masses. The corresponding branching ratios of ηc and ηb mesons are numerically estimated with a good agreement of [Formula: see text] with experimental data on ηc decays.

Hidden-bottom decays of $Z_b/Z_b^\prime$ in intermediate meson loops model

2014 ◽  
Vol 29 ◽  
pp. 1460231
Author(s):  
Gang Li
Keyword(s):  
Experimental Data ◽  
Form Factor ◽  
B Meson ◽  
Recent Measurement ◽  
Threshold Effects ◽  
Cutoff Parameter ◽  
Decay Channels ◽  
Decay Widths ◽  
Range Of Values

With the recent measurement of Zb(10610) and [Formula: see text] and [Formula: see text], we investigate the transitions from the Zb(10610) and Zb(10650) to bottomonium states with emission of a pion via intermediate B B* meson loops. The experimental data can be reproduced in this approach with a commonly accepted range of values for the form factor cutoff parameter α. The ϒ(3S)π decay channels appear to experience obvious threshold effects which can be understood by the property of the loop integrals. By investigating the α-dependence of partial decay widths and ratios between different decay channels, we show that the intermediate B B* meson loops are crucial for driving the transitions of [Formula: see text] with n = 1, 2, 3, and hb(mP)π with m = 1 and 2.

BIMODAL FISSION IN 258FM

1986 ◽  
Vol 01 (06) ◽  
pp. 377-381 ◽  
Author(s):  
K. DEPTA ◽  
J.A. MARUHN ◽  
W. GREINER ◽  
W. SCHEID ◽  
A. SANDULESCU
Keyword(s):  
Kinetic Energy ◽  
Shell Model ◽  
Fission Products ◽  
Degree Of Freedom ◽  
Total Kinetic Energy ◽  
Heavy Nuclei ◽  
Energy Distributions ◽  
Decay Channels ◽  
Symmetric Fission ◽  
Kinetic Energy Distributions

Within the 2-center shell model we present an explanation for the mass and total-kinetic-energy distributions of fission products of very heavy nuclei called “bimodal fission.” For the case of 258 FM we show that the symmetric fission can be described by a 2-dimensional treatment of the elongation and neck degree of freedom. Owing to shell corrections the system fissions via two decay channels that have distinct kinetic energies.

THE EFFECTS OF THE QCD CORRECTIONS TO $\Gamma \left( {H^0 \to b\bar b} \right)$

1994 ◽  
Vol 09 (14) ◽  
pp. 1309-1325 ◽  
Author(s):  
ANDREI L. KATAEV ◽  
VICTOR T. KIM
Keyword(s):  
Renormalization Group ◽  
Decay Width ◽  
Quark Mass ◽  
Threshold Effects ◽  
Leading Order ◽  
B Quark

We consider in detail various theoretical uncertainties of the perturbative predictions for the decay width of [Formula: see text] process in the region 60 GeV<MH≤2 MW. We calculate the order [Formula: see text]-contributions to the expression for [Formula: see text] through the pole b-quark mass mb and demonstrate that they are important for the elimination of the numerical difference between the corresponding expression and the renormalization-group (RG) which can be improved by the running b-quark mass. In the case of mb=4.8 GeV and [Formula: see text] we observe the identical cancellation of the next-to-leading order RG-improved corrections to [Formula: see text] at Mch=130 (65) GeV and the indications to the asymptotic explosion of the corresponding next-to-next-to-leading parametrization. The theoretical importance of the order [Formula: see text] massive corrections [Formula: see text] to for modeling the threshold effects is demonstrated.

scholarly journals DATA TAKING STRATEGY FOR THE PHASE STUDY IN ψ′→K+K-

2012 ◽  
Vol 27 (25) ◽  
pp. 1250150 ◽  
Author(s):  
B. Q. WANG ◽  
X. H. MO ◽  
C. Z. YUAN ◽  
Y. BAN
Keyword(s):  
Decay Width ◽  
Relative Phase ◽  
Resonance Peak ◽  
Numerical Results ◽  
Point Of View ◽  
Theoretical Point ◽  
Total Decay Width ◽  
Decay Channels ◽  
Phase Study ◽  
Scan Data

The study of the relative phase between strong and electromagnetic amplitudes is of great importance for understanding the dynamics of charmonium decays. The information of the phase can be obtained model-independently by fitting the scan data of some special decay channels, one of which is ψ′ →K+K-. To find out the optimal data taking strategy for a scan experiment in the measurement of the phase in ψ′ →K+ K-, the minimization process is analyzed from a theoretical point of view. The result indicates that for one-parameter fit, only one data taking point in the vicinity of a resonance peak is sufficient to acquire the optimal precision. Numerical results are obtained by fitting simulated scan data. Besides the results related to the relative phase between strong and electromagnetic amplitudes, the method is extended to analyze the fits of other resonant parameters, such as the mass and the total decay width of ψ′.

scholarly journals Efimov States From Triple α Resonances

2019 ◽  
Vol 26 ◽  
pp. 1
Author(s):  
S. Zhang ◽  
M. Huang ◽  
H. Zheng ◽  
G. Zhang ◽  
Z. Kohley ◽  
...  
Keyword(s):  
Experimental Data ◽  
Excitation Energy ◽  
Ground State ◽  
Beam Energy ◽  
Heavy Ion ◽  
Relative Energy ◽  
Energy Distributions ◽  
Form Complex ◽  
Ion Collisions ◽  
Efimov States

The Efimov trimers in excited 12C nuclei, which no observation exists yet, are discussed by means of analyzing the experimental data of 70(64)Zn(64Ni) +70(64)Zn(64Ni )reactions at beam energy of E/A=35 MeV/nucleon. In heavy ion collisions, the αs interact with each other and can form complex systems such as 8Be and 12C. For the 3α systems, multi resonance processes give rise to excited levels of 12C. The interaction between any two of the 3α particles provides events with one, two or three 8Be. Their interfering levels are clearly seen in the minimum relative energy distributions. Events of three couple αrelative energies consistent with the ground state of 8Be are observed with the decreasing of the instrumental error at the reconstructed 7.458 MeV excitation energy of 12C, which was suggested as the (Thomas) Efimov state.

Decay rates and masses for some heavy baryons in the hyper-central quark model

2020 ◽  
Vol 35 (10) ◽  
pp. 2050056
Author(s):  
M. Abu-Shady ◽  
M. M. A. Ahmed ◽  
N. H. Gerish
Keyword(s):  
Experimental Data ◽  
Wave Function ◽  
Decay Width ◽  
Iteration Method ◽  
Decay Rates ◽  
Cornell Potential ◽  
Heavy Baryons ◽  
Radial Schrödinger Equation ◽  
Rate Of Decay ◽  
Good Agreement

Masses and decay width for some heavy baryons are studied within Isgur–Wise formalism. The extended Cornell potential is employed. The hyper-radial Schrödinger equation with extended Cornell potential is solved to obtain eigenvalues of energy and baryonic wave function by using the extended iteration method. Masses and the rate of decay width for some heavy baryons are calculated. The present results are improved in comparison with other recent works and are in a good agreement with experimental data.

scholarly journals Semileptonic Transition of Tensorχc2(1P)toDsMeson

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
J. Y. Sungu ◽  
H. Sundu ◽  
K. Azizi
Keyword(s):  
Decay Width ◽  
Sum Rules ◽  
Decay Channel ◽  
Form Factors ◽  
Gluon Condensate ◽  
Direct Search ◽  
Meson Decay ◽  
Transition Form ◽  
Qcd Sum Rules ◽  
Decay Channels

Taking into account the two-gluon condensate corrections, the transition form factors of the semileptonicχc2→Dsl-ν(l=e,μ)decay channel are calculated via three-point QCD sum rules. These form factors are used to estimate the decay width of the transition under consideration in both electron and muon channels. The obtained results can be used both in direct search for such decay channels at charm factories and in analysis of theBcmeson decay at LHC.

Computer Simulation of Sputtering from Two Component Liquid Metal Targets

1985 ◽  
Vol 63 ◽  
Author(s):  
M. H. Shapiro ◽  
D. Y. Lo ◽  
T. A. Tombrello
Keyword(s):  
Experimental Data ◽  
Angular Distributions ◽  
Good Qualitative Agreement ◽  
Energy Distributions ◽  
Pure Indium ◽  
Two Component ◽  
Similar Information ◽  
Indium Target ◽  
Multiple Interaction ◽  
Detailed Nature

ABSTRACTThe sputtering of In and Ga atoms from a “liquid” target composedof gallium coveredby a surface monolayer of indium by incident 5 keV Ar+ ions was simulated using the multiple interaction molecular dynamics technique. Yields, energy distributions, and angular distributions of sputtered atoms were obtained at a temperature above the melting point for the eutectic alloy. Similar information was obtained for a pure gallium and a pure indium target. Our results for layer yield ratios and angular distributions are in good qualitative agreement with Dumke's experimental data for the Ar+, In-Ga system. Absolute yields, however, were found to be sensitive to the detailed nature of the two-body potentials used to describe the atom-atom interactions.

scholarly journals Time evolution of the process of doping of solids by plasma-ion beams

2021 ◽  
Vol 7 (3) ◽  
pp. 59-64
Author(s):  
A. Horodeński ◽  
C. Pochrybniak
Keyword(s):  
Experimental Data ◽  
Stainless Steel ◽  
Time Evolution ◽  
Tribological Properties ◽  
Ion Beam ◽  
Ion Beams ◽  
Energy Distributions ◽  
Temperature Growth ◽  
Junction Formation ◽  
Time And Energy

Irradiation of a solid with intense plasma-ion beams produced within a high vacuumchamber (by the so-called Rod Plasma Injector [1]) is a strongly nonequilibrium process, which enablesachieving a number of effects which are impossible to be achieved with other methods. These are,amongst other: improvement of ceramics wettability, fabrication of stable copper-ceramics interfacesand stable Ni-Cu and Al-Cu interfaces, improvement of tribological properties and high temperatureoxidation resistance of stainless steel, photovoltaic junction formation, and many others. In the paper,the process of plasma-ion beam propagation regarding its time and energy distributions and the processof ion penetration of solids, resulting with ion implementation and temperature growth have beenanalyzed mathematically on basis of experimental data. Results of numerical calculations have beenpresented concerning temperature and dopant density time evolution.

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