scholarly journals FACTORIZATION EFFECTS IN A MODEL OF UNSTABLE PARTICLES

2010 ◽  
Vol 25 (10) ◽  
pp. 2049-2062 ◽  
Author(s):  
V. I. KUKSA ◽  
N. I. VOLCHANSKIY
Keyword(s):  
Decay Width ◽  
Cross Section ◽  
Intermediate State ◽  
Decay Chain ◽  
Arbitrary Spin ◽  
Specific Structure ◽  
Unstable Particles ◽  
Particle Decay ◽  
Intermediate States ◽  
Exact Factorization

The effects of factorization are considered within the framework of the model of unstable particles with a smeared mass. It is shown that two-particle cross-section and three-particle decay width can be described by the universal factorized formulae for an unstable particles of an arbitrary spin in an intermediate state. The exact factorization is caused by the specific structure of the model unstable-particle propagators. This result is generalized to complicated scattering and decay-chain processes with unstable particles in intermediate states. We analyze applicability of the method and evaluate its accuracy.

scholarly journals FACTORIZED FORMULA FOR THE CROSS-SECTION OF TWO-PARTICLE SCATTERING

2008 ◽  
Vol 23 (27n28) ◽  
pp. 4509-4516 ◽  
Author(s):  
V. I. KUKSA
Keyword(s):  
Cross Section ◽  
Intermediate State ◽  
Factorization Method ◽  
Phenomenological Analysis ◽  
Unstable Particle ◽  
Specific Structure ◽  
Particle Scattering ◽  
Unstable Particles ◽  
The Cross ◽  
Exact Factorization

We applied the factorization method to the processes of two-particle scattering with an unstable particle in the intermediate state. It was shown, that in the framework of this method, the cross-section can be represented in the universal factorized form for an arbitrary set of particles. An exact factorization is caused by a specific structure of unstable particles propagators. Phenomenological analysis of the factorization effect is performed.

scholarly journals Factorization in the model of unstable particles with continuous masses

Open Physics ◽  
2013 ◽  
Vol 11 (2) ◽  
Author(s):  
Vladimir Kuksa ◽  
Nikolay Volchanskiy
Keyword(s):  
Cross Sections ◽  
Factorization Method ◽  
Phenomenological Analysis ◽  
Specific Structure ◽  
Interacting Particles ◽  
Unstable Particles ◽  
Decay Widths ◽  
Intermediate Time ◽  
Exact Factorization

AbstractWe study processes with unstable particles in intermediate time-like states. It is shown that the amplitudes squared of such processes factor exactly in the framework of the model of unstable particles with continuous masses. Decay widths and cross sections can then be represented in a universal factorized form for an arbitrary set of interacting particles. This exact factorization is caused by specific structure of propagators in the model. We formulate the factorization method and perform a phenomenological analysis of the factorization effects. The factorization method considerably simplifies calculations while leading to compact and reasonable results.

scholarly journals Enzymatic evolution driven by entropy production

2018 ◽  
Author(s):  
A. Arango-Restrepo ◽  
J.M. Rubi ◽  
D. Barragán
Keyword(s):  
Enzyme Kinetics ◽  
Entropy Production ◽  
Intermediate State ◽  
State Energy ◽  
Structural Evolution ◽  
Thermodynamic Efficiency ◽  
Total Entropy ◽  
Enzymatic Process ◽  
Intermediate States ◽  
Evolution Proceeds

AbstractWe show that the structural evolution of enzymes is largely influenced by the entropy produced in the enzymatic process. We have computed this quantity for the case in which the process has unstable and metastable intermediate states. By assuming that the kinetics takes place along a potential barrier, we have found that the behavior of the total entropy produced is a non-monotonic function of the intermediate state energy. By diminishing the number of metastable intermediate states, the total entropy produced decreases and consequently the enzyme kinetics and the thermodynamic efficiency are enhanced. Minimizing locally the total entropy produced for an enzymatic process with metastable intermediate states, the kinetics and the thermodynamic efficiency are raised. In contrast, in the absence of metastable intermediate states, a maximum of the entropy produced results in an improvement of the kinetic performance although the thermodynamic efficiency diminishes. Our results show that the enzymatic evolution proceeds not only to enhance the kinetics but also to optimize the total entropy produced.

EXCITON-MEDIATED RAMAN SCATTERING IN ONE-DIMENSIONAL QUANTUM DOTS

2011 ◽  
Vol 25 (32) ◽  
pp. 4387-4393 ◽  
Author(s):  
HAI-CHAO SUN ◽  
CUI-HONG LIU
Keyword(s):  
Quantum Dots ◽  
Differential Cross Section ◽  
Raman Scattering ◽  
Cross Section ◽  
Differential Cross ◽  
Semiconductor Quantum Dots ◽  
Scattering Process ◽  
One Dimensional ◽  
Intermediate States ◽  
Potential Frequency

The differential cross section (DCS) for exciton-mediated Raman scattering (EMRS) in one-dimensional semiconductor quantum dots is presented. The exciton states are considered as intermediate states in the Raman scattering process. The selection rules for the EMRS process are studied. The numerical results show that the contribution to DCS indicated by exciton is larger than that by electron. DCS of EMRS is larger when there is a bigger confinement potential frequency.

Total Compton Cross Section for Arbitrary Spin

1961 ◽  
Vol 121 (1) ◽  
pp. 314-318 ◽  
Author(s):  
C. G. Bollini
Keyword(s):  
Cross Section ◽  
Arbitrary Spin

scholarly journals FINITE-WIDTH EFFECTS IN THE NEAR-THRESHOLD ZZZ AND ZWW PRODUCTION AT ILC

2011 ◽  
Vol 26 (15) ◽  
pp. 1075-1093 ◽  
Author(s):  
ROMAN PASECHNIK ◽  
VLADIMIR KUKSA
Keyword(s):  
Higgs Boson ◽  
Cross Section ◽  
Principal Part ◽  
Mass Shell ◽  
Linear Collider ◽  
International Linear Collider ◽  
Finite Width ◽  
Leading Order ◽  
Unstable Particles ◽  
Near Threshold

We calculate the cross-section of the near-threshold off-shell ZZZ and ZW+W-production at the International Linear Collider taking into account their instability and the principal part of next-to-leading order corrections. The calculations are performed in the framework of the model of unstable particles with smeared mass-shell. We show that the contribution of the finite Z/W and H widths (their instability) is large in the Higgs resonance range (about -24% and -18% for ZZZ and ZW+W-, respectively, at [Formula: see text]) and should be taken into account in the Higgs boson studies at the future International Linear Collider.

Photoneutron Cross Sections in 14N

1972 ◽  
Vol 50 (15) ◽  
pp. 1689-1696 ◽  
Author(s):  
R. W. Gellie ◽  
K. H. Lokan ◽  
N. K. Sherman ◽  
R. G. Johnson ◽  
J. I. Lodge
Keyword(s):  
Excited States ◽  
Cross Section ◽  
Cross Sections ◽  
Neutron Emission ◽  
Giant Resonance ◽  
Sequential Decay ◽  
Dipole Resonance ◽  
Intermediate States ◽  
Integrated Cross Section ◽  
High Degree

Photoneutron distributions from 14N have been obtained by time-of-flight methods, for bremsstrahlung end-point energies increasing in 2 MeV steps from 15.5 to 29.5 MeV. A large part of the neutron yield is associated with the sequential decay of 14N to 12C, through well-defined intermediate states of 13C, at 7.55, 8.86, and 11.80 MeV, which are unstable against neutron emission. The (γ,n0) cross section for neutron emission to the ground state of 13N is found to agree very closely with the corresponding (γ,p0) cross section, implying a high degree of isospin purity for the giant dipole resonance of 14N. It is observed that the decay of the giant resonance proceeds freely through those odd-parity excited states of the A = 13 nuclei which are single hole states formed by the removal of a p-shell nucleon from the parent 14N.The integrated cross section for all neutron-producing interactions is found to be 88 ± 5 MeV mb.

scholarly journals W-PAIR PRODUCTION IN MODIFIED PERTURBATION THEORY

2011 ◽  
Vol 26 (24) ◽  
pp. 1807-1816 ◽  
Author(s):  
M. L. NEKRASOV
Keyword(s):  
Perturbation Theory ◽  
Total Cross Section ◽  
Pair Production ◽  
Cross Section ◽  
Unstable Particles ◽  
Better Than

We examine capabilities of the modified perturbation theory (MPT) for description of the processes with productions and decays of fundamental unstable particles. We calculate total cross-section for e+e- → γ, Z → W+W- → 4f in a model with the Dyson-resummed and with the MPT-expanded up to the NNLO Breit–Wigner factors, and compare the outcomes. At the ILC energies a coincidence of the outcomes is detected with precision better than one per-mille.

scholarly journals Systematic study of diphoton resonance at 750 GeV from sgoldstino

2016 ◽  
Vol 31 (26) ◽  
pp. 1650151 ◽  
Author(s):  
Ran Ding ◽  
Yizhou Fan ◽  
Li Huang ◽  
Chuang Li ◽  
Tianjun Li ◽  
...  
Keyword(s):  
Decay Width ◽  
Cross Section ◽  
Production Cross Section ◽  
Production Cross ◽  
Vector Boson ◽  
Mass Difference ◽  
Hadron Collider ◽  
Gluon Fusion ◽  
Large Mass ◽  
Decay Length

The ATLAS and CMS Collaborations of the Large Hadron Collider (LHC) have reported an excess of events in diphoton channel with invariant mass of about 750 GeV. With low energy supersymmetry breaking, we systematically consider the sgoldstino scalar S as the new resonance, which is a linear combination of the CP-even scalar [Formula: see text] and CP-odd pseudoscalar [Formula: see text]. Because we show that [Formula: see text] and [Formula: see text] can be degenerated or have large mass splitting, we consider two cases for all the following three scenarios: (1) Single resonance, [Formula: see text] is the 750 GeV resonance decays to a pair of 1 GeV pseudoscalar [Formula: see text] with suitable decay length, these two [Formula: see text] decay into collimated pair of photons which cannot be distinguished at the LHC and may appear as diphotons instead of four photons. (2) Twin resonances, [Formula: see text] with a mass difference of about 40 GeV and both [Formula: see text] and [Formula: see text] decay into diphoton pairs. For productions, we consider three scenarios: (I) vector-boson fusion; (II) gluon–gluon fusion; (III) [Formula: see text] pair production. In all these scenarios with two kinds of resonances, we find the parameter space that satisfies the diphoton production cross-section from 3 to 13 fb and all the other experimental constraints. And we address the decay width as well. In particular, in the third scenario, we observe that the production cross-section is small but the decay width of [Formula: see text] or [Formula: see text] can be from 40 to 60 GeV. Even if the 750 GeV diphoton excesses were not confirmed by the ATLAS and CMS experiments, we point out that our proposal can be used to explain the current and future diphoton excesses.

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