scholarly journals Absolute Intensity Calibration at 26 Å by Branching Ratios to the Visible

1972 ◽  
Vol 14 ◽  
pp. 561-562 ◽  
Author(s):  
F. E. Irons ◽  
N. J. Peacock
Keyword(s):  
Laser Pulse ◽  
Branching Ratio ◽  
Grazing Incidence ◽  
Absolute Intensity ◽  
Branching Ratios ◽  
Neodymium Laser ◽  
Absolute Calibration ◽  
Carbon Target ◽  
Upper Level ◽  
Carbon Plasma

The technique for absolute calibration using the branching ratio of two transitions which have a common upper level but widely separated energies has been employed and described by Griffin and McWhirter (1961).Using the plasma produced by irradiation of a carbon target with a 1 GW, 6 nsec duration, neodymium laser pulse, we have been able to calibrate a grazing incidence spectrograph at the wavelength (25.83 Å) of the 7–1 transition in C VI by direct comparison with the intensity of the 7–6 (3434 Å) transition emitted from the same ions in the plasma. The spectrum from a similar carbon plasma has been described by Boland et al. (1968) and in several ways is ideal for this type of measurement.

CONTROLLING ABOVE-THRESHOLD DISSOCIATION BRANCHING RATIOS OF HD+ WITH FEMTOSECOND LASER PULSE TRAIN

2012 ◽  
Vol 11 (04) ◽  
pp. 709-721 ◽  
Author(s):  
QIAN-ZHEN SU ◽  
JIE YU ◽  
KAI-JUN YUAN ◽  
SHU-LIN CONG
Keyword(s):  
Laser Pulse ◽  
Femtosecond Laser ◽  
Femtosecond Laser Pulse ◽  
Pulse Train ◽  
Branching Ratio ◽  
Branching Ratios ◽  
Pulse Number ◽  
Molecular Ions ◽  
Quantum Wave ◽  
Energy Dependent

Above-threshold dissociation (ATD) process of the molecular ions HD+ steered by a femtosecond laser pulse train (LPT) is investigated theoretically using the time-dependent quantum wave packet method. Energy-dependent distributions of ATD fragments are analyzed by using an asymptotic-flow expression in the momentum space. It is found that fragment kinetic energy spectra shift to low energy region with increasing pulse number of LPT. The photofragment branching ratio between the 1sσg and 2pσu dissociation channels is sensitive to the pulse number of LPT. The momentum distribution of the ATD fragments is discussed in detail.

scholarly journals High-Resolution Photoabsorption Spectrum of Cs+ (5p61So + 5p5ns, nd) Between 504A and 600A using a Laser Ionized Cs Vapor Column

1984 ◽  
Vol 86 ◽  
pp. 124-124
Author(s):  
T.J. McIlrath ◽  
V. Kaufman ◽  
J. Sugar ◽  
W.T. Hill ◽  
D. Cooper
Keyword(s):  
High Resolution ◽  
Laser Pulse ◽  
High Voltage ◽  
Power Output ◽  
Random Phase ◽  
Grazing Incidence ◽  
Fano Resonances ◽  
Line Shapes ◽  
Phase Calculation ◽  
Photoabsorption Spectrum

Rapid ionization of Cs vapor in a heat pipe at 0.05 torr was achieved by pumping the 6s 2S½ – 7p 2P½ transition (f=0.007)1 with a flash-pumped dye laser at 4593.2A and I MW power output. Photoabsorptian initiated at the end of the laser pulse(≃ 0.5/s) showed the 5p5ns and nd series below and above the 5p52P3/2 threshold at 535.4A. Broad Beutler - Fano resonances appeared in the d series above threshold. The spectrum was recorded photographically on a 10.7m grazing incidence spectrograph using a continuum background generated by a BRV high-voltage spark source with a uranium anode. We will compare the line-shapes and the quantum defect (Lu-Fano2) plot with the predictions of a relativistic random phase calculation.

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 Disentangling QCD and new physics in D → πℓ+ℓ−

2021 ◽  
Vol 2021 (4) ◽  
Author(s):  
Aoife Bharucha ◽  
Diogo Boito ◽  
Cédric Méaux
Keyword(s):  
Standard Model ◽  
Branching Ratio ◽  
Branching Ratios ◽  
New Physics ◽  
Operator Product ◽  
Beyond The Standard Model ◽  
Spectral Functions ◽  
The Standard Model ◽  
Model Independent ◽  
Weak Annihilation

Abstract In this paper we consider the decay D+ → π+ℓ+ℓ−, addressing in particular the resonance contributions as well as the relatively large contributions from the weak annihilation diagrams. For the weak annihilation diagrams we include known results from QCD factorisation at low q2 and at high q2, adapting the existing calculation for B decays in the Operator Product Expansion. The hadronic resonance contributions are obtained through a dispersion relation, modelling the spectral functions as towers of Regge-like resonances in each channel, as suggested by Shifman, imposing the partonic behaviour in the deep Euclidean. The parameters of the model are extracted using e+e− → (hadrons) and τ → (hadrons) + ντ data as well as the branching ratios for the resonant decays D+ → π+R(R → ℓ+ℓ−), with R = ρ, ω, and ϕ. We perform a thorough error analysis, and present our results for the Standard Model differential branching ratio as a function of q2. Focusing then on the observables FH and AFB, we consider the sensitivity of this channel to effects of physics beyond the Standard Model, both in a model independent way and for the case of leptoquarks.

scholarly journals THE B→Xsl+l- AND B→Xsγ DECAYS WITH THE FOURTH GENERATION

1999 ◽  
Vol 14 (35) ◽  
pp. 2453-2462 ◽  
Author(s):  
CHAO-SHANG HUANG ◽  
WU-JUN HUO ◽  
YUE-LIANG WU
Keyword(s):  
B Meson ◽  
Branching Ratio ◽  
Branching Ratios ◽  
Fourth Generation ◽  
B Meson Decays ◽  
Meson Decays

If the fourth generation fermions exist, the new quarks could influence the branching ratios of the decays of B→Xsγ and B→Xsl+l-. We obtain two solutions of the fourth generation CKM factor [Formula: see text] from the decay of B→ Xsγ. We use these two solutions to calculate the new contributions of the fourth generation quark to Wilson coefficients of the decay of B→ Xsl+l-. The branching ratio and the forward–backward asymmetry of the decay of B→ Xsl+l- in the two cases are calculated. Our results are quite different from that of SM in one case, almost the same in another case. If Nature chooses the former, the B meson decays could provide a possible test of the fourth generation existence.

Non-adiabatic photodissociation dynamics of BrCl

1994 ◽  
Vol 72 (3) ◽  
pp. 758-761 ◽  
Author(s):  
Jianying Cao ◽  
Hans-Peter Loock ◽  
Charles X.W. Qian
Keyword(s):  
Laser Radiation ◽  
Potential Energy ◽  
Multiphoton Ionization ◽  
Branching Ratio ◽  
Tunable Laser ◽  
Branching Ratios ◽  
Excitation Wavelength ◽  
Dissociation Dynamics ◽  
Adiabatic Transitions ◽  
Insight Into

Nozzle-cooled BrCl was excited with tunable laser radiation at selected wavelengths between 389 and 500 nm. The chlorine atomic fragments in their Cl*(2P1/2) and Cl(2P3/2) state were stated-selectively probed by resonance-enhanced multiphoton ionization. The branching ratio (Cl*/(Cl + Cl*)) was measured as a function of the excitation wavelength. The relative Cl* yield reaches a maximum at around λphot = 460 nm. Decomposition of these branching ratios into Cl and Cl* photofragment yield spectra provides insight into the BrCl B-state 3П(0+) non-adiabatic dissociation dynamics. Our results suggest that the dissociation mechanism involves non-adiabatic transitions among 0+ potential energy curves.

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