Doubly cabibbo suppressed $D^{+}$ decays and singly Cabibbo suppressed $D^{+}_s$ decays in 220 GeV $\gamma$ + $\pi$ interactions

1995 ◽  
Author(s):  
Gary P. Grim
Keyword(s):  
Cabibbo Suppressed ◽  
Pi Interactions

Stereospecific 1,3-H Transfer of Indenols Proceeds via Persistent Ion-Pairs Anchored By NH···Pi Interactions

2018 ◽  
Author(s):  
David Ascough ◽  
Fernanda Duarte ◽  
Robert Paton
Keyword(s):  
Computational Analysis ◽  
Ion Pairs ◽  
Ion Pair ◽  
Hydrogen Atom Transfer ◽  
Polar Solvents ◽  
Chirality Transfer ◽  
Activation Barriers ◽  
Sense And Avoid ◽  
Phase Dynamics ◽  
Pi Interactions

The base-catalyzed rearrangement of arylindenols is a rare example of a suprafacial [1,3]-hydrogen atom transfer. The mechanism has been proposed to proceed via sequential [1,5]-sigmatropic shifts, which occur in a selective sense and avoid an achiral intermediate. A computational analysis using quantum chemistry casts serious doubt on these suggestions: these pathways have enormous activation barriers and in constrast to what is observed experimentally, they overwhelmingly favor a racemic product. Instead we propose that a suprafacial [1,3]-prototopic shift occurs in a two-step deprotonation/reprotonation sequence. This mechanism is favored by 15 kcal mol<sup>-1</sup> over that previously proposed. Most importantly, this is also consistent with stereospecificity since reprotonation occurs rapidly on the same p-face. We have used explicitly-solvated molecular dynamics studies to study the persistence and condensed-phase dynamics of the intermediate ion-pair formed in this reaction. Chirality transfer is the result of a particularly resilient contact ion-pair, held together by electrostatic attraction and a critical NH···p interaction which ensures that this species has an appreciable lifetime even in polar solvents such as DMSO and MeOH.

An Experimental Study of the Cabibbo Suppressed Decay $D^0 \to K^+ K^- \pi^+ \pi^-$

1995 ◽  
Author(s):  
Lalith P. Perera
Keyword(s):  
Experimental Study ◽  
Cabibbo Suppressed

Observation of the Cabibbo Suppressed Decay D+- ---> phi pi+-

1985 ◽  
Author(s):  
Christos H. Georgiopoulos
Keyword(s):  
Cabibbo Suppressed

Unusually Strong Interactions Mediated by Both .pi.-.pi. Stacking and CH-.pi. Interactions Present in the Dimer of Nickel(II) Complex Coordinated with n-Butyl-Substituted Salen

1995 ◽  
Vol 117 (8) ◽  
pp. 2377-2378 ◽  
Author(s):  
Kazuo Miyamura ◽  
Akiko Mihara ◽  
Takashi Fujii ◽  
Yohici Gohshi ◽  
Youichi Ishii
Keyword(s):  
Strong Interactions ◽  
Pi Stacking ◽  
Pi Interactions

Doubly and singly Cabibbo suppressed charm decays into the K+π−π+ final state

1995 ◽  
Vol 359 (3-4) ◽  
pp. 403-410 ◽  
Author(s):  
P.L. Frabetti ◽  
H.W.K. Cheung ◽  
J.P. Cumalat ◽  
C. Dallapiccola ◽  
J.F. Ginkel ◽  
...  
Keyword(s):  
Final State ◽  
Charm Decays ◽  
Cabibbo Suppressed

The nature of .pi.-.pi. interactions

1990 ◽  
Vol 112 (14) ◽  
pp. 5525-5534 ◽  
Author(s):  
Christopher A. Hunter ◽  
Jeremy K. M. Sanders
Keyword(s):  
Pi Interactions

Charm Decays at B Factories

2006 ◽  
Vol 21 (27) ◽  
pp. 5436-5444
Author(s):  
◽  
Brian T. Meadows
Keyword(s):  
Baryon State ◽  
Charm Mesons ◽  
Charmed Baryons ◽  
Charm Decays ◽  
Meson Decays ◽  
Charm Baryon ◽  
Cabibbo Suppressed ◽  
Higher Spins

Recent results relating to charm baryon and meson decays from the Belle and BABAR experiments are presented. In addition to recent observations for charm hyperons, evidence for a new charm baryon state, the Λc(2940), observed in its decay to D0p is also reported. No evidence for doubly charmed baryons is seen in e+e- interactions. A measurement of the spin of the Ω- hyperon is made using decays of the [Formula: see text] and [Formula: see text] baryons. On the assumption that the spin of the parent baryons are J = 1/2, the assignment J = 3/2 is confirmed and both J = 1/2 and also higher spins are excluded. New results on rare, Cabibbo-suppressed decays of charm mesons are also presented.

scholarly journals Unexpectedly Large Couplings Between Orthogonal Units in Anthraquinone Polymers

2019 ◽  
Author(s):  
Rocco Peter Fornari ◽  
Piotr de Silva
Keyword(s):  
Molecular Dynamics ◽  
Density Functional Theory ◽  
Ab Initio ◽  
Density Functional ◽  
Lone Pair ◽  
Localized States ◽  
Ab Initio Molecular Dynamics ◽  
Coupling Mechanism ◽  
Functional Theory ◽  
Pi Interactions

Directly linked polyanthraquinones have relatively large electronic couplings between charge-localized states despite near-orthogonality of the monomer units. By using density functional theory (DFT) and ab initio molecular dynamics (AIMD) simulations, we investigate this unusual coupling mechanism and show that this is due to strong lone pair-pi interactions, which are maximized around orthogonal conformations. We find that such materials are largely resilient to dynamic disorder and are promising for organic electronics applications.

scholarly journals Measurement of strong phase in D0 → Kπ decay at BESIII

2014 ◽  
Vol 31 ◽  
pp. 1460305
Author(s):  
Xiao-Kang Zhou ◽  
Keyword(s):  
Phase Difference ◽  
Accurate Result ◽  
Branching Fractions ◽  
Ckm Matrix ◽  
Strong Phase ◽  
Mixing Parameters ◽  
The World ◽  
The Asymmetry ◽  
Cabibbo Suppressed

Based on 2.92 fb-1 of e+e- collision data collected with the BESIII detector at [Formula: see text] GeV, we measured the asymmetry [Formula: see text] of the branching fractions of DCP± → K-π+ (DCP± are the CP-odd and CP-even eigenstates) to be [Formula: see text]. [Formula: see text] is used to extract the strong phase difference δKπ between the doubly Cabibbo-suppressed process [Formula: see text] and Cabibbo-favored D0 → K-π+. By taking inputs of other parameters in world measurements, we obtain cos δKπ = 1.03 ± 0.12 ± 0.04 ± 0.01. This is the most accurate result of cos δKπ to date and can improve the world constrains on the mixing parameters and on γ/ϕ3 in the CKM matrix.

scholarly journals Role of scalar $$a_0(980)$$ in the single Cabibbo suppressed process $$D^+ \rightarrow \pi ^{+} \pi ^{0} \eta $$

2020 ◽  
Vol 80 (11) ◽  
Author(s):  
Man-Yu Duan ◽  
Jun-Ya Wang ◽  
Guan-Ying Wang ◽  
En Wang ◽  
De-Min Li
Keyword(s):  
Invariant Mass ◽  
Mass Distributions ◽  
Unitary Approach ◽  
Chiral Unitary Approach ◽  
Free Parameters ◽  
Cabibbo Suppressed ◽  
Dalitz Plots

AbstractTaking into account that the scalar $$a_0(980)$$ a 0 ( 980 ) can be dynamically generated from the pseudoscalar-pseudoscalar interaction within the chiral unitary approach, we have studied the single Cabibbo suppressed process $$D^+\rightarrow \pi ^+\pi ^0\eta $$ D + → π + π 0 η . We find clear peaks of $$a_0(980)^+$$ a 0 ( 980 ) + and $$a_0(980)^0$$ a 0 ( 980 ) 0 in the $$\pi ^+\eta $$ π + η and $$\pi ^0\eta $$ π 0 η invariant mass distributions, respectively. The predicted Dalitz plots of $$D^+\rightarrow \pi ^+\pi ^0\eta $$ D + → π + π 0 η also manifest the significant signals for $$a_0(980)^+$$ a 0 ( 980 ) + and $$a_0(980)^0$$ a 0 ( 980 ) 0 states. The uncertainties of the results due to the free parameters are also discussed. Our study shows that the process $$D^+\rightarrow \pi ^+\pi ^0\eta $$ D + → π + π 0 η can be used to explore the nature of the scalar $$a_0(980)$$ a 0 ( 980 ) , thus we encourage the experimental physicists to measure this reaction with more precision.

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