Isospin-violating contributions to Cirigliano, V.; Gisbert, H.; Pich, A. ...
The journal of high energy physics,
02/2020, Volume:
2020, Issue:
2
Journal Article
Peer reviewed
Open access
A
bstract
The known isospin-breaking contributions to the
K → ππ
amplitudes are reanalyzed, taking into account our current understanding of the quark masses and the relevant non-perturbative inputs. ...We present a complete numerical reappraisal of the direct CP-violating ratio ∈
′
/∈, where these corrections play a quite significant role. We obtain the Standard Model prediction Re (∈
′
/∈) = (14
±
5)
·
10
−
4
, which is in very good agreement with the measured ratio. The uncertainty, which has been estimated conservatively, is dominated by our current ignorance about 1
/N
C
-suppressed contributions to some relevant chiral-perturbation-theory low-energy constants.
A
bstract
Hadronic matrix elements of local four-quark operators play a central role in non-leptonic kaon decays, while vacuum matrix elements involving the same kind of operators appear in inclusive ...dispersion relations, such as those relevant in
τ
-decay analyses. Using an SU(3)
L
⊗ SU(3)
R
decomposition of the operators, we derive generic relations between these matrix elements, extending well-known results that link observables in the two different sectors. Two relevant phenomenological applications are presented. First, we determine the electroweak-penguin contribution to the kaon CP-violating ratio
ε
′
/ε
, using the measured hadronic spectral functions in
τ
decay. Second, we fit our SU(3) dynamical parameters to the most recent lattice data on
K
→
ππ
matrix elements. The comparison of this numerical fit with results from previous analytical approaches provides an interesting anatomy of the ∆
I
=
1
2
enhancement, confirming old suggestions about its underlying dynamical origin.
A
bstract
Three different approaches to precisely describe the Adler function in the Euclidean regime at around 2 GeVs are available: dispersion relations based on the hadronic production data in
e
+
...e
−
annihilation, lattice simulations and perturbative QCD (pQCD). We make a comprehensive study of the perturbative approach, supplemented with the leading power corrections in the operator product expansion. All known contributions are included, with a careful assessment of uncertainties. The pQCD predictions are compared with the Adler functions extracted from
Δ
α
QED
had
(
Q
2
), using both the DHMZ compilation of
e
+
e
−
data and published lattice results. Taking as input the FLAG value of
α
s
, the pQCD Adler function turns out to be in good agreement with the lattice data, while the dispersive results lie systematically below them. Finally, we explore the sensitivity to
α
s
of the direct comparison between the data-driven, lattice and QCD Euclidean Adler functions. The precision with which the renormalisation group equation can be tested is also evaluated.
We report a facile method to synthesize stimuli-responsive aqueous microgels containing degradable crosslinks based on the supramolecular host–guest complexes between β-cyclodextrin and cholesterol. ...A degradable crosslinker was synthesized by modification of cholesteryl-functionalized poly(ethylene glycol) with mono-methacryl-functionalized β-cyclodextrin and used in the precipitation polymerization of N -vinylcaprolactam to synthesize microgels containing cleavable crosslinks. A series of microgels with variable content of the degradable crosslinker was synthesized and incorporation of the crosslinker was confirmed by FTIR and NMR spectroscopy. Microgels were characterized by dynamic light scattering and electron microscopy to evaluate their size, size distribution and morphology. The degradation of microgels was triggered upon addition of 1-adamantanecarboxylic acid. The degradation process was followed by: (a) dynamic light scattering by monitoring the scattering intensity and hydrodynamic radii and (b) electron microscopy (FESEM) by visualization of the changes in the microgel shape and size. Size exclusion chromatography was used to analyze the degradation products.
We highlight the progress, current status, and open challenges of QCD-driven physics, in theory and in experiment. We discuss how the strong interaction is intimately connected to a broad sweep of ...physical problems, in settings ranging from astrophysics and cosmology to strongly coupled, complex systems in particle and condensed-matter physics, as well as to searches for physics beyond the Standard Model. We also discuss how success in describing the strong interaction impacts other fields, and, in turn, how such subjects can impact studies of the strong interaction. In the course of the work we offer a perspective on the many research streams which flow into and out of QCD, as well as a vision for future developments.
Full text
Available for:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
pH-responsive supramacromolecular microgels were synthesized via droplet-based microfluidics with controlled size and shape in reproducible manner. All synthesized microgels show pH-induced ...degradability independent on their shape. On-chip encapsulation of colloidal particles in the supramacromoelcular microgels and their pH-triggered release show a potential for application to deliever cargo molecules and release at targeting location.
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This study presents a versatile method to synthesize stimuli-responsive microgels with supramolecular cross-links exhibiting tunable size and shape via droplet-based microfluidics. The natural polyphenol tannic acid (TA) is used to cross-link poly(N-vinylcaprolactam) (PVCL) chains in aqueous droplets by the formation of hydrogen bonds and hydrophobic interactions between the phenolic groups of TA and the carbonyl group and the hydrophobic segments of lactam ring of PVCL chains. The obtained microgels exhibit diameters in the range of 130–150µm in swollen state in aqueous solution. Synthesized microgels exhibit pH-responsive behavior: at low pH microgels deswell and shrink due to the protonation of phenolic groups and enhanced hydrophobic interactions; at high pH microgels swell and disintegrate due to the deprotonation of phenolic groups and destruction of hydrogen bonds with PVCL chains. Additionally, we present supramacromolecular microgels in cylindrical shape with different aspect ratios using a new design of microfluidic chip by varying flow rates at high concentration of the prepolymerized precursor combined with rapid pH-triggered on-chip gelation. Furthermore, developed synthesis methodology allows on-chip encapsulation of colloidal objects into large supramacromolecular microgels during the cross-linking step. The complete and fast release of objects by pH-triggered degradation indicates that the pH-responsive supramacromolecular microgels can be used for controlled loading/release of various payloads, like probiotics. Moreover, cell studies of L929 fibroblast clearly show the biocompatibility of the microgels.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
In the present work we used microgels as colloidal containers for the loading of hydrophobic magnetic nanoparticles using the solvent exchange method. We varied systematically two parameters: (i) the ...crosslinking degree of microgels (1-4.5 mol% crosslinker) and (ii) loading of hydrophobic magnetite nanoparticles (d = 7 nm) in microgels (2-10 wt%). The experimental data show that the interplay between these two parameters provides efficient control over the clustering of magnetic nanoparticles in the microgel structure. Transverse magnetization relaxation measurements indicate that the formation of nanoparticle clusters in microgels induces non-linear enhancement of the relaxivity with the increase of nanoparticle loading in microgels. The results suggest that the modulation of the microgel network architecture can be efficiently applied to trigger self-assembly processes inside microgels and design hybrid colloids with unusual morphologies and properties.
Workshop summary: Kaons@CERN 2023 Anzivino, G.; Cuendis, Sergio Arguedas; Bernard, V. ...
European physical journal. C, Particles and fields,
04/2024, Volume:
84, Issue:
4
Journal Article
Peer reviewed
Open access
Kaon physics is at a turning point – while the rare-kaon experiments NA62 and KOTO are in full swing, the end of their lifetime is approaching and the future experimental landscape needs to be ...defined. With HIKE, KOTO-II and LHCb-Phase-II on the table and under scrutiny, it is a very good moment in time to take stock and contemplate about the opportunities these experiments and theoretical developments provide for particle physics in the coming decade and beyond. This paper provides a compact summary of talks and discussions from the Kaons@CERN 2023 workshop, held in September 2023 at CERN.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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