A
bstract
We investigate systematically dimension-9 operators in the standard model effective field theory which contains only standard model fields and respects its gauge symmetry. With the help of ...the Hilbert series approach to classifying operators according to their lepton and baryon numbers and their field contents, we construct the basis of operators explicitly. We remove redundant operators by employing various kinematic and algebraic relations including integration by parts, equations of motion, Schouten identities, Dirac matrix and Fierz identities, and Bianchi identities. We confirm counting of independent operators by analyzing their flavor symmetry relations. All operators violate lepton or baryon number or both, and are thus non-Hermitian. Including Hermitian conjugated operators there are
384
Δ
B
=
0
Δ
L
=
±
2
+
10
Δ
B
=
±
2
Δ
L
=
0
+
4
Δ
B
=
±
1
Δ
L
=
±
3
+
236
Δ
B
=
±
1
Δ
L
=
∓
1
operators without referring to fermion generations, and
44874
Δ
B
=
0
Δ
L
=
±
2
+
2862
Δ
B
=
±
2
Δ
L
=
0
+
486
Δ
B
=
±
1
Δ
L
=
±
3
+
42234
Δ
B
=
∓
1
Δ
L
=
±
1
operators when three generations of fermions are referred to, where ∆
L,
∆
B
denote the net lepton and baryon numbers of the operators. Our result provides a starting point for consistent phenomenological studies associated with dimension-9 operators.
A
bstract
We showed in a previous publication that there are six independent dimension-seven operators violating both lepton and baryon numbers (
L
= −
B
= 1) and twelve ones violating lepton but ...preserving baryon number (
L
= 2
, B
= 0) in standard model effective field theory, and we calculated one-loop renormalization for the former six operators. In this work we continue our efforts on renormalization of the operators. It turns out this could become subtle because the operators are connected by nontrivial relations when fermion flavors are counted. This kind of relations does not appear in lower dimensional operators. We show how we can extract anomalous dimension matrix for a flavor-specified basis of operators from counterterms computed for the above flavor-blind operators without introducing singular inverse Yukawa coupling matrices. As a phenomenological application, we investigate renormalization group effects on nuclear neutrinoless double
β
decay. We also discuss very briefly its analog in the meson sector,
K
±
→
π
∓
μ
±
μ
±
, and indicate potential difficulties to compute its decay width.
Photocatalytic catalysis is widely used for pollutant degradation. Since some pollutants with oxidative nature are readily reduced rather than oxidized and reductive reaction caused by photogenerated ...electrons is limited in the presence of oxygen, photocatalytic reduction process is more applicable for the degradation of pollutants with oxidative nature than oxidation. In this work, a novel bio-photoelectric reductive degradation system (BPRDS), composed of an electrochemically active bacterium Shewanella oneidensis MR-1 and a visible-light photocatalyst Ag3PO4, was established under anaerobic conditions and its photodegradation performance was evaluated through degrading rhodamine B (RhB), a typical organic pollutant. The as-synthesized Ag3PO4 nanoparticles exhibited absorption in the entire visible spectral range of 400–800 nm. RhB could be degraded in BPRDS with visible light irradiation under anaerobic conditions, but not be decomposed in the absence of Shewanella cells. Block of Mtr respiratory pathway, a transmembrane electron transport chain, resulted in a reduction in degradation rate of RHB in BPRDS. Dose of riboflavin also substantially decreased the RhB degradation. These results suggest that the electrons released by Shewanella were involved in the RhB photodegradation, which was achieved via a stepwise N-deethylation process. In BPRDS, RhB was degraded by photoreduction, rather than photooxidation. This work is useful to develop integrated physico-chemical-microbial systems for pollutant degradation, facilitate better understanding about the biophotoelectric reductive degradation mechanisms and beneficial to their applications for environmental remediation.
Display omitted
•A bio-photoelectric reductive degradation system (BPRDS) was constructed.•RhB was anaerobically degraded by BPRDS under visible light excitation.•Electrons released by Shewanella were essential for the BPRDS operation.•Shewanella acted as the hole scavenger in the photoexcitation of Ag3PO4.
We revisit the effective field theory of the standard model that is extended with sterile neutrinos, N. We examine the basis of complete and independent effective operators involving N up to mass ...dimension seven (dim-7). By employing equations of motion, integration by parts, and Fierz and group identities, we construct relations among operators that were considered independent in the previous literature, and we find 7 redundant operators at dim-6, as well as 16 redundant operators and two new operators at dim-7. The correct numbers of operators involving N are, without counting Hermitian conjugates, 16(L∩B)+1(L∩B)+2(L∩B) at dim-6 and 47(L∩B)+5(L∩B) at dim-7. Here L/B(L/B) stands for lepton/baryon number conservation (violation). We verify our counting by the Hilbert series approach for nf generations of the standard model fermions and sterile neutrinos. When operators involving different flavors of fermions are counted separately and their Hermitian conjugates are included, we find there are 29 (1614) and 80 (4206) operators involving sterile neutrinos at dim-6 and dim-7, respectively, for nf=1 (3).
This book is an ethnographic account of education and migration from the perspective of three groups of South Koreans in contemporary China: migrant parents, children/students, and educational ...agents. The book reveals how these temporary migrants make choices, plan their trajectories and engage with the authorities, both in China and South Korea. Migrant subjectivities among these groups are driven by and respond to the education-migration regimes of both the sending and receiving countries. As ‘people in between’, they occupy flexible and multiple positionalities that are transnationally distributed. However, paradoxically, they experience a juxtaposition of privilege, integration and separation, which is indicative of the Chinese style of internationalisation. The book adds weight to the argument that China is a temporary destination for foreigners and not one for long-term settlement.
The wave-particle duality dates back to Einstein's explanation of the photoelectric effect through quanta of light and de Broglie's hypothesis of matter waves. Quantum mechanics uses an abstract ...description for the behavior of physical systems such as photons, electrons, or atoms. Whether quantum predictions for single systems in an interferometric experiment allow an intuitive understanding in terms of the particle or wave picture depends on the specific configuration which is being used. In principle, this leaves open the possibility that quantum systems always behave either definitely as a particle or definitely as a wave in every experimental run by a priori adapting to the specific experimental situation. This is precisely what is tried to be excluded by delayed-choice experiments, in which the observer chooses to reveal the particle or wave character of a quantum system-or even a continuous transformation between the two-at a late stage of the experiment. The history of delayed-choice gedanken experiments, which can be traced back to the early days of quantum mechanics, is reviewed. Their experimental realizations, in particular, Wheeler's delayed choice in interferometric setups as well as delayed-choice quantum erasure and entanglement swapping are discussed. The latter is particularly interesting, because it elevates the wave-particle duality of a single quantum system to an entanglement-separability duality of multiple systems.
A
bstract
We study dimension-seven operators in standard model effective field theory. These operators are classified into two sets, one violating lepton number but preserving baryon number (Δ
L
= ...±2, Δ
B
= 0) and the other violating both but preserving their sum (−Δ
L
= Δ
B
= ±1). It has been found in the previous literature that there are respectively 13 and 7 such independent operators. We show that one operator is redundant in each set so that the complete list contains only 12 and 6 operators respectively. We accomplish this by using standard model equations of motion and various Fierz identities. We calculate the one-loop anomalous dimension matrix for the 6 operators in the second set, and illustrate its possible phenomenological implications by working out renormalization group running of the Wilson coefficients that could contribute to the type of proton decays with −Δ
L
= Δ
B
= ±1, such as
p
→
νπ
+
.
Hierarchical porosity and functionalization help to fully make use of metal–organic frameworks (MOFs) for their diverse applications. Herein, a simple strategy is reported to construct hierarchically ...porous MOFs through a competitive coordination method using tetrafluoroborate (M(BF4)x, where M is metal site) as both functional sites and etching agents. The resulting MOFs have in situ formed defect‐mesopores and functional sites without sacrificing their structure stability. The formation mechanism of the defect‐mesopores is elucidated by a combination of experimental and first‐principles calculation method, indicating the general feasibility of this new approach. Compared with the original microporous counterparts, the new hierarchical MOFs exhibit superior adsorption for the bulky dye molecules and catalytic performance for the CO2 conversion attributed to their specific hierarchical pore structures.
A simple and novel strategy is reported to fabricate a series of hierarchically porous metal–organic frameworks through the competitive coordination method. The formation mechanism of defect‐mesopores is elucidated by a combination of experimental and first‐principles calculation methods. Furthermore, the adsorption and catalytic advantage over the original microporous counterparts is also demonstrated attributed to their specific hierarchical pore structures.
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