Neutron lifetime anomaly and mirror matter theory

This paper reviews the puzzles in modern neutron lifetime measurements and related unitarity issues in the CKM matrix. It is not a comprehensive and unbiased compilation of all historic data and studies, but rather a focus on compelling evidence leading to new physics. In particular, the largely overlooked nuances of different techniques applied in material and magnetic trap experiments are clarified. Further detailed analysis shows that the ``beam'' approach of neutron lifetime measurements is likely to give the ``true'' $\beta$-decay lifetime, while discrepancies in ``bottle'' measurements indicate new physics at play. The most feasible solution to these puzzles is a newly proposed ordinary-mirror neutron ($n-n'$) oscillation model under the framework of mirror matter theory. This phenomenological model is reviewed and introduced, and its explanations of the neutron lifetime anomaly and possible non-unitarity of the CKM matrix are presented. Most importantly, various new experimental proposals, especially lifetime measurements with small/narrow magnetic traps or under super-strong magnetic fields, are discussed in order to test the surprisingly large anomalous signals that are uniquely predicted by this new $n-n'$ oscillation model.Comment: 31 pages, 6 figures, review paper for Univers

Mirror symmetry for new physics beyond the Standard Model in 4D4D spacetime

The two discrete generators of the full Lorentz group $O(1,3)$ in $4D$ spacetime are typically chosen to be parity inversion symmetry $P$ and time reversal symmetry $T$, which are responsible for the four topologically separate components of $O(1,3)$. Under general considerations of quantum field theory (QFT) with internal degrees of freedom, mirror symmetry is a natural extension of $P$, while $CP$ symmetry resembles $T$ in spacetime. In particular, mirror symmetry is critical as it doubles the full Dirac fermion representation in QFT and essentially introduces a new sector of mirror particles. Its close connection to T-duality and Calabi-Yau mirror symmetry in string theory is clarified. Extension beyond the Standard model can then be constructed using both left- and right-handed heterotic strings guided by mirror symmetry. Many important implications such as supersymmetry, chiral anomalies, topological transitions, Higgs, neutrinos, and dark energy, are discussed.Comment: 25 pages, published in Symmetry, more related papers on https://www.wanpengtan.com/smm

Longan seed and mangosteen skin based activated carbons for the removal of Pb(II) ions and rhodamine-B dye from aqueous solutions

Agricultural biomass wastes of longan seed and mangosteen skin were collected as precursors to prepare activated carbons (LS-AC-5 and MS-AC-5, respectively) through carbonization at medium temperature and KOH activation at high temperature. Their pore structures, structural properties and surface morphologies were characterized by X-ray diffractometer, Brunauer–Emmett–Teller surface measurement system, and scanning electron microscopy, respectively. Effects of contact time and pH on adsorption performances of samples were investigated by removal of Pb(II) ions and Rhodamine-b from aqueous solutions. Experimental adsorption isotherms of Rhodamine-b and Pb(II) ions on LS-AC-5 and MS-AC-5 fitted well with the Langmuir model. Results further showed that MS-AC-5 exhibited a larger surface area of 2960.56 m2/g and larger portions of micropores and mesopores (pore volume of 1.77 cm3/g) than LS-AC-5 (surface area: 2728.98 m2/g; pore volume: 1.39 cm3/g). Maximum monolayer adsorption capabilities of 1265.82 and 117.65 mg/g for Rhodamine-b and Pb(II) ions on MS-AC-5 were higher than those on LS-AC-5 (1000.20 and 107.53 mg/g), respectively

Scintillation efficiency measurement of Na recoils in NaI(Tl) below the DAMA/LIBRA energy threshold

The dark matter interpretation of the DAMA modulation signal depends on the NaI(Tl) scintillation efficiency of nuclear recoils. Previous measurements for Na recoils have large discrepancies, especially in the DAMA/LIBRA modulation energy region. We report a quenching effect measurement of Na recoils in NaI(Tl) from 3keV$_{\text{nr}}$ to 52keV$_{\text{nr}}$, covering the whole DAMA/LIBRA energy region for light WIMP interpretations. By using a low-energy, pulsed neutron beam, a double time-of-flight technique, and pulse-shape discrimination methods, we obtained the most accurate measurement of this kind for NaI(Tl) to date. The results differ significantly from the DAMA reported values at low energies, but fall between the other previous measurements. We present the implications of the new quenching results for the dark matter interpretation of the DAMA modulation signal

Improvement of the high-accuracy O 17 ( p , α ) N 14 reaction-rate measurement via the Trojan Horse method for application to O 17 nucleosynthesis

The ^{17}\text{O}(p,\ensuremath{\alpha})^{14}\text{N} and ^{17}\text{O}(p,\ensuremath{\gamma})^{18}\text{F} reactions are of paramount importance for the nucleosynthesis in a number of stellar sites, including red giants (RGs), asymptotic giant branch (AGB) stars, massive stars, and classical novae. In particular, they govern the destruction of $^{17}\text{O}$ and the formation of the short-lived radioisotope $^{18}\text{F}$, which is of special interest for \ensuremath{\gamma}-ray astronomy. At temperatures typical of the above-mentioned astrophysical scenario, $T=0.01$--0.1 GK for RG, AGB, and massive stars and $T=0.1$--0.4 GK for a classical nova explosion, the ^{17}\text{O}(p,\ensuremath{\alpha})^{14}\text{N} reaction cross section is dominated by two resonances: one at about ${E}_{R}^{cm}=65$ keV above the $^{18}\text{F}$ proton threshold energy, corresponding to the ${E}_{X}=5.673$ MeV level in $^{18}\text{F}$, and another one at ${E}_{R}^{cm}=183$ keV $({E}_{X}=5.786$ MeV). We report on the indirect study of the ^{17}\text{O}(p,\ensuremath{\alpha})^{14}\text{N} reaction via the Trojan Horse method by applying the approach recently developed for extracting the strength of narrow resonance at ultralow energies. The mean value of the strengths obtained in the two measurements was calculated and compared with the direct data available in literature. This value was used as input parameter for reaction-rate determination and its comparison with the result of the direct measurement is also discussed in the light of the electron screening effect