Neutrinoless double beta decay in chiral effective field theory: lepton number violation at dimension seven

We analyze neutrinoless double beta decay ($0\nu\beta\beta$) within the framework of the Standard Model Effective Field Theory. Apart from the dimension-five Weinberg operator, the first contributions appear at dimension seven. We classify the operators and evolve them to the electroweak scale, where we match them to effective dimension-six, -seven, and -nine operators. In the next step, after renormalization group evolution to the QCD scale, we construct the chiral Lagrangian arising from these operators. We develop a power-counting scheme and derive the two-nucleon $0\nu\beta\beta$ currents up to leading order in the power counting for each lepton-number-violating operator. We argue that the leading-order contribution to the decay rate depends on a relatively small number of nuclear matrix elements. We test our power counting by comparing nuclear matrix elements obtained by various methods and by different groups. We find that the power counting works well for nuclear matrix elements calculated from a specific method, while, as in the case of light Majorana neutrino exchange, the overall magnitude of the matrix elements can differ by factors of two to three between methods. We calculate the constraints that can be set on dimension-seven lepton-number-violating operators from $0\nu\beta\beta$ experiments and study the interplay between dimension-five and -seven operators, discussing how dimension-seven contributions affect the interpretation of $0\nu\beta\beta$ in terms of the effective Majorana mass $m_{\beta \beta}$.Comment: Matches version published in JHE

Sexuality in patients with human immunodeficiency virus at Embhuleni Hospital in Mpumalanga province

Objectives: This study explored issues of sexuality in people living with AIDS who were on highly active antiretroviral therapy (HAART).Design: This was a descriptive quantitative study. Data were collected with an administered questionnaire and entered in Excel®. Statistical analysis included frequency tables, summary statistics and 95% confidence intervals.Setting and subjects: The respondents were purposively sampled from the 850 patients attending the antiretroviral clinic at Embhuleni Hospital in Mpumalanga province.Outcome measures: The questionnaire included questions on sexual practices, number of partners, sexual experience and fertility wishes, comparing respondents’ experience before and after HAART.Results: There was a response rate of 100%, with 102 questionnaires completed. There was a significant difference between the responses to questions on sexual desire, sexual performance, sexual enjoyment and satisfaction regarding frequency of intercourse before and after HAART. Respondents reported a better sexual experience before HAART (t = 2.4387, p-value = 0.0165). There was a statistically significant difference between the number of partners before and after initiation of HAART (p-value = 0.000). Although 96% of respondents rated  condom use as being very important, 11% never used condoms during sex and 21% indicated that they had had unprotected sex in the previous six months. Eighteen per cent of respondents said it was very important for them to have a child and 20% were planning to have a child in the future. A quarter of respondents had not disclosed their HIV status to their partners. The majority (95%) of respondents indicated that it was very important to them that health workers discussed their sexual needs with them.Conclusion: Sexuality in HIV is complex, with components described as the “Ps” of sexuality: practices, partners, pleasure, pressure and pain, procreation and power. In this study, participants reported a better sexual experience before HAART. Healthcare professionals need to develop the skills to discuss sexuality, intimacy and fertility wishes with patients. Thisdiscussion will enhance healthcare professionals’ understanding of  atients’ experiences of their illness and should allow for a more effective patient-centred approach to care.Keywords: sexuality, sexual experience, HIV, HAART, reproductive health, rura

Sexuality in patients with human immunodeficiency virus at Embhuleni hospital in Mpumalanga province

Objectives: This study explored issues of sexuality in people living with AIDS who were on highly active antiretroviral therapy (HAART). Design: This was a descriptive quantitative study. Data were collected with an administered questionnaire and entered in Excel®. Statistical analysis included frequency tables, summary statistics and 95% confidence intervals. Setting and subjects: The respondents were purposively sampled from the 850 patients attending the antiretroviral clinic at Embhuleni Hospital in Mpumalanga province. Outcome measures: The questionnaire included questions on sexual practices, number of partners, sexual experience and fertility wishes, comparing respondents’ experience before and after HAART. Results: There was a response rate of 100%, with 102 questionnaires completed. There was a significant difference between the responses to questions on sexual desire, sexual performance, sexual enjoyment and satisfaction regarding frequency of intercourse before and after HAART. Respondents reported a better sexual experience before HAART (t = 2.4387, p-value = 0.0165). There was a statistically significant difference between the number of partners before and after initiation of HAART (p-value = 0.000). Although 96% of respondents rated condom use as being very important, 11% never used condoms during sex and 21% indicated that they had had unprotected sex in the previous six months. Eighteen per cent of respondents said it was very important for them to have a child and 20% were planning to have a child in the future. A quarter of respondents had not disclosed their HIV status to their partners. The majority (95%) of respondents indicated that it was very important to them that health workers discussed their sexual needs with them. Conclusion: Sexuality in HIV is complex, with components described as the “Ps” of sexuality: practices, partners, pleasure, pressure and pain, procreation and power. In this study, participants reported a better sexual experience before HAART. Healthcare professionals need to develop the skills to discuss sexuality, intimacy and fertility wishes with patients. This discussion will enhance healthcare professionals’ understanding of patients’ experiences of their illness and should allow for a more effective patient-centred approach to care

The impact of the Article 50 talks on the EU:Risk aversion and the prospects for further EU disintegration

This article explores why there was no domino effect after Brexit and reflects on what this means for the health of European integration. It shows how the UK responded to the uncertainty surrounding the Article 50 talks by testing EU unity, prompting both sides to discuss a no-deal outcome. Evidence from Eurobarometer surveys demonstrates that attachment to the EU strengthened markedly during Brexit talks in the four countries considered most likely to flirt with leaving the EU. Hence Brexit changed the benchmarking process surrounding citizens’ evaluation of the prospects of getting a better deal outside the EU. Risk aversion thus explains the lack of a Brexit domino effect. However, the volatility of public opinion before and after the Article 50 talks, combined with the weaker increase in support over the EU as a whole, means there is no room for complacency over the future prospects of disintegration

Investigating the interstellar dust through the Fe K-edge

The chemical and physical properties of interstellar dust in the densest regions of the Galaxy are still not well understood. X-rays provide a powerful probe since they can penetrate gas and dust over a wide range of column densities (up to $10^{24}\ \rm{cm}^{-2}$). The interaction (scattering and absorption) with the medium imprints spectral signatures that reflect the individual atoms which constitute the gas, molecule, or solid. In this work we investigate the ability of high resolution X-ray spectroscopy to probe the properties of cosmic grains containing iron. Although iron is heavily depleted into interstellar dust, the nature of the Fe-bearing grains is still largely uncertain. In our analysis we use iron K-edge synchrotron data of minerals likely present in the ISM dust taken at the European Synchrotron Radiation Facility. We explore the prospects of determining the chemical composition and the size of astrophysical dust in the Galactic centre and in molecular clouds with future X-ray missions. The energy resolution and the effective area of the present X-ray telescopes are not sufficient to detect and study the Fe K-edge, even for bright X-ray sources. From the analysis of the extinction cross sections of our dust models implemented in the spectral fitting program SPEX, the Fe K-edge is promising for investigating both the chemistry and the size distribution of the interstellar dust. We find that the chemical composition regulates the X-ray absorption fine structures in the post edge region, whereas the scattering feature in the pre-edge is sensitive to the mean grain size. Finally, we note that the Fe K-edge is insensitive to other dust properties, such as the porosity and the geometry of the dust.Comment: 11 pages, 10 figures. Accepted for publication in Astronomy and Astrophysic

A low-energy perspective on the minimal left-right symmetric model

We perform a global analysis of the low-energy phenomenology of the minimal left-right symmetric model (mLRSM) with parity symmetry. We match the mLRSM to the Standard Model Effective Field Theory Lagrangian at the left-right-symmetry breaking scale and perform a comprehensive fit to low-energy data including mesonic, neutron, and nuclear $\beta$-decay processes, $\Delta F=1$ and $\Delta F=2$ CP-even and -odd processes in the bottom and strange sectors, and electric dipole moments (EDMs) of nucleons, nuclei, and atoms. We fit the Cabibbo-Kobayashi-Maskawa and mLRSM parameters simultaneously and determine a lower bound on the mass of the right-handed $W_R$ boson. In models where a Peccei-Quinn mechanism provides a solution to the strong CP problem, we obtain $M_{W_R} \gtrsim 5.5$ TeV at $95\%$ C.L. which can be significantly improved with next-generation EDM experiments. In the $P$-symmetric mLRSM without a Peccei-Quinn mechanism we obtain a more stringent constraint $M_{W_R} \gtrsim 17$ TeV at $95\%$ C.L., which is difficult to improve with low-energy measurements alone. In all cases, the additional scalar fields of the mLRSM are required to be a few times heavier than the right-handed gauge bosons. We consider a recent discrepancy in tests of first-row unitarity of the CKM matrix. We find that, while TeV-scale $W_R$ bosons can alleviate some of the tension found in the $V_{ud,us}$ determinations, a solution to the discrepancy is disfavored when taking into account other low-energy observables within the mLRSM.Comment: 42 pages plus appendices. Published versio

Pion-Induced Radiative Corrections to Neutron <i>ß</i> Decay

We compute the electromagnetic corrections to neutron beta decay using a low-energy hadronic effective field theory. We identify and compute new radiative corrections arising from virtual pions that were missed in previous studies. The largest correction is a percent-level shift in the axial charge of the nucleon proportional to the electromagnetic part of the pion-mass splitting. Smaller corrections, comparable to anticipated experimental precision, impact the $\beta$-$\nu$ angular correlations and the $\beta$-asymmetry. We comment on implications of our results for the comparison of the experimentally measured axial charge with first-principle computations using lattice QCD and on the potential of $\beta$-decay experiments to constrain beyond-the-Standard-Model interactions