Brexiting European Citizenship through the Voice of Others

The British vote on 23rd June, opting by a rather slim majority to leave the European Union, has sent waves of uncertainty rippling through the island and the continent, as well as through some milestones of European integration. One of these is European citizenship. Paradoxically, it receives a hard shake at the hand of national citizenships, exercised through a referendum

Divorce Immediately, or Leave. Rights of Third Country Nationals and Family Protection in the Context of EU Citizens' Free Movement: Kuldip Singh and Others.

Case C-218/14, Kuldip Singh and Others v. Minister for Justice and Equality, judgment of the Court (Grand Chamber) of 16 July 2015, EU:C:2015:476

Higgs Mass and Unnatural Supersymmetry

Assuming that supersymmetry exists well above the weak scale, we derive the full one-loop matching conditions between the SM and the supersymmetric theory, allowing for the possibility of an intermediate Split-SUSY scale. We also compute two-loop QCD corrections to the matching condition of the Higgs quartic coupling. These results are used to improve the calculation of the Higgs mass in models with high-scale supersymmetry or split supersymmetry, reducing the theoretical uncertainty. We explore the phenomenology of a mini-split scenario with gaugino masses determined by anomaly mediation. Depending on the value of the higgsino mass, the theory predicts a variety of novel possibilities for the dark-matter particle.Comment: 36 pages, 13 pdf figures; v2: matches version published in JHE

Softened Gravity and the Extension of the Standard Model up to Infinite Energy

Attempts to solve naturalness by having the weak scale as the only breaking of classical scale invariance have to deal with two severe difficulties: gravity and the absence of Landau poles. We show that solutions to the first problem require premature modifications of gravity at scales no larger than $10^{11}$ GeV, while the second problem calls for many new particles at the weak scale. To build models that fulfil these properties, we classify 4-dimensional Quantum Field Theories that satisfy Total Asymptotic Freedom (TAF): the theory holds up to infinite energy, where all coupling constants flow to zero. We develop a technique to identify such theories and determine their low-energy predictions. Since the Standard Model turns out to be asymptotically free only under the unphysical conditions $g_1 = 0$, $M_t = 186$ GeV, $M_\tau = 0$, $M_h = 163$ GeV, we explore some of its weak-scale extensions that satisfy the requirements for TAF.Comment: 60 pages. Final version to appear on JHEP. v3: references adde

The light stop window

We show that a right-handed stop in the 200-400 GeV mass range, together with a nearly degenerate neutralino and, possibly, a gluino below 1.5 TeV, follows from reasonable assumptions, is consistent with present data, and offers interesting discovery prospects at the LHC. Triggering on an extra jet produced in association with stops allows the experimental search for stops even when their mass difference with neutralinos is very small and the decay products are too soft for direct observation. Using a razor analysis, we are able to set stop bounds that are stronger than those published by ATLAS and CMS.Comment: 21 pages, 9 figures. v2: fig. 9b has been updated and revised at large values of the stop/neutralino mass splitting. The discussion of stop co-annihilations has been upgraded including Sommerfeld enhancement

The likelihood for supernova neutrino analyses

We derive the event-by-event likelihood that allows to extract the complete information contained in the energy, time and direction of supernova neutrinos, and specify it in the case of SN1987A data. We resolve discrepancies in the previous literature, numerically relevant already in the concrete case of SN1987A data.Comment: 7 pages, 2 figures. Accepted for publication in PR

Stabilization of the Electroweak Vacuum by a Scalar Threshold Effect

We show how a heavy scalar singlet with a large vacuum expectation value can evade the potential instability of the Standard Model electroweak vacuum. The quartic interaction between the heavy scalar singlet and the Higgs doublet leads to a positive tree-level threshold correction for the Higgs quartic coupling, which is very effective in stabilizing the potential. We provide examples, such as the see-saw, invisible axion and unitarized Higgs inflation, where the proposed mechanism is automatically implemented in well-defined ranges of Higgs masses.Comment: 18 pages, 5 figure

EU integration in the (post)-migrant-crisis context: learning new integration modes?

This article explores the integration of the European Union (EU) as an institution after the 2015-2016 migrant crisis. Qualitative data from elite interviews in Brussels and policy analysis, in the framework of a bigger project about the impact of the migrant crisis on European integration, highlight the EU learning about new integration modes as a key theme following the crisis. The article focuses on this theme and argues that EU integration has been happening through intensive learning after the-migrant crisis, whereby the EU has been exploring a combination of certain integration modes: shaping the relationships with candidate countries by restraining from enlargement; shaping the relationships with (prospectively) exiting Member States by considering fuzziness at the borders; exploring differentiation among the existing Member States, possibly through promoting a two-tier EU, instead of universal deepening. A key contribution lies in applying the notion ‘learning’ to understanding EU integration modes specifically after the migrant crisis

Brexiting European Citizenship through the Voice of Others

The British vote on 23rd June, opting by a rather slim majority to leave the European Union, has sent waves of uncertainty rippling through the island and the continent, as well as through some milestones of European integration. One of these is European citizenship. Paradoxically, it receives a hard shake at the hand of national citizenships, exercised through a referendum