The muon Smasher's guide.

We lay out a comprehensive physics case for a future high-energy muon collider, exploring a range of collision energies (from 1 to 100 TeV) and luminosities. We highlight the advantages of such a collider over proposed alternatives. We show how one can leverage both the point-like nature of the muons themselves as well as the cloud of electroweak radiation that surrounds the beam to blur the dichotomy between energy and precision in the search for new physics. The physics case is buttressed by a range of studies with applications to electroweak symmetry breaking, dark matter, and the naturalness of the weak scale. Furthermore, we make sharp connections with complementary experiments that are probing new physics effects using electric dipole moments, flavor violation, and gravitational waves. An extensive appendix provides cross section predictions as a function of the center-of-mass energy for many canonical simplified models.

Domain Walls Seeding the Electroweak Phase Transition.

Topological defects can act as local impurities that seed cosmological phase transitions. In this Letter, we study the case of domain walls and how they can affect the electroweak phase transition in the singlet-extended standard model with a Z_{2}-symmetric potential. When the transition occurs in two steps, the early breaking of the Z_{2} symmetry implies the formation of domain walls which then act as nucleation sites for the second step. We develop a method based on a Kaluza-Klein decomposition to calculate the rate of the catalyzed phase transition within the 3D theory on the domain wall surface. By comparison with the standard homogeneous rate, we conclude that the seeded phase transition is generically faster and it ultimately determines the way the phase transition is completed. We finally comment on the phenomenological implications for gravitational waves.

R-Axion at Colliders.

We study the effective theory of a generic class of hidden sectors where supersymmetry is broken together with an approximate R-symmetry at low energy. The light spectrum contains the gravitino and the pseudo-Nambu-Goldstone boson of the R-symmetry, the R-axion. We derive new model-independent constraints on the R-axion decay constant for R-axion masses ranging from GeV to TeV, which are of relevance for hadron colliders, lepton colliders, and B factories. The current bounds allow for the exciting possibility that the first sign of supersymmetry will be the R-axion. We point out its most distinctive signals, providing a new experimental handle on the properties of the hidden sector and a solid motivation for searches of axionlike particles.

Contemporary techniques and outcomes of surgery for locally advanced renal cell carcinoma with focus on inferior vena cava thrombectomy: The value of a multidisciplinary team.

Objective: To report the outcomes of surgery for a contemporary series of patients with locally advanced non-metastatic renal cell carcinoma (RCC) treated at a referral academic centre, focusing on technical nuances and on the value of a multidisciplinary team. Methods: We queried our prospective institutional database to identify patients undergoing surgical treatment for locally advanced (cT3-T4 N0-1 M0) renal masses suspected of RCC at our centre between January 2017 and December 2020. Results: Overall, 32 patients were included in the analytic cohort. Of these, 12 (37.5%) tumours were staged as cT3a, 8 (25.0%) as cT3b, 5 (15.6%) as cT3c, and 7 (21.9%) as cT4; 6 (18.8%) patients had preoperative evidence of lymph node involvement. Nine (28.1%) patients underwent nephron-sparing surgery while 23 (71.9%) received radical nephrectomy. A template-based lymphadenectomy was performed in 12 cases, with evidence of disease in 3 (25.0%) at definitive histopathological analysis. Four cases of RCC with level IV inferior vena cava thrombosis were successfully treated using liver transplant techniques without the need for extracorporeal circulation. While intraoperative complications were recorded in 3 (9.4%) patients, no postoperative major complications (Clavien-Dindo ≥3) were observed. At histopathological analysis, 2 (6.2%) patients who underwent partial nephrectomy harboured oncocytoma, while the most common malignant histotype was clear cell RCC (62.5%), with a median Leibovich score of 6 (interquartile range 5-7). Conclusion: Locally advanced RCC is a complex and heterogenous disease posing several challenges to surgical teams. Our experience confirms that provided careful patient selection, surgery in experienced hands can achieve favourable perioperative, oncological, and functional outcomes.

Detection of early-universe gravitational-wave signatures and fundamental physics.

Detection of a gravitational-wave signal of non-astrophysical origin would be a landmark discovery, potentially providing a significant clue to some of our most basic, big-picture scientific questions about the Universe. In this white paper, we survey the leading early-Universe mechanisms that may produce a detectable signal-including inflation, phase transitions, topological defects, as well as primordial black holes-and highlight the connections to fundamental physics. We review the complementarity with collider searches for new physics, and multimessenger probes of the large-scale structure of the Universe.

Pseudo-Goldstino in field theory.

We consider two SUSY-breaking hidden sectors which decouple when their respective couplings to the visible particles are switched off. In such a scenario one expects to find two light fermions: the Goldstino and the pseudo-Goldstino. While the former remains massless in the rigid limit, the latter becomes massive due to radiative effects which we analyze from several different points of view. This analysis is greatly facilitated by a version of the Goldberger-Treiman relation, which allows us to write a universal nonperturbative formula for the mass. We carry out the analysis in detail in the context of gauge mediation, where we find that the pseudo-Goldstino mass is at least around the GeV scale and can be easily at the electroweak range, even in low scale models. This leads to interesting and unconventional possibilities in collider physics and it also has potential applications in cosmology.

Catalog of Hymenoptera described by Giovanni Gribodo (1846-1924) (Insecta).

Giovanni Gribodo (1846-1924) was an Italian civil engineer who described 377 new taxa of Hymenoptera, 199 of which are still valid and in use today, and proposed 6 replacement names. The present catalog provides a brief biography of Gribodo, a bibliography of his 42 publications and a complete list of the taxa proposed by Gribodo. The catalog lists, for all published names, details on the type series, type locality and collector, present status based on literature, all data labels, relevant references and remarks. A gazetteer of type-localities, a systematical list of Genus- and Species-group names, a chronological list of new names proposed by Giovanni Gribodo, with name-bearing types, and a list of Algerian species and varieties are also given. Furthermore, an unpublished manuscript by Gribodo on hymenopterological fauna of Tunisia, still kept at the Civic Museum of Natural History "Giacomo Doria" (Genoa, Italy), is described, and data on the 57 "new" taxa therein listed are reported, discussing their relevance in order to ascertain the original type series of 27 taxa validly published later. Finally, the problem posed by the enigmatic "disappearance" of a large number of Algerian types, already faced by several entomologists in the past, is analyzed, in order to prevent future mistaken designations of lectotypes and neotypes. The following six nomenclatural acts are proposed here by R. Wahis: Hemipepsis sycophanta Gribodo, 1884 = Hemipepsis bellicosa (Smith, 1873) new synonym; Anospilus sulcithorax (Gribodo, 1924) new combination; Auplopus validus (Gribodo, 1884) new combination; Dichragenia quartinae (Gribodo, 1884) new combination; Diplonyx caesar (Gribobo, 1894) new combination; Paracyphononyx melanicrus Gribodo, 1884 status revalidated (resurrected from synonymy with Pompilus ruficrus Klug, 1834). The following four nomenclatural acts are proposed by F. Penati: Parachrysis Gribodo, 1879 [subgenus of Chrysis Linnaeus] = Chrysis Linnaeus, 1760 new synonym; Psammotherma (Mutilla) quartinae Gribodo, 1884 = Psammotherma flabellata (Fabricius, 1804) new synonym; Megascolia (Regiscolia) alecto (Smith, 1858) subspecies vespillo (Gribodo, 1893) new combination; Megachile (Megachile) moutoni Gribodo, 1894 emendated name.