The Electroweak phase transition in models with gauge-Higgs unification

The dynamics of five dimensional Wilson line phases at finite temperature is studied in the oneloop approximation. We show that at temperatures of order T 3c 1/L, where L is the length of the compact space, the gauge symmetry is always restored and the electroweak phase transition appears to be of first order. We focus on a specific model where the Wilson line phase is identified with the Higgs field (gauge-Higgs unification). The transition is of first order even for values of the Higgs mass above the current experimental limit. If large localized gauge kinetic terms are present, the transition might be strong enough to give baryogenesis at the electroweak transitio

Experimental performance comparison between circular and elliptical tubes in evaporative condensers

In refrigeration systems, evaporative condensers have two main advantages compared to other condensation heat exchangers: They operate at lower condensation temperature than traditional air-cooled condensers and require a lower quantity of water and pumping power compared to evaporative towers. The heat and mass transfer that occur on tube batteries are difficult to study. The aim of this work is to apply an experimental approach to investigate the performance of an evaporative condenser on a reduced scale by means of a test bench, consisting of a transparent duct with a rectangular test section in which electric heaters, inside elliptical pipes (major axis 32 mm, minor axis 23 mm), simulate the presence of the refrigerant during condensation. By keeping the water conditions fixed and constant, the operating conditions of the air and the inclination of the heat transfer geometry were varied, and this allowed to carry out a sensitivity analysis, depending on some of the main parameters that influence the thermo-fluid dynamic phenomena, as well as a performance comparison. The results showed that the heat transfer increases with the tube surface exposed directly to the air as a result of the increase in their inclination, that has been varied in the range 0–20°. For the investigated conditions, the average increase, resulting by the inclination, is 28%

Simple and Realistic Composite Higgs Models in Flat Extra Dimensions

We construct new composite Higgs/gauge-Higgs unification (GHU) models in flat space that overcome all the difficulties found in the past in attempting to construct models of this sort. The key ingredient is the introduction of large boundary kinetic terms for gauge (and fermion) fields. We focus our analysis on the electroweak symmetry breaking pattern and the electroweak precision tests and show how both are compatible with each other. Our models can be seen as effective TeV descriptions of analogue warped models. We point out that, as far as electroweak TeV scale physics is concerned, one can rely on simple and more flexible flat space models rather than considering their unavoidably more complicated warped space counterparts. The generic collider signatures of our models are essentially undistinguishable from those expected from composite Higgs/warped GHU models, namely a light Higgs, colored fermion resonances below the TeV scale and sizable deviations to the Higgs and top coupling.Comment: 30 figures, 9 figures; v2: minor improvements, one reference added, version to appear in JHE

Laparoscopic High Uterosacral Ligament Suspension vs. Laparoscopic Sacral Colpopexy for Pelvic Organ Prolapse: A Case-Control Study

Introduction: Laparoscopic sacral colpopexy is the gold standard technique for apical prolapse correction but it is a technically challenging procedure with rare but severe morbidity. Laparoscopic high uterosacral ligament suspension could be a valid technically easier alternative using native tissue. Material and Methods: In the period from 2015 to 2018, 600 women were submitted to laparoscopic sacral colpopexy while 150 to laparoscopic high uterosacral ligament suspension in three Italian urogynecology referral centers. We enrolled women with apical prolapse stage ≥2 alone or multicompartment descensus. To reduce allocation bias, we performed a propensity matched analysis. Women undergoing laparoscopic high uterosacral ligament suspension surgery were matched 1:2 to women undergoing laparoscopic sacral colpopexy. The cumulative proportion of relapse-free women in time was analyzed by the Kaplan–Meier method. The primary objective of this multicenter case-control retrospective study was to compare the recurrence rate while the secondary objectives were to compare feasibility, safety, and efficacy of laparoscopic sacral colpopexy and laparoscopic high uterosacral ligament suspension in surgical treatment of pelvic organ prolapse. Results: Three hundred and nine women were enrolled (103 laparoscopic high uterosacral ligament suspension; 206 laparoscopic sacral colpopexy). Median operatory time was significantly shorter in the laparoscopic high uterosacral ligament suspension group (P = 0.0001). No statistically significative difference was found in terms of estimated blood loss, admission time, intraoperative, and major early postoperative complications, postoperative pelvic pain, dyspareunia and de novo stress urinary incontinence. Surgical approach was the only independent risk factor for prolapse recurrence (RR = 6.013 [2.965–12.193], P = 0.0001). The objective cure rate was higher in the laparoscopic sacral colpopexy group (93.7 vs. 68%, 193/206 vs. 70/103, P = 0.0001) with a highly reduced risk of recurrence (RR = 5.430 [1.660–17.765]). Median follow up was 22 months. Conclusion: Both techniques are safe, feasible, and effective. Laparoscopic sacral colpopexy remains the best choice in treatment of multicompartment and advanced pelvic organ prolapse while laparoscopic high uterosacral ligament suspension could be appropriate for moderate and isolated apical prolapse when laparoscopic sacral colpopexy is not suitable for the patient or to prevent prolapse in women at high risk at the time of the hysterectomy

AdS/QCD: The Relevance of the Geometry

We investigate the relevance of the metric and of the geometry in five-dimensional models of hadrons. Generically, the metric does not affect strongly the results and even flat space agrees reasonably well with the data. Nevertheless, we observe a preference for a decreasing warp factor, for example AdS space. The Sakai-Sugimoto model reduces to one of these models and the level of agreement is similar to the one of flat space. We also consider the discrete version of the five-dimensional models, obtained by dimensional deconstruction. We find that essentially all the relevant features of "holographic" models of QCD can be reproduced with a simple 3-site model describing only the states below the cut-off of the theory.Comment: 25 pages + appendix. v2 minor changes and Refs. adde

The Higgs mechanism as a cut-off effect

We compute the Coleman-Weinberg potential with a finite cut-off for pure SU(2) and SU(3) five-dimensional gauge theories compactified on an interval. We show that besides the expected Coulomb phase located at and in the vicinity of the free infrared stable or "trivial" fixed point, the theory possesses also a Higgs phase. We compare the results from the potential computation with lattice data from simulations.Comment: 22 pages, 5 figures; introduction improved, conclusions added, published in JHE