An efficient renormalization group improved implementation of the MSSM effective potential

In the context of MSSM, a novel improving procedure based on the renormalization group equation is applied to the effective potential in the Higgs sector. We focus on the one-loop radiative corrections computed in Landau gauge by using the mass independent renormalization scheme $\bar{DR}$. Thanks to the decoupling theorem, the well-known multimass scale problem is circumvented by switching to a new effective field theory every time a new particle threshold is encountered. We find that, for any field configuration, there is a convenient renormalization scale $\tilde{Q}^*$ at which the loop expansion respects the perturbation series hierarchy and the theory retains the vital property of stability.Comment: 35 pages, 5 figures, RevTe

Unification and fermion mass relations in low string scale D-brane models

In this talk, gauge coupling evolution is analyzed in D-brane inspired models with two Higgs doublets and a U(3)xU(2)xU(1)^N gauge symmetry. In particular, we focus on D-brane configurations with two or three abelian factors. We find that the correct hypercharge assignment of the Standard Model particles is reproduced for six viable models distinguished by different brane configurations. We also investigate the bottom tau quark mass relation and find that the correct low energy m_b / m_\tau ratio is obtained for equal b-\tau Yukawa couplings at a string scale around 10^3 TeV.Comment: 10 pages, 3 figures. Talk presented at the ``Corfu Summer Institute'', Corfu-Greece, September 4-14, 2005. To appear in the proceedings of RTN workshop on the Quest for Unification Theory Confronts Experimen

Anomalous U(1)'s, Chern-Simons couplings and the Standard Model

This proceeding is based on hep-th/0605225 and it shows that the most general anomaly related effective action contains Stuckelberg, axionic and Chern-Simons-like couplings. Such couplings are generically non-trivial in orientifold string vacua. A similar analysis in quantum field theories provides similar couplings. These Chern-Simons couplings generate new signals which might be visible at LHC.Comment: 9 pages, 2 eps figures, LaTeX, feynmf & youngtab packages. (v2: references added). Contribution to the proceedings of the RTN project "Constituents, Fundamental Forces and Symmetries of the Universe" conference in Naples, October 9 - 13, 2006 and the PRIN meeting in Alessandria, December 15-16, 200

Two-loop corrections to Radiative Electroweak Symmetry Breaking in the MSSM

We study the O(at*as + at^2) two-loop corrections to the minimization conditions of the MSSM effective potential, providing compact analytical formulae for the Higgs tadpoles. We connect these results with the renormalization group running of the MSSM parameters from the grand unification scale down to the weak scale, and discuss the corrections to the Higgs mixing parameter mu and to the running CP-odd Higgs mass mA in various scenarios of gravity-mediated SUSY breaking. We find that the O(at*as) and O(at^2) contributions partially cancel each other in the minimization conditions. In comparison with the full one-loop corrections, the O(at*as + at^2) two-loop corrections significantly weaken the dependence of the parameters mu and mA on the renormalization scale at which the effective potential is minimized. The residual two-loop and higher-order corrections to mu and mA are estimated to be at most 1% in the considered scenarios.Comment: 23 pages, 7 figures. Version to appear in Nucl. Phys.

On nonstandard vacuua in minimal supergravity models

The plethora of scalar fields participating in the formulation of a softly broken supersymmetric theory can threat the stability of the standard vacuum. The generic situation is twofold. Directions in scalar field space may exist along which the potential becomes unbounded from below or local minima deeper than the standard one are likely to appear where charge and/or color symmetries are broken. An investigation of these matters requires a thorough study of the tree level effective potential as well as its radiative corrections. However, the presence of many different mass scales in such a generic supersymmetric theory needs an appropriate renormalization improved treatment. Combining the decoupling theorem with a conveniently chosen renormalization scale for each field configuration, the well known multimass scale problem is circumvented. In this context, the ordinary universal soft-parameters case of the minimal supersymmetric model as well as a non-universal case of a brane world minimal supergravity model are examined closely for unphysical vacuua.Journal of High Energy Physic

Operative versus non-operative management of rib fractures in flail chest after cardiopulmonary resuscitation manoeuvres

OBJECTIVES: Blunt chest trauma after mechanical resuscitation manoeuvres appears to have a significant impact on the often complicated course. Due to a lack of data in the literature, the purpose of this study was to investigate the feasibility and immediate outcome of chest wall stabilization for flail chest in this vulnerable patient population. METHODS: We retrospectively reviewed the medical records of patients after cardiopulmonary resuscitation between January 2014 and December 2018 who were diagnosed with flail chest. We attempted to compare patients after surgery with those after conservative treatment. RESULTS: Of a total of 56 patients with blunt chest trauma after mechanical resuscitation and after coronary angiography, 25 were diagnosed with flail chest. After the exclusion of 2 patients because of an initial decision to palliate, 13 patients after surgical stabilization could be compared with 10 patients after conservative therapy. Although there was no significant difference in the total duration of ventilatory support, there was a significant advantage when the time after stabilization to extubation was compared with the duration of ventilation in the conservative group. The presence of pulmonary contusion, poor Glasgow Coma Scale score or the development of pneumonia negatively affected the outcome, but additional sternal fracture did not. CONCLUSIONS: Surgical stabilization for chest wall instability is well tolerated even by this vulnerable patient population. Our results should be used for further randomized controlled approaches. It is necessary to evaluate the situation with all parameters in an interdisciplinary manner and to decide on a possible surgical therapy at an early stage if possible

A structured curriculum for the acquisition of basic surgical endoscopic skills for surgical residents and quantification of skills improvement.

INTRODUCTION New strategies and methods are needed to ensure that new generations can train and acquire surgical skills in a safe environment. MATERIALS AND METHODS From January 2020 to October 2020, we performed a single centre, prospective observational cohort study. 19 participants (15 students, 4 residents) enrolled and 16 participants (13 students, 3 residents) successfully completed the curriculum. We performed a quantitative data analysis to evaluate its effectiveness in gaining and improving basic surgical endoscopic skills. RESULTS The time for single knot tying pre-, mid-, and post-training was reduced significantly, the average time (sec) decreased by 79.5 % (p < 0.001), the total linear distance (cm) by 74.5 % (p < 0.001) and the total angular distance (rad) by 71.7 % (p < 0.001). The average acceleration (mm/s2) increased by 20 % (p = 0.041). Additionally, the average speed increased by 23.5 % (p < 0.001), while motion smoothness (m/s3) increased by 20.4 % (p = 0.02). CONCLUSION The obtained performance scores showed a significant increase in participants improving their basic surgical performance skills on the endoscopic simulator. This curriculum can be easily implemented in any surgical specialty as part of the residency training curriculum before first exposure in the operation room. All 16 participants recommended the implementation of such simulator training in their surgical training curriculum

Surgical smoke: modern mobile smoke evacuation systems improve occupational safety in the operating theatre.

OBJECTIVES Evaluation of smoke capture efficiency of different mobile smoke evacuation devices with respect to volatile organic compounds and their noise emission. METHODS Electrosurgical incisions were performed on fresh porcine liver in an operating room with vertical laminar flow. The generated surgical smoke was analysed with proton-transfer-reaction mass spectrometry with and without the use of a mobile smoke evacuation system consisting of a smoke evacuator machine, a suction hose and a handpiece. The inlet of the mass spectrometer was positioned 40 cm above the specimen. Various devices were compared: a hard plastic funnel, a flexible foam funnel, an on-tip integrated aspirator of an electrosurgical knife and a standard secretion suction (Yankauer). Also, sound levels were measured at a distance of 40 cm from the handpieces' inlet. RESULTS The smoke capture efficiency of the secretion suction was only 53%, while foam funnel, plastic funnel and integrated aspirator were all significantly more effective with a clearance of 95%, 91% and 91%, respectively. The mean sound levels were 68 and 59 A-weighted decibels with the plastic and foam funnel, respectively, 66 A-weighted decibels with the integrated aspirator and 63 A-weighted decibels with the secretion suction. CONCLUSIONS Carcinogenic, mutagenic and reprotoxic volatile organic compounds in surgical smoke can be efficiently reduced by mobile smoke evacuation system, providing improved protection for medical personnel. Devices specifically designed for smoke evacuation are more efficient than standard suction tools. Noise exposure for the surgeon was lowest with the flexible foam funnel and higher with the other handpieces tested