On Noether's theorems and gauge theories in hamiltonian formulation

Nella tesi presente si propone una trattazione esaustiva sui teoremi di Noether, cardine delle più moderne ed avanzate teorie di gauge. In particolare si tenta di fornirne una misura matematica rigorosa senza allontanarsi dalla cruciale intuizione fisica che celano: la ricerca di simmetrie nella natura e la volontà di descrivere le interazioni conosciute con un singolo modello. Più avanti, trovando i caratteri dominanti e l'ispirazione nelle pubblicazioni di Noether, si affrontano i tratti generali della formulazione hamiltoniana delle teorie di gauge, presentando la struttura dell'azione per una particella relativistica, la teoria elettromagnetica e la teoria della relatività generale; si pongono infine alcuni interrogativi sui valori di contorno che emergono dal formalismo adottato. Inoltre, per ottenere un'esposizione più efficace e meno oscura, si accompagna ogni risultato con esempi opportuni

Uncovering New Higgses in the LHC Analyses of Differential ttˉt\bar t Cross Sections

Statistically significant tensions between the Standard Model (SM) predictions and the measured lepton distributions in differential top cross-sections emerged in LHC Run~1 data and became even more pronounced in Run~2 analyses. Due to the level of sophistication of the SM predictions and the performance of the ATLAS and CMS detectors, this is very remarkable. Therefore, one should seriously consider the possibility that these measurements are contaminated by beyond-the-SM contributions. In this article, we use differential lepton distributions from the latest ATLAS $t\bar t$ analysis to study a new physics benchmark model motivated by existing indications for new Higgses: a new scalar $H$ is produced via gluon fusion and decays to $S^\prime$ ($95\,$GeV) and $S$ ($152\,$GeV), which subsequently decay to $b\bar b$ and $WW$, respectively. In this setup, the total $\chi^2$ is reduced, compared to the SM, resulting in $\Delta\chi^2=34$ to $\Delta\chi^2=158$, depending on the SM simulation used. Notably, allowing $m_S$ to vary, the combination of the distributions points towards $m_S\!\approx\!150\,$GeV which is consistent with the existing $\gamma \gamma$ and $WW$ signals, rendering a mismodelling of the SM unlikely. Averaging the results of the different SM predictions, a non-vanishing cross-section for $pp\to H\to SS^\prime\to b\bar b WW$ of $\approx\!13$pb is preferred. If $S^\prime$ is SM-like, this cross-section, at the same time explains the $95\,$GeV $\gamma\gamma$ excess, while the dominance of $S\to WW$ suggests that $S$ is the neutral component of the $SU(2)_L$ triplet with hypercharge~0.Comment: 8 pages, 4 figures, 1 tabl

Searching for Low-Mass Resonances Decaying into WW Bosons

In this article, we recast and combine the CMS and ATLAS analyses of the Standard Model Higgs boson decaying to a pair of $W$ bosons in order to search for low-mass resonances in this channel. We provide limits on the corresponding cross section assuming direct production via gluon fusion. For the whole range of masses we consider (90$\,$GeV to 200$\,$GeV), the observed limit on the cross section turns out to be weaker than the expected one. Furthermore, at $\approx95\,$GeV the limit is weakest and a new scalar decaying into a pair of $W$ bosons (which subsequently decay leptonically) with a cross section $\approx0.5\,$pb is preferred over the Standard Model hypothesis by $\gtrsim 2.5\,\sigma$. In light of the excesses in the $\gamma\gamma$, $\tau^+\tau^-$ and $b\bar b$ channels at similar masses, this strengthens the case for such a new Higgs boson. Furthermore, this analysis also gives room for the scalar candidate at 151$\,$GeV decaying into $W$ bosons.Comment: 7 pages, 5 figures, 1 tabl

Utjecaj DL-jabučne kiseline na metabolizam L-jabučne kiseline tijekom alkoholnog vrenja

Insufficient wine acidity can affect wine quality and stability. To overcome this problem, DL-malic acid can be added to the grape juice prior to fermentation. We have investigated the effect of DL-malic acid on wine fermentations and its influence on the final concentration of L-malic acid, naturally present in grape juice. To this end yeast strains that metabolise L-malic acid in different ways were tested and compared; namely, Schizosaccharomyces pombe (efficient L-malic acid degrader), Saccharomyces cerevisiae (non-degrader), hybrid strain S. cerevisiae x S. uvarum (intermediate degrader) and Saccharomyces uvarum (promoting L-malic acid synthesis). In all cases, D-malic acid passively entered the yeast cells and did not undergo malo-alcoholic fermentation. However, its presence in the juice, as a component of the mixture of D- and L- malic acid (DL-malic acid), reduced the amount of L-malic acid that can be degraded or synthesised by yeasts during malo-alcoholic fermentation.Nedovoljna kiselost vina može utjecati na njegovu kakvoću i stabilnost. Da bi se riješio taj problem, može se moštu prije vrenja dodati DL-jabučna kiselina. Ispitan je utjecaj DL-jabučne kiseline na fermentaciju vina i njezin utjecaj na konačnu koncentraciju L jabučne kiseline koja se nalazi u moštu. Stoga su ispitani i uspoređeni sojevi kvasca koji metaboliziraju L-jabučnu kiselinu, i to Schizosaccharomyces pombe (djelotvoran razgrađivač L-jabučne kiseline), S. cerevisiae (ne razgrađuje), hibridni soj S. cerevisiae x S. uvarum (djelomično razgrađuje) i S. uvarum (promotor sinteze jabučne kiseline). U svim slučajevima D-jabučna kiselina pasivno ulazi u stanice kvasca i ne provodi jabučno-alkoholno vrenje. Međutim, njezina prisutnost u grožđanom soku, kao dio smjese D- i L jabučne kiseline (DL-jabučna kiselina) snizuje količinu jabučne kiseline koja se može razgraditi ili sintetizirati s kvascima tijekom jabučno-alkoholnog vrenja

SU(2)LSU(2)_L triplet scalar as the origin of the 95 GeV excess?

We explore the possibility that an $SU(2)_L$ triplet scalar with hypercharge $Y=0$ is the origin of the $95\,$GeV di-photon excess. For a small mixing angle with the Standard Model Higgs, its neutral component has naturally a sizable branching ratio to $\gamma\gamma$ such that its Drell-Yan production via $pp\to W^*\to H H^\pm$ is sufficient to obtain the desired signal strength, where $H^\pm$ is the charged Higgs component of the triplet. The predictions of this setup are: 1) The $\gamma\gamma$ signal has a $p_T$ spectrum different from gluon fusion but similar to associated production. 2) Photons are produced in association with tau leptons and jets, but generally do not fall into the vector-boson fusion category. 3) The existence of a charged Higgs with $m_{H^\pm}\approx\!(95\pm5)\,$GeV leading to $\sigma(pp\to \tau\tau\nu\nu)\approx0.4\,$pb, which is of the same level as the current limit and can be discovered with Run 3 data. 4) A positive definite shift in the $W$ mass as suggested by the current global electroweak fit.Comment: 11 pages, 5 figure

Whey starter addition during maturation of evening milk: effects on some characteristics of cheese milk and Parmigiano–Reggiano cheese

International audienceAbstractCheese milk “maturation” during natural creaming in large flat vat is a critical step in the production of Parmigiano–Reggiano cheese. Thanks to an improved management, during the last years, a generalized reduction of mesophilic microbial counts has occurred, which did not favour an adequate increase in milk acidity during natural creaming. For this reason, some cheesemakers have introduced the practice to add a rate of natural whey starter in active fermentation in the evening milk to favourize its “maturation”. The aim of this work was to verify the effects of this practice on the characteristics of Parmigiano–Reggiano milk and on some chemical, microbiological and sensory properties of the ripened cheese. Thirty-six cheesemaking trials were carried out in a dairy: 12 with 0.2% of young whey starter addition, 12 with 0.4% and 12 as control. The addition of young whey starter improved the coagulation properties of the cheese milk and did not affect the normal succession of thermophilic and mesophilic lactic acid bacteria during the cheese ripening. The chemical composition of the ripened cheeses was not affected by the practice of whey starter addition. From the sensory point of view, the addition of natural whey starter improved the compliance scores and decreased the defects, as eyes and cracks. This work confirmed the empirical observations of some cheesemakers. The adoption of this technique has considerable technological importance, improving the coagulation properties of the milk and the sensory characteristics of the cheese

Reduction of concentrated feed in dairy cows in the Parmigiano Reggiano area: effects on milk production and quality.

A project of technological research, funded by Emilia Romagna Region and aimed to a higher sustainability of dairy chain, involved an experimental trial testing the effect of a reduction of concentrate feed in Frisona cows producing milk for Parmigiano Reggiano Cheese making. Two groups of 15 cows each, with milk production at 9 days in milk (DIM) of 31.7 and 32.1 kg/d, were fed mixed meadow hay ad libitum and a growing amount of concentrate feed up to 15 kg (C group) or 12 kg (T group) at the peak of lactation (about 60 days). Milk production, milk fat and protein were recorded from each cow at 9, 47, 96, 131, 166, and 207 DIM; fatty acid composition of milk was analysed on 5 pooled samples/group at 47, 131, and 207 DIM. Milk collected from the two groups of cows at day 161 and 168 was used for micro cheese making. Milk production and milk fat were unaffected by diet, whereas milk protein was lower in T cows at 166 (3.18 vs 3.39%; p<.01) and 207 (3.17 vs 3.31%; p<.05) DIM. Fatty acid composition of T milk showed at 47 DIM significantly lower % of MUFA and PUFA, and higher % of SFA, resulting in higher SFA/UFA ratio (1.70 vs 1.38; p<.01). Both n-3 and n-6 fatty acids were significantly lower in T milk at 47 DIM (n-3: 1.21 vs 1.44%; n-6: 4.05 vs 4.57%) and at 131 DIM (n-3: 1.18 vs 1.37%: n-6: 3.89 vs 4.83%). CLA levels were similar in the milk of the two groups. The milk collected for cheese making (60 l/group) had similar chemical and bacteriological composition, with the exception of a higher content of thermophilic Lactobacilli in T milk. Rennet coagulation characteristics showed lower curd firmness at 30’ in T milk (a30: 24.80 vs 29.48 mm; p<.05), whereas the other cheese making traits were not significantly different between the two groups. Bacteriological traits of the ripened cheese (60 days) from the two groups were also similar. The results of this field trial indicate that a reduction of 20% of concentrate feed in the diet of high producing cows did not affect milk amount, milk fat and cheese making traits, but caused a partial deterioration in milk protein, fatty acid composition and rennet coagulation. Further research might evaluate the whole lactation, reproductive performances, nutritional and health status. A part of the results of the research was presented at 6th AITeL Congress (Trento, September 20th 2018)

Case report of a patient who survived after cardiac arrest and cardiogenic shock by anaphylactic reaction to gadolinium during magnetic resonance imaging

We report the case of a young adult which survived to anaphylactic shock caused by gadolinium-based contrast agent (GBCA) contrast agent infusion. The patient had no comorbidities and previous history of allergic reactions to contrast agents and underwent elective magnetic resonance imaging (MRI) for parotid swelling. Seven years before he received intravenous GBCA administration during an MRI, which exact chemical composition is unknown, without any allergic reaction. After intravenous injection of GBCA for MRI the patient developed anaphylactic shock, causing respiratory failure, cardiac arrest, and cardiogenic shock after return of spontaneous circulation. Because of the rarity of the described event, this report has the aim to raise awareness in the healthcare personnel of the possibility of these life-threatening adverse reactions from GBCAs also in a patient without history of allergy to contrast agents and suggest a possible clinical management of these patients

Automatic Milking Systems in the Production of Parmigiano Reggiano Cheese: Effects on the Milk Quality and on Cheese Characteristics

The adoption of innovative processes, such as the automatic milking system (AMS), in the production of typical PDO cheeses, such as Parmigiano Reggiano, needs to be evaluated and tested, to verify its influence on milk quality and the typicality of the product. The present research was aimed to study the effect of the introduction of the AMS on the cheesemaking characteristics of the milk and the ripening process and the sensory properties of the Parmigiano Reggiano PDO cheese. Six cheesemaking trials were performed and, in each trial, two different separated pools of milk were submitted to the cheesemaking process in parallel, one from AMS and the other from a traditional milking parlor (TMP). AMS milk, in comparison with TMP one, showed higher content of lactose and calcium and lower contents of somatic cells, thermophilic lactic acid bacteria and chloride. Nevertheless, these changes were too small to influence the efficiency of the cheesemaking process and the cheese composition and its sensory profile. Moreover, cheeses made with AMS milk fully complied with the sensory characteristics of Parmigiano Reggiano cheese PDO, as defined by the PDO rules