Uncovering tau leptons-enriched semi-visible jets at the LHC

This Letter proposes a new signature for confining dark sectors at the Large Hadron Collider. Under the assumption of a QCD-like hidden sector, hadronic jets containing stable dark bound states could manifest in proton-proton collisions. We present a simplified model with a $Z'$ boson yielding the production of jets made up of dark bound states and subsequently leading to the decays of those that are unstable to $\tau$ leptons and Standard Model quarks. The resulting signature is characterised by non-isolated $\tau$ lepton pairs inside semi-visible jets. We estimate the constraints on our model from existing CMS and ATLAS analyses. We propose a set of variables that leverage the leptonic content of the jet and exploit them in a supervised jet tagger to enhance the signal-to-background separation. Furthermore, we discuss the performance and limitations of current triggers for accessing sub-TeV $Z'$ masses, as well as possible strategies that can be adopted by experiments to access such low mass regions. We estimate that with the currently available triggers, a high mass search can claim a $5 \sigma$ discovery (exclusion) of the $Z'$ boson with a mass up to 4.5TeV (5.5TeV) with the full Run2 data of the LHC when the fraction of unstable dark hadrons decaying to $\tau$ lepton pairs is around $50\%$, and with a coupling of the $Z'$ to right-handed up-type quarks of 0.25. Furthermore, we show that, with new trigger strategies for Run3, it may be possible to access $Z'$ masses down to 700 GeV, for which the event topology is still composed of two resolved semi-visible jets.Comment: 11 pages, 8 figures, 2 tables, (published on EPJ C as Letter

MITP Colours in Darkness workshop summary report

This report summarises the talks and discussions that took place over the course of the MITP Youngst@rs Colours in Darkness workshop 2023. All talks can be found at https://indico.mitp.uni-mainz.de/event/377/

Discovery and characterization of non-canonical E2 conjugating enzymes

E2 conjugating enzymes (E2s) play a central role in the enzymatic cascade that leads to the attachment of ubiquitin to a substrate. This process, termed ubiquitylation is fundamental for maintaining cellular homeostasis and impacts almost all cellular process. By interacting with multiple E3 ligases, E2s direct the ubiquitylation landscape within the cell. Since its discovery, ubiquitylation has been regarded as a post-translational modification that specifically targets lysine side chains (canonical ubiquitylation). We used MALDI-TOF Mass Spectrometry to discover and characterize a family of E2s that are instead able to conjugate ubiquitin to serine and/or threonine. We employed protein modelling and prediction tools to identify the catalytic determinants that these E2s use to interact with ubiquitin as well as their substrates. Our results join a stream of recent literature that challenges the definition of ubiquitylation as an exquisitely lysine-specific modification and provide crucial insights into the missing E2 element responsible for non-canonical ubiquitylation.<br/

Tumor size, stage and grade alterations of urinary peptidome in RCC

Background: Several promising biomarkers have been found for RCC, but none of them has been used in clinical practice for predicting tumour progression. The most widely used features for predicting tumour aggressiveness still remain the cancer stage, size and grade. Therefore, the aim of our study is to investigate the urinary peptidome to search and identify peptides whose concentrations in urine are linked to tumour growth measure and clinical data. Methods: A proteomic approach applied to ccRCC urinary peptidome (n = 117) based on prefractionation with activated magnetic beads followed by MALDI-TOF profiling was used. A systematic correlation study was performed on urinary peptide profiles obtained from MS analysis. Peptide identity was obtained by LC-ESI-MS/MS. Results: Fifteen, twenty-six and five peptides showed a statistically significant alteration of their urinary concentration according to tumour size, pT and grade, respectively. Furthermore, 15 and 9 signals were observed to have urinary levels statistically modified in patients at different pT or grade values, even at very early stages. Among them, C1RL, A1AGx, ZAG2G, PGBM, MMP23, GP162, ADA19, G3P, RSPH3, DREB, NOTC2 SAFB2 and CC168 were identified. Conclusions: We identified several peptides whose urinary abundance varied according to tumour size, stage and grade. Among them, several play a possible role in tumorigenesis, progression and aggressiveness. These results could be a useful starting point for future studies aimed at verifying their possible use in the managements of RCC patients

Discovery and characterization of noncanonical E2-conjugating enzymes

E2-conjugating enzymes (E2s) play a central role in the enzymatic cascade that leads to the attachment of ubiquitin to a substrate. This process, termed ubiquitylation, is required to maintain cellular homeostasis and affects almost all cellular process. By interacting with multiple E3 ligases, E2s dictate the ubiquitylation landscape within the cell. Since its discovery, ubiquitylation has been regarded as a posttranslational modification that specifically targets lysine side chains (canonical ubiquitylation). We used Matrix-Assisted Laser Desorption/Ionization-Time Of Flight Mass Spectrometry to identify and characterize a family of E2s that are instead able to conjugate ubiquitin to serine and/or threonine. We used structural modeling and prediction tools to identify the key activity determinants that these E2s use to interact with ubiquitin as well as their substrates. Our results unveil the missing E2s necessary for noncanonical ubiquitylation, underscoring the adaptability and versatility of ubiquitin modifications.</p

Discovery and characterization of noncanonical E2-conjugating enzymes

E2-conjugating enzymes (E2s) play a central role in the enzymatic cascade that leads to the attachment of ubiquitin to a substrate. This process, termed ubiquitylation, is required to maintain cellular homeostasis and affects almost all cellular process. By interacting with multiple E3 ligases, E2s dictate the ubiquitylation landscape within the cell. Since its discovery, ubiquitylation has been regarded as a posttranslational modification that specifically targets lysine side chains (canonical ubiquitylation). We used Matrix-Assisted Laser Desorption/Ionization-Time Of Flight Mass Spectrometry to identify and characterize a family of E2s that are instead able to conjugate ubiquitin to serine and/or threonine. We used structural modeling and prediction tools to identify the key activity determinants that these E2s use to interact with ubiquitin as well as their substrates. Our results unveil the missing E2s necessary for noncanonical ubiquitylation, underscoring the adaptability and versatility of ubiquitin modifications.</p

Roadmap of Dark Matter models for Run 3

The Hidden Valley scenario consists of a set of models where the Standard Model is accompanied by a Hidden Sector and connected with it via a heavy mediator or a weak coupling. If realised in nature, the Hidden Valley scenario may result in unusual and little-studied phenomena at the LHC. Under the assumption of a QCD-like confining dark sector, novel experimental signatures emerge, characterized by sprays of particles resembling hadronic jets containing stable invisible dark matter bound states. The resulting signature is characterised by missing momentum aligned with one of the jets, defining an orthogonal phase-space compared to traditional WIMPs searches. These semi-visible jets have been studied theoretically and experimentally in the fully hadronic signature where the unstable composite dark bound states can only decay promptly back to Standard Model quarks. We present a set of new simplified models allowing the decays of the unstable dark bound states to leptons, photons and b-quarks. The new resulting signatures are semi-visible jets characterised by an enhanced presence of non-isolated leptons or photons, coming directly from dark bound states decays or from subsequent decays of tau leptons or B mesons. We discuss possible constraints from previous searches from the CMS and ATLAS experiments, as well as propose possible realistic analysis strategies for Run2 and Run3 leveraging the enhanced leptonic or photon content of these anomalous jets

Leptons lurking in semi-visible jets at the LHC

This Letter proposes a new search for confining dark sectors at the Large Hadron Collider. As a result of the strong dynamics in the hidden sector, dark matter could manifest in proton-proton collisions at the Large Hadron Collider in form of hadronic jets containing stable invisible bound states. These semi-visible jets have been studied theoretically and experimentally in the fully hadronic signature where the unstable composite dark matter can only decay promptly back to Standard Model quarks. We present a simplified model based on two messenger fields separated by a large mass gap allowing dark bound states to decay into pairs of oppositely charged leptons. The resulting experimental signature is characterized by non-isolated lepton pairs inside semi-visible jets. We propose a search strategy independent from the underlying model assumptions targeting this new signature, and discuss the orthogonality with respect to the existing searches. Remaining agnostic on the shape of the di-lepton spectrum, we determine the sensitivity of a dedicated analysis to the target signal. The proposed search can claim the $$3 \sigma$$ evidence (exclusion) of the heavier mediator up to masses of 3.5 TeV (4.5 TeV) with the full Run 2 data of the LHC. Exploiting the resonant feature of the lepton pairs can enhance the sensitivity reach on a specific model. We estimate that an analysis using the di-lepton invariant mass information can reach $$5 \sigma$$ discovery up to masses of 3.5 TeV and improve the exclusion up to more than 5 TeV

Dislessia e trattamento sublessicale

Primo programma studiato specificamente per il trattamento sublessicale della dislessia, questo volume rappresenta una novit\ue0 assoluta nel panorama editoriale italiano. Si tratta di un materiale semplice e di utilizzo immediato che pu\uf2 essere impiegato anche dai genitori o dagli insegnanti senza l'aiuto di un operatore specializzato. Lo scopo del programma non \ue8 quello di insegnare a leggere, ma di intervenire sui bambini che leggono stentatamente, lentamente o facendo molti errori; per questo propone numerosi esercizi per il consolidamento di strategie di lettura che consentano di automatizzare l'identificazione delle sillabe e di abbandonare la strategia di conversione grafema-fonema. Il programma, rivolto soprattutto agli alunni della scuola primaria (o pi\uf9 grandi, con particolari difficolt\ue0), \ue8 strutturato in sei specifiche aree di lavoro indipendenti, che permettono di realizzare percorsi individualizzati in base alle problematiche espresse da ogni singolo bambino. In ogni unit\ue0, oltre alle schede operative, sono raccolti alcuni materiali per l'operatore e una lettera che il personaggio guida, \uabMartina la Lumachina\ubb, indirizza direttamente al bambino, per motivarlo e farlo sentire immediatamente protagonista del suo percorso di apprendimento