980 research outputs found

    Fixed target measurements at LHCb for cosmic rays physics

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    The LHCb experiment has the unique possibility, among the LHC experiments, to be operated in fixed target mode, using its internal gas target. The energy scale achievable at the LHC, combined with the LHCb forward geometry and detector capabilities, allow to explore particle production in a wide Bjorken-xx range at the sNN100\sqrt{s_{\scriptscriptstyle\rm NN}} \sim 100 GeV energy scale, providing novel inputs to nuclear and cosmic ray physics. The first measurement of antiproton production in collisions of LHC protons on helium nuclei at rest is presented. The knowledge of this cross-section is of great importance for the study of the cosmic antiproton flux, and the LHCb results are expected to improve the interpretation of the recent high-precision measurements of cosmic antiprotons performed by the space-borne PAMELA and AMS-02 experiments.Comment: Proceedings for the 52nd Rencontres de Moriond EW 201

    Recent LHCb Results

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    The LHCb experiment started its physics program with the 37/pb of pp collisions at 7 TeV c.m. energy delivered by the LHC during 2010. The performances and capability of the experiment, conceived for precision measurements in the heavy flavour sector, are illustrated through the first results from the experimental core program. A rich set of production studies provide precision QCD and EW tests in the unique high rapidity region covered by LHCb. Notably, results for W and Z production are very encouraging for setting constraints on the parton PDFs.Comment: Proceedings for the "XIX International Workshop on Deep-Inelastic Scattering and Related Subjects" (DIS2011), Newport News (USA), April 11th -15th 201

    Results on heavy ion physics at LHCb

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    In the last years, the \lhcb experiment established itself as an important contributor to heavy ion physics by exploiting some of its specific features. Production of particles, notably heavy flavour states, can be studied in p-p, p-Pb and Pb-Pb collisions at LHC energies in the forward rapidity region (pseudorapidity between 2 and 5), providing measurements which are highly complementary to the other LHC experiments. Moreover, owing to its forward geometry, the detector is also well suited to study fixed-target collisions, obtained by impinging the LHC beams on gas targets with different mass numbers. In this configuration, p-A collisions can be studied at the relatively unexplored scale of sqrt(sNN) ~ 100 GeV, also providing valuable inputs to cosmic ray physics. An overview of the measurements obtained so far by the LHCb ion program is presented.Comment: on behalf of the LHCb collaboration. Prepared for the fifth biennial "Workshop on Discovery Physics at the LHC" (Kruger2018), 3-7 December 2018, Hazyview (South Africa

    BiHom-Associative Algebras, BiHom-Lie Algebras and BiHom-Bialgebras

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    A BiHom-associative algebra is a (nonassociative) algebra AA endowed with two commuting multiplicative linear maps α,β ⁣:AA\alpha,\beta\colon A\rightarrow A such that α(a)(bc)=(ab)β(c)\alpha (a)(bc)=(ab)\beta (c), for all a,b,cAa, b, c\in A. This concept arose in the study of algebras in so-called group Hom-categories. In this paper, we introduce as well BiHom-Lie algebras (also by using the categorical approach) and BiHom-bialgebras. We discuss these new structures by presenting some basic properties and constructions (representations, twisted tensor products, smash products etc)

    BiHom-Associative Algebras, BiHom-Lie Algebras and BiHom-Bialgebras

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    Infrared finite solutions for the gluon propagator and the QCD vacuum energy

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    Nonperturbative infrared finite solutions for the gluon polarization tensor have been found, and the possibility that gluons may have a dynamically generated mass is supported by recent Monte Carlo simulation on the lattice. These solutions differ among themselves, due to different approximations performed when solving the Schwinger-Dyson equations for the gluon polarization tensor. Only approximations that minimize energy are meaningful, and, according to this, we compute an effective potential for composite operators as a function of these solutions in order to distinguish which one is selected by the vacuum.Comment: 16 pages, latex file, 1 postscript figure, uses epsf.sty and axodraw.sty. To be published in Phys. Lett.

    MRONJ in breast cancer patients under bone modifying agents for cancer treatment-induced bone loss (CTIBL): a multi-hospital-based case series

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    BackgroundCancer treatment-induced bone loss (CTIBL) is the most common adverse event experienced by patients affected by breast cancer (BC) patients, without bone metastases. Bone modifying agents (BMAs) therapy is prescribed for the prevention of CTIBL, but it exposes patients to the risk of MRONJ.MethodsThis multicentre hospital-based retrospective study included consecutive non-metastatic BC patients affected by MRONJ related to exposure to low-dose BMAs for CTIBL prevention. Patients' data were retrospectively collected from the clinical charts of seven recruiting Italian centres.ResultsMRONJ lesions were found in fifteen females (mean age 67.5 years), mainly in the mandible (73.3%). The mean duration of BMAs therapy at MRONJ presentation was 34.9 months. The more frequent BMAs was denosumab (53.3%). Ten patients (66.7%) showed the following local risk factors associated to MRONJ development: periodontal disease (PD) in three cases (20%) and the remaining six (40%) have undergone PD-related tooth extractions. One patient presented an implant presence-triggered MRONJ (6.7%). In five patients (33.3%) no local risk factors were observed.ConclusionsThis is the first case series that investigated BC patients under BMAs for CTIBL prevention suffering from MRONJ. These patients seem to have similar probabilities of developing MRONJ as osteo-metabolic ones. Breast cancer patients under BMAs for CTIBL prevention need a regular prevention program for MRONJ, since they may develop bone metastases and be treated with higher doses of BMAs, potentially leading to a high-risk of MRONJ

    Targeted Metabolomics Highlights Dramatic Antioxidant Depletion, Increased Oxidative/Nitrosative Stress and Altered Purine and Pyrimidine Concentrations in Serum of Primary Myelofibrosis Patients

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    To date, little is known concerning the circulating levels of biochemically relevant metabolites (antioxidants, oxidative/nitrosative stress biomarkers, purines, and pyrimidines) in patients with primary myelofibrosis (PMF), a rare form of myeloproliferative tumor causing a dramatic decrease in erythropoiesis and angiogenesis. In this study, using a targeted metabolomic approach, serum samples of 22 PMF patients and of 22 control healthy donors were analyzed to quantify the circulating concentrations of hypoxanthine, xanthine, uric acid (as representative purines), uracil, β-pseudouridine, uridine (as representative pyrimidines), reduced glutathione (GSH), ascorbic acid (as two of the main water-soluble antioxidants), malondialdehyde, nitrite, nitrate (as oxidative/nitrosative stress biomarkers) and creatinine, using well-established HPLC method for their determination. Results showed that PMF patients have dramatic depletions of both ascorbic acid and GSH (37.3- and 3.81-times lower circulating concentrations, respectively, than those recorded in healthy controls, p < 0.0001), accompanied by significant increases in malondialdehyde (MDA) and nitrite + nitrate (4.73- and 1.66-times higher circulating concentrations, respectively, than those recorded in healthy controls, p < 0.0001). Additionally, PMF patients have remarkable alterations of circulating purines, pyrimidines, and creatinine, suggesting potential mitochondrial dysfunctions causing energy metabolism imbalance and consequent increases in these cell energy-related compounds. Overall, these results, besides evidencing previously unknown serum metabolic alterations in PMF patients, suggest that the determination of serum levels of the aforementioned compounds may be useful to evaluate PMF patients on hospital admission for adjunctive therapies aimed at recovering their correct antioxidant status, as well as to monitor patients’ status and potential pharmacological treatments

    The 2016–2017 earthquake sequence in Central Italy: macroseismic survey and damage scenario through the EMS-98 intensity assessment

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    In this paper we describe the macroseismic effects produced by the long and destructive seismic sequence that hit Central Italy from 24 August 2016 to January 2017. Starting from the procedure adopted in the complex field survey, we discuss the characteristics of the building stock and its classification in terms of EMS-98 as well as the issues associated with the intensity assessment due to the evolution of damage caused by multiple shocks. As a result, macroseismic intensity for about 300 localities has been determined; however, most of the intensities assessed for the earthquakes following the first strong shock on 24 August 2016, represent the cumulative effect of damage during the sequence. The earthquake parameters computed from the macroseismic datasets are compared with the instrumental determinations in order to highlight critical issues related to the assessment of macroseismic parameters of strong earthquakes during a seismic sequence. The results also provide indications on how location and magnitude computation can be strongly biased when dealing with historical seismic sequences.Presidenza del Consiglio dei Ministri - Dipartimento della Protezione Civile (DPC)Published2407–24314T. Sismicità dell'Italia1SR TERREMOTI - Sorveglianza Sismica e Allerta Tsunami2SR TERREMOTI - Gestione delle emergenze sismiche e da maremoto5SR TERREMOTI - Convenzioni derivanti dall'Accordo Quadro decennale INGV-DPCJCR Journa

    Measurements of Higgs boson production and couplings in diboson final states with the ATLAS detector at the LHC

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    Measurements are presented of production properties and couplings of the recently discovered Higgs boson using the decays into boson pairs, H →γ γ, H → Z Z∗ →4l and H →W W∗ →lνlν. The results are based on the complete pp collision data sample recorded by the ATLAS experiment at the CERN Large Hadron Collider at centre-of-mass energies of √s = 7 TeV and √s = 8 TeV, corresponding to an integrated luminosity of about 25 fb−1. Evidence for Higgs boson production through vector-boson fusion is reported. Results of combined fits probing Higgs boson couplings to fermions and bosons, as well as anomalous contributions to loop-induced production and decay modes, are presented. All measurements are consistent with expectations for the Standard Model Higgs boson
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