Publications by authors named "Zak Z"

Z boson events at the Large Hadron Collider can be selected with high purity and are sensitive to a diverse range of QCD phenomena. As a result, these events are often used to probe the nature of the strong force, improve Monte Carlo event generators, and search for deviations from standard model predictions. All previous measurements of Z boson production characterize the event properties using a small number of observables and present the results as differential cross sections in predetermined bins.

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High-energy nuclear collisions create a quark-gluon plasma, whose initial condition and subsequent expansion vary from event to event, impacting the distribution of the eventwise average transverse momentum [P([p_{T}])]. Disentangling the contributions from fluctuations in the nuclear overlap size (geometrical component) and other sources at a fixed size (intrinsic component) remains a challenge. This problem is addressed by measuring the mean, variance, and skewness of P([p_{T}]) in ^{208}Pb+^{208}Pb and ^{129}Xe+^{129}Xe collisions at sqrt[s_{NN}]=5.

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A search for the exclusive hadronic decays W^{±}→π^{±}γ, W^{±}→K^{±}γ, and W^{±}→ρ^{±}γ is performed using up to 140  fb^{-1} of proton-proton collisions recorded with the ATLAS detector at a center-of-mass energy of sqrt[s]=13  TeV. If observed, these rare processes would provide a unique test bench for the quantum chromodynamics factorization formalism used to calculate cross sections at colliders. Additionally, at future colliders, these decays could offer a new way to measure the W boson mass through fully reconstructed decay products.

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Article Synopsis
  • - The ATLAS experiment at the LHC conducted a search for long-lived particles (LLPs) using a large dataset (140 fb^{-1}) from proton-proton collisions at 13 TeV, focusing on LLPs with masses from 5 to 55 GeV that decay within the inner detector.
  • - The study considered scenarios where LLPs are produced from exotic Higgs boson decays and models involving axionlike particles (ALPs).
  • - No significant findings above expected background levels were detected, leading to the establishment of upper limits on various production rates involving the Higgs boson and the top quark related to LLPs and ALPs.
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  • The study investigates the associated production of Higgs and W bosons, focusing on how the relative signs of the Higgs couplings to W and Z bosons impact the process.
  • Two specific searches were conducted using large amounts of collision data from the LHC to analyze different coupling scenarios: one for opposite-sign couplings and another for same-sign (standard model-like) couplings.
  • The results significantly exclude the opposite-sign coupling hypothesis and set a strict upper limit on the production rate of this process compared to standard model predictions.
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  • Acute myeloid leukemia (AML) is a serious blood cancer with few treatment options and a high chance of coming back after chemotherapy.
  • Researchers studied N-myristoylation, a protein modification linked to cancer cell survival, and found that the level of N-myristoyltransferase 2 (NMT2) can indicate patient outcomes.
  • They tested a drug called zelenirstat, which inhibits myristoylation, and found it caused cancer cell death and reduced leukemia in models, suggesting it could be an effective new treatment for AML patients with poor prognoses.
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This Letter presents results from a combination of searches for Higgs boson pair production using 126-140  fb^{-1} of proton-proton collision data at sqrt[s]=13  TeV recorded with the ATLAS detector. At 95% confidence level (CL), the upper limit on the production rate is 2.9 times the standard model (SM) prediction, with an expected limit of 2.

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This Letter presents the first study of the energy dependence of diboson polarization fractions in WZ→ℓνℓ^{'}ℓ^{'}(ℓ,ℓ^{'}=e,μ) production. The dataset used corresponds to an integrated luminosity of 140  fb^{-1} of proton-proton collisions at a center-of-mass energy of 13 TeV recorded by the ATLAS detector. Two fiducial regions with an enhanced presence of events featuring two longitudinally polarized bosons are defined.

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Statistical combinations of searches for charginos and neutralinos using various decay channels are performed using 139  fb^{-1} of pp collision data at sqrt[s]=13  TeV with the ATLAS detector at the Large Hadron Collider. Searches targeting pure-wino chargino pair production, pure-wino chargino-neutralino production, or Higgsino production decaying via standard model W, Z, or h bosons are combined to extend the mass reach to the produced supersymmetric particles by 30-100 GeV. The depth of the sensitivity of the original searches is also improved by the combinations, lowering the 95% C.

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Article Synopsis
  • * The measurements utilized both semileptonic and hadronic decays of top quarks, along with events focused on single top quark production in the electroweak t channel.
  • * The combined result for the top quark mass is 172.52 GeV, with a reduced total uncertainty of 0.33 GeV, showcasing an improvement of 31% over previous measurements.
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A combination of searches for a new resonance decaying into a Higgs boson pair is presented, using up to 139  fb^{-1} of pp collision data at sqrt[s]=13  TeV recorded with the ATLAS detector at the LHC. The combination includes searches performed in three decay channels: bb[over ¯]bb[over ¯], bb[over ¯]τ^{+}τ^{-}, and bb[over ¯]γγ. No excess above the expected Standard Model background is observed and upper limits are set at the 95% confidence level on the production cross section of Higgs boson pairs originating from the decay of a narrow scalar resonance with mass in the range 251 GeV-5 TeV.

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Higgsinos with masses near the electroweak scale can solve the hierarchy problem and provide a dark matter candidate, while detecting them at the LHC remains challenging if their mass splitting is O(1  GeV). This Letter presents a novel search for nearly mass-degenerate Higgsinos in events with an energetic jet, missing transverse momentum, and a low-momentum track with a significant transverse impact parameter using 140  fb^{-1} of proton-proton collision data at sqrt[s]=13  TeV collected by the ATLAS experiment. For the first time since LEP, a range of mass splittings between the lightest charged and neutral Higgsinos from 0.

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Angular correlations between heavy quarks provide a unique probe of the quark-gluon plasma created in ultrarelativistic heavy-ion collisions. Results are presented of a measurement of the azimuthal angle correlations between muons originating from semileptonic decays of heavy quarks produced in 5.02 TeV Pb+Pb and pp collisions at the LHC.

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People living with human immunodeficiency virus (HIV) are at higher risk of morbidity and mortality due to vaccine-preventable diseases. At the same time, they are less likely to respond to vaccinations, and might have a higher rate of vaccine adverse event and faster waning of protective effect. International and national guidelines emphasize the importance of vaccinating people living with HIV against respiratory system disease pathogens including seasonal influenza, , and COVID-19, as well as against sexually transmitted infections, i.

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This Letter presents the first study of Higgs boson production in association with a vector boson (V=W or Z) in the fully hadronic qqbb final state using data recorded by the ATLAS detector at the LHC in proton-proton collisions at sqrt[s]=13  TeV and corresponding to an integrated luminosity of 137  fb^{-1}. The vector bosons and Higgs bosons are each reconstructed as large-radius jets and tagged using jet substructure techniques. Dedicated tagging algorithms exploiting b-tagging properties are used to identify jets consistent with Higgs bosons decaying into bb[over ¯].

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ATLAS measured the centrality dependence of the dijet yield using 165  nb^{-1} of p+Pb data collected at sqrt[s_{NN}]=8.16  TeV in 2016. The event centrality, which reflects the p+Pb impact parameter, is characterized by the total transverse energy registered in the Pb-going side of the forward calorimeter.

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Prolactinomas (PRLomas) constitute approximately half of all pituitary adenomas and approximately one-fifth of them are diagnosed in males. The clinical presentation of PRLomas results from direct prolactin (PRL) action, duration and severity of hyperprolactinemia, and tumor mass effect. Male PRLomas, compared to females, tend to be larger and more invasive, are associated with higher PRL concentration at diagnosis, present higher proliferative potential, are more frequently resistant to standard pharmacotherapy, and thus may require multimodal approach, including surgical resection, radiotherapy, and alternative medical agents.

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Synthesis and characterization of two novel copper β-diketone complexes, where halogen bonds play a pivotal role in shaping their multifaceted structural landscape, have been done in the present study. This study employs X-ray diffraction, ultraviolet-visible (UV-vis) spectroscopy, and infrared (IR) spectroscopy to investigate two copper β-diketone complexes, [Cu(L1)(ttfa)]·2CHOH () and [Cu(L1)(dfpb)] (), where Httfa is 4,4,4-trifluoro-1-(thiophen-2-yl)butan-3,1-dione and Hdfpb is 4,4-difluoro-1-phenylbutane-1,3-dione. Complex displays a halogen bond, which contributes to its uniqueness.

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Introduction: Cardiovascular disease (CVD) is a major cause of morbidity and mortality throughout the world. The LIPIDOGRAM2015 study was performed to estimate the prevalence of risk factors for atherosclerotic diseases as well as cardiovascular and related disorders in the primary care setting in Poland. The LIPIDOGEN2015 sub-study was designed to include a random cohort of patients in order to analyse parameters related to lipid metabolism, oxidative stress, inflammatory responses, autoimmune disorders, and gene variants that confer susceptibility to cardiometabolic and atherosclerotic diseases.

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Purpose: Mycosis fungoides is one of the most common types of extranodal T-cell lymphomas, considered to be caused by malignant transformation of the mature T cells residing in the skin. However, some clinical observations such as the multifocal distribution of mycosis fungoides lesions or patterns of relapse after radiotherapy are not readily explainable by the mature T-cell origin theory.

Experimental Design: We have performed a detailed analysis of T-cell receptor (TCR) rearrangements in single malignant cells and in biopsies from mycosis fungoides tumors composed of >80% of malignant cells using next-generation sequencing (NGS) to pinpoint the relationship between neoplastic cells in mycosis fungoides.

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In spite of high complete remission rates in Acute Myeloid Leukemia (AML), little progress has been made in the long-term survival of relapsing AML patients, urging for the development of novel therapies. The CXCR4/SDF-1 axis is a potential therapeutic target in AML to reduce the enhanced survival and proliferation of leukemic cells, with current drug development efforts focusing on antagonists and blocking antibodies. The RNAi technology mediated by siRNA is a promising alternative; however, further development of clinically relevant siRNA carriers is needed since siRNA on its own is an incompetent silencing agent.

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The reaction of (SeO3)4 with 1,4-dioxane (diox, dioxane) with or without diluting solvent led to the isolation of the unprecedented esters of selenic acid-1,2-ethyl selenate (CH2O)2SeO2 and the glyoxal diselenate O2Se[(OCHO)2]SeO2. It was possible to isolate an unknown dimeric form of Se2O5 (Se4O10·(diox)2) and a geometrical isomer of the mixed-valence oxide trans-Se3O7, both stabilized by dioxane. The dioxane adduct of monomeric selenium trioxide SeO3·diox was obtained from the reaction of (SeO3)4 with dioxane in liquid SO2.

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Two novel heterometallic complexes [Cd(NH3)6][{VO(O2)2(OH)}2{μ-Cd(NH3)4}] (2) and [{VO(O2)2(Im)}2{μ-Cu(Im)4}] (3) (Im = imidazole) containing peroxidovanadium complexes as metalloligands were prepared and characterized by spectral methods. X-ray single-crystal analysis revealed the presence of unique trinuclear complexes in the crystal structures of 2 and 3. The structure of 2 contains an anionic complex, whose two {VO(O2)2(OH)}(2-) ions are interconnected by a {μ-Cd(NH3)4}(2+) group.

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The significance of loss of SOCS3, a negative regulator of signalling pathways including those of STAT3 and NF-κB, was examined in mantle cell lymphoma (MCL). The protein expression and gene methylation status of SOCS3 were detected using immunohistochemistry/Western blots and methylation-specific polymerase chain reaction, respectively. To evaluate its functional importance, SOCS3 was restored in two SOCS3-negative MCL cell lines using a lentiviral vector.

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Fatty acid synthase (FASN), a key player in the de novo synthetic pathway of long-chain fatty acids, has been shown to contribute to the tumorigenesis in various types of solid tumors. We here report that FASN is highly and consistently expressed in mantle cell lymphoma (MCL), an aggressive form of B-cell lymphoid malignancy. Specifically, the expression of FASN was detectable in all four MCL cell lines and 15 tumors examined.

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