Displaying publications 1 - 20 of 209 in total

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  1. Khachatryan V, Sirunyan AM, Tumasyan A, Adam W, Asilar E, Bergauer T, et al.
    Eur Phys J C Part Fields, 2017;77(1):15.
    PMID: 28260978 DOI: 10.1140/epjc/s10052-016-4504-z
    A measurement of the top quark pair production ([Formula: see text]) cross section in proton-proton collisions at the centre-of-mass energy of 8[Formula: see text] is presented using data collected with the CMS detector at the LHC, corresponding to an integrated luminosity of 19.6[Formula: see text]. This analysis is performed in the [Formula: see text] decay channels with one isolated, high transverse momentum electron or muon and at least four jets, at least one of which is required to be identified as originating from hadronization of a b quark. The calibration of the jet energy scale and the efficiency of b jet identification are determined from data. The measured [Formula: see text] cross section is [Formula: see text]. This measurement is compared with an analysis of 7[Formula: see text] data, corresponding to an integrated luminosity of 5.0[Formula: see text], to determine the ratio of 8[Formula: see text] to 7[Formula: see text] cross sections, which is found to be [Formula: see text]. The measurements are in agreement with QCD predictions up to next-to-next-to-leading order.
  2. Murugesu, S., Khatib, A., Ibrahim, Z., Ahmed, Q. U., Uzir, B.F., Nik-Yusoff, N.I., et al.
    MyJurnal
    Clinacanthus nutans (Acanthaceae) is a local plant consumed as tisane in Indonesia and ‘ulam’ in Malaysia. This plant has been claimed for its ability to prevent many diseases including diabetes. However, the scientific proof on this claim is still lacking. Therefore, the present work study was designed to evaluate the antidiabetic potential and antioxidant capacity of C. nutans leaves extracts using in vitro bioassay tests. The 80% methanolic crude extract of this plant was further partitioned using different polarity solvents namely hexane, hexane:ethyl acetate (1:1, v/v), ethyl acetate, ethyl acetate:methanol (1:1, v/v), and methanol. All the sub-fractions were analysed for antioxidant effect via 2, 2-diphenyl-2-picrylhydrazil (DPPH) scavenging activity, ferric reducing power (FRAP) and xanthine oxidase (XO) assays followed by antidiabetic evaluation via α-glucosidase and dipeptidyl peptidase-IV (DPP-IV) inhibitory assays and glucose uptake experiment. The ethyl acetate fraction showed a good antioxidant potential while the hexane fraction exhibited high α-glucosidase and DPP-IV enzyme inhibition. The hexane fraction also improved glucose uptake in a dose-dependent manner. The present work thus provides an informative data on the potential of C. nutans to be developed as a functional food in preventing diabetes.
  3. Mohd Hamidin FA, Adznam SN, Ibrahim Z, Chan YM, Abdul Aziz NH
    SAGE Open Med, 2018;6:2050312118775581.
    PMID: 29872529 DOI: 10.1177/2050312118775581
    Objective: Frailty is a clinical syndrome with increased risk of poor health outcomes and particularly prevalent in older adults and community population. The study's aim was therefore to determine the prevalence of frailty and its association with sociodemographic and socioeconomic characteristics, health-related status, and anthropometric measurements among community-dwelling older adults.

    Methods: A total of 279 older adults aged 60 years and above were randomly selected. Respondents were classified as non-frail (<2 criteria) or frail (≥3 criteria) based on the 'phenotype of frailty'. A binary logistic regression was used to determine predictors of frailty.

    Results: The prevalence of frailty was 18.3%. The frail older adults were positively associated with advanced age, being unmarried, hospitalisation in the previous year, poor self-rated health, and lower body mass index.

    Discussion: These results give an overview on underlying effects and guiding actions for prevention programmes functioning to reverse and minimise the adverse effects of frailty syndrome.

  4. Yousefi S, Bayat S, Rahman MB, Ibrahim Z, Abdulmalek E
    Chem Biodivers, 2017 Apr;14(4).
    PMID: 28036129 DOI: 10.1002/cbdv.201600362
    Inflammatory bowel disease (IBD) is the main risk factor for developing colorectal cancer which is common in patients of all ages. 5-Aminosalicylic acid (5-ASA), structurally related to the salicylates, is highly active in the treatment of IBD with minor side effects. In this study, the synthesis of galactose and fructose esters of 5-ASA was planned to evaluate the role of glycoconjugation on the bioactivity of the parent drug. The antibacterial activity of the new compounds were evaluated against two Gram-negative and two Gram-positive species of bacteria, with a notable effect observed against Staphylococcus aureus and Escherichia coli in comparisons with the 5-ASA. Cytotoxicity testing over HT-29 and 3T3 cell lines indicated that the toxicity of the new products against normal cells was significantly reduced compared with the original drug, whereas their activity against cancerous cells was slightly decreased. The anti-inflammatory activity test in RAW264.7 macrophage cells indicated that the inhibition of nitric oxide by both of the monosaccharide conjugated derivatives was slightly improved in comparison with the non-conjugated drug.
  5. Shahar S, Ibrahim Z, Fatah AR, Rahman SA, Yusoff NA, Arshad F, et al.
    Asia Pac J Clin Nutr, 2007;16(2):346-53.
    PMID: 17468093
    A multidimensional assessment of nutritional and health status comprised of subjective global assessment (SGA), anthropometry function, biochemistry, dietary intake, social and health aspects was carried out on 820 older people (52.8% men and 47.2% women) from four rural areas of Peninsular Malaysia. A proportion of the subjects had been classified as either overweight (25.7%) or chronic energy deficient (20.3%). Although 49% of subjects had normal body weight, 68.4% have been classified as having mild to moderate malnutrition according to the SGA. Only 1.1% and 2.3% had low serum albumin and ferritin, respectively. Almost 80% of subjects, especially men, were at high risk of cardiovascular diseases on the basis of the assessment of total cholesterol and LDL-cholesterol. The majority of the subjects (87.2%) were fully independent in performing daily tasks, with men having a significantly higher score compared to women (p<0.001). However, men were less likely to be able to perform a flexibility test (50.7%) than were women (27.0%) (p<0.05). The mean energy intake for men (1412 +/- 461 kcal/d) and women (1201 +/- 392 kcal/d) were below the Recommended Nutrient Intake (RNI) for Malaysia, although this is a difficult assertion to make in an age-group which generally experiences declining energy expenditure. Moreover, 52.5% of men and 47.5% of women might have underreported their food intake. Dietary micronutrients most likely to be deficient were thiamin, riboflavin and calcium. It is concluded that a substantial proportion of rural elderly Malays had problems related to both undernutrition and overnutrition. An appropriate nutrition intervention program is needed to improve the nutritional status of rural elderly Malays.
  6. Latiff LA, Ibrahim Z, Pei CP, Rahman SA, Akhtari-Zavare M
    Asian Pac J Cancer Prev, 2015;16(18):8495-501.
    PMID: 26745108
    PURPOSE: This study was conducted to assess the agreement and differences between cervical self-sampling with a Kato device (KSSD) and gynecologist sampling for Pap cytology and human papillomavirus DNA (HPV DNA) detection.

    MATERIALS AND METHODS: Women underwent self-sampling followed by gynecologist sampling during screening at two primary health clinics. Pap cytology of cervical specimens was evaluated for specimen adequacy, presence of endocervical cells or transformation zone cells and cytological interpretation for cells abnormalities. Cervical specimens were also extracted and tested for HPV DNA detection. Positive HPV smears underwent gene sequencing and HPV genotyping by referring to the online NCBI gene bank. Results were compared between samplings by Kappa agreement and McNemar test.

    RESULTS: For Pap specimen adequacy, KSSD showed 100% agreement with gynecologist sampling but had only 32.3% agreement for presence of endocervical cells. Both sampling showed 100% agreement with only 1 case detected HSIL favouring CIN2 for cytology result. HPV DNA detection showed 86.2%agreement (K=0.64, 95% CI 0.524-0.756, p=0.001) between samplings. KSSD and gynaecologist sampling identified high risk HPV in 17.3% and 23.9% respectively (p= 0.014).

    CONCLUSION: The self-sampling using Kato device can serve as a tool in Pap cytology and HPV DNA detection in low resource settings in Malaysia. Self-sampling devices such as KSSD can be used as an alternative technique to gynaecologist sampling for cervical cancer screening among rural populations in Malaysia.

  7. Ibrahim ZH, Al-Diwan JK
    Med J Malaysia, 2023 Nov;78(6):717-720.
    PMID: 38031212
    INTRODUCTION: Coronavirus disease 2019 (COVID-19) has high morbidity and mortality especially in preexisting risk groups. In atopic diseases the IgE and eosinophils are commonly elevated. This study aims to determine the potential association between COVID-19 and atopic diseases in Iraqi patients.

    MATERIALS AND METHODS: A cross-sectional study done in Baghdad on 112 patients who attended Al-Zahraa Allergic Center. Their demographic characteristics, total IgE, eosinophil counts and PCR result for COVID-19 were determined.

    RESULTS: The means for IgE and eosinophils were 245.7±260.1IU/ml and 444.5±117.1cells/microliter sequentially. Around 32.1% had high IgE level (i.e., atopic) and 11.6% had COVID-19. Among the atopic patients, 33.3%, 30.5% and 36.2% had atopic dermatitis, allergic rhinitis and asthma respectively. More than half (58.3%) of them were male, 55.5% aged <45 years, 36.2% were retired or had no job, 69.5% were graduated from secondary school or more and 88.8% lived in urban areas. There is no significant association in IgE level between those with and without COVID-19, which means that exposure to SARS Cov2 virus could not be a trigger or exacerbation for atopic diseases. Also, there was no association between atopic patients with COVID-19 and those without it regarding type of atopy, age, sex, occupation, education, type of living area.

    CONCLUSIONS: Atopy is not a risk factor for COVID-19.

  8. Nassir KF, Ali BM, Ibrahim ZH, Qasim ZJ, Mahdi SG, Mustafa NM, et al.
    Med J Malaysia, 2024 Jan;79(1):74-79.
    PMID: 38287761
    INTRODUCTION: Salmonella typhi could infect the intestinal tract and the bloodstream or invade body organs and secrete endotoxins. It is endemic in developing countries. It is increasingly evolving antimicrobial resistance to several commonly used antimicrobial agents.

    MATERIALS AND METHODS: A cross-sectional study was done at Iraqi Communicable Disease Control Center, where all confirmed cases of Salmonella typhi are reported, for a period 2019-2021. All demographic, epidemiological and clinical characteristics of patients, comorbidities, type of samples, distribution of S. typhi by age and gender, time distribution in each year and profile of bacterial resistance and sensitivity to antibiotics were gathered and analysed.

    RESULTS: Most samples were taken from blood. The mean age of cases during 2019, 2020 and 2021 was 18.7 ± 6.5, 17.7 ± 14.1 and 17.3 ± 12.8. Males constituted 56.7%, 58.5% and 39.8%, respectively. Some cases had comorbidities. Most cases had headache and fever. Some of them had nausea, diarrhoea, vomiting and epigastric pain. The age and sex were significantly associated with years of reporting. The most months of case reporting were June-July (2019 and 2021), Jan. -Feb. (2020). There was an obvious increase in S. typhi resistance to ceftriaxone (92.2%, 86.1%, 88.8%) and ampicillin (77.1%, 76.9%, 81.27%). There was a gradual increase in sensitivity to tetracycline (83.1%, 88.1%, 94%), cotrimoxazole (86.7%, 86.1%, 92.2%), ciprofloxacin (78.3%, 90.1%, 87.8%) and cefixime (77.7%, 72.3%, 72.7%).

    CONCLUSIONS: There was a sharp rise in resistance rates of the S. typhi in Iraq (during 2019-2021) to ceftriaxone and ampicillin, while there were highest sensitivity rates to imipenem, aztreonam and chloramphenicol. The following recommendations were made: (1) Improvement of general hygiene and food safety measures. (2) Emphasis on vaccination and surveillance of Salmonella infection. (3) Rational use of appropriate antibiotics through implementation of treatment guidelines. (5) Educate communities and travelers about the risks of S. typhi and its preventive measures.

  9. Zainal Fithri HH, Ibrahim Z, Ali EZ
    Comput Biol Chem, 2023 Dec;107:107962.
    PMID: 37847978 DOI: 10.1016/j.compbiolchem.2023.107962
    Protein arginine deiminase IV (PAD4) is a potential target for diseases including rheumatoid arthritis and cancers. Currently, GSK199 is a potent, selective yet reversible PAD4 inhibitor. Its derivative, GSK106, on the other hand, was reported as an inactive compound when tested against PAD4 assay. Although they had similar skeleton, their impact towards PAD4 structural and flexibility is unknown. In order to fill the research gap, the impact of GSK199 and GSK106 binding towards PAD4 stability and flexibility is investigated via a combination of computational methods. Molecular docking indicates that GSK199 and GSK106 are capable to bind at PAD4 pocket by using its back door with -10.6 kcal/mol and -9.6 kcal/mol, respectively. The simulations of both complexes were stable throughout 100 ns. The structure of PAD4 exhibited a tighter packing in the presence of GSK106 compared to GSK199. The RMSF analysis demonstrates significant changes between the PAD4-GSK199 and PAD4-GSK106 simulations in the regions containing residues 136, 160, 220, 438, and 606. The Molecular Mechanics Poisson-Boltzmann Surface Area (MMPBSA) analysis shows a marked difference in binding free energies, with -11.339 kcal/mol for the PAD4-GSK199 complex and 1.063 kcal/mol for the PAD4-GSK106 complex. The hydrogen bond analysis revealed that the GSK199 and GSK106 binding to PAD4 are assisted by six hydrogen bonds and three hydrogen bonds, respectively. The visualisation of the MD simulations revealed that GSK199 remained in the PAD4 pocket, whereas GSK106 shifted away from the catalytic site. Meanwhile, molecular dockings of benzoyl arginine amide (BAEE) substrate have shown that BAEE is able to bind to PAD4 catalytic site when GSK106 was present but not when GSK199 occupied the site. Overall, combination of computational approaches successfully described the behaviour of binding pocket of PAD4 structure in the presence of the active and inactive compounds.
  10. Sinniah B, Hassan A KR, Sabaridah I, Soe MM, Ibrahim Z, Ali O
    Trop Biomed, 2014 Jun;31(2):190-206.
    PMID: 25134888 MyJurnal
    Intestinal parasitic infections are among the most common diseases affecting mankind causing major public health problems to billions of people living in developing countries. The aim of this study is to determine the prevalence of intestinal parasites in various communities residing in different habitats in Malaysia and compare the findings with 101 studies conducted over the past 42 years (1970-2013). A cross-sectional study design was conducted with the aid of a questionnaire to collect relevant information about the study population. Faecal samples were examined using the direct smear and formal ether sedimentation techniques. A total of 342 children were examined amongst whom 24.6% were positive for intestinal parasitic infections. Results showed that 32.3% of rural children, 20.6% of urban squatters and 5.4% of children from flats were positive for one or more parasites. The most common parasite encountered was Trichuris trichiura (20.2%) followed by Ascaris lumbricoides (10.5%) and hookworm (6.7%). No case of hookworm was reported in urban children whereas 12.2% of rural children were positive. The most common protozoan parasite detected was Entamoeba coli (3.2%) followed by Giardia intestinalis (1.8%), Entamoeba histolytica (1.8%) and Blastocystis hominis (1.2%). Nearly one-fifth (18.4%) of the children had single infection followed by double (12.0%) and triple infections (1.2%). Orang Asli (indigenous) children (44.3%) had the highest infection rate followed by Indians (20.2%), Malays (14.0%) and Chinese (11.9%). Twenty-eight studies carried out on plantation communities with regards to intestinal parasitic infections in Malaysia from 1970 to 2013 showed a steady decline in the prevalence rate ranging from 95.0% in the seventies to 37.0 % in 2012. Intestinal parasitic infections were more common in Orang Asli communities with prevalence ranging from over 90% in the seventies and fluctuating below 70% in most studies between 2000 to 2013 except for two studies that showed a prevalence of 98.2% and 100%. The prevalence rate among urban squatters, urban residents and those living in flats showed dramatic decrease in prevalence rate.
  11. Razak AA, Abu-Hassan MI, Al-Makramani BM, Al-Sanabani FA, Al-Shami IZ, Almansour HM
    J Contemp Dent Pract, 2016 Nov 01;17(11):920-925.
    PMID: 27965501
    AIM: The aim of this study was to evaluate the effect of surface treatments on shear bond strength (SBS) of Turkom-Cera (Turkom-Ceramic (M) Sdn. Bhd., Puchong, Malaysia) all-ceramic material cemented with resin cement Panavia-F (Kuraray Medical Inc., Okayama, Japan).

    MATERIALS AND METHODS: Forty Turkom-Cera ceramic disks (10 mm × 3 mm) were prepared and randomly divided into four groups. The disks were wet ground to 1000-grit and subjected to four surface treatments: (1) No treatment (Control), (2) sandblasting, (3) silane application, and (4) sandblasting + silane. The four groups of 10 specimens each were bonded with Panavia-F resin cement according to manufacturer's recommendations. The SBS was determined using the universal testing machine (Instron) at 0.5 mm/min crosshead speed. Failure modes were recorded and a qualitative micromorphologic examination of different surface treatments was performed. The data were analyzed using the one-way analysis of variance (ANOVA) and Tukey honestly significant difference (HSD) tests.

    RESULTS: The SBS of the control, sandblasting, silane, and sandblasting + silane groups were: 10.8 ± 1.5, 16.4 ± 3.4, 16.2 ± 2.5, and 19.1 ± 2.4 MPa respectively. According to the Tukey HSD test, only the mean SBS of the control group was significantly different from the other three groups. There was no significant difference between sandblasting, silane, and sandblasting + silane groups.

    CONCLUSION: In this study, the three surface treatments used improved the bond strength of resin cement to Turkom-Cera disks.

    CLINICAL SIGNIFICANCE: The surface treatments used in this study appeared to be suitable methods for the cementation of glass infiltrated all-ceramic restorations.

  12. Koosha S, Mohamed Z, Sinniah A, Ibrahim Z, Seyedan A, Alshawsh MA
    Life Sci, 2019 Jul 03.
    PMID: 31278947 DOI: 10.1016/j.lfs.2019.116633
    AIMS: The compound 8-prenylnaringenin (8-PN) is a prenylflavonoid that can be isolated from hops and beer and has anti-cancer properties against breast cancer. The aim of this study is to investigate the anti-proliferative and apoptotic activities of 8-PN against human colon cancer HCT-116 cells.

    MAIN METHODS: Colon cancer HCT-116 cells were treated with 8-PN and subjected to MTT and acridine orange/propidium iodide (AO/PI) staining to investigate the cytotoxicity of 8-PN. Arrest of the cells at different phases of cell cycle was monitored in the presence of 8-PN. Moreover, the apoptotic effects of 8-PN was assessed via annexin V and caspase activity assays and compared to the untreated cells.

    KEY FINDINGS: The findings showed that 8-PN revealed strong inhibitory effect against HCT-116 cells with an IC50 value of 23.83 ± 2.9 μg/ml after 48 h. However, at similar concentrations and experimental time-points, the compound did not show cytotoxic effect to non-cancerous colon cells (CCD-41). Annexin-V assay indicates that 38.5% and 14.4% of HCT-116 cells had entered early and late stages of apoptosis, respectively after exposure of the cells to 8-PN for 48 h. Caspase activity assay illustrates that apoptosis is activated through both intrinsic and extrinsic pathways. Moreover, flow cytometry cell cycle results indicate that treatment with 8-PN significantly arrested the HCT-116 cells at G0/G1 phase.

    SIGNIFICANCE: These findings reveal that 8-PN has anti-proliferative activity against HCT-116 colon cancer cells via induction of intrinsic and extrinsic pathway-mediated apoptosis. Further investigations should be carried out to unravel the mechanistic pathways underlying these activities.

  13. Sahari NS, Shahir S, Ibrahim Z, Hasmoni SH, Altowayti WAH
    Environ Sci Pollut Res Int, 2023 Nov;30(51):110069-110078.
    PMID: 37814051 DOI: 10.1007/s11356-023-30067-w
    This review discusses the application of bacterial nanocellulose (BNC) and modified BNC in treating wastewater containing heavy metals and dye contaminants. It also highlights the challenges and future perspectives of BNC and its composites. Untreated industrial effluents containing toxic heavy metals are systematically discharged into public waters. In particular, lead (Pb), copper (Cu), cadmium (Cd), nickel (Ni), zinc (Zn), and arsenic (As) are very harmful to human health and, in some cases, may lead to death. Several methods such as chemical precipitation, ion exchange, membrane filtration, coagulation, and Fenton oxidation are used to remove these heavy metals from the environment. However, these methods involve the use of numerous chemicals whilst producing high amount of toxic sludge. Meanwhile, the development of the adsorption-based technique has provided an alternative way of treating wastewater using BNC. Bacterial nanocellulose requires less energy for purification and has higher purity than plant cellulose. In general, the optimum growth parameters are crucial in BNC production. Even though native BNC can be used for the removal of heavy metals and dyes, the incorporation of other materials, such as polyethyleneimine, graphene oxide, calcium carbonate and polydopamine can improve sorption efficiencies.
  14. Javanmardi A, Ibrahim Z, Ghaedi K, Khan NB, Benisi Ghadim H
    PLoS One, 2018;13(7):e0200482.
    PMID: 30059506 DOI: 10.1371/journal.pone.0200482
    This paper investigated the seismic retrofitting of an existing cable-stayed bridge through the use of a seismic isolation system. The bridge is situated in a high seismic zone. During the Saguenay earthquake 1988, one of the anchorage plates of the bridge supports failed. Herein, several configurations of seismic isolation system were considered to identify an appropriate solution for the seismic retrofitting of the bridge in both the longitudinal and transverse directions. A three-dimensional model of the bridge was created, and its seismic behavior studied through nonlinear dynamic time-history analysis. The comparative performance study among the five retrofitting configurations showed that the partial seismic isolation of the bridge led to an enhancement of the seismic response of the bridge in one direction only. However, the overall seismic response of the cable-stayed bridge substantially improved in the longitudinal and transverse directions in cases where the isolation systems were utilized between the supports and the deck-tower connection of the bridge.
  15. Alajerami YS, Hashim S, Ghoshal SK, Ramli AT, Saleh MA, Ibrahim Z, et al.
    Appl Radiat Isot, 2013 Dec;82:12-9.
    PMID: 23948307 DOI: 10.1016/j.apradiso.2013.07.005
    Understanding the influence of co-dopants in the luminescence enhancement of carbonate glasses is the key issue in dosimetry. A series of borate glasses modified by lithium and potassium carbonate were synthesized by the melt-quenching method. The glass mixture activated with various concentrations of TiO2 and MgO was subjected to various doses of gamma-rays ((60)Co). The amorphous nature of the samples was confirmed by x-ray diffraction (XRD) spectra. The simple glowing curve of the glass doped with TiO2 features a peak at 230°C, whose intensity is maximal at 0.5 mol% of the dopant. The intensity of the glowing curve increases with the concentration of MgO added as a co-dopant up to 0.25 mol%, where it is two times higher than for the material without MgO thermoluminescence properties, including dose response, reproducibility, and fading were studied. The effective atomic number of the material was also determined. Kinetic parameters, such as kinetics order, activation energy, and frequency factor are estimated. The photoluminescence spectra of the titanium-doped glass consist of a prominent peaks at 480 nm when laser excitation at 650 nm is used. A three-fold photoluminescence enhancement and a blue shift of the peak were observed when 0.1% MgO was introduced. In addition, various physical parameters, such as ion concentration, polaron radius and internuclear distances were calculated. The mechanism for the thermoluminescence and photoluminescence enhancements are discussed.
  16. Khachatryan V, Sirunyan AM, Tumasyan A, Adam W, Asilar E, Bergauer T, et al.
    Phys Rev Lett, 2016 Feb 19;116(7):071801.
    PMID: 26943527 DOI: 10.1103/PhysRevLett.116.071801
    A search for narrow resonances in proton-proton collisions at sqrt[s]=13  TeV is presented. The invariant mass distribution of the two leading jets is measured with the CMS detector using a data set corresponding to an integrated luminosity of 2.4  fb^{-1}. The highest observed dijet mass is 6.1 TeV. The distribution is smooth and no evidence for resonant particles is observed. Upper limits at 95% confidence level are set on the production cross section for narrow resonances with masses above 1.5 TeV. When interpreted in the context of specific models, the limits exclude string resonances with masses below 7.0 TeV, scalar diquarks below 6.0 TeV, axigluons and colorons below 5.1 TeV, excited quarks below 5.0 TeV, color-octet scalars below 3.1 TeV, and W^{'} bosons below 2.6 TeV. These results significantly extend previously published limits.
  17. Khachatryan V, Sirunyan AM, Tumasyan A, Adam W, Asilar E, Bergauer T, et al.
    Phys Rev Lett, 2016 Jan 22;116(3):032301.
    PMID: 26849587 DOI: 10.1103/PhysRevLett.116.032301
    The production cross sections of the B^{+}, B^{0}, and B_{s}^{0} mesons, and of their charge conjugates, are measured via exclusive hadronic decays in p+Pb collisions at the center-of-mass energy sqrt[s_{NN}]=5.02  TeV with the CMS detector at the CERN LHC. The data set used for this analysis corresponds to an integrated luminosity of 34.6  nb^{-1}. The production cross sections are measured in the transverse momentum range between 10 and 60  GeV/c. No significant modification is observed compared to proton-proton perturbative QCD calculations scaled by the number of incoherent nucleon-nucleon collisions. These results provide a baseline for the study of in-medium b quark energy loss in Pb+Pb collisions.
  18. Sirunyan AM, Tumasyan A, Adam W, Asilar E, Bergauer T, Brandstetter J, et al.
    Phys Rev Lett, 2018 Apr 06;120(14):142301.
    PMID: 29694144 DOI: 10.1103/PhysRevLett.120.142301
    The relative yields of ϒ mesons produced in pp and Pb-Pb collisions at sqrt[s_{NN}]=5.02  TeV and reconstructed via the dimuon decay channel are measured using data collected by the CMS experiment. Double ratios are formed by comparing the yields of the excited states, ϒ(2S) and ϒ(3S), to the ground state, ϒ(1S), in both Pb-Pb and pp collisions at the same center-of-mass energy. The double ratios, [ϒ(nS)/ϒ(1S)]_{Pb-Pb}/[ϒ(nS)/ϒ(1S)]_{pp}, are measured to be 0.308±0.055(stat)±0.019(syst) for the ϒ(2S) and less than 0.26 at 95% confidence level for the ϒ(3S). No significant ϒ(3S) signal is found in the Pb-Pb data. The double ratios are studied as a function of collision centrality, as well as ϒ transverse momentum and rapidity. No significant dependencies are observed.
  19. Sirunyan AM, Tumasyan A, Adam W, Ambrogi F, Asilar E, Bergauer T, et al.
    Phys Rev Lett, 2020 Sep 04;125(10):102001.
    PMID: 32955327 DOI: 10.1103/PhysRevLett.125.102001
    The first study of charm quark diffusion with respect to the jet axis in heavy ion collisions is presented. The measurement is performed using jets with p_{T}^{jet}>60  GeV/c and D^{0} mesons with p_{T}^{D}>4  GeV/c in lead-lead (Pb-Pb) and proton-proton (pp) collisions at a nucleon-nucleon center-of-mass energy of sqrt[s_{NN}]=5.02  TeV, recorded by the CMS detector at the LHC. The radial distribution of D^{0} mesons with respect to the jet axis is sensitive to the production mechanisms of the meson, as well as to the energy loss and diffusion processes undergone by its parent parton inside the strongly interacting medium produced in Pb-Pb collisions. When compared to Monte Carlo event generators, the radial distribution in pp collisions is found to be well described by pythia, while the slope of the distribution predicted by sherpa is steeper than that of the data. In Pb-Pb collisions, compared to the pp results, the D^{0} meson distribution for 4
  20. Sirunyan AM, Tumasyan A, Adam W, Ambrogi F, Asilar E, Bergauer T, et al.
    Phys Rev Lett, 2018 May 18;120(20):202005.
    PMID: 29864318 DOI: 10.1103/PhysRevLett.120.202005
    A search for resonancelike structures in the B_{s}^{0}π^{±} invariant mass spectrum is performed using proton-proton collision data collected by the CMS experiment at the LHC at sqrt[s]=8  TeV, corresponding to an integrated luminosity of 19.7  fb^{-1}. The B_{s}^{0} mesons are reconstructed in the decay chain B_{s}^{0}→J/ψϕ, with J/ψ→μ^{+}μ^{-} and ϕ→K^{+}K^{-}. The B_{s}^{0}π^{±} invariant mass distribution shows no statistically significant peaks for different selection requirements on the reconstructed B_{s}^{0} and π^{±} candidates. Upper limits are set on the relative production rates of the X(5568) and B_{s}^{0} states times the branching fraction of the decay X(5568)^{±}→B_{s}^{0}π^{±}. In addition, upper limits are obtained as a function of the mass and the natural width of possible exotic states decaying into B_{s}^{0}π^{±}.
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