MyMedR

Fulltext The Bird Flu Threat - Why Aren't We Worrying?

Idris FM

Malays J Med Sci, 2005 Jan;12(1):1-2.

Study of viridans streptococci and Staphylococcus species in cleft lip and palate patients before and after surgery

Arief EM, Mohamed Z, Idris FM

Cleft Palate Craniofac J, 2005 May;42(3):277-9.

OBJECTIVE: To determine the effect of surgery on types and colony count of Streptococcus and Staphylococcus species in cleft lip and palate (CLP) patients.

DESIGN: Saliva samples were collected after the morning meal by placing a sterile cotton swab in the vestibule of the oral cavity from cleft lip and palate patients immediately preoperative and 12 weeks postoperative. Normal children were examined as a control group. Samples were cultured; Staphylococcus and Streptococcus isolates were identified and quantified.

PATIENTS: Fifteen cleft lip and palate patients and 22 normal children, aged 3 to 39 months were examined.

RESULTS: Streptococcus mitis biovar 1, Streptococcus salivarius and Streptococcus oralis of the viridans group of streptococci were the most commonly found in normal children, as well as in cleft lip and palate children. In the cleft lip and palate group, mean streptococcal count was 32.41 (29.80) and 46.46 (42.80) in the pre- and postoperative periods, respectively; in the normal group, the count was 20.93 (27.93) and 49.92 (34.72) at 0 week and 12 weeks, respectively. Staphylococcus aureus was the most common Staphylococcus species found in CLP patients, representing 47.4% postoperatively. In the cleft lip and palate children, mean staphylococcal count was 5.34 (8.13) and 0.56 (0.92) in the pre- and postoperative periods, respectively; in normal children, the count was 0.82 (1.98) and 0.60 (2.55) at 0 and 12 weeks, respectively. The differences were statistically significant only for the staphylococcal count between pre- and postoperative periods in children with cleft lip and palate as tested by analysis of variance (p < .05).

CONCLUSIONS: Cleft lip and palate patients had more colonization by S. aureus compared with normal children, and the colony count decreased significantly following surgical repair of the cleft lip and palate.

Expression of Bax and Bcl-2 in tumour cells and blood vessels of breast cancer and their association with angiogenesis and hormonal receptors

Jaafar H, Abdullah S, Murtey MD, Idris FM

Asian Pac J Cancer Prev, 2012;13(8):3857-62.

PMID: 23098483

A total of 96 cases of invasive breast ductal carcinoma were examined for immunohistochemical expression of Bax and Bcl-2 in the epithelial tumor cells and endothelial cells of the blood vessels. We also investigated the association between both proteins in the epithelium in relation to tumor characteristics such as tumor size, grade, lymph node involvement, microvessel density (MVD), hormonal receptors expression and c-erbB-2 overexpression. Bax expression showed a significant association between tumor and endothelial cells (p<0.001) while Bcl-2 expression in tumor cells was inversely associated with that in the endothelial cells (p<0.001). Expression of Bcl-2 in tumor cells was strongly associated with expression of estrogen and progesterone receptors (p=0.003 and p=0.004, respectively). In addition, intratumoral MVD was significantly higher than peritumoral MVD (p<0.001) but not associated with Bax or Bcl-2 expression and other tumor characteristics. We concluded that the number of endothelial cells undergoing apoptosis was in direct linkage with the number of apoptotic tumor cells. Anti-apoptotic activity of the surviving tumor cells appears to propagate cancer progression and this was influenced by the hormonal status of the cells. Tumor angiogenesis was especially promoted in the intratumoral region and angiogenesis was independent of anti-apoptotic activity.

Fulltext Dengue virus type 2 (DENV2)-induced oxidative responses in monocytes from glucose-6-phosphate dehydrogenase (G6PD)-deficient and G6PD normal subjects

Al-Alimi AA, Ali SA, Al-Hassan FM, Idris FM, Teow SY, Mohd Yusoff N

PLoS Negl Trop Dis, 2014 Mar;8(3):e2711.

PMID: 24625456 DOI: 10.1371/journal.pntd.0002711

Dengue virus is endemic in peninsular Malaysia. The clinical manifestations vary depending on the incubation period of the virus as well as the immunity of the patients. Glucose-6-phosphate dehydrogenase (G6PD) deficiency is prevalent in Malaysia where the incidence is 3.2%. It has been noted that some G6PD-deficient individuals suffer from more severe clinical presentation of dengue infection. In this study, we aim to investigate the oxidative responses of DENV2-infected monocytes from G6PD-deficient individuals.

Fulltext Prevalence of Clostridium difficile toxin in diarhoeal stool samples of patients from a tertiary hospital in North Eastern Penisular Malaysia

Hassan SA, Othman N, Idris FM, Abdul Rahman Z, Maning N, Abdul Rahman R, et al.

Med J Malaysia, 2012 Aug;67(4):402-5.

PMID: 23082450 MyJurnal

This study describes the prevalence of Clostridium difficile toxin (CDT) in loose stool samples from inpatients aged more than two years of a tertiary hospital. A total of 175 samples that had been examined were from stool samples that were sent to the Medical Microbiology & Parasitology Laboratory for various clinical indications. The toxin was detected by a commercial immunochromatograhic test, and the patients' demography, clinical features, treatment and outcomes were analyzed from their medical records. Clostridium difficile toxin was positive in 24 (13.7%) of the stool samples. Male and female were 11 (45.8%) and 13 (54.2%) respectively, with the majority of them aged more than 50 years. Most were from medical wards (n = 21, 87.5%), with the rest from surgical wards (n = 2, 8.3%) and intensive care units (n = 1, 3.4%). All the CDT positive patients had history of prior antibiotic usage within 6 weeks before the detection of the toxin. The mean duration of antibiotics usage was 17.75 (+/- 13.75) days, while the mean duration of diarrhea was 5.21((+/- 5.85) days. Eighteen patients had underlying medical illnesses that were diabetes mellitus, chronic renal disease, hypertension, ischaemic heart disease, cerebrovascular disease and malignancy; with seven of them being CDT positive while on chemotherapy. Stool occult blood test was positive in 15 patients whereas presence of pus cells in the CD positive stool samples were detected in 21 patients. The duration of hospitalization among the patients was 27.96 (+/- 23.22) days.

Detection of Epstein-Barr virus in lower gastrointestinal tract lymphomas: a study in Malaysian patients

Yunos AM, Jaafar H, Idris FM, Kaur G, Mabruk MJ

Mol Diagn Ther, 2006;10(4):251-6.

PMID: 16884329

Many studies in the literature have shown that Epstein-Barr virus (EBV) is associated with several human lymphoid and epithelial malignancies. However, the prevalence of EBV in non-Hodgkin lymphoma (NHL) of the lower gastrointestinal (GI) tract has not been fully elucidated.

Fulltext MicroRNA expression profile of bone marrow mesenchymal stem cell-derived neural progenitor by microarray under the influence of EGF, bFGF and IGF-1

Huat TJ, Khan AA, Abdullah JM, Idris FM, Jaafar H

Genom Data, 2015 Sep;5:201-5.

PMID: 26484256 DOI: 10.1016/j.gdata.2015.06.015

Recently there has been growing interest in the differentiation of mesenchymal stem cells (MSCs) into neural lineages. Research suggests that MSCs can be differentiated into neural progenitor-like cells (NPCs) under the specific influence of paracrine factors particularly epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF). Our recent research has found that the addition of insulin-like growth factor 1 (IGF-1) with the combination of the EGF and bFGF could significantly improve the growth and survivability of MSC-derived NPCs. To unravel the molecular mechanism of the improved differentiation we compared the microRNA expression profiles of the differentiation under various combinations of growth factors. MSCs were differentiated into neural lineage in 3 groups; Group A (EGF + bFGF), Group B (EGF + bFGF + IGF-1), and Group C (without growth factor). Regulated microRNAs during the early differentiation were identified by detailed microRNA profiling using Affymetrix GeneChip version 2.0 at three time intervals (day 1, day 3 and day 5). The data were deposited in the Gene Expression Omnibus, series GSE60060.

Fulltext MicroRNA Expression Profile of Neural Progenitor-Like Cells Derived from Rat Bone Marrow Mesenchymal Stem Cells under the Influence of IGF-1, bFGF and EGF

Huat TJ, Khan AA, Abdullah JM, Idris FM, Jaafar H

Int J Mol Sci, 2015;16(5):9693-718.

PMID: 25938966 DOI: 10.3390/ijms16059693

Insulin-like growth factor 1 (IGF-1) enhances cellular proliferation and reduces apoptosis during the early differentiation of bone marrow derived mesenchymal stem cells (BMSCs) into neural progenitor-like cells (NPCs) in the presence of epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF). BMSCs were differentiated in three groups of growth factors: (A) EGF + bFGF, (B) EGF + bFGF + IGF-1, and (C) without growth factor. To unravel the molecular mechanisms of the NPCs derivation, microarray analysis using GeneChip miRNA arrays was performed. The profiles were compared among the groups. Annotated microRNA fingerprints (GSE60060) delineated 46 microRNAs temporally up-regulated or down-regulated compared to group C. The expressions of selected microRNAs were validated by real-time PCR. Among the 46 microRNAs, 30 were consistently expressed for minimum of two consecutive time intervals. In Group B, only miR-496 was up-regulated and 12 microRNAs, including the let-7 family, miR-1224, miR-125a-3p, miR-214, miR-22, miR-320, miR-708, and miR-93, were down-regulated. Bioinformatics analysis reveals that some of these microRNAs (miR-22, miR-214, miR-125a-3p, miR-320 and let-7 family) are associated with reduction of apoptosis. Here, we summarize the roles of key microRNAs associated with IGF-1 in the differentiation of BMSCs into NPCs. These findings may provide clues to further our understanding of the mechanisms and roles of microRNAs as key regulators of BMSC-derived NPC maintenance.

Fulltext Microvessel density and vascular endothelial growth factor receptors in breast carcinoma under the influence of rapamycin and platelet factor 4

Muhammad Sakri MS, Abdul Rahman WFW, Tengku Din TADA, Idris FM, Jaafar H

Indian J Pathol Microbiol, 2020 4 23;63(2):205-209.

PMID: 32317516 DOI: 10.4103/IJPM.IJPM_496_19

Background: Vascular endothelial growth factor receptors (VEGFRs) are major endothelial growth factor receptors that influence the growth of a tumor. Microvessel density.

(: MVD) is the quantification method of various aspects of tumor vasculature that indicates angiogenic activity. This study aims to analyze the correlation between MVD to the expression of VEGFRs on breast cancer tissue.

Materials and Method: A total of 60 N-methyl-N-nitrosourea (MNU)-induced breast carcinomas in rats were suppressed by using antiangiogenic drugs. The rats were then sacrificed, and the tumor was fixed in 10% formalin, paraffin embedded, and immunohistochemistry stained using VEGFRs and CD34.

Result: One-way ANOVA test showed a significant difference in all markers that have been used (P < 0.05) on MNU-breast tumor treated with rapamycin (M= 90.1664, SD= 7.4487), PF4 (M= 93.7946, SD= 7.1303) and rapamycin + PF4 (M= 93.6990, SD= 1.8432). We obtained a significant reduction of MVD count on breast carcinoma for rapamycin group (M= 25.6786, SD= 9.7075) and rapamycin + PF4 group (M= 30.5250, SD= 13.6928) while PF4 group (M=47.7985, SD=4.8892) showed slightly increase compared to control (M= 45.1875, SD= 4.4786). There was a moderately strong, positive correlation between angiogenic markers; Flt-1 (r= 0.544, n=60, P < 0.005) and Flt-4 (r= 0.555, n= 60, P < 0.005) while Flk-1 (r= 0.797, n= 60, P < 0.005) showed a strong, positive correlation with MVD.

Conclusion: MVD was strongly correlated to the VEGFRs expression on breast carcinoma.

Rapamycin and PF4 induce apoptosis by upregulating Bax and down-regulating survivin in MNU-induced breast cancer

Al-Astani Tengku Din TA, Shamsuddin SH, Idris FM, Ariffin Wan Mansor WN, Abdul Jalal MI, Jaafar H

Asian Pac J Cancer Prev, 2014;15(9):3939-44.

PMID: 24935577

BACKGROUND: To elucidate the role of rapamycin and PF4 on apoptosis regulation via Bax (pro-apoptosis), Bcl-2 (anti-apoptosis) and survivin activation on the growth in the 1-methyl-1-nitrosourea -induced invasive breast carcinoma model.

MATERIALS AND METHODS: Thirty five female Sprague Dawley rats at age 21-day old were divided into 4 groups; Group 1 (control, n=10), Group 2 (PF4, n=5), Group 3 (rapamycin, n=10) and Group 4 (rapamycin+PF4, n=10). MNU was administered intraperitionally, dosed at 70 mg/kg body weight. The rats were treated when the tumors reached the size of 14.5 ± 0.5 mm and subsequently sacrificed after 5 days. Rapamycin and PF4 were administered as focal intralesional injections at the dose of 20 μg/lesion. The tumor tissue was then subjected to histopathological examinations for morphological appraisal and immunohistochemical assessment of the pro-apoptotic marker, Bax and anti-apoptotic markers, Bcl-2 and survivin.

RESULTS: The histopathological pattern of the untreated control cohort showed that the severity of the malignancy augments with mammary tumor growth. Tumors developing in untreated groups were more aggressive whilst those in treated groups demonstrated a transformation to a less aggressive subtype. Combined treatment resulted in a significant reduction of tumor size without phenotypic changes. Bax, the pro-apoptotic marker, was significantly expressed at higher levels in the rapamycin-treated and rapamycin+PF4-treated groups compared to controls (p<0.05). Consequently, survivin was also significantly downregulated in the rapamycin-treated and rapamycin+PF4-treated group and this was significantly different when compared to controls (p).

CONCLUSIONS: In our rat model, it could be clearly shown that rapamycin specifically affects Bax and survivin signaling pathways in activation of apoptosis. We conclude that rapamycin plays a critical role in the induction of apoptosis in MNU-induced mammary carcinoma.

Fulltext MicroRNA profiling reveals unique miRNA signatures in IGF-1 treated embryonic striatal stem cell fate decisions in striatal neurogenesis in vitro

Pati S, Supeno NE, Muthuraju S, Abdul Hadi R, Ghani AR, Idris FM, et al.

Biomed Res Int, 2014;2014:503162.

PMID: 25254208 DOI: 10.1155/2014/503162

The striatum is considered to be the central processing unit of the basal ganglia in locomotor activity and cognitive function of the brain. IGF-1 could act as a control switch for the long-term proliferation and survival of EGF+bFGF-responsive cultured embryonic striatal stem cell (ESSC), while LIF imposes a negative impact on cell proliferation. The IGF-1-treated ESSCs also showed elevated hTERT expression with demonstration of self-renewal and trilineage commitment (astrocytes, oligodendrocytes, and neurons). In order to decipher the underlying regulatory microRNA (miRNA)s in IGF-1/LIF-treated ESSC-derived neurogenesis, we performed in-depth miRNA profiling at 12 days in vitro and analyzed the candidates using the Partek Genome Suite software. The annotated miRNA fingerprints delineated the differential expressions of miR-143, miR-433, and miR-503 specific to IGF-1 treatment. Similarly, the LIF-treated ESSCs demonstrated specific expression of miR-326, miR-181, and miR-22, as they were nonsignificant in IGF-treated ESSCs. To elucidate the possible downstream pathways, we performed in silico mapping of the said miRNAs into ingenuity pathway analysis. Our findings revealed the important mRNA targets of the miRNAs and suggested specific interactomes. The above studies introduced a new genre of miRNAs for ESSC-based neuroregenerative therapeutic applications.

Fulltext IGF-1 acts as controlling switch for long-term proliferation and maintenance of EGF/FGF-responsive striatal neural stem cells

Supeno NE, Pati S, Hadi RA, Ghani AR, Mustafa Z, Abdullah JM, et al.

Int J Med Sci, 2013;10(5):522-31.

PMID: 23532711 DOI: 10.7150/ijms.5325

Long-term maintenance of neural stem cells in vitro is crucial for their stage specific roles in neurogenesis. To have an in-depth understanding of optimal conditional microenvironmental niche for long-term maintenance of neural stem cells (NSCs), we imposed different combinatorial treatment of growth factors to EGF/FGF-responsive cells. We hypothesized, that IGF-1-treatment can provide an optimal niche for long-term maintenance and proliferation of EGF/FGF-responsive NSCs.

Fulltext Measurements of triple-differential cross sections for inclusive isolated-photon+jet events in p p collisions at s = 8 TeV

Sirunyan AM, Tumasyan A, Adam W, Ambrogi F, Asilar E, Bergauer T, et al.

Eur Phys J C Part Fields, 2019;79(11):969.

PMID: 31886778 DOI: 10.1140/epjc/s10052-019-7451-7

Measurements are presented of the triple-differential cross section for inclusive isolated-photon+jet events in

p
p

collisions at

s

=
8

TeV as a function of photon transverse momentum (

p

T

γ

), photon pseudorapidity (

η

γ

), and jet pseudorapidity (

η
jet

). The data correspond to an integrated luminosity of

19.7

fb

-
1

that probe a broad range of the available phase space, for

|

η

γ

|
<
1.44

and

1.57
<
|

η

γ

|
<
2.50

,

|

η
jet

|
<
2.5

,

40
<

p

T

γ

<
1000

GeV

, and jet transverse momentum,

p

T

jet

, > 25

GeV

. The measurements are compared to next-to-leading order perturbative quantum chromodynamics calculations, which reproduce the data within uncertainties.

Fulltext Search for dark matter produced in association with heavy-flavor quark pairs in proton-proton collisions at s = 13 TeV

Sirunyan AM, Tumasyan A, Adam W, Asilar E, Bergauer T, Brandstetter J, et al.

Eur Phys J C Part Fields, 2017;77(12):845.

PMID: 31985736 DOI: 10.1140/epjc/s10052-017-5317-4

A search is presented for an excess of events with heavy-flavor quark pairs (

t

t
¯

and

b

b
¯

) and a large imbalance in transverse momentum in data from proton-proton collisions at a center-of-mass energy of 13

TeV

. The data correspond to an integrated luminosity of 2.2

fb

-
1

collected with the CMS detector at the CERN LHC. No deviations are observed with respect to standard model predictions. The results are used in the first interpretation of dark matter production in

t

t
¯

and

b

b
¯

final states in a simplified model. This analysis is also the first to perform a statistical combination of searches for dark matter produced with different heavy-flavor final states. The combination provides exclusions that are stronger than those achieved with individual heavy-flavor final states.

Fulltext Measurement of the top quark mass in the all-jets final state at s = 13 TeV and combination with the lepton+jets channel

Sirunyan AM, Tumasyan A, Adam W, Ambrogi F, Asilar E, Bergauer T, et al.

Eur Phys J C Part Fields, 2019;79(4):313.

PMID: 31031568 DOI: 10.1140/epjc/s10052-019-6788-2

A top quark mass measurement is performed using 35.9 fb - 1 of LHC proton-proton collision data collected with the CMS detector at s = 13 TeV . The measurement uses the t t ¯ all-jets final state. A kinematic fit is performed to reconstruct the decay of the t t ¯ system and suppress the multijet background. Using the ideogram method, the top quark mass ( m t ) is determined, simultaneously constraining an additional jet energy scale factor ( JSF ). The resulting value of m t = 172.34 ± 0.20 (stat+JSF) ± 0.70 (syst) GeV is in good agreement with previous measurements. In addition, a combined measurement that uses the t t ¯ lepton+jets and all-jets final states is presented, using the same mass extraction method, and provides an m t measurement of 172.26 ± 0.07 (stat+JSF) ± 0.61 (syst) GeV . This is the first combined m t extraction from the lepton+jets and all-jets channels through a single likelihood function.

Fulltext Search for new physics in events with a leptonically decaying Z boson and a large transverse momentum imbalance in proton-proton collisions at s = 13 TeV

Sirunyan AM, Tumasyan A, Adam W, Ambrogi F, Asilar E, Bergauer T, et al.

Eur Phys J C Part Fields, 2018;78(4):291.

PMID: 31007582 DOI: 10.1140/epjc/s10052-018-5740-1

A search for new physics in events with a Z boson produced in association with large missing transverse momentum at the LHC is presented. The search is based on the 2016 data sample of proton-proton collisions recorded with the CMS experiment at s = 13 TeV , corresponding to an integrated luminosity of 35.9 fb - 1 . The results of this search are interpreted in terms of a simplified model of dark matter production via spin-0 or spin-1 mediators, a scenario with a standard-model-like Higgs boson produced in association with the Z boson and decaying invisibly, a model of unparticle production, and a model with large extra spatial dimensions. No significant deviations from the background expectations are found, and limits are set on relevant model parameters, significantly extending the results previously achieved in this channel.

Fulltext Measurement of associated Z + charm production in proton-proton collisions at s = 8 TeV

Sirunyan AM, Tumasyan A, Adam W, Ambrogi F, Asilar E, Bergauer T, et al.

Eur Phys J C Part Fields, 2018;78(4):287.

PMID: 31007580 DOI: 10.1140/epjc/s10052-018-5752-x

A study of the associated production of a Z boson and a charm quark jet ( Z + c ), and a comparison to production with a b quark jet ( Z + b ), in p p collisions at a centre-of-mass energy of 8 TeV are presented. The analysis uses a data sample corresponding to an integrated luminosity of 19.7 fb - 1 , collected with the CMS detector at the CERN LHC. The Z boson candidates are identified through their decays into pairs of electrons or muons. Jets originating from heavy flavour quarks are identified using semileptonic decays of c or b flavoured hadrons and hadronic decays of charm hadrons. The measurements are performed in the kinematic region with two leptons with p T ℓ > 20 GeV , | η ℓ | < 2.1 , 71 < m ℓ ℓ < 111 GeV , and heavy flavour jets with p T jet > 25 GeV and | η jet | < 2.5 . The Z + c production cross section is measured to be σ ( p p → Z + c + X ) B ( Z → ℓ + ℓ - ) = 8.8 ± 0.5 (stat) ± 0.6 (syst) pb . The ratio of the Z + c and Z + b production cross sections is measured to be σ ( p p → Z + c + X ) / σ ( p p → Z + b + X ) = 2.0 ± 0.2 (stat) ± 0.2 (syst) . The Z + c production cross section and the cross section ratio are also measured as a function of the transverse momentum of the Z boson and of the heavy flavour jet. The measurements are compared with theoretical predictions.

Fulltext Measurement of the average very forward energy as a function of the track multiplicity at central pseudorapidities in proton-proton collisions at s = 13 TeV

Sirunyan AM, Tumasyan A, Adam W, Ambrogi F, Bergauer T, Brandstetter J, et al.

Eur Phys J C Part Fields, 2019;79(11):893.

PMID: 31886779 DOI: 10.1140/epjc/s10052-019-7402-3

The average total energy as well as its hadronic and electromagnetic components are measured with the CMS detector at pseudorapidities - 6.6 < η < - 5.2 in proton-proton collisions at a centre-of-mass energy s = 13 TeV . The results are presented as a function of the charged particle multiplicity in the region | η | < 2 . This measurement is sensitive to correlations induced by the underlying event structure over a very wide pseudorapidity region. The predictions of Monte Carlo event generators commonly used in collider experiments and ultra-high energy cosmic ray physics are compared to the data. All generators considered overestimate the fraction of energy going into hadrons.

Fulltext Studies of B s 2 ∗ ( 5840 ) 0 and B s 1 ( 5830 ) 0 mesons including the observation of the B s 2 ∗ ( 5840 ) 0 → B 0 K S 0 decay in proton-proton collisions at s = 8 TeV

Sirunyan AM, Tumasyan A, Adam W, Ambrogi F, Asilar E, Bergauer T, et al.

Eur Phys J C Part Fields, 2018;78(11):939.

PMID: 30881211 DOI: 10.1140/epjc/s10052-018-6390-z

Measurements of B s 2 ∗ ( 5840 ) 0 and B s 1 ( 5830 ) 0 mesons are performed using a data sample of proton-proton collisions corresponding to an integrated luminosity of , collected with the CMS detector at the LHC at a centre-of-mass energy of 8 TeV . The analysis studies P-wave B s 0 meson decays into B ( ∗ ) + K - and B ( ∗ ) 0 K S 0 , where the B + and B 0 mesons are identified using the decays B + → J / ψ K + and B 0 → J / ψ K ∗ ( 892 ) 0 . The masses of the P-wave B s 0 meson states are measured and the natural width of the B s 2 ∗ ( 5840 ) 0 state is determined. The first measurement of the mass difference between the charged and neutral B ∗ mesons is also presented. The B s 2 ∗ ( 5840 ) 0 decay to B 0 K S 0 is observed, together with a measurement of its branching fraction relative to the B s 2 ∗ ( 5840 ) 0 → B + K - decay.

Fulltext Measurement of exclusive ρ 770 0 photoproduction in ultraperipheral pPb collisions at s NN = 5.02 Te

Sirunyan AM, Tumasyan A, Adam W, Ambrogi F, Asilar E, Bergauer T, et al.

Eur Phys J C Part Fields, 2019;79(8):702.

PMID: 31524889 DOI: 10.1140/epjc/s10052-019-7202-9

Exclusive ρ 770 0 photoproduction is measured for the first time in ultraperipheral pPb collisions at s NN = 5.02 Te with the CMS detector. The cross section σ ( γ p → ρ 770 0 p ) is 11.0 ± 1.4 (stat) ± 1.0 (syst) μ b at ⟨ W γ p ⟩ = 92.6 Ge for photon-proton centre-of-mass energies W γ p between 29 and 213 Ge . The differential cross section d σ / d | t | is measured in the interval 0.025 < | t | < 1 Ge 2 as a function of W γ p , where t is the squared four-momentum transfer at the proton vertex. The results are compared with previous measurements and theoretical predictions. The measured cross section σ ( γ p → ρ 770 0 p ) has a power-law dependence on the photon-proton centre-of-mass, consistent with electron-proton collision measurements performed at HERA. The W γ p dependence of the exponential slope of the differential cross section d σ / d | t | is also measured.

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