MyMedR

Fulltext Search for Narrow Resonances in Dijet Final States at sqrt[s]=8 TeV with the Novel CMS Technique of Data Scouting

Khachatryan V, Sirunyan AM, Tumasyan A, Adam W, Asilar E, Bergauer T, et al.

Phys Rev Lett, 2016 Jul 15;117(3):031802.

PMID: 27472109 DOI: 10.1103/PhysRevLett.117.031802

A search for narrow resonances decaying into dijet final states is performed on data from proton-proton collisions at a center-of-mass energy of 8 TeV, corresponding to an integrated luminosity of 18.8 fb^{-1}. The data were collected with the CMS detector using a novel technique called data scouting, in which the information associated with these selected events is much reduced, permitting collection of larger data samples. This technique enables CMS to record events containing jets at a rate of 1 kHz, by collecting the data from the high-level-trigger system. In this way, the sensitivity to low-mass resonances is increased significantly, allowing previously inaccessible couplings of new resonances to quarks and gluons to be probed. The resulting dijet mass distribution yields no evidence of narrow resonances. Upper limits are presented on the resonance cross sections as a function of mass, and compared with a variety of models predicting narrow resonances. The limits are translated into upper limits on the coupling of a leptophobic resonance Z_{B}^{'} to quarks, improving on the results obtained by previous experiments for the mass range from 500 to 800 GeV.

Fulltext Measurements of the [Formula: see text] production cross section in lepton+jets final states in pp collisions at 8 [Formula: see text] and ratio of 8 to 7 [Formula: see text] cross sections

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.

Fulltext Forward-backward asymmetry of Drell-Yan lepton pairs in pp collisions at [Formula: see text][Formula: see text]

Khachatryan V, Sirunyan AM, Tumasyan A, Adam W, Asilar E, Bergauer T, et al.

Eur Phys J C Part Fields, 2016;76(6):325.

PMID: 28280439 DOI: 10.1140/epjc/s10052-016-4156-z

A measurement of the forward-backward asymmetry [Formula: see text] of oppositely charged lepton pairs ([Formula: see text] and [Formula: see text]) produced via [Formula: see text] boson exchange in pp collisions at [Formula: see text] [Formula: see text] is presented. The data sample corresponds to an integrated luminosity of 19.7[Formula: see text] collected with the CMS detector at the LHC. The measurement of [Formula: see text] is performed for dilepton masses between 40[Formula: see text] and 2[Formula: see text] and for dilepton rapidity up to 5. The [Formula: see text] measurements as a function of dilepton mass and rapidity are compared with the standard model predictions.

Measurements of the associated production of a Z boson and b jets in pp collisions at s = 8 TeV

Khachatryan V, Sirunyan AM, Tumasyan A, Adam W, Asilar E, Bergauer T, et al.

Eur Phys J C Part Fields, 2017;77(11):751.

PMID: 31999282 DOI: 10.1140/epjc/s10052-017-5140-y

Measurements of the associated production of a
Z
boson with at least one jet originating from a b quark in proton-proton collisions at

s

=
8

TeV

are presented. Differential cross sections are measured with data collected by the CMS experiment corresponding to an integrated luminosity of 19.8

fb

-
1

.
Z
bosons are reconstructed through their decays to electrons and muons. Cross sections are measured as a function of observables characterizing the kinematics of the
b
jet and the
Z
boson. Ratios of differential cross sections for the associated production with at least one
b
jet to the associated production with any jet are also presented. The production of a
Z
boson with at least two
b
jets is investigated, and differential cross sections are measured for the dijet system. Results are compared to theoretical predictions, testing two different flavour schemes for the choice of initial-state partons.

Fulltext Measurement of the WZ production cross section in pp collisions at [Formula: see text] and 8[Formula: see text] and search for anomalous triple gauge couplings at [Formula: see text]

Khachatryan V, Sirunyan AM, Tumasyan A, Adam W, Asilar E, Bergauer T, et al.

Eur Phys J C Part Fields, 2017;77(4):236.

PMID: 28515665 DOI: 10.1140/epjc/s10052-017-4730-z

The WZ production cross section is measured by the CMS experiment at the CERN LHC in proton-proton collision data samples corresponding to integrated luminosities of 4.9[Formula: see text] collected at [Formula: see text], and 19.6[Formula: see text] at [Formula: see text]. The measurements are performed using the fully-leptonic WZ decay modes with electrons and muons in the final state. The measured cross sections for [Formula: see text] are [Formula: see text] [Formula: see text] and [Formula: see text] [Formula: see text]. Differential cross sections with respect to the [Formula: see text] boson [Formula: see text], the leading jet [Formula: see text], and the number of jets are obtained using the [Formula: see text] data. The results are consistent with standard model predictions and constraints on anomalous triple gauge couplings are obtained.

Measurement of the [Formula: see text] cross section in pp collisions at [Formula: see text] TeVand limits on anomalous gauge couplings

Khachatryan V, Sirunyan AM, Tumasyan A, Adam W, Asilar E, Bergauer T, et al.

Eur Phys J C Part Fields, 2016;76(7):401.

PMID: 28286414 DOI: 10.1140/epjc/s10052-016-4219-1

A measurement of the W boson pair production cross section in proton-proton collisions at [Formula: see text] TeV is presented. The data collected with the CMS detector at the LHC correspond to an integrated luminosity of 19.4[Formula: see text]. The [Formula: see text] candidates are selected from events with two charged leptons, electrons or muons, and large missing transverse energy. The measured [Formula: see text] cross section is [Formula: see text], consistent with the standard model prediction. The [Formula: see text] cross sections are also measured in two different fiducial phase space regions. The normalized differential cross section is measured as a function of kinematic variables of the final-state charged leptons and compared with several perturbative QCD predictions. Limits on anomalous gauge couplings associated with dimension-six operators are also given in the framework of an effective field theory. The corresponding 95 % confidence level intervals are [Formula: see text], [Formula: see text], [Formula: see text], in the HISZ basis.

Fulltext Search for lepton flavour violating decays of heavy resonances and quantum black holes to an [Formula: see text] pair in proton-proton collisions at [Formula: see text]

Khachatryan V, Sirunyan AM, Tumasyan A, Adam W, Asilar E, Bergauer T, et al.

Eur Phys J C Part Fields, 2016;76(6):317.

PMID: 28775662 DOI: 10.1140/epjc/s10052-016-4149-y

A search for narrow resonances decaying to an electron and a muon is presented. The [Formula: see text] [Formula: see text] mass spectrum is also investigated for non-resonant contributions from the production of quantum black holes (QBHs). The analysis is performed using data corresponding to an integrated luminosity of 19.7[Formula: see text] collected in proton-proton collisions at a centre-of-mass energy of 8[Formula: see text] with the CMS detector at the LHC. With no evidence for physics beyond the standard model in the invariant mass spectrum of selected [Formula: see text] pairs, upper limits are set at 95 [Formula: see text] confidence level on the product of cross section and branching fraction for signals arising in theories with charged lepton flavour violation. In the search for narrow resonances, the resonant production of a [Formula: see text] sneutrino in R-parity violating supersymmetry is considered. The [Formula: see text] sneutrino is excluded for masses below 1.28[Formula: see text] for couplings [Formula: see text], and below 2.30[Formula: see text] for [Formula: see text] and [Formula: see text]. These are the most stringent limits to date from direct searches at high-energy colliders. In addition, the resonance searches are interpreted in terms of a model with heavy partners of the [Formula: see text] boson and the photon. In a framework of TeV-scale quantum gravity based on a renormalization of Newton's constant, the search for non-resonant contributions to the [Formula: see text] [Formula: see text] mass spectrum excludes QBH production below a threshold mass [Formula: see text] of 1.99[Formula: see text]. In models that invoke extra dimensions, the bounds range from 2.36[Formula: see text] for one extra dimension to 3.63[Formula: see text] for six extra dimensions. This is the first search for QBHs decaying into the [Formula: see text] [Formula: see text] final state.

Fulltext Search for heavy resonances decaying to two Higgs bosons in final states containing four b quarks

Khachatryan V, Sirunyan AM, Tumasyan A, Adam W, Asilar E, Bergauer T, et al.

Eur Phys J C Part Fields, 2016;76(7):371.

PMID: 28280444 DOI: 10.1140/epjc/s10052-016-4206-6

A search is presented for narrow heavy resonances X decaying into pairs of Higgs bosons ([Formula: see text]) in proton-proton collisions collected by the CMS experiment at the LHC at [Formula: see text]. The data correspond to an integrated luminosity of 19.7[Formula: see text]. The search considers [Formula: see text] resonances with masses between 1 and 3[Formula: see text], having final states of two b quark pairs. Each Higgs boson is produced with large momentum, and the hadronization products of the pair of b quarks can usually be reconstructed as single large jets. The background from multijet and [Formula: see text] events is significantly reduced by applying requirements related to the flavor of the jet, its mass, and its substructure. The signal would be identified as a peak on top of the dijet invariant mass spectrum of the remaining background events. No evidence is observed for such a signal. Upper limits obtained at 95 % confidence level for the product of the production cross section and branching fraction [Formula: see text] range from 10 to 1.5[Formula: see text] for the mass of X from 1.15 to 2.0[Formula: see text], significantly extending previous searches. For a warped extra dimension theory with a mass scale [Formula: see text] [Formula: see text], the data exclude radion scalar masses between 1.15 and 1.55[Formula: see text].

Aleukemic bcr-abl positive granulocytic sarcoma

Kuan JW, Pathmanathan R, Chang KM, Tan SM

Leuk. Res., 2009 Nov;33(11):1574-7.

PMID: 19215983 DOI: 10.1016/j.leukres.2009.01.016

Granulocytic sarcoma (GS) can occur de novo or in association with intramedullary myeloid disorders. With the advent of sophisticated molecular detection techniques to detect diagnostic genes such as bcr-abl, PML-RARA and CBFB/MYH11 in bone marrow or peripheral blood, many cases of the so called 'primary' GS are questionable. We report a case of primary GS where the tumor mass bcr-abl translocation was demonstrated by fluorescent in situ hybridization in which there was no evidence of chronic myeloid leukemia (CML). This is an important finding as it highlights the possibility that CML may present as a sole extramedullary form, and illustrates potential treatment by tyrosine kinase inhibitor.

A randomized double blind control trial comparing filgrastim and pegfilgrastim in cyclophosphamide peripheral blood hematopoietic stem cell mobilization

Kuan JW, Su AT, Wong SP, Sim XY, Toh SG, Ong TC, et al.

Transfus Apher Sci, 2015 Oct;53(2):196-204.

PMID: 25910537 DOI: 10.1016/j.transci.2015.03.017

There are few randomized trials comparing filgrastim and pegfilgrastim in peripheral blood stem cell mobilization (PBSCM). None of the trials studied the effects of the timing of pegfilgrastim administration on the outcomes of mobilization. We conducted a randomized triple blind control trial comparing the outcomes of filgrastim 5 µg/kg daily from day 3 onwards, 'early' pegfilgrastim 6 mg on day 3 and 'delayed' pegfilgrastim 6 mg on day 7 in cyclophosphamide PBSCM in patients with no previous history of mobilization. Peripheral blood (PB) CD34+ cell count was checked on day 8 and day 11 onward. Apheresis was started when PB CD34+ ≥ 10/µl from day 11 onward. The primary outcome was the successful mobilization rate, defined as cumulative collection of ≥2 × 10(6)/kg CD34+ cells in three or less apheresis. The secondary outcomes were the day of neutrophil and platelet engraftment post transplantation. There were 156 patients randomized and 134 patients' data analyzed. Pegfilgrastim 6 mg day 7 produced highest percentage of successful mobilization, 34 out of 48 (70.8%) analyzed patients, followed by daily filgrastim, 28 out of 44 (63.6%) and day 3 pegfilgrastim, 20 out of 42 (47.6%) (p = 0.075). Pegfilgrastim day 7 and daily filgrastim reported 1.48 (p = 0.014) and 1.49 (p = 0.013) times higher successful mobilization rate respectively as compared to pegfilgrastim day 3 after adjusting for disease, gender and exposure to myelotoxic agent. Multiple myeloma patients were three times more likely to achieve successful mobilization as compared to acute leukemia or lymphoma patients. Pegfilgrastim avoided the overshoot of white cells compared to filgrastim. There was no difference in the duration of both white cells and platelet recovery post transplantation between the three interventional arms.

Fulltext Autologous stem cell transplantation (ASCT) outcome for multiple myeloma in a tertiary referral centre in Malaysia

Liam CCK, Boo YL, Lee YL, Law KB, Ho KW, Shahnaz SAKS, et al.

Blood Cell Ther, 2021 Feb 25;4(1):1-8.

PMID: 36712843 DOI: 10.31547/bct-2020-009

BACKGROUND: Multiple Myeloma (MM) is characterized by the presence of clonal plasma cells. These often result in complications including bone destruction, hypercalcemia, renal insufficiency, and anaemia. Induction with a triplet or quadruplet regimen followed by autologous stem cell transplantation (ASCT) has been the standard of care for transplant eligible patients to achieve durable remission.

PURPOSE: This is a retrospective analytical study to determine the outcome of Multiple Myeloma patients who underwent ASCT in Ampang Hospital.

MATERIALS AND METHODS: We included a 5-year cohort of patients transplanted from 1st July 2014 to 30th June 2019. Data were obtained through electronic medical records. Prognostic factors for progression-free survival (PFS) and overall survival (OS) were analyzed using simple and multiple Cox proportional hazard regression analysis. All analyses were done using software R version 3.6.2 with validated statistical packages.

RESULTS: 139 patients were analyzed. The median age at transplant was 56 years old and 56.1% are males (n＝78). The most common subtype is IgG Kappa (n＝67, 48.2%). Only 93 patients in which the International Staging System (ISS) could be determined, and among them, 33.3% of patients (n＝31) have advanced stage Ⅲ disease. The most common induction received before ASCT was a bortezomib based regimen and/or an immunomodulatory (IMiD) based regimen. 63.3% of patients achieved at least a very good partial response (VGPR) before ASCT. Most patients received myeloablative conditioning (MAC) (n＝119, 85.6%). The mean cell dose is 3.68×106/kg. The median time to engraftment was 11 days for both platelet and absolute neutrophil count (ANC). With the median follow-up of 17.3 (range, 6.2-33.4) months, the median OS and PFS were not reached. The 1-year and 2-year PFS were 75% (95% CI 66-82%) and 52% (95% CI 42-62%), respectively. The 1-year and 2-year OS were 82% (95% CI 74-88%) and 70% (95% CI 60-78%), respectively. 6 patients (4.3%) had transplant-related mortality (TRM). IgA subtype was found to adversely affect PFS. Maintenance therapy and the absence of renal impairment was associated with better PFS and OS.

DISCUSSION AND CONCLUSIONS: Our study found that ASCT following induction treatment is safe and beneficial to achieve a deeper remission status. In our study, the addition of maintenance therapy is associated with an improved outcome in PFS and OS.

Fulltext I am Alexa, your virtual tutor!: The effects of Amazon Alexa's text-to-speech voice enthusiasm in a multimedia learning environment

Liew TW, Tan SM, Pang WM, Khan MTI, Kew SN

Educ Inf Technol (Dordr), 2023;28(2):1455-1489.

PMID: 35967831 DOI: 10.1007/s10639-022-11255-6

Modern text-to-speech voices can convey social cues ideal for narrating multimedia learning materials. Amazon Alexa has a unique feature among modern text-to-speech vocalizers as she can infuse enthusiasm cues into her synthetic voice. In this first study examining modern text-to-speech voice enthusiasm effects in a multimedia learning environment, a between-subjects online experiment was conducted where learners from a large Asian university (n = 244) listened to either Alexa's: (1) neutral voice, (2) low-enthusiastic voice, (3) medium-enthusiastic voice, or (4) high-enthusiastic voice, narrating a multimedia lesson on distributed denial-of-service attack. While Alexa's enthusiastic voices did not enhance persona ratings compared to Alexa's neutral voice, learners could infer more enthusiasm expressed by Alexa's medium-and high-enthusiastic voices than Alexa's neutral voice. Regarding cognitive load, Alexa's low-and high-enthusiastic voices decreased intrinsic and extraneous cognitive load ratings compared to Alexa's neutral voice. While Alexa's enthusiastic voices did not impact affective-motivational ratings differently from Alexa's neutral voice, learners reported a significant increase of positive emotions from their baseline positive emotions after listening to Alexa's medium-enthusiastic voice. Finally, Alexa's enthusiastic voices did not enhance the learning performance on immediate retention and transfer tests compared to Alexa's neutral voice. This study demonstrates that a modern text-to-speech voice enthusiasm can positively affect learners' emotions and cognitive load during multimedia learning. Theoretical and practical implications are discussed through the lens of the Cognitive Affective Model of E-learning, Integrated-Cognitive Affective Model of Learning with Multimedia, and Cognitive Load Theory. We further outline this study's limitations and recommendations for extending and widening the text-to-speech voice emotions research.

Fulltext Childhood adversity and adult depressive disorder: a case-controlled study in Malaysia

Loh SF, Maniam T, Tan SM, Badi'ah Y

East Asian Arch Psychiatry, 2010 Jun;20(2):87-91.

PMID: 22351814

Objective: To describe the association between childhood adversity and depression in adult depressed patients in a Malaysian population.
Methods: Fifty-two patients, who met the criteria for major depressive disorder or dysthymia according to the Structured Clinical Interview based on the revised 3rd edition of the Diagnostic and Statistical Manual of Mental Disorders, were used as cases and compared with 52 controls matched for age and sex. Cases and controls were assessed using a sexual and physical abuse questionnaire and a Parental Bonding Instrument.
Results: There was a positive relationship between childhood abuse in general and childhood physical abuse with adult depressive disorder in particular. Nearly a quarter (23%) of depressed patients reported being abused in childhood compared with none in the control group. There was no significant association between childhood loss and depression in adulthood. Low level of parental care during childhood was significantly correlated with adult depressive disorder.
Conclusion: Clinicians should assiduously seek a history of childhood adversities in adult patients with depression. This information can influence clinical management by way of implementing secondary preventive measures. In all depressed patients, mental health professionals also need to look out for their poor attachment with parents during childhood. This may enable interventions directed at parenting skills and improved attachment relationships with their own children. These types of interventions together
with pharmacotherapy may provide the optimal approach to the management of depression in adults and help prevent the cycle of depression perpetuating itself in the next generation.
Key words: Child abuse; Depression; Maternal behavior

Amplification of BCR-ABL and t(3;21) in a patient with blast crisis of chronic myelogenous leukemia

Phan CL, Megat Baharuddin PJ, Chin LP, Zakaria Z, Yegappan S, Sathar J, et al.

Cancer Genet. Cytogenet., 2008 Jan 1;180(1):60-4.

PMID: 18068536

The Philadelphia (Ph) chromosome, or t(9;22), is the hallmark of chronic myelogenous leukemia (CML). It results in juxtaposition of the 5' part of the BCR gene on chromosome 22 to the 3' part of the ABL1 gene (previously ABL) on chromosome 9. CML is clinically characterized by three distinct phases: chronic, accelerated, and blast phase. Blast crisis is characterized by the rapid expansion of a population of differentiation arrested blast cells (myeloid or lymphoid cells population), with secondary chromosomal abnormalities present. We report a case of myeloid blast crisis of CML resistant to imatinib mesylate and chemotherapy. By use of cytogenetic, fluorescence in situ hybridization, and comparative genomic hybridization methods, we identified a cluster of BCR-ABL amplification on inverted duplication of the Ph chromosome with t(3;21)(q26;q22) and increased genomic levels of the RUNX1 gene (previously AML1). The t(3;21)(q26;q22) is a recurrent chromosomal abnormality in some cases of CML blast phase and in treatment-related myelodysplastic syndrome and acute myeloid leukemia. Amplification or copy number increase of RUNX1 has been reported in childhood acute lymphoblastic leukemia. Our study indicated that the progenitor of CML was BCR-ABL dependent through the amplification of Ph chromosome as a mechanism of resistance to imatinib therapy. The coexistence of BCR-ABL and t(3;21)(q26;q22) with RUNX1 rearrangement might play a pivotal role in the CML blast transformation.

A variant e13a3 BCR-ABL1 fusion transcript in refractory adult B-cell acute lymphoblastic leukemia achieving complete remission with CAR-Tcell therapy

Phan CL, Tan SN, Tan SM, Kadir SSSA, Ramli NLM, Lim TO, et al.

Cancer Genet, 2021 01;250-251:20-24.

PMID: 33220656 DOI: 10.1016/j.cancergen.2020.11.003

Acute lymphoblastic leukemia (ALL) cases with e13a3 fusion transcripts are extremely rare. We report a 24-year-old male with Ph-positive (Ph+) ALL with an aberrant e13a3 fusion transcript treated with CD19-specific chimeric antigen receptor T-cell (CAR-T) therapy. He developed refractory disease post-chemotherapy induction, andreceived allogeneic hematopoietic stem cell transplantation (allo-HSCT) after salvage with imatinib in combination with chemotherapy regimen. Unfortunately, the patient relapsed after +90 days post-transplant. He was consented to CAR-T therapy trial and achieved complete remission, highlighting the efficacy of CAR-T treatment in relapsed-refractory B-ALL irrespective of the underlying genetic drivers in leukemia cells .

The effect of a clinical posting in psychiatry on the attitudes of medical students towards psychiatry and mental illness in a Malaysian medical school

Reddy JP, Tan SM, Azmi MT, Shaharom MH, Rosdinom R, Maniam T, et al.

Ann Acad Med Singap, 2005 Sep;34(8):505-10.

PMID: 16205829

INTRODUCTION: The stigma attached to mental illness and the mentally ill is a universal phenomenon and a major barrier to the provision of mental health services. Stigmatising attitudes among doctors themselves can result in compromised patient care. The aim of this research project is to study the impact of a clinical posting in psychiatry on the attitudes of medical students to mental illness and to psychiatry. This paper reports the results of the first phase of a longitudinal study.

MATERIALS AND METHODS: A total of 122 year 4 medical students responded to this study. The Attitudes Towards Mental Illness (AMI) and Attitudes Towards Psychiatry (ATP) questionnaires were administered before and after an 8-week attachment in psychiatry.

RESULTS: We found that students had somewhat favourable attitudes towards psychiatry and mental illness at the start of their attachment, with a mean score of 108.34 on ATP (neutral score, 90) and 68.24 on AMI (neutral score, 60). There was a significant increase in the mean scores of both scales following the psychiatric attachment for female students (ATP: P = 0.003; AMI: P <0.0005), but not male students (ATP: P = 0.435; AMI: P = 0.283).

CONCLUSIONS: An 8-week clinical posting of fourth-year medical students in psychiatry was associated with an increase in positive attitudes to mental illness and to psychiatry among female students but not among male students.

Fulltext Suppression of Excited ϒ States Relative to the Ground State in Pb-Pb Collisions at sqrt[s]_{NN}=5.02 TeV

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.

Studies of Charm Quark Diffusion inside Jets Using Pb-Pb and pp Collisions at sqrt[s_{NN}]=5.02 TeV

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

Observation of the B_{s}^{0}→X(3872)ϕ Decay

Sirunyan AM, Tumasyan A, Adam W, Ambrogi F, Bergauer T, Dragicevic M, et al.

Phys Rev Lett, 2020 Oct 09;125(15):152001.

PMID: 33095627 DOI: 10.1103/PhysRevLett.125.152001

Using a data sample of proton-proton collisions at sqrt[s]=13 TeV, corresponding to an integrated luminosity of 140 fb^{-1} collected by the CMS experiment in 2016-2018, the B_{s}^{0}→X(3872)ϕ decay is observed. Decays into J/ψπ^{+}π^{-} and K^{+}K^{-} are used to reconstruct, respectively, the X(3872) and ϕ. The ratio of the product of branching fractions B[B_{s}^{0}→X(3872)ϕ]B[X(3872)→J/ψπ^{+}π^{-}] to the product B[B_{s}^{0}→ψ(2S)ϕ]B[ψ(2S)→J/ψπ^{+}π^{-}] is measured to be [2.21±0.29(stat)±0.17(syst)]%. The ratio B[B_{s}^{0}→X(3872)ϕ]/B[B^{0}→X(3872)K^{0}] is found to be consistent with one, while the ratio B[B_{s}^{0}→X(3872)ϕ]/B[B^{+}→X(3872)K^{+}] is two times smaller. This suggests a difference in the production dynamics of the X(3872) in B^{0} and B_{s}^{0} meson decays compared to B^{+}. The reported observation may shed new light on the nature of the X(3872) particle.

Search for the X(5568) State Decaying into B_{s}^{0}π^{±} in Proton-Proton Collisions at sqrt[s]=8 TeV

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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