Search for exotic decays of the Higgs boson to a pair of pseudoscalars in the μμbb and ττbb final states

A search for exotic decays of the Higgs boson (H ) with a mass of 125Ge V to a pair of light pseudoscalars a 1 is performed in final states where one pseudoscalar decays to two b quarks and the other to a pair of muons or τ leptons. A data sample of proton-proton collisions at s = 13 Te V corresponding to an integrated luminosity of 138fb - 1 recorded with the CMS detector is analyzed. No statistically significant excess is observed over the standard model backgrounds. Upper limits are set at 95% confidence level (CL ) on the Higgs boson branching fraction to μ μ b b and to τ τ b b , via a pair of a 1 s. The limits depend on the pseudoscalar mass m a 1 and are observed to be in the range (0.17-3.3) × 10 - 4 and (1.7-7.7) × 10 - 2 in the μ μ b b and τ τ b b final states, respectively. In the framework of models with two Higgs doublets and a complex scalar singlet (2HDM+S), the results of the two final states are combined to determine upper limits on the branching fraction B ( H → a 1 a 1 → ℓ ℓ b b ) at 95% CL , with ℓ being a muon or a τ lepton. For different types of 2HDM+S, upper bounds on the branching fraction B ( H → a 1 a 1 ) are extracted from the combination of the two channels. In most of the Type II 2HDM+S parameter space, B ( H → a 1 a 1 ) values above 0.23 are excluded at 95% CL for m a 1 values between 15 and 60Ge V .

The effect of circadian timing program for evening-chronotype individuals with obesity on obesity management and sleep quality: A randomized controlled trial

OBJECTIVES

The study aimed to investigate the effect of the circadian timing program (SİZAP) developed for evening-chronotype individuals with obesity on obesity management and sleep quality.

METHODS

This single-site, randomized controlled trial with an experimental research design was registered in ClinicalTrials.gov. It was reported in accordance with the "Consolidated Standards of Reporting Trials" (CONSORT) randomized controlled trial guidelines. The study sample consisted of 38 evening-chronotype individuals with first-degree obesity, with 19 individuals in each study group. The intervention group's sleep hygiene training was conducted and their lifestyle changes were ensured through SİZAP. The control group followed their normal daily lifestyle. No intervention was made in terms of the dietary practices of both groups. Study data were collected using the personal information form, the anthropometric measurement form, the Horne and Ostberg Morning and Evening Questionnaire (MEQ), the Impact of weight on quality of life-lite (IWQOL-lite), the Pittsburgh Sleep Quality Index (PSQI), the Epworth Sleepiness Scale (ESS), the sleep diary, and the data tracked via the website and smart bracelets.

RESULTS

It was determined that the participants in the SİZAP group had a statistically significant decrease in the anthropometric measurements and daytime sleepiness (p < 0.05). The sleep quality scores and the scores of the bodily functions sub-dimension of the quality of life scale were significantly better in the intervention group than in the control group (p < 0.05).

CONCLUSION

It was found that SİZAP is effective in obesity management in evening-chronotype individuals and increases weight loss success and sleep quality.

Observation of WWγ Production and Search for Hγ Production in Proton-Proton Collisions at sqrt[s]=13 TeV

The observation of WWγ production in proton-proton collisions at a center-of-mass energy of 13 TeV with an integrated luminosity of 138  fb^{-1} is presented. The observed (expected) significance is 5.6 (5.1) standard deviations. Events are selected by requiring exactly two leptons (one electron and one muon) of opposite charge, moderate missing transverse momentum, and a photon. The measured fiducial cross section for WWγ is 5.9±0.8(stat)±0.8(syst)±0.7(modeling)  fb, in agreement with the next-to-leading order quantum chromodynamics prediction. The analysis is extended with a search for the associated production of the Higgs boson and a photon, which is generated by a coupling of the Higgs boson to light quarks. The result is used to constrain the Higgs boson couplings to light quarks.

New Structures in the J/ψJ/ψ Mass Spectrum in Proton-Proton Collisions at sqrt[s]=13 TeV

A search is reported for near-threshold structures in the J/ψJ/ψ invariant mass spectrum produced in proton-proton collisions at sqrt[s]=13  TeV from data collected by the CMS experiment, corresponding to an integrated luminosity of 135  fb^{-1}. Three structures are found, and a model with quantum interference among these structures provides a good description of the data. A new structure is observed with a local significance above 5 standard deviations at a mass of 6638_{-38}^{+43}(stat)_{-31}^{+16}(syst)  MeV. Another structure with even higher significance is found at a mass of 6847_{-28}^{+44}(stat)_{-20}^{+48}(syst)  MeV, which is consistent with the X(6900) resonance reported by the LHCb experiment and confirmed by the ATLAS experiment. Evidence for another new structure, with a local significance of 4.7 standard deviations, is found at a mass of 7134_{-25}^{+48}(stat)_{-15}^{+41}(syst)  MeV. Results are also reported for a model without interference, which does not fit the data as well and shows mass shifts up to 150 MeV relative to the model with interference.

Search for Scalar Leptoquarks Produced via τ-Lepton-Quark Scattering in pp Collisions at sqrt[s]=13 TeV

The first search for scalar leptoquarks produced in τ-lepton-quark collisions is presented. It is based on a set of proton-proton collision data recorded with the CMS detector at the LHC at a center-of-mass energy of 13 TeV corresponding to an integrated luminosity of 138  fb^{-1}. The reconstructed final state consists of a jet, significant missing transverse momentum, and a τ lepton reconstructed through its hadronic or leptonic decays. Limits are set on the product of the leptoquark production cross section and branching fraction and interpreted as exclusions in the plane of the leptoquark mass and the leptoquark-τ-quark coupling strength.

Search for Inelastic Dark Matter in Events with Two Displaced Muons and Missing Transverse Momentum in Proton-Proton Collisions at sqrt[s]=13 TeV

A search for dark matter in events with a displaced nonresonant muon pair and missing transverse momentum is presented. The analysis is performed using an integrated luminosity of 138  fb^{-1} of proton-proton (pp) collision data at a center-of-mass energy of 13 TeV produced by the LHC in 2016-2018. No significant excess over the predicted backgrounds is observed. Upper limits are set on the product of the inelastic dark matter production cross section σ(pp→A^{'}→χ_{1}χ_{2}) and the decay branching fraction B(χ_{2}→χ_{1}μ^{+}μ^{-}), where A^{'} is a dark photon and χ_{1} and χ_{2} are states in the dark sector with near mass degeneracy. This is the first dedicated collider search for inelastic dark matter.

Luminosity determination using Z boson production at the CMS experiment

The measurement of Z boson production is presented as a method to determine the integrated luminosity of CMS data sets. The analysis uses proton-proton collision data, recorded by the CMS experiment at the CERN LHC in 2017 at a center-of-mass energy of 13Te V . Events with Z bosons decaying into a pair of muons are selected. The total number of Z bosons produced in a fiducial volume is determined, together with the identification efficiencies and correlations from the same data set, in small intervals of 20pb - 1 of integrated luminosity, thus facilitating the efficiency and rate measurement as a function of time and instantaneous luminosity. Using the ratio of the efficiency-corrected numbers of Z bosons, the precisely measured integrated luminosity of one data set is used to determine the luminosity of another. For the first time, a full quantitative uncertainty analysis of the use of Z  bosons for the integrated luminosity measurement is performed. The uncertainty in the extrapolation between two data sets, recorded in 2017 at low and high instantaneous luminosity, is less than 0.5%. We show that the Z boson rate measurement constitutes a precise method, complementary to traditional methods, with the potential to improve the measurement of the integrated luminosity.

Occupational fatigue, compassion competence and caring behaviours of intensive care nurses: A structural equation modelling approach

BACKGROUND

No previous study has examined the direct effect of occupational fatigue, inter-shift recovery and compassion competence on caring behaviours, including assurance, knowledge-skill, respect and commitment in intensive care nurses.

AIM

We studied the direct effect of participating nurses' occupational fatigue, inter-shift recovery and compassion competence levels on their caring behaviours and the relationship among these variables.

STUDY DESIGN

This was a descriptive correlational study. All nurses who were registered members of the Turkish Intensive Care Nurses Association were invited to participate in this online survey. This study was conducted with 315 intensive care nurses using convenience sampling between April and July 2022. The data were collected using the Occupational Fatigue Exhaustion/Recovery Scale, which consists of three subscales: acute fatigue, chronic fatigue and inter-shift recovery; the Compassion Competence Scale, including communication, sensitivity and insight subscales; and the Caring Behaviours Inventory-24. In addition, a structural equation model was established using variables correlating with caring behaviours. Independent variables were occupational fatigue, inter-ship recovery and compassion competence; and the dependent variable was caring behaviours in this hypothesized model.

RESULTS

Three hundred and fifteen nurses completed the survey (315/1000) with a response rate of 31.5%. The increase in the inter-shift recovery levels of participants was statistically and positively associated with caring behaviours (95% confidence interval [CI]: 0.001-0.011, β = .154 [moderate effect size], p < .05). The sub-dimensions of the Compassion Competence Scale, that is, communication (95% CI: 0.110-0.443, β = .251 [moderate effect size]) and sensitivity (95% CI: 0.084-0.427, β = .241 [moderate effect size]), were statistically and positively associated with the caring behaviours of participants (p < .05). In addition, independent variables accounted for 35% (large effect size) of the total change in caring behaviours (R2  = 0.350).

CONCLUSIONS

This study suggests that the high inter-shift recovery and compassion competence levels of intensive care nurses are positively associated with their caring behaviours.

RELEVANCE TO CLINICAL PRACTICE

Nursing managers should consider the direct effect of occupational fatigue, inter-shift recovery and the compassion competence levels of intensive care nurses on their caring behaviours to provide high-quality care.

Depression, anxiety, stress, and job performance among Turkish nurses in the early post-earthquake period

BACKGROUND

Individual and social concerns can negatively affect nurses' mental health during a large-scale earthquake's early stages, making it challenging to perform their professional responsibilities.

AIM

This cross-sectional correlational study aimed to examine the relationship between depression, anxiety, and stress levels Turkish nurses experienced during an earthquake's early period. The nurses participating in this study were not directly present in the earthquake-affected area.

METHODS

The study was conducted on 232 nurses between February 10 and 25, 2023. The data were collected using the Depression, Anxiety, Stress-21 Scale and the Job Performance Evaluation Form developed by the researchers through a literature review. These were used to investigate nurses' work motivation changes due to the earthquake. The study followed the STROBE checklist for cross-sectional studies.

RESULTS

The participants' depression levels were severe, anxiety levels were extremely severe, and stress levels were moderate following the earthquake. Nurses who felt exhausted experienced reduced energy levels toward their work and reported a decrease in their desire, effort, and work motivation to perform well. In addition, they had higher depression, anxiety, and stress scores (p < 0.005).

CONCLUSION

Psychological difficulties, including depression, anxiety, and stress experienced by nurses not directly present in an earthquake-affected area, reduced their professional efforts and motivation and negatively affected the patient care process. Further studies should focus on conducting comparative studies in different cultures affected by natural disasters on the longitudinal analysis of the impacts of nurses' psychological distress on their job performance.

IMPLICATIONS FOR NURSING AND HEALTH POLICY

Nursing policymakers should be aware of the negative psychological effects experienced by nurses during the early post-earthquake period, even if they are not directly present in the earthquake-affected area. The study recommended that nurses should be provided with psychological support to deal with the negative effects of natural disasters and maintain job performance, including the nursing care process.

Comparing the Efficacy of Zinc Oxide Versus Barrier Creams for Pressure Injury Prevention: A Retrospective Cross-sectional Study

OBJECTIVE

To compare the efficacy of zinc oxide versus barrier creams for the maintenance of skin integrity in intensive care patients with a risk of pressure injury (PI).

METHODS

This was a retrospective and cross-sectional study. The authors included data from 95 patients treated in the neurology and respiratory ICUs of a training and research hospital between January and June 2022. Patients in the neurology ICU were treated with zinc oxide cream (group 1, n = 48), and patients in the respiratory ICU received classic barrier cream (group 2, n = 47). Sociodemographic characteristics and PI data (Braden Scale score, Pressure Ulcer Healing Assessment Scale [PUSH] score, and PI stage) were obtained from each patient's file.

RESULTS

The mean PUSH score of the patients who received zinc oxide cream was 3.83 ± 4.39 at discharge versus 6.79 ± 4.40 for the group who received barrier cream. When PUSH scores and PI stages during hospitalization and discharge were compared, the authors found a statistically significant between-group difference in mean discharge scores (P < .05).

CONCLUSIONS

Within the limitations of this retrospective study based on patient records, zinc oxide creams had more positive effects on the prevention of PIs than barrier creams.

Development of the sleep quality scale for coronary care patients (SQ-CC)

OBJECTIVES

In this study, it was aimed to develop a valid and reliable measurement instrument to measure sleep quality in coronary care patients.

RESEARCH METHODOLOGY/DESIGN

This is a methodological study that was carried out with 201 patients at the coronary care unit of a university hospital. The validity and reliability of the scale were tested using exploratory and confirmatory factor analyses, Cronbach's alpha analysis, and Pearson's correlation analysis.

RESULTS

The scale's Cronbach's alpha coefficient was found to be 0.816. There were significant positive relationships between the overall scale and its dimensions. The Pearson's correlation analysis showed a significant negative relationship between the Sleep Quality Scale for Coronary Care Patients and the Richards-Campbell Sleep Questionnaire.

CONCLUSION

The Sleep Quality Scale for Coronary Care Patients was determined to be a valid and reliable measurement instrument for assessing the sleep quality of patients who are receiving care in coronary care units.

IMPLICATIONS FOR CLINICAL PRACTICE

The scale that was developed in this study can be applied to coronary care patients because it is easy to implement and specific to intensive care settings. This way, the sleep quality levels of patients can be assessed quickly, and nursing interventions for potential problems can be defined. Hence, the emergence of sleep-related health problems can be prevented. Although RCSQ is the most commonly used scale to evaluate the sleep quality of patients treated in the intensive care unit, SQ-CC is thought to be more inclusive in considering noise-, environment-, and patient-related subjective factors. The evaluation of environmental factors can also provide objective data for improvements to be made to eliminate these factors in clinics. Furthermore, the use of this scale in national and international scientific studies where the sleep quality of coronary care patients is evaluated will contribute to not only our colleagues but also the relevant scientific field.

Observation of the Rare Decay of the η Meson to Four Muons

A search for the rare η→μ^{+}μ^{-}μ^{+}μ^{-} double-Dalitz decay is performed using a sample of proton-proton collisions, collected by the CMS experiment at the CERN LHC with high-rate muon triggers during 2017 and 2018 and corresponding to an integrated luminosity of 101  fb^{-1}. A signal having a statistical significance well in excess of 5 standard deviations is observed. Using the η→μ^{+}μ^{-} decay as normalization, the branching fraction B(η→μ^{+}μ^{-}μ^{+}μ^{-})=[5.0±0.8(stat)±0.7(syst)±0.7(B_{2μ})]×10^{-9} is measured, where the last term is the uncertainty in the normalization channel branching fraction. This work achieves an improved precision of over 5 orders of magnitude compared to previous results, leading to the first measurement of this branching fraction, which is found to agree with theoretical predictions.

Measurements of jet multiplicity and jet transverse momentum in multijet events in proton-proton collisions at s=13TeV

Multijet events at large transverse momentum (p T ) are measured at s = 13 Te V using data recorded with the CMS detector at the LHC, corresponding to an integrated luminosity of 36.3 fb - 1 . The multiplicity of jets with p T > 50 Ge V that are produced in association with a high-p T dijet system is measured in various ranges of the p T of the jet with the highest transverse momentum and as a function of the azimuthal angle difference Δ ϕ 1 , 2 between the two highest p T jets in the dijet system. The differential production cross sections are measured as a function of the transverse momenta of the four highest p T jets. The measurements are compared with leading and next-to-leading order matrix element calculations supplemented with simulations of parton shower, hadronization, and multiparton interactions. In addition, the measurements are compared with next-to-leading order matrix element calculations combined with transverse-momentum dependent parton densities and transverse-momentum dependent parton shower.

Azimuthal correlations in Z +jets events in proton-proton collisions at s=13TeV

The production of Z bosons associated with jets is measured in pp collisions at s = 13 Te V with data recorded with the CMS experiment at the LHC corresponding to an integrated luminosity of 36.3fb - 1 . The multiplicity of jets with transverse momentum p T > 30 Ge V is measured for different regions of the Z boson's p T ( Z ) , from lower than 10Ge V to higher than 100Ge V . The azimuthal correlation Δ ϕ between the Z boson and the leading jet, as well as the correlations between the two leading jets are measured in three regions of p T ( Z ) . The measurements are compared with several predictions at leading and next-to-leading orders, interfaced with parton showers. Predictions based on transverse-momentum dependent parton distributions and corresponding parton showers give a good description of the measurement in the regions where multiple parton interactions and higher jet multiplicities are not important. The effects of multiple parton interactions are shown to be important to correctly describe the measured spectra in the low p T ( Z ) regions.

Azimuthal Correlations within Exclusive Dijets with Large Momentum Transfer in Photon-Lead Collisions

The structure of nucleons is multidimensional and depends on the transverse momenta, spatial geometry, and polarization of the constituent partons. Such a structure can be studied using high-energy photons produced in ultraperipheral heavy-ion collisions. The first measurement of the azimuthal angular correlations of exclusively produced events with two jets in photon-lead interactions at large momentum transfer is presented, a process that is considered to be sensitive to the underlying nuclear gluon polarization. This study uses a data sample of ultraperipheral lead-lead collisions at sqrt[s_{NN}]=5.02  TeV, corresponding to an integrated luminosity of 0.38  nb^{-1}, collected with the CMS experiment at the LHC. The measured second harmonic of the correlation between the sum and difference of the two jet transverse momentum vectors is found to be positive, and rising, as the dijet transverse momentum increases. A well-tuned model that has been successful at describing a wide range of proton scattering data from the HERA experiments fails to describe the observed correlations, suggesting the presence of gluon polarization effects.

Measurement of the mass dependence of the transverse momentum of lepton pairs in Drell-Yan production in proton-proton collisions at s=13TeV

The double differential cross sections of the Drell-Yan lepton pair (ℓ + ℓ - , dielectron or dimuon) production are measured as functions of the invariant mass m ℓ ℓ , transverse momentum p T ( ℓ ℓ ) , and φ η ∗ . The φ η ∗ observable, derived from angular measurements of the leptons and highly correlated with p T ( ℓ ℓ ) , is used to probe the low-p T ( ℓ ℓ ) region in a complementary way. Dilepton masses up to 1Te V are investigated. Additionally, a measurement is performed requiring at least one jet in the final state. To benefit from partial cancellation of the systematic uncertainty, the ratios of the differential cross sections for various m ℓ ℓ ranges to those in the Z mass peak interval are presented. The collected data correspond to an integrated luminosity of 36.3fb - 1 of proton-proton collisions recorded with the CMS detector at the LHC at a centre-of-mass energy of 13Te V . Measurements are compared with predictions based on perturbative quantum chromodynamics, including soft-gluon resummation.

CMS pythia 8 colour reconnection tunes based on underlying-event data

New sets of parameter tunes for two of the colour reconnection models, quantum chromodynamics-inspired and gluon-move, implemented in the pythia  8 event generator, are obtained based on the default CMS pythia  8 underlying-event tune, CP5. Measurements sensitive to the underlying event performed by the CMS experiment at centre-of-mass energies s = 7 and 13Te V , and by the CDF experiment at 1.96Te V are used to constrain the parameters of colour reconnection models and multiple-parton interactions simultaneously. The new colour reconnection tunes are compared with various measurements at 1.96, 7, 8, and 13Te V including measurements of the underlying-event, strange-particle multiplicities, jet substructure observables, jet shapes, and colour flow in top quark pair (t t ¯ ) events. The new tunes are also used to estimate the uncertainty related to colour reconnection modelling in the top quark mass measurement using the decay products of t t ¯ events in the semileptonic channel at 13Te V .

Search for light Higgs bosons from supersymmetric cascade decays in pp collisions at s=13TeV

A search is reported for pairs of light Higgs bosons (H 1 ) produced in supersymmetric cascade decays in final states with small missing transverse momentum. A data set of LHC pp collisions collected with the CMS detector at s = 13 TeV and corresponding to an integrated luminosity of 138fb - 1 is used. The search targets events where both H 1 bosons decay into pairs that are reconstructed as large-radius jets using substructure techniques. No evidence is found for an excess of events beyond the background expectations of the standard model (SM). Results from the search are interpreted in the next-to-minimal supersymmetric extension of the SM, where a "singlino" of small mass leads to squark and gluino cascade decays that can predominantly end in a highly Lorentz-boosted singlet-like H 1 and a singlino-like neutralino of small transverse momentum. Upper limits are set on the product of the squark or gluino pair production cross section and the square of the branching fraction of the H 1 in a benchmark model containing almost mass-degenerate gluinos and light-flavour squarks. Under the assumption of an SM-like branching fraction, H 1 bosons with masses in the range 40-120GeV arising from the decays of squarks or gluinos with a mass of 1200-2500GeV are excluded at 95% confidence level.

Relationship between burnout levels of nurses and their circadian preference, sleep quality, and personality traits

Occupational stress and burnout are widely encountered among many healthcare professionals, including nurses and doctors, as well as among members of other professions. For example, nurses, who have disrupted circadian rhythms, are seen to have sleep problems. In addition, their personality traits are also considered to be related with burnout. This study aimed to identify nurses' circadian preference and personality traits along with their effects on sleep quality and their relationship with burnout. In this study, 211 nurses (40 male, 171 female) using the correlational model from quantitative research methods was used since the variables of morningness/eveningness, personality trait, sleep quality, and burnout were aimed to be investigated at once, without intervention, within the predictivity context of the relationship among them. When the scores obtained from the burnout scale were examined, it was observed that the emotional exhaustion and personal accomplishment subdimensions were so close to the median value and mean, while depersonalization was quite low compared to these sub-dimensions. The participants' sleep quality was seen to be at the lowest step of the poor sleep quality class. When the scores obtained from the MESSI scale are examined, it is seen that the scores obtained from the morning affect dimension are above the median value, and the highest average according to the Five-Factor Personality Traits Scale is obtained in the subdimensions of agreeableness and conscientiousness. Female gender, constantly work at night, having a high number of weekly working hours increased burnout level. Additionally Evening chronotype, poor sleep quality, neuroticism, agreeableness, extroversion and conscientiousness personality traits were found to be associated with burnout in this study. In the study, being of different chronotypes, having other personality traits, and varying sleep quality scores were seen to affect the sub-dimensions of burnout.

Experiences of Patients With Type 2 Diabetes Who Recovered From COVID-19 in the Pandemic Period: A Qualitative Study

Coronavirus disease 2019 (COVID-19) infection can induce acute and chronic complications by affecting the self-management behaviors of individuals with diabetes. The objective of this study is to examine the physical, psychosocial health, and self-management experiences of type 2 diabetes patients who have recovered from COVID-19, 1 year after the infection. The study adopted a qualitative research design, specifically content analysis. In all, 14 patients with type 2 diabetes who presented to the diabetes outpatient clinic were interviewed by teleconferencing, which lasted approximately 25 to 30 minutes. The Standards for Reporting Qualitative Research guidelines were used. Based on the participants' responses, four main themes were determined: obstacles in activities of daily living, feeling of psychosocial problems, changes in health and treatment management, and patient self-management practices. Amid the pandemic, diabetes nurses should strive to recognize the issues that diabetes patients encounter. To assist patients, telemedicine should be leveraged, and evidence-based practices must be developed.

Anxiety, Dyspnea Management, and Quality of Life in Palliative Care Patients: A Randomized Controlled Trial

AIM

This study aimed to determine the influence of nursing care grounded on Watson's Human Care Model on anxiety, dyspnea control, and life quality in palliative care patients.

METHOD

A randomized controlled study was designed. It was conducted on 64 participants hospitalized in a training and research hospital and 2 state hospital palliative care services in Turkey. The data were collected face to face using the patient information form, the Beck Anxiety Scale, the Hospital Anxiety and Depression Scale, the Medical Research Council Dyspnea Scale, and the Short Form-36 Quality of Life Scale.

RESULTS

It was detected that there was no statistically considerable difference in the median points of the Beck Anxiety Scale, Hospital Anxiety and Depression Scale, Medical Research Council Dyspnea Scale, and Short Form-36 domains between the two groups in the pretest. However, the posttest median points were remarkably lower and the posttest median points of the Short Form-36 scale were meaningfully higher in the intervention group (p < 0.05).

CONCLUSION

Nursing care grounded on Human Care Model reduced the grade of anxiety and dyspnea in patients and raised their life quality.

Effectiveness of Interventions on Death Anxiety and Fear in Adults with Chronic Disease: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

This systematic review and meta-analysis aimed to synthesize the outcomes of various interventions to alleviate death anxiety and fear. Studies published between January 2010 and June 2022 were searched in the ScienceDirect, Scopus, Web of Science, PubMed, Cochrane Library, and CHINAL databases. The Preferred Reporting Items for Systematic Reviews and Meta-analyses statement guidelines were used in this meta-analysis. The results were examined using 95% confidence intervals, p-values, and fixed- or random-effects models based on the heterogeneity test. Sixteen studies involving 1262 participants were included in this systematic review. Interventions in seven studies using the Templer Death Anxiety Scale (TDAS) significantly decreased death anxiety levels in the intervention groups compared to the control groups (z = -4.47; p < 0.001; 95% CI: -3.36 to -1.31). This meta-analysis provides insights into implementing logotherapy, cognitive behavioral therapy, spirituality-based care, and educational interventions for death anxiety and the fear experienced by patients with chronic diseases.

The relationship between chronotype and obesity: A systematic review

Referring to the hours during a day when a person's physical and cognitive functions are active, the chronotype indicates the differences in individual preferences in sleep timing and other behaviors. The fact that the evening chronotype has been associated with adverse health outcomes has raised the issue of relationship between chronotype and obesity. This study aims to synthesize the evidence regarding the relationship between chronotype and obesity. As part of the study, the PubMed, OVID-LWW, Scopus, Taylor & Francis, ScienceDirect, MEDLINE Complete, Cochrane Library and ULAKBIM databases were screened for the articles published between January 01, 2010 and December 31, 2020. The quality of each study was assessed independently by the two researchers using the "Quality Assessment Tool for Quantitative Studies." Upon evaluating the screening results, a total of seven studies, one of high quality and six of medium quality, were included in the systematic review. The rate of the minor allele (C) genes, which have been associated with obesity, and SIRT1-CLOCK genes, which have an additional effect in favor of resistance against weight loss, is higher in individuals of evening chronotype, and such individuals have been observed to have significantly higher resistance to weight loss. The evening chronotype individuals have been associated with a higher homeostasis model assessment (HOMA) value, higher plasma ghrelin levels, and a tendency toward a higher body mass index (BMI). The evening chronotypes have been reported to adhere less to a healthy diet and have more unhealthy behaviors and eating patterns. A diet adjusted to the chronotype has been seen to be more effective than conventional hypocaloric diet therapy in terms of anthropometric parameters. Most people who eat their main meals late are of evening chronotype, and such people have been determined to lose significantly less weight than those who eat early. It has been shown that bariatric surgery is less effective in weight loss in evening chronotype patients than in morning chronotype patients. The evening chronotypes are less successful in adapting to weight loss treatments and long-term weight control than the morning chronotypes.

Measurements of the associated production of a W boson and a charm quark in proton-proton collisions at s = 8 TeV

Measurements of the associated production of a W boson and a charm ( c ) quark in proton-proton collisions at a centre-of-mass energy of 8 TeV are reported. The analysis uses a data sample corresponding to a total integrated luminosity of 19.7 fb - 1 collected by the CMS detector at the LHC. The W bosons are identified through their leptonic decays to an electron or a muon, and a neutrino. Charm quark jets are selected using distinctive signatures of charm hadron decays. The product of the cross section and branching fraction σ ( pp → W + c + X ) B ( W → ℓ ν ) , where ℓ = e or μ , and the cross section ratio σ ( pp → W + + c ¯ + X ) / σ ( pp → W - + c + X ) are measured in a fiducial volume and differentially as functions of the pseudorapidity and of the transverse momentum of the lepton from the W boson decay. The results are compared with theoretical predictions. The impact of these measurements on the determination of the strange quark distribution is assessed.

The effect of probiotic and synbiotic use on glycemic control in women with gestational diabetes: A systematic review and meta-analysis

AIMS

To investigate the impact of probiotic/synbiotic use on glycemic control in women with gestational diabetes.

METHODS

We searched the PubMed, Medline, Scopus, ScienceDirect, Web of Science, Cochrane Central Register of Controlled Trials, Dergipark, and Council of Higher Education Thesis Center databases through March 2022. Screening was performed according to the population, intervention, comparison, outcome and study type. This systematic review and meta-analysis were performed in accordance with the Preferred Reporting Items for Systematic Review and meta-analyses (PRISMA-2020) statement.

RESULTS

Eight RCTs involving 551 patients were included in the meta-analysis. Probiotic use in women with gestational diabetes significantly decreased fasting blood glucose (mean difference: -1.43; 95 % CI: -2.78 to -0.09, p: 0.04) and serum insulin (mean difference: -3.66; 95 % CI: -5.04 to -2.27, p < 0.001). Moreover, the use of probiotics and synbiotics significantly reduced the HOMA-IR level compared to the control group (probiotic group: mean difference: -0.74; 95 % CI: -1.05 to -0.44, p < 0.001; synbiotic group: mean difference: -0.68; 95 % CI: -1.26 to -0.09, p: 0.02).

CONCLUSIONS

The use of probiotics in women with GDM reduced fasting plasma glucose, fasting serum insulin, and HOMA-IR levels. In addition, the use of synbiotics decreased HOMA-IR. Probiotic/synbiotic use is promising as a potential therapy to assist in glycemic control in gestational diabetes. Further high-quality studies are required to determine their safety.

The effect of standard, ketogenic, and Western-type diets applied to rats in pressure wound therapy

OBJECTIVE

This study aimed at investigating the effect of ketogenic and Western diets on pressure wounds.

MATERIALS AND METHODS

This randomized controlled study used 33 male Sprague-Dawley rats. They were randomly divided into the control, ketogenic, and Western diet groups. Pressure wounds were created on the rats' backs.

RESULTS

Wound healing of the Western diet group on day 42 was better than the ketogenic and standard groups. In the microscopic examinations, wound closure, damaged muscle tissue repair, angiogenesis, vascularization, granulation, and collagenization in the Western diet group were faster than in the ketogenic and standard groups.

CONCLUSIONS

The Western diet was potentially effective for pressure wound healing. Future research should be conducted to clarify how this affects the wound-healing process.

The significance of a novel inflammatory biomarker, presepsin, in predicting disease prognosis in patients with COVID-19

OBJECTIVE

This study aims at determining the significance of a novel inflammatory biomarker, presepsin, in predicting disease prognosis in patients with COVID-19.

PATIENTS AND METHODS

This retrospective study was concluded at the University Hospital between April and August 2020. The study involved 88 COVID-19 patients (48 men and 40 women). The patients were categorized into two groups: the patients admitted to the COVID-19 clinic, described as the moderate COVID-19 patients (Group-1; n=44), and those admitted to the internal medicine outpatient clinic, who were the mild COVID-19 patients (Group-2; n=44). The groups were compared using inflammatory markers: presepsin, C-Reactive Protein to Albumin Ratio, Neutrophil to Lymphocyte Ratio, and procalcitonin.

RESULTS

Serum presepsin levels (195.29 vs. 52.12 pg/ml) were significantly higher in the Group-1 compared to the Group-2 (p=0.001). The gender distribution and average age were similar in both groups (p > 0.05). While ferritin, lactate dehydrogenase, D-Dimer, platelet lymphocyte ratio, C-Reactive Protein to Albumin Ratio (p=0.001), erythrocyte sedimentation ratio, C-Reactive Protein and presepsin were significantly higher in the Group-1 compared to Group-2 (p<0.05), while hemoglobin and lymphocyte were significantly lower in the Group-1 than in Group-2 (p<0.05).

CONCLUSIONS

Serum presepsin levels were found to be significantly higher in moderate clinical group COVID-19 patients compared to mild group. Presepsin, a new inflammatory biomarker, may be useful in predicting the prognosis and early treatment of COVID-19 infection.

Search for Higgs Boson Pair Production in the Four b Quark Final State in Proton-Proton Collisions at sqrt[s]=13 TeV

A search for pairs of Higgs bosons produced via gluon and vector boson fusion is presented, focusing on the four b quark final state. The data sample consists of proton-proton collisions at a center-of-mass energy of 13 TeV, collected with the CMS detector at the LHC, and corresponds to an integrated luminosity of 138  fb^{-1}. No deviation from the background-only hypothesis is observed. A 95% confidence level upper limit on the Higgs boson pair production cross section is observed at 3.9 times the standard model prediction for an expected value of 7.8. Constraints are also set on the modifiers of the Higgs field self-coupling, κ_{λ}, and of the coupling of two Higgs bosons to two vector bosons, κ_{2 V}. The observed (expected) allowed intervals at the 95% confidence level are -2.3<κ_{λ}<9.4 (-5.0<κ_{λ}<12.0) and -0.1<κ_{2 V}<2.2 (-0.4<κ_{2 V}<2.5). These are the most stringent observed constraints to date on the HH production cross section and on the κ_{2 V } coupling.

The novel biomarker, neopterin, can predict the severity of COVID-19

OBJECTIVE

SARS-CoV-2 infection primarily affects T-lymphocytes, particularly CD4+ and CD8+ T cells. However, there is a need for simpler and less expensive laboratory tests with predictive values comparable to CD4+ cell counts. Thus, the goal of this study was to investigate the role of neopterin levels in predicting intensive care and mortality in coronavirus disease patients in 2019.

PATIENTS AND METHODS

This retrospective study included 87 hospitalized patients who were diagnosed with COVID-19. Patients were divided into two groups: those receiving intensive care (Severe COVID-19; S-COVID-19) and those receiving non-intensive care (Moderate COVID-19; M-COVID-19). Patients' clinical characteristics, serum neopterin levels, and other laboratory data were compared across groups.

RESULTS

The average age was 63.9±155.2 years, and 44 (%) of the participants were male. WBC (p = 0.008), neutrophil (p = 0.002), HDL (p = 0.009), ferritin, calcium, albumin, LDH, APTT, lymphocyte, INR, D-dimer, troponin, prothrombin time sedimentation, and PaO2 (p = 0.001) were all associated with death. The neopterin level in the M-COVID-19 group was 3 (min-max; 3.1-5.9) and 3.2 (2.3-7) in the S-COVID-19 group, with no statistically significant difference (p = 0.456). Gender differences between groups were not significant (p = 0.183). According to the ROC analysis, if parameters such as age, D-Dimer, troponin, ferritin, albumin, LDH, CRP, procalcitonin, and PaO2 exceed the cut-off values and lymphocyte levels are below, it can predict the need for intensive care and mortality in COVID-19 patients.

CONCLUSIONS

Although we did not find statistically significant results with neopterin in terms of mortality in COVID-19 individuals in our study, more thorough, prospective, randomized controlled studies with expanded patient populations at various phases of the disease are needed.

Search for Flavor-Changing Neutral Current Interactions of the Top Quark and Higgs Boson in Final States with Two Photons in Proton-Proton Collisions at sqrt[s]=13 TeV

Proton-proton interactions resulting in final states with two photons are studied in a search for the signature of flavor-changing neutral current interactions of top quarks (t) and Higgs bosons (H). The analysis is based on data collected at a center-of-mass energy of 13 TeV with the CMS detector at the LHC, corresponding to an integrated luminosity of 137  fb^{-1}. No significant excess above the background prediction is observed. Upper limits on the branching fractions (B) of the top quark decaying to a Higgs boson and an up (u) or charm (c) quark are derived through a binned fit to the diphoton invariant mass spectrum. The observed (expected) 95% confidence level upper limits are found to be 0.019% (0.031%) for B(t→Hu) and 0.073% (0.051%) for B(t→Hc). These are the strictest upper limits yet determined.

Search for Resonances Decaying to Three W Bosons in Proton-Proton Collisions at sqrt[s]=13 TeV

A search for resonances decaying into a W boson and a radion, where the radion decays into two W bosons, is presented. The data analyzed correspond to an integrated luminosity of 138  fb^{-1} recorded in proton-proton collisions with the CMS detector at sqrt[s]=13  TeV. One isolated charged lepton is required, together with missing transverse momentum and one or two massive large-radius jets, containing the decay products of either two or one W bosons, respectively. No excess over the background estimation is observed. The results are combined with those from a complementary channel with an all-hadronic final state, described in an accompanying paper. Limits are set on parameters of an extended warped extra-dimensional model. These searches are the first of their kind at the LHC.

Probing Charm Quark Dynamics via Multiparticle Correlations in Pb-Pb Collisions at sqrt[s_{NN}]=5.02 TeV

Multiparticle azimuthal correlations of prompt D^{0} mesons are measured in Pb-Pb collisions at a nucleon-nucleon center-of-mass energy of sqrt[s_{NN}]=5.02  TeV. For the first time, a four-particle cumulant method is used to extract the second Fourier coefficient of the azimuthal distribution (v_{2}) of D^{0} mesons as a function of event centrality and the D^{0} transverse momentum. The ratios of the four-particle v_{2} values to previously measured two-particle cumulant results provide direct experimental access to event-by-event fluctuations of charm quark azimuthal anisotropies. These ratios are also found to be comparable to those of inclusive charged particles in the event. However, hints of deviations are seen in the most central and peripheral collisions. To investigate the origin of flow fluctuations in the charm sector, these measurements are compared to a model implementing fluctuations of charm quark energy loss via collisional or radiative processes in the quark-gluon plasma. These models cannot quantitatively describe the data over the full transverse momentum and centrality ranges, although the calculations with collisional energy loss provide a better description of the data.

First Search for Exclusive Diphoton Production at High Mass with Tagged Protons in Proton-Proton Collisions at sqrt[s]=13 TeV

A search for exclusive two-photon production via photon exchange in proton-proton collisions, pp→pγγp with intact protons, is presented. The data correspond to an integrated luminosity of 9.4  fb^{-1} collected in 2016 using the CMS and TOTEM detectors at a center-of-mass energy of 13 TeV at the LHC. Events are selected with a diphoton invariant mass above 350 GeV and with both protons intact in the final state, to reduce backgrounds from strong interactions. The events of interest are those where the invariant mass and rapidity calculated from the momentum losses of the forward-moving protons match the mass and rapidity of the central, two-photon system. No events are found that satisfy this condition. Interpreting this result in an effective dimension-8 extension of the standard model, the first limits are set on the two anomalous four-photon coupling parameters. If the other parameter is constrained to its standard model value, the limits at 95% confidence level are |ζ_{1}|<2.9×10^{-13}  GeV^{-4} and |ζ_{2}|<6.0×10^{-13}  GeV^{-4}.

Observation of the B_{c}^{+} Meson in Pb-Pb and pp Collisions at sqrt[s_{NN}]=5.02 TeV and Measurement of its Nuclear Modification Factor

The B_{c}^{+} meson is observed for the first time in heavy ion collisions. Data from the CMS detector are used to study the production of the B_{c}^{+} meson in lead-lead (Pb-Pb) and proton-proton (pp) collisions at a center-of-mass energy per nucleon pair of sqrt[s_{NN}]=5.02  TeV, via the B_{c}^{+}→(J/ψ→μ^{+}μ^{-})μ^{+}ν_{μ} decay. The B_{c}^{+} nuclear modification factor, derived from the Pb-Pb-to-pp ratio of production cross sections, is measured in two bins of the trimuon transverse momentum and of the Pb-Pb collision centrality. The B_{c}^{+} meson is shown to be less suppressed than quarkonia and most of the open heavy-flavor mesons, suggesting that effects of the hot and dense nuclear matter created in heavy ion collisions contribute to its production. This measurement sets forth a promising new probe of the interplay of suppression and enhancement mechanisms in the production of heavy-flavor mesons in the quark-gluon plasma.

Observation of B 0 → ψ (2S)K S 0 π + π - and B s 0 → ψ (2S)K S 0 decays

Using a data sample of s = 13 TeV proton-proton collisions collected by the CMS experiment at the LHC in 2017 and 2018 with an integrated luminosity of 103 fb - 1 , the B s 0 → ψ ( 2S ) K S 0 and B 0 → ψ ( 2S ) K S 0 π + π - decays are observed with significances exceeding 5 standard deviations. The resulting branching fraction ratios, measured for the first time, correspond to B ( B s 0 → ψ ( 2S ) K S 0 ) / B ( B 0 → ψ ( 2S ) K S 0 ) = ( 3.33 ± 0.69 ( stat ) ± 0.11 ( syst ) ± 0.34 ( f s / f d ) ) × 10 - 2 and B ( B 0 → ψ ( 2S ) K S 0 π + π - ) / B ( B 0 → ψ ( 2S ) K S 0 ) = 0.480 ± 0.013 ( stat ) ± 0.032 ( syst ) , where the last uncertainty in the first ratio is related to the uncertainty in the ratio of production cross sections of B s 0 and B 0 mesons, f s / f d .

Search for low-mass dilepton resonances in Higgs boson decays to four-lepton final states in proton-proton collisions at s = 13 TeV

A search for low-mass dilepton resonances in Higgs boson decays is conducted in the four-lepton final state. The decay is assumed to proceed via a pair of beyond the standard model particles, or one such particle and a Z boson. The search uses proton-proton collision data collected with the CMS detector at the CERN LHC, corresponding to an integrated luminosity of 137 fb - 1 , at a center-of-mass energy s = 13 TeV . No significant deviation from the standard model expectation is observed. Upper limits at 95% confidence level are set on model-independent Higgs boson decay branching fractions. Additionally, limits on dark photon and axion-like particle production, based on two specific models, are reported.

Using Z Boson Events to Study Parton-Medium Interactions in Pb-Pb Collisions

The spectra measurements of charged hadrons produced in the shower of a parton originating in the same hard scattering with a leptonically decaying Z boson are reported in lead-lead nuclei (Pb-Pb) and proton-proton (pp) collisions at a nucleon-nucleon center-of-mass energy of 5.02 TeV. Both Pb-Pb and pp data sets are recorded by the CMS experiment at the LHC and correspond to an integrated luminosity of 1.7  nb^{-1} and 320  pb^{-1}, respectively. Hadronic collision data with one reconstructed Z boson candidate with the transverse momentum p_{T}>30  GeV/c are analyzed. The Z boson constrains the initial energy and direction of the associated parton. In heavy ion events, azimuthal angular distributions of charged hadrons with respect to the direction of a Z boson are sensitive to modifications of the in-medium parton shower and medium response. compared to reference data from pp interactions, the results for central Pb-Pb collisions indicate a modification of the angular correlations. The measurements of the fragmentation functions and p_{T} spectra of charged particles in Z boson events, which are sensitive to medium modifications of the parton shower longitudinal structure, are also reported. Significant modifications in central Pb-Pb events compared to the pp reference data are also found for these observables.

Search for strongly interacting massive particles generating trackless jets in proton-proton collisions at s = 13 TeV

A search for dark matter in the form of strongly interacting massive particles (SIMPs) using the CMS detector at the LHC is presented. The SIMPs would be produced in pairs that manifest themselves as pairs of jets without tracks. The energy fraction of jets carried by charged particles is used as a key discriminator to suppress efficiently the large multijet background, and the remaining background is estimated directly from data. The search is performed using proton-proton collision data corresponding to an integrated luminosity of 16.1 fb - 1 , collected with the CMS detector in 2016. No significant excess of events is observed above the expected background. For the simplified dark matter model under consideration, SIMPs with masses up to 100 GeV are excluded and further sensitivity is explored towards higher masses.

Measurement of the Inclusive and Differential Higgs Boson Production Cross Sections in the Decay Mode to a Pair of τ Leptons in pp Collisions at sqrt[s]=13 TeV

Measurements of the inclusive and differential fiducial cross sections of the Higgs boson are presented, using the τ lepton decay channel. The differential cross sections are measured as functions of the Higgs boson transverse momentum, jet multiplicity, and transverse momentum of the leading jet in the event, if any. The analysis is performed using proton-proton collision data collected with the CMS detector at the LHC at a center-of-mass energy of 13  TeV and corresponding to an integrated luminosity of 138  fb^{-1}. These are the first differential measurements of the Higgs boson cross section in the final state of two τ leptons. In final states with a large jet multiplicity or with a Lorentz-boosted Higgs boson, these measurements constitute a significant improvement over measurements performed in other final states.

Search for long-lived particles decaying to leptons with large impact parameter in proton-proton collisions at s = 13 Te

A search for new long-lived particles decaying to leptons using proton-proton collision data produced by the CERN LHC at s = 13 Te is presented. Events are selected with two leptons (an electron and a muon, two electrons, or two muons) that both have transverse impact parameter values between 0.01 and 10 cm and are not required to form a common vertex. Data used for the analysis were collected with the CMS detector in 2016, 2017, and 2018, and correspond to an integrated luminosity of 118 (113) fb - 1 in the e e channel ( e μ and μ μ channels). The search is designed to be sensitive to a wide range of models with displaced e μ , e e , and μ μ final states. The results constrain several well-motivated models involving new long-lived particles that decay to displaced leptons. For some areas of the available phase space, these are the most stringent constraints to date.

Evidence for X(3872) in Pb-Pb Collisions and Studies of its Prompt Production at sqrt[s_{NN}]=5.02 TeV

The first evidence for X(3872) production in relativistic heavy ion collisions is reported. The X(3872) production is studied in lead-lead (Pb-Pb) collisions at a center-of-mass energy of sqrt[s_{NN}]=5.02  TeV per nucleon pair, using the decay chain X(3872)→J/ψπ^{+}π^{-}→μ^{+}μ^{-}π^{+}π^{-}. The data were recorded with the CMS detector in 2018 and correspond to an integrated luminosity of 1.7  nb^{-1}. The measurement is performed in the rapidity and transverse momentum ranges |y|<1.6 and 15<p_{T}<50  GeV/c. The significance of the inclusive X(3872) signal is 4.2 standard deviations. The prompt X(3872) to ψ2S yield ratio is found to be ρ^{Pb-Pb}=1.08±0.49(stat)±0.52(syst), to be compared with typical values of 0.1 for pp collisions. This result provides a unique experimental input to theoretical models of the X(3872) production mechanism, and of the nature of this exotic state.

Search for Long-Lived Particles Decaying in the CMS End Cap Muon Detectors in Proton-Proton Collisions at sqrt[s]=13 TeV

A search for long-lived particles (LLPs) produced in decays of standard model (SM) Higgs bosons is presented. The data sample consists of 137  fb^{-1} of proton-proton collisions at sqrt[s]=13  TeV, recorded at the LHC in 2016-2018. A novel technique is employed to reconstruct decays of LLPs in the end cap muon detectors. The search is sensitive to a broad range of LLP decay modes and to masses as low as a few GeV. No excess of events above the SM background is observed. The most stringent limits to date on the branching fraction of the Higgs boson to LLPs subsequently decaying to quarks and τ^{+}τ^{-} are found for proper decay lengths greater than 6, 20, and 40 m, for LLP masses of 7, 15, and 40 GeV, respectively.

Measurements of the Electroweak Diboson Production Cross Sections in Proton-Proton Collisions at sqrt[s]=5.02 TeV Using Leptonic Decays

The first measurements of diboson production cross sections in proton-proton interactions at a center-of-mass energy of 5.02 TeV are reported. They are based on data collected with the CMS detector at the LHC, corresponding to an integrated luminosity of 302  pb^{-1}. Events with two, three, or four charged light leptons (electrons or muons) in the final state are analyzed. The WW, WZ, and ZZ total cross sections are measured as σ_{WW}=37.0_{-5.2}^{+5.5}(stat)_{-2.6}^{+2.7}(syst)  pb, σ_{WZ}=6.4_{-2.1}^{+2.5}(stat)_{-0.3}^{+0.5}(syst)  pb, and σ_{ZZ}=5.3_{-2.1}^{+2.5}(stat)_{-0.4}^{+0.5}(syst)  pb. All measurements are in good agreement with theoretical calculations at combined next-to-next-to-leading order quantum chromodynamics and next-to-leading order electroweak accuracy.

Combined searches for the production of supersymmetric top quark partners in proton-proton collisions at s = 13 Te

A combination of searches for top squark pair production using proton-proton collision data at a center-of-mass energy of 13 Te at the CERN LHC, corresponding to an integrated luminosity of 137 fb - 1 collected by the CMS experiment, is presented. Signatures with at least 2 jets and large missing transverse momentum are categorized into events with 0, 1, or 2 leptons. New results for regions of parameter space where the kinematical properties of top squark pair production and top quark pair production are very similar are presented. Depending on the model, the combined result excludes a top squark mass up to 1325 Ge for a massless neutralino, and a neutralino mass up to 700 Ge for a top squark mass of 1150 Ge . Top squarks with masses from 145 to 295 Ge , for neutralino masses from 0 to 100 Ge , with a mass difference between the top squark and the neutralino in a window of 30 Ge around the mass of the top quark, are excluded for the first time with CMS data. The results of theses searches are also interpreted in an alternative signal model of dark matter production via a spin-0 mediator in association with a top quark pair. Upper limits are set on the cross section for mediator particle masses of up to 420 Ge .

Measurements of angular distance and momentum ratio distributions in three-jet and Z + two-jet final states in pp collisions

Collinear (small-angle) and large-angle, as well as soft and hard radiations are investigated in three-jet and Z  + two-jet events collected in proton-proton collisions at the LHC. The normalized production cross sections are measured as a function of the ratio of transverse momenta of two jets and their angular separation. The measurements in the three-jet and Z  + two-jet events are based on data collected at a center-of-mass energy of 8 TeV , corresponding to an integrated luminosity of 19.8 fb - 1 . The Z  + two-jet events are reconstructed in the dimuon decay channel of the Z  boson. The three-jet measurement is extended to include s = 13 TeV data corresponding to an integrated luminosity of 2.3 fb - 1 . The results are compared to predictions from event generators that include parton showers, multiple parton interactions, and hadronization. The collinear and soft regions are in general well described by parton showers, whereas the regions of large angular separation are often best described by calculations using higher-order matrix elements.

Observation of Forward Neutron Multiplicity Dependence of Dimuon Acoplanarity in Ultraperipheral Pb-Pb Collisions at sqrt[s_{NN}]=5.02 TeV

The first measurement of the dependence of γγ→μ^{+}μ^{-} production on the multiplicity of neutrons emitted very close to the beam direction in ultraperipheral heavy ion collisions is reported. Data for lead-lead interactions at sqrt[s_{NN}]=5.02  TeV, with an integrated luminosity of approximately 1.5  nb^{-1}, are collected using the CMS detector at the LHC. The azimuthal correlations between the two muons in the invariant mass region 8<m_{μμ}<60  GeV are extracted for events including 0, 1, or at least 2 neutrons detected in the forward pseudorapidity range |η|>8.3. The back-to-back correlation structure from leading-order photon-photon scattering is found to be significantly broader for events with a larger number of emitted neutrons from each nucleus, corresponding to interactions with a smaller impact parameter. This observation provides a data-driven demonstration that the average transverse momentum of photons emitted from relativistic heavy ions has an impact parameter dependence. These results provide new constraints on models of photon-induced interactions in ultraperipheral collisions. They also provide a baseline to search for possible final-state effects on lepton pairs caused by traversing a quark-gluon plasma produced in hadronic heavy ion collisions.