Subacute Cutaneous Toxicity with Single-Fraction Electron FLASH RT in Yorkshire Swine

PURPOSE/OBJECTIVE(S)

Information regarding acute/subacute skin toxicity of electron FLASH radiation therapy (RT) is limited. We evaluated short-term safety of electron FLASH for human trials by investigating subacute toxicity compared to conventional dose-rate RT (CONV) in the Yorkshire pig, an animal model known to closely approximate human skin and routinely used for toxicity studies.

MATERIALS/METHODS

Two healthy 50 kg pigs underwent CT imaging for RT treatment planning with field visualization via BBs and tattoos on each dorsolateral flank. Each target received a single fraction of 20, 25 or 30 Gy with FLASH and CONV on opposing sides delivered using a dedicated mobile linear accelerator. FLASH dose rates ranged from 164-245 Gy/sec (12 pulses delivered over 0.122 sec) while the CONV dose rate was set at 0.18 Gy/sec. Doses were verified using thermo- and optically stimulated luminescent dosimeters, and Gafchromic films. We obtained baseline and weekly images up to 98 days post-RT (D98) for blinded toxicity grading by 3 expert radiation oncologists using the modified RTOG radiation dermatitis (RD) scale. We measured erythema and pigmentation indices on those timepoints using a handheld spectrophotometer. We also obtained punch biopsies of targets and non-irradiated controls on D10 and D30 for RNA sequencing and two 6-marker multiplex immunofluorescence analyses of inflammation, immune response, and fibrosis. FLASH and CONV data were compared using repeated measures ANOVA and transcriptomic analyses using DESeq2.

RESULTS

All RT targets developed peak median grade 4 (ulceration, hemorrhage, or necrosis) RD by D84 regardless of FLASH or CONV delivery. However, FLASH targets developed peak RD later than CONV targets after 20 Gy (D84 vs D63), 25 Gy (D84 vs D49) and 30 Gy (D63 vs D42). FLASH induced qualitatively lower mean pigmentation and erythema indices than CONV for all 3 doses. Similarly, peak mean pigmentation indices occurred later with FLASH vs CONV for 20 Gy (D84 vs D63), 25 Gy (D84 vs D49) and 30 Gy (D77 vs D63). However, peak mean erythema indices occurred on the same day for FLASH and CONV (D63 for 20 Gy and D42 for 25 and 30 Gy). Transcriptomic analyses revealed significantly upregulated signals for wound healing (including TGF-beta, cell adhesion and extracellular matrix receptor interaction) and leukocyte infiltration with 20 Gy CONV mostly by D10, while FLASH upregulated those pathways only after 25 or 30 Gy, or by D30, or never at all. Preliminary immunofluorescence data showed FLASH may induce less T cell infiltrate and TGF-beta-expressing macrophages than CONV.

CONCLUSION

Single-fraction electron FLASH resulted in delayed onsets of both subacute cutaneous toxicity and wound healing with leukocytic infiltration signaling than dose-matched CONV based on both subjective and objective metrics of skin injury. Our findings suggest further investigations of optimal dose of electron FLASH for safe clinical translation is warranted, and we have a dose-finding study currently underway.

"It's about sharing a moment": Parents' views and experiences of home reading with their autistic children with moderate-to-severe intellectual disabilities

BACKGROUND

The home literacy environment plays a critical role in the development of children's literacy and language development. Little is known, however, about the home literacy environment of autistic children, especially those with moderate-to-severe intellectual disabilities.

AIMS

The current study used a sequential mixed-methods design to understand how parents attempt to engage their autistic children in reading activities and support them in learning to read.

METHODS AND PROCEDURE

First, 63 parents (53 mothers) whose autistic children attended an autism-specific special school completed a bespoke questionnaire about the home literacy environments for their children (n = 69, age range = 3-11 years, 61 boys, 8 girls). Second, a subsample of parents (n = 19, 15 mothers) participated in focus groups to understand in-depth their views and experiences of home reading with their children (n = 20, age range = 3-11 years, 19 boys, 1 girl). We used reflexive thematic analysis to analyse the focus group data.

OUTCOMES AND RESULTS

Across questionnaire and focus group methods, parents were united in considering reading to be an important life skill, a sentiment that was reflected both by their often literacy-rich homes and the ingenuity in their efforts to engage their children in shared home-reading activities - even when such engagement could be challenging. They also emphasised, however, the importance of valuing these activities as an opportunity to "catch a moment" with their child.

CONCLUSIONS AND IMPLICATIONS

Parents and teachers should work together to identify ways to enhance autistic children's engagement in shared home-reading activities, listening to and learning from each other's experiences and expertise, and to show what is possible within each learning context.

P-230 Senescence in mammalian embryos as a novel assay for quality control in the IVF laboratory

Study question

Can senescence biomarkers be used as a more sensitive assay for IVF laboratory quality control than a conventional mouse embryo assay (MEA)?

Summary answer

Senescence biomarkers are more sensitive than a MEA and should be considered as a novel quality control assay in assessing overall IVF laboratory environment.

What is known already

An MEA is a bioassay that is utilized to detect toxicity and suboptimal conditions, but only assesses the ability of the embryos to develop to the blastocyst stage. The majority of human embryos created during IVF do not result in a live birth, most either arrest or degenerate. Suboptimal culture conditions and accompanying environmental stressors may be responsible or some of this lack of embryo development. Senescence or developmental arrest, like apoptosis, is a defensive mechanism that halts further development of stress, poor quality or abnormal embryos. Senescence should be considered a possible reason for a high embryos loss rate.

Study design, size, duration

Murine zygotes from the strain B6C3F1 x B6D2F1 (N = 263) were exposed to 12.5nM Doxorubicin (DOX), a known inducer of senescence as a positive control, either 250nM or 500nM H2O2 or atmospheric oxygen conditions (20%) to mimic oxidative stress. These treatment groups were compared to embryos cultured without H2O2 in a low oxygen (5% 02) environment. The zygotes were cultured for 72 hours, and biomarkers of senescence were assessed.

Participants/materials, setting, methods

Embryos were assessed at 72 hours with a confocal microscope (Zeiss) and blastocyst conversion rate and number of cells/blastocyst was calculated. The following senescence markers were examined, SAβ-gal (SPiDER-β-Gal), IL-6 mRNA (RT-qPCR) and CellRox Deep Red, a fluorogenic reactive oxygen species (ROS) indicator was also evaluated. Fiji Image J software was used to calculate Corrected Total Cell Fluorescence (CTCF) as a percentage of the low oxygen group and GraphPad Prism was used for data analysis.

Main results and the role of chance

When comparing the blastocyst conversion rate, all treatment groups showed a blastocyst conversion rate of > 80% after 72 hours of exposure, indicating that all would have “passed” assessment with a conventional MEA (p > 0.05). However, when the average number of cells per blastocyst was compared to the low oxygen group, all groups had a significantly lower average number of cells per blastocyst (112±26.65 for low oxygen, 74±7.95 for high oxygen, 82± 24.54 for 500 nM H2O2, 89 ± 34 for 250 nM H2O2 and 63± 20.01 for 12.5 nM DOX, p < 0.05). All of the treatment groups had a significant increase in the relative fold change of IL-6 mRNA compared to the low oxygen environment (2.2 for the high oxygen, 2.5 for 500 nM H2O2, 2.9 for 250 nM H2O2, and 7.4 for 12.5 nM DOX, p < 0.05). The CTCF for SAβ-Gal using the SPIDER-β- Gal assay was significantly elevated in all treatment groups (145% for high oxygen, 162% for H2O2250 nM, 193% for 12.5 nM DOX and 196% for 500 nM H2O2, p < 0.05). A significant increase in the CTCF for CellRox Deep Red was also observed (289% for 12.5 nM DOX, 492% for 250 nM H2O2, 763% for 500 nM H2O2, and 925% for high oxygen, p < 0.05).

Limitations, reasons for caution

This analysis is currently limited by the lack of a specific senescence marker. This approach is also invasive, destroying the embryo, not lending itself to clinical human embryo selection. Although the mouse model has advantages, translating these results into human embryos is a limitation of this study.

Wider implications of the findings

This optimized novel assay can be used to provide great insight about the subtle laboratory culture/environmental conditions in the IVF laboratory. The results support the hypothesis that environmental stressors can induce senescence biomarkers and implicate their participation in the degeneration of previously viable embryos.

Trial registration number

not applicable

Approaching Retirement After a Working Life in Poverty

This paper uses a life course perspective to explore and understand how an individual’s experiences over their lifetime contribute to the formation of a growing consciousness about their impending retirement. The fieldwork took place in 2016 and was part of a wider mixed methods study about retirement in the UK, which used data from the 1958 birth cohort study (also known as the National Child Development Study). The paper focuses on the qualitative dimension of the study and uses in-depth case studies of four people approaching 60 to consider, in particular, the effects of health, financial resources and employment history on their views on retiring, including the anticipated timing of their exit from the labour market. All four were purposively chosen because they had experienced low pay or poverty during their lifetime and were employed in relatively low paid jobs. State Pension Ages (SPAs) are on the rise in many countries, including the UK, and the authors maintain that it is important to study the working poor, who, even though are more likely to continue working until SPA, are more prone to suffer from poor health, and less likely to be able to put savings aside for their retirement.

Predictors of Need for First and Recurrent Emergency Medical Service Transport to Emergency Department after Dialysis Initiation

Background: Dialysis patients are frequently transported to the emergency department (ED) by Emergency Medical Services (EMS) due to acute and severe illness. However, little is known about predictors of first and recurrent transport to the ED (EMS-ED), based on characteristics at the time of dialysis initiation.Methods: We analyzed a cohort of adult (≥18 years) patients affiliated with a large quaternary care center who initiated chronic dialysis from 2009 to 2013 (last follow-up: 2015). Data on patient characteristics at the time of dialysis initiation were linked to regional EMS data. Candidate predictors of first and recurrent EMS-ED transport included comorbid conditions, dialysis characteristics and frailty severity (using the first version of the clinical frailty scale score; CFS). Time to first EMS-ED was analyzed using a multivariable sub-hazards regression model accounting for competing events (transplantation or death). Time to recurrent EMS-ED was analyzed using the Anderson-Gill counting approach, accounting for competing risks.Results: A total of 455 patients were included in the study, 243 (53%) had 1+ EMS-ED events, 90 (20%) never required an EMS-ED at last follow-up, and 69 (15%) and 53 (12%) experienced transplant or death as their first event, respectively. The mean age of the cohort was 62 ± 15 years, 89% were Caucasian, and 35% were female sex. Patients were highly comorbid and 97/381 (25.5%) with available data on frailty severity had a CFS score of ≥5, inclusive of CFS scores ranging from mildly to severely frail. After adjustment, a CFS score of ≥5 (relative to 1-2) was associated with a > 2-fold increase in the risk of first EMS-ED (subdistribution relative hazard; SHR 2.28, 95% confidence interval; CI 1.30-3.98). A history of peripheral vascular disease (SHR 1.43, 95% CI 1.00-2.03) and rheumatologic disease (SHR 1.84, 95% CI 1.00-3.38) was also associated with first EMS-ED. Frailty severity was the only factor associated with recurrent EMS-ED.Conclusion: Patients are at a high risk of EMS-ED after dialysis initiation. Frailty severity (at the time of dialysis initiation) is a strong predictor of first and recurrent EMS-ED and this may be important to guide informed decision making and resource planning for dialysis patients who require EMS.

Challenge and Threat: A Critical Review of the Literature and an Alternative Conceptualization

In this article, the authors describe a new theory, the Evaluative Space Approach to Challenge and Threat (ESACT). Prompted by the Biopsychosocial model of challenge and threat (BPS: Blascovich and Tomaka, 1996) and the development of the Theory of Challenge and Threat States in Athletes (Jones et al., 2009), recent years have witnessed a considerable increase in research examining challenge and threat in sport. This manuscript provides a critical review of the literature examining challenge and threat in sport, tracing its historical development and some of the current empirical ambiguities. To reconcile some of these ambiguities, and utilizing neurobiological evidence associated with approach and avoidance motivation (c.f. Elliot and Covington, 2001), this paper draws upon the Evaluative Space Model (ESM; Cacioppo et al., 1997) and considers the implications for understanding challenge and threat in sport. For example, rather than see challenge and threat as opposite ends of a single bipolar continuum, the ESM implies that individuals could be (1) challenged, (2) threatened, (3) challenged and threatened, or (4) neither challenged or threatened by a particular stimulus. From this perspective, it could be argued that the appraisal of some sport situations as both challenging and threatening could be advantageous, whereas the current literature seems to imply that the appraisal of stress as a threat is maladaptive for performance. The ESACT provides several testable hypotheses for advancing understanding of challenge and threat (in sport) and we describe a number of measures that can be used to examine these hypotheses. In sum, this paper provides a significant theoretical, empirical, and practical contribution to our understanding of challenge and threat (in sport).

Search for Magnetic Monopoles with the MoEDAL Forward Trapping Detector in 13 TeV Proton-Proton Collisions at the LHC

MoEDAL is designed to identify new physics in the form of long-lived highly ionizing particles produced in high-energy LHC collisions. Its arrays of plastic nuclear-track detectors and aluminium trapping volumes provide two independent passive detection techniques. We present here the results of a first search for magnetic monopole production in 13 TeV proton-proton collisions using the trapping technique, extending a previous publication with 8 TeV data during LHC Run 1. A total of 222 kg of MoEDAL trapping detector samples was exposed in the forward region and analyzed by searching for induced persistent currents after passage through a superconducting magnetometer. Magnetic charges exceeding half the Dirac charge are excluded in all samples and limits are placed for the first time on the production of magnetic monopoles in 13 TeV pp collisions. The search probes mass ranges previously inaccessible to collider experiments for up to five times the Dirac charge.

Testing Hadronic Interactions at Ultrahigh Energies with Air Showers Measured by the Pierre Auger Observatory

Ultrahigh energy cosmic ray air showers probe particle physics at energies beyond the reach of accelerators. Here we introduce a new method to test hadronic interaction models without relying on the absolute energy calibration, and apply it to events with primary energy 6-16 EeV (E_{CM}=110-170  TeV), whose longitudinal development and lateral distribution were simultaneously measured by the Pierre Auger Observatory. The average hadronic shower is 1.33±0.16 (1.61±0.21) times larger than predicted using the leading LHC-tuned models EPOS-LHC (QGSJetII-04), with a corresponding excess of muons.

Incremental Exercise, Plasma Concentrations of Catecholamines, Reaction Time, and Motor Time during Performance of a Noncompatible Choice Response Time Task

The primary purpose was to examine the effect of incremental exercise on a noncompatible response time task. Participants ( N = 9) undertook a 4-choice noncompatible response time task under 3 conditions, following rest and during exercise at 70% and 100% of their maximum power output. Reaction and movement times were the dependent variables. Maximum power output had been previously established on an incremental test to exhaustion. A repeated-measures multivariate analysis of variance yielded a significant effect of exercise intensity on the task, but observation of the separate univariate repeated-measures analyses of variance showed that only movement time was significantly affected. Post hoc Tukey tests indicated movement time during maximal intensity exercise was significantly faster than in the other two conditions. The secondary purpose of the study was to assess whether increases in plasma concentrations of adrenaline and nor-adrenaline during exercise and power output would act as predictor variables of reaction and movement times during exercise. Catecholamine concentrations were based on venous blood samples taken during the maximum power output test. None of the variables were significant predictors of reaction time. Only power output was a significant predictor of movement time ( R2 = .24). There was little support for the notion that peripheral concentrations of catecholamines directly induce a central nervous system response.

From Mental Health to Mental Wealth in Athletes: Looking Back and Moving Forward

Considerations of athletes’ mental health are typically framed in the language of mental illness (Hughes and Leavey, 2012), a situation that contributes to stigmatization, denial, and the prevention of effective care. In this article, we provide a critical, narrative review of the extant literature on athlete mental health. Specifically, we begin by providing a brief synopsis of the extant literature on athletes’ mental health, illustrating both what we know about (i) the prevalence of mental health issues in sport and (ii) variables contributing to help-seeking behaviors in athletes. Against, this backdrop, we outline Keyes’ (2002) two-continuum model of mental health as a theoretical framework that has considerable promise in understanding, talking-about, and intervening to enhance, athletes’ mental health. This model posits two related, but distinct dimensions: one continuum indicates the presence or absence of mental health, the other the presence or absence of mental illness. From this perspective, a number of possibilities emerge. For instance, athletes could simultaneously have both positive mental health and experience of mental illness. Alternatively, athletes could be free from mental illness, but in Keyes’ terms be “languishing” (i.e., experiencing low levels of mental health). Implications for interventions based on the two-continuum model are discussed, particularly drawing on assets-based approaches to enhance flourishing (Theokas et al., 2005). We conclude the review by considering limitations in our understanding of how to promote flourishing and suggest avenues for further research.

Measurement of the Radiation Energy in the Radio Signal of Extensive Air Showers as a Universal Estimator of Cosmic-Ray Energy

We measure the energy emitted by extensive air showers in the form of radio emission in the frequency range from 30 to 80 MHz. Exploiting the accurate energy scale of the Pierre Auger Observatory, we obtain a radiation energy of 15.8±0.7(stat)±6.7(syst)  MeV for cosmic rays with an energy of 1 EeV arriving perpendicularly to a geomagnetic field of 0.24 G, scaling quadratically with the cosmic-ray energy. A comparison with predictions from state-of-the-art first-principles calculations shows agreement with our measurement. The radiation energy provides direct access to the calorimetric energy in the electromagnetic cascade of extensive air showers. Comparison with our result thus allows the direct calibration of any cosmic-ray radio detector against the well-established energy scale of the Pierre Auger Observatory.

Search for patterns by combining cosmic-ray energy and arrival directions at the Pierre Auger Observatory

Energy-dependent patterns in the arrival directions of cosmic rays are searched for using data of the Pierre Auger Observatory. We investigate local regions around the highest-energy cosmic rays with [Formula: see text] eV by analyzing cosmic rays with energies above [Formula: see text] eV arriving within an angular separation of approximately 15[Formula: see text]. We characterize the energy distributions inside these regions by two independent methods, one searching for angular dependence of energy-energy correlations and one searching for collimation of energy along the local system of principal axes of the energy distribution. No significant patterns are found with this analysis. The comparison of these measurements with astrophysical scenarios can therefore be used to obtain constraints on related model parameters such as strength of cosmic-ray deflection and density of point sources.

Inflammatory characteristics of adipose tissue collected by surgical excision vs needle aspiration

Subcutaneous adipose tissue can be obtained for research during an elective, clinically indicated operation by standard surgical excision approaches and by needle aspiration in pure research settings. Whether measurements of inflammatory markers and cells made in tissue collected these two different ways are comparable is debatable. We sought to determine whether these two techniques yield systematically different results for measurements of inflammation, cellular senescence, and adipose tissue composition. Twelve subjects undergoing surgery participated. At the time of surgery abdominal subcutaneous adipose tissue from adjacent sites was removed by excision and needle aspiration. Stromovascular cell composition (flow cytometry), the number of senescent cells (senescence-associated-β-galactosidase staining), and IL-6, IL-1, TNF-α, MCP1 mRNA (RT-PCR) were measured in each sample. We found no statistically significant differences between the two sample collection approaches for any of the parameters measured. We conclude that these two methods of obtaining adipose tissue do not systematically differ in the results of cytokine mRNA content, cellular senescence, or stromovascular cell composition.

Measurement of the proton-air cross section at √s=57 TeV with the Pierre Auger Observatory

We report a measurement of the proton-air cross section for particle production at the center-of-mass energy per nucleon of 57 TeV. This is derived from the distribution of the depths of shower maxima observed with the Pierre Auger Observatory: systematic uncertainties are studied in detail. Analyzing the tail of the distribution of the shower maxima, a proton-air cross section of [505±22(stat)(-36)(+28)(syst)] mb is found.

Search for a vectorlike quark with charge 2/3 in t+Z events from pp collisions at √s=7 TeV

A search for pair-produced heavy vectorlike charge-2/3 quarks, T, in pp collisions at a center-of-mass energy of 7 TeV, is performed with the CMS detector at the LHC. Events consistent with the flavor-changing-neutral-current decay of a T quark to a top quark and a Z boson are selected by requiring two leptons from the Z-boson decay, as well as an additional isolated charged lepton. In a data sample corresponding to an integrated luminosity of 1.14  fb(-1), the number of observed events is found to be consistent with the standard model background prediction. Assuming a branching fraction of 100% for the decay T→tZ, a T quark with a mass less than 475  GeV/c(2) is excluded at the 95% confidence level.

Search for supersymmetry at the LHC in events with jets and missing transverse energy

A search for events with jets and missing transverse energy is performed in a data sample of pp collisions collected at √s=7 TeV by the CMS experiment at the LHC. The analyzed data sample corresponds to an integrated luminosity of 1.14 fb(-1). In this search, a kinematic variable α(T) is used as the main discriminator between events with genuine and misreconstructed missing transverse energy. No excess of events over the standard model expectation is found. Exclusion limits in the parameter space of the constrained minimal supersymmetric extension of the standard model are set. In this model, squark masses below 1.1 TeV are excluded at 95% C.L. Gluino masses below 1.1 TeV are also ruled out at 95% C.L. for values of the universal scalar mass parameter below 500 GeV.

Search for new physics with a monojet and missing transverse energy in pp collisions at √s = 7 TeV

A study of events with missing transverse energy and an energetic jet is performed using pp collision data at a center-of-mass energy of 7 TeV. The data were collected by the CMS detector at the LHC, and correspond to an integrated luminosity of 36 pb(-1). An excess of these events over standard model contributions is a signature of new physics such as large extra dimensions and unparticles. The number of observed events is in good agreement with the prediction of the standard model, and significant extension of the current limits on parameters of new physics benchmark models is achieved.

Search for B(s)(0) → μ+ μ- and B(0) → μ+ μ- decays in pp collisions at sqrt[s] = 7 TeV

A search for the rare decays B(s)(0) → μ+ μ- and B(0) → μ+ μ- is performed in pp collisions at sqrt[s] = 7 TeV, with a data sample corresponding to an integrated luminosity of 1.14 fb(-1), collected by the CMS experiment at the LHC. In both cases, the number of events observed after all selection requirements is consistent with expectations from background and standard-model signal predictions. The resulting upper limits on the branching fractions are B(B(s)(0) → μ+ μ-) < 1.9 × 10(-8) and B(B(0) → μ+ μ-)<4.6 × 10(-9), at 95% confidence level.

Measurement of the inclusive jet cross section in pp collisions at √s = 7 TeV

The inclusive jet cross section is measured in pp collisions with a center-of-mass energy of 7 TeV at the Large Hadron Collider using the CMS experiment. The data sample corresponds to an integrated luminosity of 34 pb(-1). The measurement is made for jet transverse momenta in the range 18-1100 GeV and for absolute values of rapidity less than 3. The measured cross section extends to the highest values of jet p(T) ever observed and, within the experimental and theoretical uncertainties, is generally in agreement with next-to-leading-order perturbative QCD predictions.

Search for three-jet resonances in pp collisions at square root(s)=7 TeV

A search for three-jet hadronic resonance production in pp collisions at a center-of-mass energy of 7 TeV has been conducted by the CMS Collaboration at the LHC, using a data sample corresponding to an integrated luminosity of 35  pb(-1). Events with high jet multiplicity and a large scalar sum of jet transverse momenta are analyzed using a signature-based approach. The number of expected standard model background events is found to be in good agreement with the observed events. Limits on the cross section times branching ratio are set in a model of gluino pair production with an R-parity-violating decay to three quarks, and the data rule out such particles within the mass range of 200 to 280  GeV/c2.

Measurement of the t-channel single top quark production cross section in pp collisions at √s=7 TeV

Electroweak production of the top quark is measured for the first time in pp collisions at √=7  TeV, using a data set collected with the CMS detector at the LHC and corresponding to an integrated luminosity of 36  pb⁻¹. With an event selection optimized for t-channel production, two complementary analyses are performed. The first one exploits the special angular properties of the signal, together with background estimates from the data. The second approach uses a multivariate analysis technique to probe the compatibility with signal topology expected from electroweak top-quark production. The combined measurement of the cross section is 83.6±29.8(stat+syst)±3.3(lumi)  pb, consistent with the standard model expectation.

Indications of suppression of excited Υ states in Pb-Pb collisions at √(s(NN))=2.76 TeV

A comparison of the relative yields of Υ resonances in the μ(+)μ(-) decay channel in Pb-Pb and pp collisions at a center-of-mass energy per nucleon pair of 2.76 TeV is performed with data collected with the CMS detector at the LHC. Using muons of transverse momentum above 4  GeV/c and pseudorapidity below 2.4, the double ratio of the Υ(2S) and Υ(3S) excited states to the Υ(1S) ground state in Pb-Pb and pp collisions, [Υ(2S+3S)/Υ(1S)](Pb-Pb)/[Υ(2S+3S)/Υ(1S)](pp), is found to be 0.31(-0.15)(+0.19)(stat)±0.03(syst). The probability to obtain the measured value, or lower, if the true double ratio is unity, is calculated to be less than 1%.

Measurement of the polarization of W bosons with large transverse momenta in W + jets events at the LHC

A first measurement of the polarization of W bosons with large transverse momenta in pp collisions is presented. The measurement is based on 36 pb⁻¹ of data recorded at √s = 7 TeV by the CMS detector at the LHC. The left-handed, right-handed, and longitudinal polarization fractions (f(L), f(R), and f₀, respectively) of W bosons with transverse momenta larger than 50 GeV are determined by using decays to both electrons and muons. The muon final state yields the most precise measurement: (f(L) - f(R))⁻ = 0.240 ± 0.036(stat) ± 0.031(syst) and f₀⁻ = 0.183 ± 0.087(stat) ± 0.123(syst) for negatively charged W bosons and (f(L) - f(R))⁺ = 0.310 ± 0.036(stat) ± 0.017(syst) and f₀⁺ = 0.171 ± 0.085(stat) ± 0.099(syst) for positively charged W bosons. This establishes, for the first time, that W bosons produced in pp collisions with large transverse momenta are predominantly left-handed, as expected in the standard model.

Measurement of the B0 production cross section in pp collisions at sqrt[s] = 7 TeV

Measurements of the differential production cross sections dσ/dpTB and dσ/dyB for B0 mesons produced in pp collisions at sqrt[s] = 7 TeV are presented. The data set used was collected by the CMS experiment at the LHC and corresponds to an integrated luminosity of 40 pb-1. The production cross section is measured from B0 meson decays reconstructed in the exclusive final state J/ψKS0, with the subsequent decays J/ψ → μ + μ - and KS0 → π+}π-. The total cross section for pTB>5 GeV and |yB|<2.2 is measured to be 33.2 ± 2.5 ± 3.5 μb, where the first uncertainty is statistical and the second is systematic.

Search for neutral minimal supersymmetric standard model Higgs bosons decaying to tau pairs in pp collisions at √s=7 TeV

A search for neutral minimal supersymmetric standard model (MSSM) Higgs bosons in pp collisions at the LHC at a center-of-mass energy of 7 TeV is presented. The results are based on a data sample corresponding to an integrated luminosity of 36  pb(-1) recorded by the CMS experiment. The search uses decays of the Higgs bosons to tau pairs. No excess is observed in the tau-pair invariant-mass spectrum. The resulting upper limits on the Higgs boson production cross section times branching fraction to tau pairs, as a function of the pseudoscalar Higgs boson mass, yield stringent new bounds in the MSSM parameter space.

Search for supersymmetry in pp collisions at √7 TeV in events with two photons and missing transverse energy

A search for supersymmetry in the context of general gauge-mediated breaking with the lightest neutralino as the next-to-lightest supersymmetric particle and the gravitino as the lightest is presented. The data sample corresponds to an integrated luminosity of 36 pb(-1) recorded by the CMS experiment at the LHC. The search is performed by using events containing two or more isolated photons, at least one hadronic jet, and significant missing transverse energy. No excess of events at high missing transverse energy is observed. Upper limits on the signal cross section for general gauge-mediated supersymmetry between 0.3 and 1.1 pb at the 95% confidence level are determined for a range of squark, gluino, and neutralino masses, excluding supersymmetry parameter space that was inaccessible to previous experiments.

Study of Z Boson Production in PbPb Collisions at √S(NN)=2.76 TeV

A search for Z bosons in the μ(+)μ(-) decay channel has been performed in PbPb collisions at √S(NN)=2.76  TeV with the CMS detector at the LHC, in a 7.2 μb(-1) data sample. The number of opposite-sign muon pairs observed in the 60-120 GeV/c(2) invariant mass range is 39, corresponding to a yield per unit of rapidity (y) and per minimum bias event of [33.8±5.5(stat)±4.4(syst)]×10(-8), in the |y|<2.0 range. Rapidity, transverse momentum, and centrality dependencies are also measured. The results agree with next-to-leading order QCD calculations, scaled by the number of incoherent nucleon-nucleon collisions.

Measurement of dijet angular distributions and search for quark compositeness in pp collisions at √s = 7 TeV

Dijet angular distributions are measured over a wide range of dijet invariant masses in pp collisions at √s = 7 TeV, at the CERN LHC. The event sample, recorded with the CMS detector, corresponds to an integrated luminosity of 36 pb⁻¹. The data are found to be in good agreement with the predictions of perturbative QCD, and yield no evidence of quark compositeness. With a modified frequentist approach, a lower limit on the contact interaction scale for left-handed quarks of Λ⁺ = 5.6 TeV (Λ⁻ = 6.7 TeV) for destructive (constructive) interference is obtained at the 95% confidence level.

Search for pair production of second-generation scalar leptoquarks in pp collisions at √s = 7 TeV

A search for pair production of second-generation scalar leptoquarks in the final state with two muons and two jets is performed using proton-proton collision data at √s = 7 TeV collected by the CMS detector at the LHC. The data sample used corresponds to an integrated luminosity of 34 pb⁻¹. The number of observed events is in good agreement with the predictions from the standard model processes. An upper limit is set on the second-generation leptoquark cross section times β² as a function of the leptoquark mass, and leptoquarks with masses below 394 GeV are excluded at a 95% confidence level for β = 1, where β is the leptoquark branching fraction into a muon and a quark. These limits are the most stringent to date.

Search for pair production of first-generation scalar leptoquarks in pp collisions at √s = 7 TeV

A search for pair production of first-generation scalar leptoquarks is performed in the final state containing two electrons and two jets using proton-proton collision data at √s = 7 TeV. The data sample used corresponds to an integrated luminosity of 33 pb⁻¹ collected with the CMS detector at the CERN LHC. The number of observed events is in good agreement with the predictions for the standard model background processes, and an upper limit is set on the leptoquark pair production cross section times β² as a function of the leptoquark mass, where β is the branching fraction of the leptoquark decay to an electron and a quark. A 95% confidence level lower limit is set on the mass of a first-generation scalar leptoquark at 384 GeV for β = 1, which is the most stringent direct limit to date.