Measurement of the pseudorapidity and centrality dependence of the transverse energy density in Pb-Pb collisions at √(s(NN))=2.76 TeV

The transverse energy (E(T)) in Pb-Pb collisions at 2.76 TeV nucleon-nucleon center-of-mass energy (√(s(NN)) has been measured over a broad range of pseudorapidity (η) and collision centrality by using the CMS detector at the LHC. The transverse energy density per unit pseudorapidity (dE(T)/dη) increases faster with collision energy than the charged particle multiplicity. This implies that the mean energy per particle is increasing with collision energy. At all pseudorapidities, the transverse energy per participating nucleon increases with the centrality of the collision. The ratio of transverse energy per unit pseudorapidity in peripheral to central collisions varies significantly as the pseudorapidity increases from η=0 to |η|=5.0. For the 5% most central collisions, the energy density per unit volume is estimated to be about 14 GeV/fm(3) at a time of 1 fm/c after the collision. This is about 100 times larger than normal nuclear matter density and a factor of 2.6 times higher than the energy density reported at √(s(NN))=200 GeV at the Relativistic Heavy Ion Collider.

Search for a W' or techni-ρ decaying into WZ in pp Collisions at sqrt[s] = 7 TeV

A search is performed in pp collisions at sqrt[s]=7  TeV for exotic particles decaying via WZ to final states with electrons and muons. The data sample corresponds to an integrated luminosity of approximately 5  fb(-1). No significant excess is observed in the data above the expected standard model background. Upper bounds at 95% confidence level are set on the production cross section of the W' boson described by the sequential standard model and on the W' WZ coupling. W' bosons with masses below 1143 GeV are excluded. Limits are also set in the context of low-scale technicolor models, under a range of assumptions concerning the model parameters.

Search for a light pseudoscalar Higgs boson in the dimuon decay channel in pp collisions at √s = 7 TeV

The dimuon invariant mass spectrum is searched in the range between 5.5 and 14 GeV for a light pseudoscalar Higgs boson a, predicted in a number of new physics models, including the next-to-minimal supersymmetric standard model. The data sample used in the search corresponds to an integrated luminosity of 1.3 fb(-1) collected in pp collisions at √s = 7 TeV with the CMS detector at the LHC. No excess is observed above the background predictions and upper limits are set on the cross section times branching fraction σ × B(pp→a→μ(+)μ(-)) in the range of 1.5-7.5 pb. These results improve on existing bounds on the abb coupling for m(a) < m(Υ(1S)) and are the first significant limits for m(a) > m(Υ(3S)). Constraints on the supersymmetric parameter space are presented in the context of the next-to-minimal model.

Measurement of the electron charge asymmetry in inclusive W production in pp collisions at sqrt[s]=7 TeV

A measurement of the electron charge asymmetry in inclusive pp→W+X→eν+X production at sqrt[s]=7  TeV is presented based on data recorded by the CMS detector at the LHC and corresponding to an integrated luminosity of 840  pb(-1). The electron charge asymmetry reflects the unequal production of W(+) and W(-) bosons in pp collisions. The electron charge asymmetry is measured in bins of the absolute value of electron pseudorapidity in the range of |η|<2.4. The asymmetry rises from about 0.1 to 0.2 as a function of the pseudorapidity and is measured with a relative precision better than 7%. This measurement provides new stringent constraints for parton distribution functions.

Search for new physics with same-sign isolated dilepton events with jets and missing transverse energy

A search for new physics is performed in events with two same-sign isolated leptons, hadronic jets, and missing transverse energy in the final state. The analysis is based on a data sample corresponding to an integrated luminosity of 4.98 fb(-1) produced in pp collisions at a center-of-mass energy of 7 TeV collected by the CMS experiment at the LHC. This constitutes a factor of 140 increase in integrated luminosity over previously published results. The observed yields agree with the standard model predictions and thus no evidence for new physics is found. The observations are used to set upper limits on possible new physics contributions and to constrain supersymmetric models. To facilitate the interpretation of the data in a broader range of new physics scenarios, information on the event selection, detector response, and efficiencies is provided.

Upper lid entropion post ptosis correction: is tarsal buckling the cause?

PURPOSE

To report two cases of the rare complication of entropion following involutional ptosis surgery and its successful management.

METHODS

Clinical findings and management of the patients are presented.

RESULTS

Case 1: An 89-year-old female underwent aponeurosis advancement surgery for left involutional ptosis. Post-operatively she achieved good lid height, but had developed entropion of the upper lid which resulted in a persistent corneal epithelial defect. The patient underwent repeat surgery during which the aponeurosis was found to be inserted into the lower part of middle one third of tarsus with the tarsus itself being extremely thin. The aponeurosis was reinserted into upper third of tarsus, followed by greyline split with anterior lamellar repositioning. Post-operatively the patient achieved good lid height with correction of the entropion.Case 2: A 70-year-old male who had previously undergone bilateral brow lift and ptosis correction two years ago, was referred with right upper lid entropion. During surgery the aponeurosis was found to be inserted into the lower part of middle one third of tarsus, with a very thin tarsus. This patient was also managed by reinserting aponeurosis into upper third of tarsus with grey line split and anterior lamellar repositioning following which he achieved good lid height and correction of the entropion.

COMMENT

Entropion has rarely been reported as a complication of ptosis surgery. This case series highlights the importance of taking special care when advancing the aponeurosis, in cases where the tarsus is thin, as it may result in vertical buckling of the tarsus.

Observation of a new Ξb baryon

The observation of a new b baryon via its strong decay into Ξ(b)(-) π(+) (plus charge conjugates) is reported. The measurement uses a data sample of pp collisions at sqrt[s] = 7 TeV collected by the CMS experiment at the LHC, corresponding to an integrated luminosity of 5.3 fb(-1). The known Ξ(b)(-) baryon is reconstructed via the decay chain Ξ(b)(-) → J/ψΞ(-) → μ(+) μ(-) Λ(0) π(-), with Λ(0) → pπ(-). A peak is observed in the distribution of the difference between the mass of the Ξ(b)(-) π(+) system and the sum of the masses of the Ξ(b)(-) and π(+), with a significance exceeding 5 standard deviations. The mass difference of the peak is 14.84 ± 0.74(stat) ± 0.28(syst) MeV. The new state most likely corresponds to the J(P) = 3/2(+) companion of the Ξ(b).

Budd-Chiari disease in infancy: three cases

Budd-Chiari syndrome (BCS) is rare in infancy. Three cases are presented. Case 1, an 8-month-old boy, presented with abdominal distension and oliguria. Doppler study of the abdomen showed ascites, hepatomegaly and normal hepatic veins. However, a CT scan demonstrated hepatic vein thrombosis. Case 2, a 5-month-old boy, presented with abdominal distension and diarrhoea. Ultrasound of the abdomen showed hepatic vein thrombosis and hepatomegaly. Case 3, a 7-month-old girl, presented with abdominal distension, diarrhoea and oliguria. Ultrasound of the abdomen showed hepatomegaly and obstructed hepatic veins. None of the cases had fever or jaundice before presentation. Case 1 developed fungal septicaemia and was lost to follow-up. Cases 2 and 3 succumbed to the disease before further intervention.

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.

P4-10-08: Risk Factor Profiles of Women with DCIS and Invasive Ductal Breast Cancers

Background There are well established risk factors for breast cancer, including elements of personal and family history. Ductal carcinoma in situ (DCIS) and invasive ductal carcinoma (IDC) have long been viewed as representing two points on the spectrum of one disease. There is limited and conflicting information in the literature regarding risk factor profiles for DCIS as compared with IDC. The purpose of this study was to investigate the relationship of established risk factors in a population of women newly diagnosed with pure DCIS and IDC. Methods

The Breast Cancer Database at NYU Langone Medical Center was queried for women who were diagnosed with pure DCIS and IDC from 1/2010-3/2011. Variables of interest included: age, family history of breast cancer (FHBC), BRCA1/2 status, age at menarche and menopause, parity, age at first birth, breast feeding, body mass index (BMI), history of atypical hyperplasia or lobular carcinoma in situ (ADH, ALH, LCIS), stage, ER/PR status, and method of presentation. Wilcoxon non-parametric tests, Chi-Square tests, and Fisher's Exact Tests were used to evaluate differences among DCIS and IDC patients.

Results Of the 593 women identified in this study, 140 (24%) had pure DCIS and 453 (76%) had IDC. The median age at diagnosis was 59 years. There were 9 (1.5%) BRCA1/2 mutation carriers. Of these, 7 had IDC and 2 had DCIS. The majority of patients with IDC were stage I (67%) and ER/PR+ (73%). The majority of patients with DCIS were also ER/PR+ (71%). In our cohort, the majority of DCIS (83%) was mammographically detected versus 47% of IDC cases. There were no statistically significant differences in breast cancer risk factors between the two groups.

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.

Optimizing the electrode size and arrangement in a microbial electrolysis cell

This study investigates the influence of anode and cathode size and arrangement on hydrogen production in a membrane-less flat-plate microbial electrolysis cell (MEC). Protein measurements were used to evaluate microbial density in the carbon felt anode. The protein concentration was observed to significantly decrease with the increase in distance from the anode-cathode interface. Cathode placement on both sides of the carbon felt anode was found to increase the current, but also led to increased losses of hydrogen to hydrogenotrophic activity leading to methane production. Overall, the best performance was obtained in the flat-plate MEC with a two-layer 10 mm thick carbon felt anode and a single gas-diffusion cathode sandwiched between the anode and the hydrogen collection compartments.

Outcomes of Endovascular Coiling in Patients with Intracranial Aneurysms Presenting with Poor Clinical and SAH Grade

Although the treatment of intracranial aneurysms has made significant advances, prediction of outcomes in poor grades has always been difficult. We present our findings of patients in poor clinical and SAH grade treated with endovascular coiling. We aimed to evaluate the clinical outcomes in patients presenting with poorer neurological and SAH grades treated by endovascular techniques. Of 190 patients who presented with SAH over a period of nine years, 34 were of poorer clinical grade (Hunt & Hess Grades 4 and 5), of whom 30 presented with H&H grade 4 and four with grade 5. 44.1% of the 34 patients belonged to Fischer grade 4. We assessed the technical success and final outcomes based on the Glasgow outcome scale. Of the 30 patients with grade 4, 81.4% had a good outcome. Two out of four patients with grade 5 had a poor outcome. 82.5% of the patients with Fischer grade 4 had a good outcome. None of the poor outcomes were procedure-related. Endovascular treatment with its higher rates of technical success, lower complication rates and better outcomes should be recommended as the treatment of choice in patients with intracranial aneurysms even in patients with poorer clinical and SAH grades.

All-optical modulation using two-photon absorption in silicon core optical fibers

All-optical modulation based on degenerate and non-degenerate two-photon absorption (TPA) is demonstrated within a hydrogenated amorphous silicon core optical fiber. The nonlinear absorption strength is determined by comparing the results of pump-probe experiments with numerical simulations of the coupled propagation equations. Subpicosecond modulation is achieved with an extinction ratio of more than 4 dB at telecommunications wavelengths, indicating the potential for these fibers to find use in high speed signal processing applications.

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.