Supersymmetric particle mass measurement with invariant mass correlations

The kinematic end-point technique for measuring the masses of supersymmetric particles in R-Parity conserving models at hadron colliders is re-examined with a focus on exploiting additional constraints arising from correlations in invariant mass observables. The use of such correlations is shown to potentially resolve the ambiguity in the interpretation of quark+lepton end-points and enable discrimination between sequential two-body and three-body lepton-producing decays. The use of these techniques is shown to improve the SUSY particle mass measurement precision for the SPS1a benchmark model by at least 20-30% compared to the conventional end-point technique.Comment: 29 pages, 23 .eps figures, JHEP3 style; v2 adds some references and small clarifications to text; v3 adds some more clarifications to the tex

A Class of Selenocentric Retrograde Orbits With Innovative Applications to Human Lunar Operations

Selenocentric distant retrograde orbits with radii from approx. 12,500 km to approx. 25,000 km are assessed for stability and for suitability as crewed command and control infrastructure locations in support of telerobotic lunar surface operations and interplanetary human transport. Such orbits enable consistent transits to and from Earth at virtually any time if they are coplanar with the Moon's geocentric orbit. They possess multiple attributes and applications distinct from NASA's proposed destination orbit for a redirected asteroid about 70,000 km from the Moon

Lymphoepithelial Carcinoma of Salivary Gland EBV-association in Endemic versus Non-Endemic Patients: A Report of 16 Cases

Lymphoepithelial carcinoma of salivary glands (LECSG) are rare neoplasms, reported in endemic populations (southeastern Chinese) with a strong Epstein-Barr virus (EBV) association. A retrospective series comparing EBV status within an ethnically diverse population (endemic vs. non-endemic patients) has not been reported. Sixteen LECSG were equally distributed between males (n = 8) and females (n = 8) with a median age of 54 years (range 18 to 85 years) at initial diagnosis. Ten patients were white, 4 Asian, and 2 black. The patients typically presented with swelling or mass for an average of 11.6 months. Tumors affected only major salivary glands: parotid (n = 13); submandibular (n = 3). Tumors were an average of 2.9 cm (range 1.5 to 5.8 cm). Nine of 16 (56%) patients had cervical lymph node metastases at presentation. No patients had nasopharyngeal or oropharyngeal tumors. Microscopically, the tumors were widely infiltrative, characterized by large polygonal to spindled cells arranged in a syncytial, lattice-like network in a background of lymphoplasmacytic cells. The neoplastic cells showed an open-vesicular nuclear chromatin to a more basaloid-morphology, the latter showing hyperchromatic nuclei and less cytoplasm, while nearly all of the cases had associated lymphoepithelial lesions/sialadenitis. By in situ hybridization, 8 of 16 cases had a strong, diffuse EBER expression (4 of 4 Asians; 4 of 12 non-Asians), while with immunohistochemistry all cases tested were pan-cytokeratin, CK5/6 and p63 reactive; none of the cases tested were p16 reactive. All patients were managed with wide or radical excision, 4 with concurrent chemoradiation, and 6 with radiation alone. Distant metastasis (lung, brain, and bone) developed in 2 patients. Overall follow-up (mean 3.8 years) revealed 12 patients alive and 2 dead, none with evidence of disease (mean 4.3 years); one white male alive with disease at 1.9 years, and one Asian female dead of disease at 4.2 years; both of these latter patients had Group IV stage disease. High stage (Group IV) patients had a shorter mean survival than lower stage patients: 3.1 versus 4.8 years, respectively. In conclusion, LECSG are uncommon primary neoplasms. Concurrent lymphoepithelial lesions may help suggest a primary tumor. The tumors, irrespective of race or ethnicity, may express EBER. There is an overall good survival, perhaps better for EBV-negative patients and for those with lower stage disease

Certified Computer Algebra on top of an Interactive Theorem Prover

Contains fulltext : 35027.pdf (publisher's version ) (Open Access

Radiotherapy for pediatric adrenocortical carcinoma – review of the literature

none13Background and purpose Pediatric adrenocortical carcinoma (pACC) is a rare disease with poor prognosis. Publications on radiotherapy (RT) are scarce. This review summarizes the current data on RT for pACC and possibly provides first evidence to justify its use in this setting. Materials and methods We searched the PubMed and Embase database for manuscripts regarding RT for pACC. Results We included 17 manuscripts reporting on 76 patients treated with RT, after screening 2961 references and 269 full articles. In addition, we added data of 4 unreported pACC patients treated by co-authors. All reports based on retrospective data. Median age at first diagnosis was 11.1 years (70% female); 78% of patients presented with hormonal activity. RT was mostly performed for curative intent (78%). 88% of RT were administered during primary therapy. The site of RT was predominantly the local tumor bed (76%). Doses of RT ranged from 15 to 62 Gy (median 50 Gy). Information on target volumes or fractionation were lacking. Median follow-up was 6,9 years and 64% of the patients died of disease, with 33% alive without disease. In 16 of 48 patients with available follow-up data after adjuvant RT (33%) no recurrence was reported and in 3 of 9 patients palliative RT seemed to induce some benefit for the patient. Conclusions Our first systematic review on RT for pACC provides too few data for any general recommendation, but adjuvant RT in patients with high risk might be considered. International collaborative studies are urgently needed to establish better evidence on the role of RT in this rare malignancy.noneWiegering, Verena; Riedmeier, Maria; Thompson, Lester D.R.; Virgone, Calogero; Redlich, Antje; Kuhlen, Michaela; Gultekin, Melis; Yalcin, Bilgehan; Decarolis, Boris; Härtel, Christoph; Schlegel, Paul-Gerhardt; Fassnacht, Martin; Timmermann, BeateWiegering, Verena; Riedmeier, Maria; Thompson, Lester D. R.; Virgone, Calogero; Redlich, Antje; Kuhlen, Michaela; Gultekin, Melis; Yalcin, Bilgehan; Decarolis, Boris; Härtel, Christoph; Schlegel, Paul-Gerhardt; Fassnacht, Martin; Timmermann, Beat

Using Subsystem MT2 for Complete Mass Determinations in Decay Chains with Missing Energy at Hadron Colliders

We propose to use the MT2 concept to measure the masses of all particles in SUSY-like events with two unobservable, identical particles. To this end we generalize the usual notion of MT2 and define a new MT2(n,p,c) variable, which can be applied to various subsystem topologies, as well as the full event topology. We derive analytic formulas for its endpoint MT2{max}(n,p,c) as a function of the unknown test mass Mc of the final particle in the subchain and the transverse momentum pT due to radiation from the initial state. We show that the endpoint functions MT2{max}(n,p,c)(Mc,pT) may exhibit three different types of kinks and discuss the origin of each type. We prove that the subsystem MT2(n,p,c) variables by themselves already yield a sufficient number of measurements for a complete determination of the mass spectrum (including the overall mass scale). As an illustration, we consider the simple case of a decay chain with up to three heavy particles, X2 -> X1 -> X0, which is rather problematic for all other mass measurement methods. We propose three different MT2-based methods, each of which allows a complete determination of the masses of particles X0, X1 and X2. The first method only uses MT2(n,p,c) endpoint measurements at a single fixed value of the test mass Mc. In the second method the unknown mass spectrum is fitted to one or more endpoint functions MT2{max}(n,p,c)(Mc,pT) exhibiting a kink. The third method is hybrid, combining MT2 endpoints with measurements of kinematic edges in invariant mass distributions. As a practical application of our methods, we show that the dilepton W+W- and tt-bar samples at the Tevatron can be used for an independent determination of the masses of the top quark, the W boson and the neutrino, without any prior assumptions.Comment: 47 pages, 9 figures. revised version, published in JHEP. Major addition: a new appendix with the complete set of formulas for the MT2 endpoints as functions of the upstream transverse momentum pT and test mass M

Using kinematic boundary lines for particle mass measurements and disambiguation in SUSY-like events with missing energy

We revisit the method of kinematical endpoints for particle mass determination, applied to the popular SUSY decay chain squark -> neutralino -> slepton -> LSP. We analyze the uniqueness of the solutions for the mass spectrum in terms of the measured endpoints in the observable invariant mass distributions. We provide simple analytical inversion formulas for the masses in terms of the measured endpoints. We show that in a sizable portion of the SUSY mass parameter space the solutions always suffer from a two-fold ambiguity, due to the fact that the original relations between the masses and the endpoints are piecewise-defined functions. The ambiguity persists even in the ideal case of a perfect detector and infinite statistics. We delineate the corresponding dangerous regions of parameter space and identify the sets of "twin" mass spectra. In order to resolve the ambiguity, we propose a generalization of the endpoint method, from single-variable distributions to two-variable distributions. In particular, we study analytically the boundaries of the (m_{jl(lo)}, m_{jl(hi)}) and (m_{ll}, m_{jll}) distributions and prove that their shapes are in principle sufficient to resolve the ambiguity in the mass determination. We identify several additional independent measurements which can be obtained from the boundary lines of these bivariate distributions. The purely kinematical nature of our method makes it generally applicable to any model that exhibits a SUSY-like cascade decay.Comment: 47 pages, 19 figure

Precise reconstruction of sparticle masses without ambiguities

We critically reexamine the standard applications of the method of kinematical endpoints for sparticle mass determination. We consider the typical decay chain in supersymmetry (SUSY) squark -> neutralino -> slepton -> LSP, which yields a jet j and two leptons ln and lf. The conventional approaches use the upper kinematical endpoints of the individual distributions m_{jll}, m_{jl(lo)} and m_{jl(hi)}, all three of which suffer from parameter space region ambiguities and may lead to multiple solutions for the SUSY mass spectrum. In contrast, we do not use m_{jll}, m_{jl(lo)} and m_{jl(hi)}, and instead propose a new set of (infinitely many) variables whose upper kinematic endpoints exhibit reduced sensitivity to the parameter space region. We then outline an alternative, much simplified procedure for obtaining the SUSY mass spectrum. In particular, we show that the four endpoints observed in the three distributions m^2_{ll}, m^2_{jln} U m^2_{jlf} and m^2_{jln}+m^2_{jlf} are sufficient to completely pin down the squark mass and the two neutralino masses, leaving only a discrete 2-fold ambiguity for the slepton mass. This remaining ambiguity can be easily resolved in a number of different ways: for example, by a single additional measurement of the kinematic endpoint of any one out of the many remaining 1-dimensional distributions at our disposal, or by exploring the correlations in the 2-dimensional distribution of m^2_{jln} U m^2_{jlf} versus m^2_{ll}. We illustrate our method with two examples: the LM1 and LM6 CMS study points. An additional advantage of our method is the expected improvement in the accuracy of the SUSY mass determination, due to the multitude and variety of available measurements.Comment: 37 pages, added a new figure in the Appendix, published versio

‘Can you dig it?’ Developing an approach to validly assessing diverse skills in an archaeological context

This paper outlines a case study of an assessment development process which contrasts with more recent ‘top-down’ trends in assessment which tend to leave assessment development processes opaque to users. This paper describes the processes of a collaborative, multi-agency project which set out to develop an assessment framework which would appropriately recognise the various skills present in the Higher Education Field Academy; a widening participation programme aiming to boost the educational aspirations, enthusiasm and attainment of secondary school students through their engagement in archaeological excavation. The case study describes the stages of building an assessment framework that was sympathetic to the intentions of a learning programme whilst providing robust observation-based outcomes that avoided heavy assessment processes that could corrupt learning relationships. The challenges involved in this development process have important parallels with vocational assessment; not least in providing an example of a localised development of an observation-based assessment model which can be used in diverse settings. The insights gained from this case study are useful for others who are engaged in localised assessment development processes

Clinical management of pain in advanced lung cancer

Lung cancer is the most common cancer in the world and pain is its most common symptom. Pain can be brought about by several different causes including local effects of the tumor, regional or distant spread of the tumor, or from anti-cancer treatment. Patients with lung cancer experience more symptom distress than patients with other types of cancer. Symptoms such as pain may be associated with worsening of other symptoms and may affect quality of life. Pain management adheres to the principles set out by the World Health Organization's analgesic ladder along with adjuvant analgesics. As pain can be caused by multiple factors, its treatment requires pharmacological and non-pharmacological measures from a multidisciplinary team linked in with specialist palliative pain management. This review article examines pain management in lung cancer