Reconstruction of the Extended Gauge Structure from Z′Z' Observables at Future Colliders

The discovery of a new neutral gauge boson $Z'$ with a mass in the TeV region would allow for determination of gauge couplings of the $Z'$ to ordinary quarks and leptons in a model independent way. We show that these couplings in turn would allow us to determine the nature of the extended gauge structure. As a prime example we study the $E_6$ group. In this case two discrete constraints on experimentally determined couplings have to be satisfied. If so, the couplings would then uniquely determine the two parameters, $\tan \beta$ and $\delta$, which fully specify the nature of the $Z'$ within $E_6$. If the $Z'$ is part of the $E_6$ gauge structure, then for $M_{Z'}=1$ TeV $\tan \beta$ and $\delta$ could be determined to around $10\%$ at the future colliders. The NLC provides a unique determination of the two constraints as well as of $\tan \beta$ and $\delta$, though with slightly larger error bars than at the LHC. On the other hand, since the LHC primarily determines three out of four normalized couplings, it provides weaker constraints for the underlying gauge structure.Comment: 14 pages LaTeX using RevTeX and psfig.sty. TeX source and 3 PS figures, tarred, compressed and uuencoded; also available via anonymous ftp to ftp://dept.physics.upenn.edu/pub/Cvetic/UPR-636-T

Searching for Lee-Wick Gauge Bosons at the LHC

In an extension of the Standard Model(SM) based on the ideas of Lee and Wick, Grinstein, O'Connell and Wise have found an interesting way to remove the usual quadratically divergent contributions to the Higgs mass induced by radiative corrections. Phenomenologically, the model predicts the existence of Terascale, negative-norm copies of the usual SM fields with rather unique properties: ghost-like propagators and negative decay widths, but with otherwise SM-like couplings. The model is both unitary and causal on macroscopic scales. In this paper we examine whether or not such states with these unusual properties can be uniquely identified as such at the LHC. We find that in the extended strong and electroweak gauge boson sector of the model, which is the simplest one to analyze, such an identification can be rather difficult. Observation of heavy gluon-like resonances in the dijet channel offers the best hope for this identification.Comment: 17 pages, 4 figs; discussion adde

Computed tomography–based body composition in patients with ovarian cancer: association with chemotoxicity and prognosis

PurposeTo assess the association between computed tomography (CT)-derived quantitative measures of body composition profiling and chemotherapy-related complications, in terms of dose reduction, premature discontinuation of chemotherapy, and cycle delays in patients with ovarian cancer. Secondary purposes were to evaluate associations between sarcopenia and survival, and to evaluate differences in body composition profiling at baseline and after neoadjuvant chemotherapy. Materials and MethodsThe study population was retrospectively selected from a database of patients with newly diagnosed ovarian cancer (any stage) referred to our Institution between Feb 2011 and Mar 2020. Clinical data were recorded, and CT images at the level of the 3(rd) lumbar vertebra were stored. By using specific software, skeletal muscle area (SMA), subcutaneous adipose tissue (SAT), visceral adipose tissue (VAT), and skeletal muscle density (SMD) were extracted. Skeletal muscle index (SMI) was then calculated. Statistical analysis was performed by logistic regression models to identify body composition features predictive of dose reduction, premature end of chemotherapy, and cycle delays. Kaplan-Meier analyses were performed to assess overall survival (OS) and progression-free survival (PFS). The log-rank test was used to determine differences in OS and PFS between sarcopenic and non-sarcopenic patients. Wilcoxon test was performed to compare body composition features before and after neoadjuvant chemotherapy (NACT). ResultsSixty-nine patients were included. A significant association was found between VAT and cycle delays (OR = 1.01, z = 2.01, 95% CI: 1.00-1.02, p < 0.05), between SMA and early discontinuation of chemotherapy (OR = 1.03, z = 2.10, 95% CI: 1.00-1.05, p < 0.05), and between mean SMD and cycle delays (OR = 0.92, z = -2.70, 95%CI: 0.87-0.98, p < 0.01). No significant difference emerged for OS in sarcopenic and non-sarcopenic patients, nor in CT body composition features before and after NACT. ConclusionsIn ovarian cancer patients, CT-derived body composition profiling might predict the risk of chemotoxicity. In particular, VAT and SMD are associated with chemotherapy cycle delays, and SMA with early discontinuation of chemotherapy

Hemodynamic benefits of the Toronto stentless valve

AbstractWe report on 254 consecutive patients (170 male, 84 female) undergoing aortic valve replacement with the Toronto SPV Stentless Valve (St. Jude Medical, Inc., St. Paul, Minn.). Mean age (± standard deviation) was 62.1 ± 11.6 years. Three patients (1%) received sizes 21 or 22 mm, 24 (9%) received size 23 mm, and 227 patients (89%) received sizes 25, 27, or 29 mm. Serial echocardiography was used to assess valve performance during a 3-year follow-up. Mean gradient decreased by 35.8% ( p < 0.0001; 95% confidence interval -39.6%, -31.7%) from postoperative values to the 3- to 6-month follow-up and by 6.1% ( p = 0.004; 95% confidence interval -10.1%, -2%) at each subsequent interval; effective orifice area increased by 17.2% ( p = 0.0001; 95% confidence interval 12.0%, 22.6%) initially and by 4.4% ( p < 0.001; 95% confidence interval 1.8%, 7.0%) thereafter. At 2 years of follow-up, mean gradient was 3.3 ± 2.1 mm Hg and mean effective orifice area was 2.2 ± 0.8 cm 2 . Studies on left ventricular mass were carried out on 84 patients. Left ventricular mass decreased by 14.3% (37.8 ± 57.9 gm; p < 0.0001; 95% confidence interval -53.7, -21.9 gm) and left ventricular mass index decreased by 15.2% (21.1 ± 30.5 gm/m 2; p < 0.0001; 95% confidence interval -29.5, -12.7 gm/m 2) from postoperative values to the 3- to 6-month follow-up interval. The reduction in residual gradient and potential regression in left ventricular hypertrophy may have a beneficial prognostic implication. We believe that the unique stentless design of the Toronto SPV Stentless Valve allows this to occur. (J T horac C ardiovasc S urg 1996;112:431-46

Body composition as a predictor of chemotherapy-related toxicity in ovarian cancer patients: a systematic review

Objectives:The main objective of this systematic review was to examine the literature evaluating association of image-based body composition with chemotherapy-related toxicity in ovarian cancer patients. A secondary objective was to evaluate the different definitions of sarcopenia across studies. Methods:This systematic review was conducted according to the PRISMA-DTA statement and the protocol was registered on Prospero. A comprehensive literature search of 3 electronic databases was performed by two authors. For each eligible article, information was collected concerning the clinical setting; basic study data; population characteristics; technical aspects; body composition features; chemotherapy drugs administered; association of body composition values and toxicities. The overall quality of the included studies was critically evaluated. Results:After the initial retrieval of 812 articles, the systematic review included 6 articles (5/6 studies were retrospective; one was prospective). The number of patients ranged between 69 and 239; mean/median age ranged between 55 and 65 years; the percentage of sarcopenic patients ranged between 25% and 54%. The cut-off values to define sarcopenia and the vertebral levels for evaluation of body composition were different. Five studies included chemotherapy based on carboplatin and paclitaxel, 1 included chemotherapy based on pegylated liposomal doxorubicin. Among the studies including carboplatin and paclitaxel, 3/5 demonstrated an association with toxicity, whereas 2/5 did not. Altogether, 4/6 papers demonstrated an association between the body composition values and the development of chemotherapy-related toxicities. Conclusions:There is a wide variability of results about the association of body composition and chemotherapy-related toxicity in ovarian cancer patients. Therefore further studies, possibly including a comprehensive assessment of body compartments and where the definition of body composition cut-offs is constant, are warranted to better understand this association

The Production of Z′Z' Associated With Photons or Jets as a Probe of New Gauge Boson Couplings

We examine the production of a new $Z'$ gauge boson in association with photons or jets at future hadron supercolliders as a probe of its couplings to fermions. Associated jet production is found to be rather insensitive to these couplings and suffers from large uncertainties as well as substantial backgrounds. On the other hand, the ratio of rates for associated photon $Z'$ production to that of conventional $Z'$ production has a rather clean signature (once appropriate cuts are made), and is found to be quite sensitive to the choice of extended electroweak model, while being simultaneously insensitive to structure function uncertainties and QCD corrections. Rates at both the SSC and LHC are significant for $Z'$ masses in the 1 TeV range.Comment: 14pp, 6 figs(not included), LaTex, ANL-HEP-PR-92-5

Brane-localized Kinetic Terms in the Randall-Sundrum Model

We examine the effects of boundary kinetic terms in the Randall-Sundrum model with gauge fields in the bulk. We derive the resulting gauge Kaluza-Klein (KK) state wavefunctions and their corresponding masses, as well as the KK gauge field couplings to boundary fermions, and find that they are modified in the presence of the boundary terms. In particular, for natural choices of the parameters, these fermionic couplings can be substantially suppressed compared to those in the conventional Randall-Sundrum scenario. This results in a significant relaxation of the bound on the lightest gauge KK mass obtained from precision electroweak data; we demonstrate that this bound can be as low as a few hundred GeV. Due to the relationship between the lightest gauge KK state and the electroweak scale in this model, this weakened constraint allows for the electroweak scale to be near a TeV in this minimal extension of the Randall-Sundrum model with bulk gauge fields, as opposed to the conventional scenario.Comment: 24 pages, 8 figures, LaTex. Discussion and figure added addressing the effects of this analysis on the hierarch

Whole-body composition features by computed tomography in ovarian cancer: pilot data on survival correlations

Background: The primary objective of this study was to assess the associations of computed tomography (CT)-based whole-body composition values with overall survival (OS) and progression-free survival (PFS) in epithelial ovarian cancer (EOC) patients. The secondary objective was the association of body composition with chemotherapy-related toxicity. Methods: Thirty-four patients (median age 64.9 years; interquartile range 55.4–75.4) with EOC and thorax and abdomen CT scans were included. Clinical data recorded: age; weight; height; stage; chemotherapy-related toxicity; and date of last contact, progression and death. Automatic extraction of body composition values was performed by dedicated software. Sarcopenia was defined according to predefined cutoffs. Statistical analysis included univariate tests to investigate associations of sarcopenia and body composition with chemotoxicity. Association of body composition parameters and OS/PFS was evaluated by log-rank test and Cox proportional hazard model. Multivariate models were adjusted for FIGO stage and/or age at diagnosis. Results: We found significant associations of skeletal muscle volume with OS (p = 0.04) and PFS (p = 0.04); intramuscular fat volume with PFS (p = 0.03); and visceral adipose tissue, epicardial and paracardial fat with PFS (p = 0.04, 0.01 and 0.02, respectively). We found no significant associations between body composition parameters and chemotherapy-related toxicity. Conclusions: In this exploratory study, we found significant associations of whole-body composition parameters with OS and PFS. These results open a window to the possibility to perform body composition profiling without approximate estimations

The effects of non-universal extra dimensions on the radiative lepton flavor decays \mu\to e\gamma and \tau\to \mu\gamma in the two Higgs doublet model

We study the effect of non-universal extra dimensions on the branching ratios of the lepton flavor violating processes \mu\to e\gamma and \tau\to \mu\gamma in the general two Higgs doublet model. We observe that these effects are small for a single extra dimension, however, in the case of two extra dimensions there is a considerable enhancement in the additional contributions.Comment: 16 Pages, 9 Figure

Z' Decays into Four Fermions

If a new $Z'$ is discovered with a mass $\sim 1 \ TeV$ at LHC/SSC, its (rare) decays into two charged leptons plus missing transverse energy will probe the $Z'$ coupling to the lepton doublet $(\nu,e)_L$ and to $W^+W^-$, allowing further discrimination among extended electroweak models.Comment: 9 pages plus 1 figure (not included but available), UG-FT-22/9