331 research outputs found
Resummation of Threshold Corrections for Single-Particle Inclusive Cross Sections
We derive threshold resummations for single-particle and single-jet inclusive
cross sections, thus generalizing previous results at fixed invariant mass to a
wider class of cross sections with phenomenological interest. We confirm the
structure of our resummed expressions by comparison with explicit one-loop
calculations for direct photons and heavy quarks.Comment: 14 page
Outstanding problems in the phenomenology of hard diffractive scattering
This paper is a summary of the discussion within the Diffractive and Low-x
Physics Working Group at the 1999 Durham Collider Workshop of the
interpretation of the Tevatron and HERA measurements of inclusive hard
diffraction.Comment: 5 pages, 1 figure. Talks and discussions from the UK Phenomenology
Workshop on Collider Physics, Durham, September 199
Energy Flow in Interjet Radiation
We study the distribution of transverse energy, Q_Omega, radiated into an
arbitrary interjet angular region, Omega, in high-p_T two-jet events. Using an
approximation that emphasizes radiation directly from the partons that undergo
the hard scattering, we find a distribution that can be extrapolated smoothly
to Q_Omega=Lambda_QCD, where it vanishes. This method, which we apply
numerically in a valence quark approximation, provides a class of predictions
on transverse energy radiated between jets, as a function of jet energy and
rapidity, and of the choice of the region Omega in which the energy is
measured. We discuss the relation of our approximation to the radiation from
unobserved partons of intermediate energy, whose importance was identified by
Dasgupta and Salam.Comment: 26 pages, 8 eps figures. Revised to include a discussion of
non-global logarithm
The resummation of inter-jet energy flow for gaps-between-jets processes at HERA
We calculate resummed perturbative predictions for gaps-between-jets
processes and compare to HERA data. Our calculation of this non-global
observable needs to include the effects of primary gluon emission (global
logarithms) and secondary gluon emission (non-global logarithms) to be correct
at the leading logarithm (LL) level. We include primary emission by calculating
anomalous dimension matrices for the geometry of the specific event definitions
and estimate the effect of non-global logarithms in the large limit. The
resulting predictions for energy flow observables are consistent with
experimental data.Comment: 31 pages, 4 figures, 2 table
Low levels of urinary psa better identify prostate cancer patients
SIMPLE SUMMARY: Elevated PSA levels in blood tests are the gold standard for early prostate cancer detection, but its lack of specificity limits its clinical use as a mass screening test. The paradox is that it has long been known that advanced prostate cancers can lose PSA expression. We have observed that in the presence of tumors, the prostate produces and secretes less PSA than in healthy or benign conditions. Therefore, the PSA evaluation in urine provided more accurate information on the presence of prostate tumors than the blood test, representing a new method for the screening of prostate cancer. ABSTRACT: Serum prostatic specific antigen (PSA) has proven to have limited accuracy in early diagnosis and in making clinical decisions about different therapies for prostate cancer (PCa). This is partially due to the fact that an increase in PSA in the blood is due to the compromised architecture of the prostate, which is only observed in advanced cancer. On the contrary, PSA observed in the urine (uPSA) reflects the quantity produced by the prostate, and therefore can give more information about the presence of disease. We enrolled 574 men scheduled for prostate biopsy at the urology clinic, and levels of uPSA were evaluated. uPSA levels resulted lower among subjects with PCa when compared to patients with negative biopsies. An indirect correlation was observed between uPSA amount and the stage of disease. Loss of expression of PSA appears as a characteristic of prostate cancer development and its evaluation in urine represents an interesting approach for the early detection of the disease and the stratification of patients
Predictors of Bone Metastases at68Ga-PSMA-11 PET/CT in Hormone-Sensitive Prostate Cancer (HSPC) Patients with Early Biochemical Recurrence or Persistence
Prostate-specific-membrane-antigen/positron-emission-tomography (PSMA-PET) can accurately detect disease localizations in prostate cancer (PCa) patients with early biochemical recurrence/persistence (BCR/BCP), allowing for more personalized image-guided treatments in oligometastatic patients with major impact in the case of bone metastases (BM). Therefore, this study aimed to identify predictors of BM at PSMA-PET in early-BCR/BCP hormone-sensitive PCa (HSPC) patients, previously treated with radical intent (radiotherapy or radical prostatectomy ± salvage-radiotherapy (SRT)). A retrospective analysis was performed on 443 (68)Ga-PSMA-11-PET/CT scans. The cohort median PSA at PET-scan was 0.60 (IQR: 0.38–1.04) ng/mL. PSMA-PET detection rate was 42.0% (186/443), and distant lesions (M1a/b/c) were found in 17.6% (78/443) of cases. BM (M1b) were present in 9.9% (44/443) of cases, with 70.5% (31/44) showing oligometastatic spread (≤3 PSMA-positive lesions). In the multivariate binary logistic regression model (accuracy: 71.2%, Nagelkerke-R(2): 13%), T stage ≥ 3a (OR: 2.52; 95% CI: 1.13–5.60; p = 0.024), clinical setting (previous SRT vs. first-time BCR OR: 2.90; 95% CI: 1.32–6.35; p = 0.008), and PSAdt (OR: 0.93; 95% CI: 0.88–0.99; p = 0.026) were proven to be significant predictors of bone metastases, with a 7% risk increment for each single-unit decrement of PSAdt. These predictors could be used to further refine the indication for PSMA-PET in early BCR/BCP HSPC patients, leading to higher detection rates of bone disease and more personalized treatments
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