The exclusive photoproduction reaction γp→ϒp has been studied with the ZEUS experiment in ep collisions at HERA using an integrated luminosity of 468 pb−1. The measurement covers the kinematic range ...60<W<220 GeV and Q2<1 GeV2, where W is the photon–proton centre-of-mass energy and Q2 is the photon virtuality. These results, which represent the analysis of the full ZEUS data sample for this channel, are compared to predictions based on perturbative QCD.
Inclusive-jet cross sections have been measured in the reaction ep→e+jet+X for photon virtuality Q2<1 GeV2 and γp centre-of-mass energies in the region 142<Wγp<293 GeV with the ZEUS detector at HERA ...using an integrated luminosity of 300 pb−1. Jets were identified using the kT, anti-kT or SIScone jet algorithms in the laboratory frame. Single-differential cross sections are presented as functions of the jet transverse energy, ETjet, and pseudorapidity, ηjet, for jets with ETjet>17 GeV and −1<ηjet<2.5. In addition, measurements of double-differential inclusive-jet cross sections are presented as functions of ETjet in different regions of ηjet. Next-to-leading-order QCD calculations give a good description of the measurements, except for jets with low ETjet and high ηjet. The influence of non-perturbative effects not related to hadronisation was studied. Measurements of the ratios of cross sections using different jet algorithms are also presented; the measured ratios are well described by calculations including up to O(αs2) terms. Values of αs(MZ) were extracted from the measurements and the energy-scale dependence of the coupling was determined. The value of αs(MZ) extracted from the measurements based on the kT jet algorithm is αs(MZ)=0.1206−0.0022+0.0023(exp.)−0.0035+0.0042(th.); the results from the anti-kT and SIScone algorithms are compatible with this value and have a similar precision.
Summary Background Fewer than half of the patients with completely resected non-small-cell lung cancer (NSCLC) are cured. Since the introduction of adjuvant chemotherapy in 2004, no substantial ...progress has been made in adjuvant treatment. We aimed to assess the efficacy of the MAGE-A3 cancer immunotherapeutic in surgically resected NSCLC. Methods In this randomised, double-blind, placebo-controlled trial, we recruited patients aged at least 18 years with completely resected stage IB, II, and IIIA MAGE-A3-positive NSCLC who did or did not receive adjuvant chemotherapy from 443 centres in 34 countries (Europe, the Americas, and Asia Pacific). Patients were randomly assigned (2:1) to receive 13 intramuscular injections of recMAGE-A3 with AS15 immunostimulant (MAGE-A3 immunotherapeutic) or placebo during 27 months. Randomisation and treatment allocation at the investigator site was done centrally via internet with stratification for chemotherapy versus no chemotherapy. Participants, investigators, and those assessing outcomes were masked to group assignment. A minimisation algorithm accounted for the number of chemotherapy cycles received, disease stage, lymph node sampling procedure, performance status score, and lifetime smoking status. The primary endpoint was broken up into three co-primary objectives: disease-free survival in the overall population, the no-chemotherapy population, and patients with a potentially predictive gene signature. The final analyses included the total treated population (all patients who had received at least one treatment dose). This trial is registered with ClinicalTrials.gov , number NCT00480025. Findings Between Oct 18, 2007, and July 17, 2012, we screened 13 849 patients for MAGE-A3 expression; 12 820 had a valid sample and of these, 4210 (33%) had a MAGE-A3-positive tumour. 2312 of these patients met all eligibility criteria and were randomly assigned to treatment: 1515 received MAGE-A3 and 757 received placebo and 40 were randomly assigned but never started treatment. 784 patients in the MAGE-A3 group also received chemotherapy, as did 392 in the placebo group. Median follow-up was 38·1 months (IQR 27·9–48·4) in the MAGE-A3 group and 39·5 months (27·9–50·4) in the placebo group. In the overall population, median disease-free survival was 60·5 months (95% CI 57·2–not reached) for the MAGE-A3 immunotherapeutic group and 57·9 months (55·7–not reached) for the placebo group (hazard ratio HR 1·02, 95% CI 0·89–1·18; p=0·74). Of the patients who did not receive chemotherapy, median disease-free survival was 58·0 months (95% CI 56·6–not reached) in those in the MAGE-A3 group and 56·9 months (44·4–not reached) in the placebo group (HR 0·97, 95% CI 0·80–1·18; p=0·76). Because of the absence of treatment effect, we could not identify a gene signature predictive of clinical benefit to MAGE-A3 immunotherapeutic. The frequency of grade 3 or worse adverse events was similar between treatment groups (246 16% of 1515 patients in the MAGE-A3 group and 122 16% of 757 in the placebo group). The most frequently reported grade 3 or higher adverse events were infections and infestations (37 2% in the MAGE-A3 group and 19 3% in the placebo group), vascular disorders (30 2% vs 17 3%), and neoplasm (benign, malignant, and unspecified (29 2% vs 16 2%). Interpretation Adjuvant treatment with the MAGE-A3 immunotherapeutic did not increase disease-free survival compared with placebo in patients with MAGE-A3-positive surgically resected NSCLC. Based on our results, further development of the MAGE-A3 immunotherapeutic for use in NSCLC has been stopped. Funding GlaxoSmithKline Biologicals SA.
Isolated photon production in deep inelastic ep scattering has been measured with the ZEUS detector at HERA using an integrated luminosity of 320 pb−1. Measurements were made in the isolated-photon ...transverse-energy and pseudorapidity ranges 4<ETγ<15 GeV and −0.7<ηγ<0.9 for exchanged photon virtualities, Q2, in the range 10<Q2<350 GeV2 and for invariant masses of the hadronic system WX>5 GeV. Differential cross sections are presented for inclusive isolated photon production as functions of Q2, x, ETγ and ηγ. Leading-logarithm parton-shower Monte Carlo simulations and perturbative QCD predictions give a reasonable description of the data over most of the kinematic range.
For the first time, differential inclusive-jet cross sections have been measured in neutral current deep inelastic ep scattering using the anti-kT and SIScone algorithms. The measurements were made ...for boson virtualities Q2>125 GeV2 with the ZEUS detector at HERA using an integrated luminosity of 82 pb−1 and the jets were identified in the Breit frame. The performance and suitability of the jet algorithms for their use in hadron-like reactions were investigated by comparing the measurements to those performed with the kT algorithm. Next-to-leading-order QCD calculations give a good description of the measurements. Measurements of the ratios of cross sections using different jet algorithms are also presented; the measured ratios are well described by calculations including up to O(αs3) terms. Values of αs(MZ) were extracted from the data; the results are compatible with and have similar precision to the value extracted from the kT analysis.
Summary Background Effective maintenance therapies after chemoradiotherapy for lung cancer are lacking. Our aim was to investigate whether the MUC1 antigen-specific cancer immunotherapy tecemotide ...improves survival in patients with stage III unresectable non-small-cell lung cancer when given as maintenance therapy after chemoradiation. Methods The phase 3 START trial was an international, randomised, double-blind trial that recruited patients with unresectable stage III non-small-cell lung cancer who had completed chemoradiotherapy within the 4–12 week window before randomisation and received confirmation of stable disease or objective response. Patients were stratified by stage (IIIA vs IIIB), response to chemoradiotherapy (stable disease vs objective response), delivery of chemoradiotherapy (concurrent vs sequential), and region using block randomisation, and were randomly assigned (2:1, double-blind) by a central interactive voice randomisation system to either tecemotide or placebo. Injections of tecemotide (806 μg lipopeptide) or placebo were given every week for 8 weeks, and then every 6 weeks until disease progression or withdrawal. Cyclophosphamide 300 mg/m2 (before tecemotide) or saline (before placebo) was given once before the first study drug administration. The primary endpoint was overall survival in a modified intention-to-treat population. This study is registered with ClinicalTrials.gov , number NCT00409188. Findings From Feb 22, 2007, to Nov 15, 2011, 1513 patients were randomly assigned (1006 to tecemotide and 507 to placebo). 274 patients were excluded from the primary analysis population as a result of a clinical hold, resulting in analysis of 829 patients in the tecemotide group and 410 in the placebo group in the modified intention-to-treat population. Median overall survival was 25·6 months (95% CI 22·5–29·2) with tecemotide versus 22·3 months (19·6–25·5) with placebo (adjusted HR 0·88, 0·75–1·03; p=0·123). In the patients who received previous concurrent chemoradiotherapy, median overall survival for the 538 (65%) of 829 patients assigned to tecemotide was 30·8 months (95% CI 25·6–36·8) compared with 20·6 months (17·4–23·9) for the 268 (65%) of 410 patients assigned to placebo (adjusted HR 0·78, 0·64–0·95; p=0·016). In patients who received previous sequential chemoradiotherapy, overall survival did not differ between the 291 (35%) patients in the tecemotide group and the 142 (35%) patients in the placebo group (19·4 months 95% CI 17·6–23·1 vs 24·6 months 18·8–33·0, respectively; adjusted HR 1·12, 0·87–1·44; p=0·38). Grade 3–4 adverse events seen with a greater than 2% frequency with tecemotide were dyspnoea (49 5% of 1024 patients in the tecemotide group vs 21 4% of 477 patients in the placebo group), metastases to central nervous system (29 3% vs 6 1%), and pneumonia (23 2% vs 12 3%). Serious adverse events with a greater than 2% frequency with tecemotide were pneumonia (30 3% in the tecemotide group vs 14 3% in the placebo group), dyspnoea (29 3% vs 13 3%), and metastases to central nervous system (32 3% vs 9 2%). Serious immune-related adverse events did not differ between groups. Interpretation We found no significant difference in overall survival with the administration of tecemotide after chemoradiotherapy compared with placebo for all patients with unresectable stage III non-small-cell lung cancer. However, tecemotide might have a role for patients who initially receive concurrent chemoradiotherapy, and further study in this population is warranted. Funding Merck KGaA (Darmstadt, Germany).
A
bstract
The production of
D
*±
mesons in deep inelastic
ep
scattering has been measured for exchanged photon virtualities 5 <
Q
2
< 1000 GeV
2
, using an integrated luminosity of 363 pb
−1
with ...the ZEUS detector at HERA. Differential cross sections have been measured and compared to next-to-leading-order QCD calculations. The cross-sections are used to extract the charm contribution to the proton structure functions, expressed in terms of the reduced charm cross section,
. Theoretical calculations based on fits to inclusive HERA data are compared to the results.
A
bstract
Charm production in deep inelastic
ep
scattering was measured with the ZEUS detector using an integrated luminosity of 354 pb
−1
. Charm quarks were identified by reconstructing
D
±
mesons ...in the
D
±
→
K
∓
π
±
π
±
decay channel. Lifetime information was used to reduce combinatorial background substantially. Differential cross sections were measured in the kinematic region 5
< Q
2
<
1000 GeV
2
, 0
.
02
< y <
0
.
7, 1
.
5
< p
T
(
D
±
)
<
15 GeV and |
η
(
D
±
)|
<
1
.
6, where
Q
2
is the photon virtuality,
y
is the inelasticity, and
p
T
(
D
±
) and
η
(
D
±
) are the transverse momentum and the pseudorapidity of the
D
±
meson, respectively. Next-to-leading-order QCD predictions are compared to the data. The charm contribution,
, to the proton structure-function
F
2
was extracted.
The design and performance of the ZEUS global tracking trigger Allfrey, P.D.; Bell, M.A.; Coppola, N. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
10/2007, Letnik:
580, Številka:
3
Journal Article
Recenzirano
Odprti dostop
The Global Tracking Trigger (GTT) of the ZEUS experiment is described. The GTT is data driven at the ZEUS first level trigger rate of
⩽
600
Hz
and performs event-based track finding on data from the ...experiment's Central Tracking Detector (CTD), silicon Micro Vertex Detector (MVD) and Straw Tube Tracker (STT) forward detectors. The resulting track-based trigger quantities calculated (track multiplicity, vertices, vector meson masses, background event probabilities, etc.) are available within
∼
9
ms
and are used in the experiment's second level trigger to improve the selection of physics events. Detector information is pushed to the PC farm of the GTT using PowerPC VME board computers which are either embedded within the detector's frontend readout system (MVD) or are parasitically attached to them via multiple serial transputer links (CTD and STT). Data flow and control is performed via point-to-point Fast and Giga ethernet switched network connections using the TCP protocol. The principal design challenges were: integrating new and interfacing to existing frontend systems, providing a useful trigger result, satisfying the rate and latency requirements and not interfering with ongoing data taking during commissioning. These aims have been achieved. The GTT has been actively used in the ZEUS trigger since 2004 when an initial CTD-only algorithm was used; in 2005 this was upgraded to use MVD information which significantly improves track and primary vertex resolutions. Commissioning problems delayed the STT implementation and its use in the GTT has only been tested.
PDF
