A. Ranieri

We study CPT-odd non-minimal Lorentz-symmetry violating couplings in the electroweak sector modifying the interactions between leptons, gauge mediators and the Higgs boson. The tree-level (differential) cross sections for three important electroweak processes are discussed: e+e−→ZH, e+e−→ZZ and γγ→W+W−. By considering next-generation e+e− colliders reaching center-of-mass energies at the TeV scale and the estimated improved precision for the measurements of the respective cross sections, we are able to project upper bounds on the purely time-like background 4-vector as strict as ≲10−5GeV−1, in agreement with previous work on similar Lorentz-violating couplings.

The performance of the ALEPH detector at the LEP e+e− collider is reviewed. The accuracy of the tracking detectors to measure the impact parameter and momentum of charged tracks is specified. Calorimeters are used to measure photons and neutral hadrons, and the accuracy obtained in energy and angle is given. An essential property of the detector is its ability to identify particles; the performance in identification of electrons, muons, neutrinos (from missing energy), charged hadrons, π0's and V0's is described.

The full LEP-1 data set collected with the ALEPH detector at the Z pole during 1991–1995 is analysed in order to measure the τ decay branching fractions. The analysis follows the global method used in the published study based on 1991–1993 data, but several improvements are introduced, especially concerning the treatment of photons and π0's. Extensive systematic studies are performed, in order to match the large statistics of the data sample corresponding to over 300 000 measured and identified τ decays. Branching fractions are obtained for the two leptonic channels and 11 hadronic channels defined by their respective numbers of charged particles and π0's. Using previously published ALEPH results on final states with charged and neutral kaons, corrections are applied to the hadronic channels to derive branching ratios for exclusive final states without kaons. Thus the analyses of the full LEP-1 ALEPH data are combined to yield a complete description of τ decays, encompassing 22 non-strange and 11 strange hadronic modes. Some physics implications of the results are given, in particular related to universality in the leptonic charged weak current, isospin invariance in a1 decays, and the separation of vector and axial-vector components of the total hadronic rate. Finally, spectral functions are determined for the dominant hadronic modes and updates are given for several analyses. These include: tests of isospin invariance between the weak charged and electromagnetic hadronic currents, fits of the ρ resonance lineshape, and a QCD analysis of the non-strange hadronic decays using spectral moments, yielding the value αs(mτ2)=0.340±0.005exp±0.014th. The evolution to the Z mass scale yields αs(MZ2)=0.1209±0.0018. This value agrees well with the direct determination from the Z width and provides the most accurate test to date of asymptotic freedom in the QCD gauge theory.

Investigation at a $\phi$--factory can shed light on several debated issues in particle physics. We discuss: i) recent theoretical development and experimental progress in kaon physics relevant for the Standard Model tests in the flavor sector, ii) the sensitivity we can reach in probing CPT and Quantum Mechanics from time evolution of entangled kaon states, iii) the interest for improving on the present measurements of non-leptonic and radiative decays of kaons and eta/eta$^\prime$ mesons, iv) the contribution to understand the nature of light scalar mesons, and v) the opportunity to search for narrow di-lepton resonances suggested by recent models proposing a hidden dark-matter sector. We also report on the $e^+ e^-$ physics in the continuum with the measurements of (multi)hadronic cross sections and the study of gamma gamma processes.

The flavour changing neutral current decay b→sγ has been detected in hadronic Z decays collected by ALEPH at LEP. The signal is isolated in lifetime-tagged bb̄ events by the presence of a hard photon associated with a system of high momentum and high rapidity hadrons. The background processes are normalised from the data themselves. The inclusive branching ratio is measured to be(3.11±0.80stat±0.72syst)×10−4,consistent with the Standard Model expectation via penguin processes.

Previously published and as yet unpublished QCD results obtained with the ALEPH detector at LEP1 are presented. The unprecedented statistics allows detailed studies of both perturbative and non-perturbative aspects of strong interactions to be carried out using hadronic Z and tau decays. The studies presented include precise determinations of the strong coupling constant, tests of its flavour independence, tests of the SU(3) gauge structure of QCD, study of coherence effects, and measurements of single-particle inclusive distributions and two-particle correlations for many identified baryons and mesons.

In approximately 12-14% of young normogonadotrophic women treated with a depot GnRH agonist long protocol, the initial ovarian response to recombinant human FSH (rFSH) can be suboptimal. We have tested the hypothesis that these women may benefit from recombinant human LH (rLH) supplementation in a multicentre, prospective, randomized trial compared with patients treated with an rFSH step-up protocol.A total of 260 young normogonadotrophic women undergoing controlled ovarian stimulation with a GnRH agonist long protocol for IVF/ICSI were enrolled. The starting dose of rFSH was 225 IU. One hundred and thirty patients with serum estradiol levels <180 pg/ml and with at least six follicles with a mean diameter >5 mm but none >10 mm on both day 5 and day 8 of stimulation were randomly allocated to two groups. From the eighth day of stimulation, women in group A (n=65) received 150 IU of rLH in addition to rFSH, while those in group B (n=65) had an increase of 150 IU in the daily dose of rFSH (step-up protocol). One hundred and thirty normally responding women continued monotherapy with rFSH and served as a further control population (group C).The mean number of cumulus-oocyte complexes retrieved in group A (9.0+/-4.3) was significantly higher (P<0.01) compared with group B (rFSH 6.1+/-2.6) but significantly lower compared with group C (10.49+/-3.7, P<0.05). Implantation and pregnancy rates were significantly lower (P<0.05) in the rFSH step-up group (10.5 and 29.3% respectively) when compared with normal responders (18.1 and 47.3% respectively).rLH supplementation is more effective than increasing the dose of rFSH in terms of ovarian outcome in patients with an initial inadequate ovarian response to rFSH alone.

We present a new limit on the production of a light dark-force mediator with the KLOE detector at DAΦNE. This boson, called U, has been searched for in the decay ϕ→ηU, U→e+e−, analyzing the decay η→π0π0π0 in a data sample of 1.7 fb−1. No structures are observed in the e+e− invariant mass distribution over the background. This search is combined with a previous result obtained from the decay η→π+π−π0, increasing the sensitivity. We set an upper limit at 90% C.L. on the ratio between the U boson coupling constant and the fine structure constant of α′/α<1.7×10−5 for 30<MU<400 MeV and α′/α⩽8×10−6 for the sub-region 50<MU<210 MeV. This result assumes the Vector Meson Dominance expectations for the ϕηγ⁎ transition form factor. The dependence of this limit on the transition form factor has also been studied.

First results from ultrarelativistic 16O+Pb collisions at 200 GeV/nucleon are presented. The transverse energy ET in average central collisions is ≈ 75 GeV for the interval 2.2⩽y⩽3.8. A 16-fold convolution of the inelastic p+Au transverse energy spectrum, also measured at 200 GeV, reproduces the mean ET of 16O+Pb. The amount of nuclear stopping power appears to be high.

Interactions of 200-GeV/c protons and antiprotons on hydrogen, argon, and xenon targets were studied with a streamer-chamber vertex spectrometer at the CERN SPS. Results on multiplicities, rapidity distributions, and correlations are presented and compared with predictions of current models.

We have measured the ratio σ(e+e−→π+π−γ)/σ(e+e−→μ+μ−γ), with the KLOE detector at DAΦNE for a total integrated luminosity of ∼240 pb−1. From this ratio we obtain the cross section σ(e+e−→π+π−). From the cross section we determine the pion form factor |Fπ|2 and the two-pion contribution to the muon anomaly aμ for 0.592<Mππ<0.975 GeV, Δππaμ=(385.1±1.1stat±2.7sys+theo)×10−10. This result confirms the current discrepancy between the Standard Model calculation and the experimental measurement of the muon anomaly.

The existence of a light dark force mediator has been tested with the KLOE detector at DAΦNE. This particle, called U, is searched for using the decay chain ϕ→ηU, η→π+π−π0, U→e+e−. No evidence is found in 1.5 fb−1 of data. The resulting exclusion plot covers the mass range 5<MU<470 MeV, setting an upper limit on the ratio between the U boson coupling constant and the fine structure constant, α′/α, of ⩽2×10−5 at 90% C.L. for 50<MU<420 MeV.

The existence of a new force beyond the Standard Model is compelling because it could explain several striking astrophysical observations which fail standard interpretations. We searched for the light vector mediator of this dark force, the $\mathrm{U}$ boson, with the KLOE detector at the DA$Φ$NE $\mathrm{e}^{+}\mathrm{e}^{-}$ collider. Using an integrated luminosity of 1.54 fb$^{-1}$, we studied the process $\mathrm{e}^{+}\mathrm{e}^{-} \to \mathrm{U}γ$, with $\mathrm{U} \to \mathrm{e}^{+}\mathrm{e}^{-}$, using radiative-return to search for a resonant peak in the dielectron invariant-mass distribution. We did not find evidence for a signal, and set a 90\%~CL upper limit on the mixing strength between the Standard Model photon and the dark photon, $\varepsilon^2$, at $10^{-6}$--$10^{-4}$ in the 5--520~MeV/c$^2$ mass range.

We have searched for a light vector boson U, the possible carrier of a "dark force", with the KLOE detector at the DAΦNE e+e− collider, motivated by astrophysical evidence for the presence of dark matter in the Universe. Using e+e− collisions collected with an integrated luminosity of 239.3 pb−1, we look for a dimuon mass peak in the reaction e+e−→μ+μ−γ, corresponding to the decay U→μ+μ−. We find no evidence for a U vector boson signal. We set a 90% CL upper limit for the mixing parameter squared between the photon and the U boson of 1.6×10−5 to 8.6×10−7 for the mass region 520<mU<980 MeV.

The recent interest in a light gauge boson in the framework of an extra U(1) symmetry motivates searches in the mass range below 1 GeV. We present a search for such a particle, the dark photon, in ${\rm e^+ e^-}\rightarrow {\rm U}γ$, U$\rightarrow π^+π^-$ based on 28 million $\mathrm{e^+ e^-} \rightarrow π^+ π^-γ$ events collected at DA$Φ$NE by the KLOE experiment. The $π^+ π^-$ production by initial-state radiation compensates for a loss of sensitivity of previous KLOE ${\rm U} \rightarrow \mathrm{e^+ e^-}$, $μ^+μ^-$ searches due to the small branching ratios in the $ρ-ω$ resonance region. We found no evidence for a signal and set a limit at 90\% CL on the mixing strength between the photon and the dark photon, $\varepsilon^2$, in the U mass range between $527$ and $987$~MeV. Above 700 MeV this new limit is more stringent than previous ones.

A search has been performed for the Standard Model Higgs boson in the data sample collected with the ALEPH detector at LEP, at centre-of-mass energies up to 209GeV. An excess of 3sigma beyond the background expectation is found, consistent with the production of the Higgs boson with a mass near 114GeV/c2. Much of this excess is seen in the four-jet analyses, where three high purity events are selected.

A measurement of the partial width ratio ΓbbΓhad using a method which tags the Z→ bb decays through the lif etime of the produced heavy hadrons is presented. This method relies on the tracking precision afforded by a double-sided silicon vertex detector. The tag algorithm makes a probabilistic interpretation of three-dimensional track impact parameters, using the data to measure the resolution. By tagging the two b hadrons separately, both ΓbbΓhad and the tag efficiency can be determined from the data. For a 26% efficiency of tagging a single b hadron within the vertex detector solid angle coverage, a purity of 96% is achieved. A value of ΓbbΓhad= 0.2192±0.0026(stat.)±0.0016(Γcc/ Γhad) is found. Combining this result with other recent ALEPH ΓbbΓhad measurements gives a 95% confidence upper limit on the Standard Model top mass of Mt < 228 GeV.

The fragmentation of b quarks into B mesons is studied with four million hadronic Z decays collected by the ALEPH experiment during the years 1991–1995. A semi-exclusive reconstruction of B→ℓνD(★) decays is performed, by combining lepton candidates with fully reconstructed D(★) mesons while the neutrino energy is estimated from the missing energy of the event. The mean value of xBwd, the energy of the weakly-decaying B meson normalised to the beam energy, is found to be 〈xBwd〉=0.716±0.006(stat)±0.006(syst), using a model-independent method; the corresponding value for the energy of the leading B meson is 〈xBL〉=0.736±0.006(stat)±0.006(syst). The reconstructed spectra are compared with different fragmentation models.

More extensive and precise results are reported on the parameters of Z decay. On the basis of 20 000 Z decays collected with the ALEPH detector at LEP we find Mz=91.182±0.026 (exp.) ±0.030 (beam) GeV, Γz=2.541±0.056 GeV and σhad0=41.4±0.8 nb. The partial widths for the hadronic and leptonic channels are Γhad=1804±44 MeV, Γe+e−=82.1±3.4 MeV, Γμ+μ−=87.9±6.0 MeV and Γτ+τ−=86.1±5.6 MeV, in good agreement with the standard model. On the basis of the average leptonic width Γℓ+ℓ−=83.9±2.2 MeV, the effective weak mixing angle is found to be sin2θw(Mz)=0.231±0.008. Usin g the partial widths calculated in the standard model, the number of light neutrino families is Nν=3.01±0.15 (exp.)±0.05 (theor.).

From an analysis of inclusive leptons in data collected by the ALEPH detector at LEP, we measure the fractions of bb and cc events in hadronic Z decays. The bb fraction times semileptonic branching ratio is measured to be Br(b→e)·Γbb/Γhad= 0.0224 ± 0.0016 ± 0.0010. Assuming a b semileptonic branching ratio of 0.102 ± 0.010 gives Γbb/Γhad= 0.220 ± 0.016 ± 0.024, in good agreement with the standard model prediction of 0.217. The cc fraction times semileptonic branching ratio is measured to be Br(c→e)·Γcc/Γhad= 0.0133 ± 0.0040−0.0031+0.0038. Assuming a c semileptonic branching ratio of 0.090 ± 0.013 gives Γcc/Γhad= 0.148 ± 0.044−0.038+0.045, in agreement with the standard model prediction of 0.171.

The impact of foundry-to-foundry variability and bias conditions during irradiation on the Total Ionizing Dose (TID) response of commercial 130-nm CMOS technologies have been investigated for applications in High Energy Physics (HEP) experiments. n- and p-channel MOSFETs from three different manufacturers have been irradiated with X-rays up to more than 100 Mrad (SiO2). Even though the effects of TID are qualitatively similar, the amount of degradation is shown to vary considerably from foundry to foundry, probably depending on the processing of the STI oxide and/or doping profile in the substrate. The bias during irradiation showed to have a strong impact as well on the TID response, proving that exposure at worst case bias conditions largely overestimates the degradation a device may experience during its lifetime. Overall, our results increase the confidence that 130-nm CMOS technologies can be used in future HEP experiments even without Hardness-By-Design solutions, provided that constant monitoring of the radiation response is carried out during the full manufacturing phase of the circuits.

Neutral kaon pairs produced in ϕ decays in anti-symmetric entangled state can be exploited to search for violation of CPT symmetry and Lorentz invariance. We present an analysis of the CP-violating process ϕ→KSKL→π+π−π+π− based on 1.7 fb−1 of data collected by the KLOE experiment at the Frascati ϕ-factory DAΦNE. The data are used to perform a measurement of the CPT-violating parameters Δaμ for neutral kaons in the context of the Standard Model Extension framework. The parameters measured in the reference frame of the fixed stars are:Δa0=(−6.0±7.7stat±3.1syst)×10−18GeV,ΔaX=(0.9±1.5stat±0.6syst)×10−18GeV,ΔaY=(−2.0±1.5stat±0.5syst)×10−18GeV,ΔaZ=(3.1±1.7stat±0.5syst)×10−18GeV. These are presently the most precise measurements in the quark sector of the Standard Model Extension.

<h3>Objective</h3> To compare the safety, efficacy, and tolerability of subcutaneous progesterone (Prolutex, 25 mg; IBSA Institut Biochimique SA) with vaginal progesterone gel (Crinone, 8%; Merck Serono) for luteal phase support (LPS) in assisted reproduction technologies (ART) patients. <h3>Design</h3> Prospective, open-label, randomized, controlled, parallel-group, multicenter, two-arm, noninferiority study. <h3>Setting</h3> Thirteen European fertility clinics. <h3>Patient(s)</h3> A total of 683 ART patients randomized to two groups: Prolutex, 25 mg subcutaneously daily (n = 339); and Crinone, 90 mg 8% gel daily (n = 344). <h3>Intervention(s)</h3> In vitro fertilization and embryo transfer were performed according to site-specific protocols. On the day of oocyte retrieval, Prolutex or Crinone gel was begun for LPS and continued for up to 10 weeks. <h3>Main Outcome Measure(s)</h3> Ongoing pregnancy rate. <h3>Result(s)</h3> The primary end point, ongoing pregnancy rates at 10 weeks of treatment were 27.4% and 30.5% in the Prolutex and Crinone groups, respectively (intention to treat [ITT]). The nonsignificant difference between the groups was −3.09% (95% confidence interval [CI] −9.91–3.73), indicating noninferiority of Prolutex to Crinone. Delivery and live birth rates resulted to be equivalent between the two treatments (26.8% vs. 29.9% in the Prolutex and Crinone groups, respectively [ITT]; difference −3.10 [95% CI −9.87–3.68]). No statistically significant differences were reported for any of the other secondary efficacy endpoints, including comfort of usage and overall satisfaction. <h3>Conclusion(s)</h3> Implantation rate, pregnancy rate, live birth rate, and early miscarriage rate for Prolutex were similar to those for Crinone. The adverse event profiles were similar and Prolutex was safe and well tolerated. <h3>Clinical Trial Registration Number</h3> NCT00827983.

The polarization of Λ baryons from Z decays is studied with the Aleph apparatus. Evidence of longitudinal polarization of s quarks from Z decay is observed for the first time. The measured longitudinal Λ polarization is PLΛ = −0.32 ± 0.07 for z =ppbeam> 0.3. This agrees with the prediction of −0.39 ± 0.08 from the standard model and the constituent quark model, where the error is due to uncertainties in the mechanism for Λ production. The observed Λ polarization is diluted with respect to the primary s quark polarization by Λ baryons without a primary s quark. Measurements of the Λ forward-backward asymmetry and of the correlation between back-to-back ΛΛ pairs are used to check this dilution. In addition the transverse Λ polarization is measured. An indication of transverse polarization, more than two standard deviations away from zero, is found along the normal to the plane defined by the thrust axis and the Λ direction.

A search for charginos nearly mass degenerate with the lightest neutralino is performed with the data collected by the ALEPH detector at LEP, at centre-of-mass energies between 189 and 209 GeV, corresponding to an integrated luminosity of 628 pb−1. The analysis is based on the detection of isolated and energetic initial state radiation photons, produced in association with chargino pairs whose decay products have little visible energy. The number of candidate events observed is in agreement with that expected from Standard Model background sources. These results are combined with those of other direct searches for charginos, and a lower limit of 88 GeV/c2 at 95% confidence level is derived for the chargino mass in the case of heavy sfermions, irrespective of the chargino-neutralino mass difference.

The results on spectra of negative particles produced in16O+Au andp-Au collisions at 200 GeV/nucleon and16O+Au at 60 GeV/nucleon are presented. The correlations of average rapidity and average transverse momentum with event multiplicity are studied. Spectral shapes are similar for central16O+Au andp-Au collisions. The transverse momentum and rapidity distributions for central16O+Au andp-Au collisions differ strongly from corresponding distributions forp+p interactions. The FRITIOF model fails to describe the shapes of the transverse momentum distributions. The simple thermodynamical model of a single fireball does not fit the midrapidity transverse momentum distributions, and the rapidity distributions.

Inclusive π±, K± and $$(p,\bar p)$$ differential cross-sections in hadronic decays of the Z have been measured as a function ofz=P hadron/P beam, the scaled momentum. The results are based on approximately 520 000 events measured by the ALEPH detector at LEP during 1992. Charged particles are identified by their rate of ionization energy loss in the ALEPH Time Projection Chamber. The position, ξ*, of the peak in the ln(1/z) distribution is determined, and the evolution of the peak position with centre-of-mass energy is compared with the prediction of QCD.

We report results from a pion interferometry analysis of 200 GeV/nucleon 16O+Au collisions. Both a gaussian source model and a model based on the inside-outside cascade are used to fit the experimental correlation function, giving transverse and longitudinal shape parameters, a freeze-out time parameter, and a chaoticity parameter for the pion emitting source. We find a transverse source size consistent with the projectile radius except at the CM rapidity, where significantly larger transverse and longitudinal sizes and a longer freeze-out time are measured suggesting a thermalized source. Calculation of correlation lengths, and comparisons with a simple freeze-out model and other pion interferometry experiments are presented.

We have performed a search for supersymmetric particles using acoplanar pairs of oppositely-charged particles in decays of the Z0. In 0.53 pb−1 of integrated luminosity near the Z0 peak, we observe two events where approximately four are expected from background, allowing limits to be extended on combined photino and slepton masses, and also on combined photino and chargino masses.

Recent results from the NA35 Collaboration are presented for the reactions of 60 and 200 GeV/nucleon p and 16O, and 200 GeV/nucleon 32S with various targets ranging from S to Au. Midrapidity transverse energy distributions and forward energy flow, p⊥ spectra and rapidity distributions of hadrons are presented. Two-pion interferometry results are discussed. Neutral strange particle yields and p⊥ distributions are presented. Conclusions are drawn from the experimental results.

Large transverse energy cross sections of 300 GeV/c pions and protons on hydrogen have been measured with a segmented calorimeter covering the central rapidity region −0.88 < y < 0.67 and 2π in azimuth. The selected events show large multiplicities and no jet-like event structure. Processes more complicated than the scattering of two constituents appear to dominate these inelastic collisions.

A search for Z0 decays into pairs of possible new heavy quarks (t and b′), new heavy charged leptons (L±), stable heavy neutral leptons (νL) and unstable heavy neutral leptons (L0) is performed on data collected by the ALEPH detector corresponding to 11 550 events of Z0→hadrons. The limits on the masses of the heavy quarks are Mt > 45.8 GeV and Mb′ > 46.0 GeV, allowing for both charged-current and flavor-changing neutral-current decays of the b′. If an L± decays into a stable νL, then for MνL<42.7 GeV, the mass of L± is excluded for all values of ML± > MνL. Finally, while the mass of the stable νL is excluded up to 42.7 GeV, the mass of the unstable L0 is excluded up to 45.7 GeV with the mixing parameters |UℓL0|2 down to 10−13 at this mass. For 25.0 GeV < ML0 < 42.7 GeV, all values of |UℓL0|2 are excluded. All limits are given at 95% CL.

The aim of this study was to investigate the effects of adding human menopausal gonadotrophin (HMG) during controlled ovarian stimulation in normoovulatory normogonadotrophic patients showing an initial suboptimal response to a standardized long protocol therapy with recombinant FSH (rFSH) (300 IU/day).A total of 43 such patients were randomized in two groups. In Group A, 150 IU rFSH was substituted by 150 IU HMG after day 8 of stimulation. The stimulation protocol of Group B involved a simple increase of the daily rFSH dose to 375 IU after day 8. A total of 40 BMI and age matched patients with an optimal ovarian response formed the control group (Group C).The mean Group A serum concentration of oestradiol on the day of HCG administration and average number of oocytes retrieved were significantly higher than Group B (P < 0.001) and equivalent to Group C. A total of 10 pregnancies (50%) in Group A, 8 (34.8%) in Group B and 19 (47.5%) in the control group were achieved.The data suggest that LH supplementation improves the ovarian outcome in patients characterized by an inadequate initial response to rFSH therapy in a long protocol.

The final results of the ALEPH search for the Standard Model Higgs boson at LEP, with data collected in the year 2000 at centre-of-mass energies up to 209 GeV, are presented. The changes with respect to the preceding publication are described and a complete study of systematic effects is reported. The findings of this final analysis confirm the preliminary results published in November 2000 shortly after the closing down of the LEP collider: a significant excess of events is observed, consistent with the production of a $115 \Gcs$ Standard Model Higgs boson. The final results of the searches for the neutral Higgs bosons of the MSSM are also reported, in terms of limits on $\mh$, $\mA$ and $\tanb$. Limits are also set on $\mh$ in the case of invisible decays.

A search for selectron, smuon and stau pair production is performed with the data collected by the ALEPH detector at LEP at centre-of-mass energies up to 209 GeV. The numbers of candidate events are consistent with the background predicted by the Standard Model. Final mass limits from ALEPH are reported.

A data sample corresponding to 1.23 million hadronic Z decays collected by the ALEPH detector at LEP has been searched for signals of the production of a non-minimal CP-even Higgs boson h in the reaction e+e−→hZ∗. The h decay modes considered were: those of the minimal standard model Higgs boson, with modified branching ratios; decays into a pair of CP-odd Higgs bosons A; and decays into invisible final states. Only one event was found, a very acoplanar e+e− pair which could originate from the standard model background process e+e−→e+e−vv̄. Upper limits for the cross-section of the reaction e+e−→hZ∗ have been derived as a function of mh, the mass of the Higgs boson h. In the case of invisible decays, the 95% CL lower limit on mh is 65 GeV/c2 for a production cross-section equal to that of a minimal standard model Higgs boson. When combined with previous ALEPH results on the reaction e+e− → hA, these cross-section upper limits exclude a domain in the (mhmA) plane of the MSSM such that if invisible h and A decays can be neglected, 95% CL lower limits of 44 and 21 GeV/c2 result for mh and mA, respectively, independent of the other parameters of the model.

This study was aimed to evaluate the effect of different recombinant LH (rLH) doses on the ovarian outcome of normogonadotrophic women with an initial inadequate response to recombinant FSH (rFSH) after pituitary downregulation.Only women undergoing a 'long protocol' with a GnRH-agonist followed by rFSH administration were enrolled. On the eighth day of stimulation, 46 patients with serum E2 levels < 180 pg/ml and with no follicle > 10 mm were randomized in two groups to receive a supplementation with a daily rLH dose of 75 (group A) or 150 IU (group B), respectively. Forty-six normal responders continuing their monotherapy with rFSH formed the control group (C).The mean number of oocytes retrieved and the percentage of mature oocytes in the group B (9.65 +/- 2.16, 79.0%) were comparable with those observed in the group C (10.65 +/- 2.8, 82.5%) and significantly higher when compared with the group A (6.39 +/- 1.53, 65.7%). The mean number of ampoules of rLH was significantly higher in the group B (14.4 +/- 2.0 vs. 9.65 +/- 1.1), whereas these patients received a significantly lower mean number of rFSH ampoules (44.6 +/- 7.4 vs. 36.1 +/- 3.8). Seven (30.4%), 9 (39.1%) and 22 (47.8%) pregnancies were achieved in the groups A, B and C, respectively.These results suggest that patients with initial inadequate responses to rFSH after pituitary downregulation benefit from the addition of a daily dose of 150 IU of rLH, starting from the eighth day of stimulation.

From a sample of 152,000 τ decays collected by the ALEPH detector at LEP an upper limit of 24 MeV at 95% CL on the τ neutrino mass has been determined. The limit is obtained using a two dimensional likelihood fit of the visible energy and the invariant mass distribution of 25 τ → 5π(π0)ντ events.

The charged particle multiplicity distribution of hadronic Z decays was measured on the peak of the Z resonance using the ALEPH detector at LEP. Using a model independent unfolding procedure the distribution was found to have a mean 〈n〉=20.85±0.24 and a dispersion D=6.34±0.12. Comparison with lower energy data supports the KNO scaling hypothesis in the energy range s=29−91.25 GeV. At s=91.25 GeV the shape of the multiplicity distribution is well described by a log-normal distribution, as predicted from a cascading model for multi-particle production. The same model also successfully describes the energy dependence of the mean and width of the multiplicity distribution. A next-to-leading order QCD prediction in the framework of the modified leading-log approximation and local parton-hadron duality is found to fit the energy dependence of the mean but not the width of the charged multiplicity distribution, indicating that the width of the multiplicity distribution is a sensitive probe for higher order QCD or non-perturbative effects.

A search for the neutral Higgs boson in the mass range above 11 GeV (above the H0→bb threshold), using the process Z0→H0e+e−, Z0→H0μ+μ− and Z0→H0vv, is performed on data collected by the ALEPH detector corresponding to about 25 000 events of Z0→ hadrons. Combining all these processes, the mass range excluded is 11 GeV at 95% CL. Together with a previously published result from ALEPH, the mass range excluded is 32 MeV to 24 GeV at 95% CL. This result also extends the excluded mass region for neutral Higgs bosons from supersymmetry.

A data sample corresponding to about 100 000 hadronic Z decays collected by ALEPH at LEP has been used to search for the standard Higgs boson produced in the reaction e+e− → H0Z0∗. No indication for any signal was found, and a 95% CL lower limit on the Higgs boson mass has been set at 41.6 GeV.

The polarization of τ leptons produced in the reaction e+e−→τ+τ− at the Z resonance has been measured using the τ decay modes eνeντ, μνμντ, πντ, ϱντ, and a1ντ. The mean value obtained is Pτ = −0.152±0.045, indicating that parity is violated in the neutral current process e+e− → τ+τ−. The result corresponds to a ratio of a neutral current vector and axial vector coupling constants of the τ lepton gVτ(M2Z)gAτ(M2Z)= 0.076±0.023 and a value of the electroweak mixing parameter sin2θw(M2Z) = 0.2302 ± 0.0058.

Objective To retrospectively review patients with strictures (&lt;3 cm) of the bulbous urethra who had undergone urethroplasty with excision of the stenotic segment and end‐to‐end anastomosis. Patients and methods The review included 74 patients (all men, mean age 39 years, range 18–70) treated between 1989 and 1999 for strictures 5–30 mm long. Forty‐one of the patients (55%) had been treated previously, 39 endoscopically (urethrotomy and/or dilatation) and two surgically. Surgical access was perineal, with the patient in an exaggerated lithotomy position; the stenotic segment was excised and the stumps spatulated for end‐to‐end anastomosis. The mean (range) duration of surgery was 140 (75–280) min. There were no complications during or after surgery, and none related to the duration in the lithotomy position. Results At a mean follow‐up of 60 months, 93% of the patients had no recurrence of the stricture and were therefore considered cured. There were no treatment‐related complications. Conclusion End‐to‐end anastomosis is confirmed as the treatment of choice for short bulbous urethral strictures, giving cure rates close to 100%.

The light scalar Higgs boson h and the pseudoscalar Higgs boson A of the minimal supersymmetric standard model have been searched for in the processes e+e−→hff and e+e−→hA using data collected by ALEPH at the LEP e+e− collider, with center of mass energies at and near the Z peak. Using a variety of signatures adapted to various mass ranges for h and A, we have excluded a large domain in the parameter space. For large values of ν2ν1, the ratio of the vacuum expectation values of the two Higgs fields, the whole range from 0 to 38.8 GeV is excluded for Mh and MA at 95% CL.

We report on properties of hadronic events from e+e− annihilation observed by the ALEPH detector at the large Electron Positron Collider at CERN. The center-of-mass energy was s=91.0−91.3 GeV. Measured distributions of the global event-shape variables sphericity, aplanarity, thrust and minor value, and of the inclusive variables xp, p⊥in, p⊥out and y are presented. We measure a mean charged multiplicity in hadronic events of 〈Nch〉=21.3±0.1 (statistical)±0.6 (systematic). The data are in good agreement with QCD-based models which use the leading-logarithm approximation, and are less well described by a model using O(αs2) QCD.

The aim of this observational preliminary trial was to estimate the association between the most common polymorphism of LH (LH-β variant: v-βLH), with different profiles of ovarian response to recombinant human FSH (rhFSH). A total of 60 normogonadotrophic patients undergoing a gonadotrophin-releasing hormone analogue long down-regulation protocol followed by stimulation with recombinant human FSH (rhFSH) for IVF/intracytoplasmic sperm injection, and in whom at least five oocytes were retrieved were retrospectively included. On the basis of the total rhFSH consumption, patients were divided into three groups: Group A: 22 women requiring a cumulative dose of rhFSH >3500 IU; Group B: 15 patients requiring 2000-3500 IU; Group C (control): 23 women requiring <2000 IU. The presence of v-βLH was evaluated using specific immunoassays. Peak oestradiol concentrations were significantly lower in Group A when compared with both groups B (P < 0.05) and C (P < 0.001). Group A had a significantly lower (P < 0.05) number of oocytes retrieved (7.3 ± 1.5, 11.7 ± 2.4 and 14.7 ± 4.1 in the three groups, respectively). Seven carriers (31.8%) of v-βLH were found in Group A, whereas only one variant (6.7%) was observed in Group B; no variant was detected in Group C. These preliminary results suggest that v-βLH is more frequent in women with ovarian resistance to rhFSH.

Part of the upgrade of the KLOE detector at the DAΦNE Φ-factory consists of the insertion of a tracking device around the interaction region, composed of four tracking layers with radii from 130 mm to 205 mm and an active length of 700 mm. Each layer was realized as a cylindrical triple-GEM (CGEM) kapton-based detector, a solution that allows us to keep the total material budget below 2% of X0, of utmost importance to limit the multiple scattering of low-momentum tracks at KLOE-2, and to minimize dead spaces. The peculiar readout pattern with XV strips provides a spatial resolution of about 200 μm on both views, while a dedicated readout system has been developed by the KLOE-2 collaboration. It is composed of a digital readout front-end card based on the GASTONE ASIC and a General Interface Board with a configurable FPGA architecture and Gigabit Ethernet. The construction of the four CGEM layers has been completed and the detectors have been tested with a beta source and cosmic-ray muons. The insertion inside the KLOE apparatus was performed in July 2013. The construction procedure and the results of the validation tests will be reported.

Using 1.6 fb−1 of e + e − → ϕ → ηγ data collected with the KLOE detector at DAΦNE, the Dalitz plot distribution for the η → π + π − π 0 decay is studied with the world's largest sample of ∼ 4.7 · 106 events. The Dalitz plot density is parametrized as a polynomial expansion up to cubic terms in the normalized dimensionless variables X and Y . The experiment is sensitive to all charge conjugation conserving terms of the expansion, including a gX 2 Y term. The statistical uncertainty of all parameters is improved by a factor two with respect to earlier measurements.

A measurement of the vector to pseudoscalar conversion decay $\phi \to \pi^0 e^+e^-$ with the KLOE experiment is presented. A sample of $\sim 9500$ signal events was selected from a data set of 1.7 fb$^{-1}$ of $e^+e^-$ collisions at $\sqrt{s} \sim m_{\phi}$ collected at the DA$\Phi$NE $e^+e^-$ collider. These events were used to obtain the first measurement of the transition form factor $| F_{\phi \pi^0}(q^2) |$ and a new measurement of the branching ratio of the decay: $\rm{BR}\,(\phi \to \pi^0 e^+e^-) = (\,1.35 \pm 0.05^{\,\,+0.05}_{\,\,-0.10}\,) \times 10 ^{-5}$. The result improves significantly on previous measurements and is in agreement with theoretical predictions.

Two samples of exclusive semileptonic decays, 579 B0 →D∗+ℓ−νℓ events and 261 B0 → D+ℓ−νℓ events, are selected from approximately 3.9 million hadronic Z decays collected by the ALEPH detector at LEP. From the reconstructed differential decay rate of each sample, the product of the hadronic form factor F(ω) at zero recoil of the D(∗)+ meson and the CKM matrix element |Vcb| are measured to be FD∗+(1)|Vcb| = (31.9 ± 1.8stat ± 1.9syst) × 10−3, FD+(1)|Vcb| = (27.8 ± 6.8stat ± 6.5syst) × 10−3. The ratio of the form factors FD+(1) and FD∗+(1) is measured to be FD+(1)FD∗+(1) = 0.87 ± 0.22stat ± 0.21syst. A value of |Vcb| is extracted from the two samples, using theoretical constraints on the slope and curvature of the hadronic form factors and their normalization at zero recoil, with the result |Vcb| = (34.4 ± 1.6stat ± 2.3syst ± 1.4th) × 10−3. The branching fractions are measured from the two integrated spectra to be Br(B0 → D∗+ℓ−νℓ) = (5.53 ± 0.26stat ±0.52syst)%, Br(B0 → D∗+ℓ−νℓ) = (2.35 ± 0.20stat ± 0.44syst)%.

The strong coupling constant is determined from the leptonic branching ratios, the lifetime, and the invariant mass distribution of the hadronic final state of the τ lepton, using data accumulated at LEP with the ALEPH detector. The strong coupling constant measurement, αs(mτ2) = 0.330±0.046, evolved to the Z mass yields αs(MZ2) = 0.188±0.005. The error includes experimental and theoretical uncertainties, the latter evaluated in the framework of the Shifman, Vainshtein and Zakharov (SVZ) approach. The method allows the non-perturbative contribution to the hadronic decay rate to be determined to be 0.3±0.5%.

In this paper detailed curves showing the behaviour of resistive plate chambers efficiency and time resolution as a function of temperature and operating voltage are presented. The results show that the operating voltage scales well according to the rule: operating voltage/gas density = constant.

Using 1.45 million hadronic Z decays collected by the ALEPH experiment at LEP, the b → τ−ν-τX branching ratio is measured to be 2.75 ± 0.30 ± 0.37%. In addition an upper limit of 1.8 × 10−3 at 90% confidence level is placed upon the exclusive branching ratio of B−→ τ−ν-τ. These measurements are consistent with SM expectations, and put the constraint tan βMh±< 0.52 GeV−1 at 90% confidence level on all Type II two Higgs doublet models (such as the MSSM).

Distributions are presented of event shape variables, jet roduction rates and charged particle momenta obtained from 53 000 hadronicZ decays. They are compared to the predictions of the QCD+hadronization models JETSET, ARIADNE and HERWIG, and are used to optimize several model parameters. The JETSET and ARIADNE coherent parton shower (PS) models with running αs and string fragmentation yield the best description of the data. The HERWIG parton shower model with cluster fragmentation fits the data less well. The data are in better agreement with JETSET PS than with JETSETO(α S 2 ) matrix elements (ME) even when the renormalization scale is optimized.

Searches for scalar top, scalar bottom and mass-degenerate scalar quarks are performed in the data collected by the ALEPH detector at LEP, at centre-of-mass energies up to 209 GeV, corresponding to an integrated luminosity of 675 pb−1. No evidence for the production of such particles is found in the decay channels t̃→c/uχ, t̃→bℓν̃, b̃→bχ, q̃→qχ or in the stop four-body decay channel t̃→bχff̄′ studied for the first time at LEP. The results of these searches yield improved mass lower limits. In particular, an absolute lower limit of 63 GeV/c2 is obtained for the stop mass, at 95% confidence level, irrespective of the stop lifetime and decay branching ratios.

A search for charged Higgs bosons produced in pairs is performed with data collected at centre-of-mass energies ranging from 189 to 209 GeV by ALEPH at LEP, corresponding to a total luminosity of 629 invpb. The three final states taunutaunu, taunucs and cscs are considered. No evidence for a signal is found and lower limits are set on the mass M_H+ as a function of the branching fraction B(H to taunu). In the framework of a two-Higgs-doublet model, and assuming B(H+ to taunu + B(H+ to cs) = 1 charged Higgs bosons with masses below 79.3 Gev/c2 are excluded at 95% confidence level independently of the branching ratios.

This paper describes a study of Bose-Einstein correlations made using the ALEPH detector at LEP. The correlations are found to enhance the two particle differential cross section for pairs of identical pions by a factor which can be roughly parametrized byR(Q)=1+λ exp(-Q2σ2), whereQ is the difference in the 3-momenta of the two pions in their centre of mass frame, λ=0.51±0.04±0.11 and σ=3.3±0.2±0.8 GeV−1, which corresponds to a source size of 0.65±0.04±0.16 fm. The large systematic errors on these results reflect their strong dependence on the choice of the reference sample used in the analysis. This problem is believed to occur primarily because of uncertainties in the rates of resonance production and a lack of knowledge about the pion-pion strong interaction. No significant correlations are seen amongst like-charged pion-kaon pairs.

We present predictions of the distribution of groomed heavy jet mass in electron-positron collisions at the next-to-next-to-leading order accuracy matched with the resummation of large logarithms to next-to-next-to-next-to-leading logarithmic accuracy. Resummation at this accuracy is possible through extraction of necessary two-loop constants and three-loop anomalous dimensions from fixed-order codes.

Using a data sample corresponding to about 1 233 000 hadronic Z decays collected by the ALEPH experiment at LEP, the reaction e+e−→HZ∗ has been used to search for the standard model Higgs boson, in association with missing energy when Z∗→ vv̄, or with a pair of energetic leptons when Z∗→e+e−orμ+μ−. No signal was found and, at the 95% confidence level, mH exceeds 58.4 GeV/c2.

Deuteron and anti-deuteron production in Z decays has been observed in the ALEPH experiment at LEP. The production rate of anti-deuterons is measured to be 5.9+-1.8+-0.5 10^-6 per hadronic Z decay in the anti-deuteron momentum range 0.62 to 1.03 GeV/c. The coalescence parameter B_2, which characterizes the likelihood of anti-deuteron production, is measured to be 0.0033+-0.0013 GeV^2 in Z dedays. These measurements indicate that the production of anti-deuterons is suppressed in e+e- collisions compared to pp and photoproduction collisions.

An analysis of global event-shape variables has been carried out for the reaction e+e−→Z0→hadrons to measure the strong coupling constant αs. This study is based on 52 720 hadronic events obtained in 1989/90 with the ALEPH detector at the LEP collider at energies near the peak of the Z-resonance. In order to determine αs, second order QCD predictions modified by effects of perturbative higher orders and hadronization were fitted to the experimental distributions of event-shape variables. From a detailed analysis of the theoretical uncertainties we find that this approach is best justified for the differential two-jet rate, from which we obtain αs(MZ2) = 0.121 ± 0.002(stat.)±0.003(sys.)±0.007(theor.) using a renormalization scale ω =12MZ. The dependence of αs(MZ2) on ω is parameterized. For scales mb<ω<MZ the result varies by −0.012+0.007.

Cross sections, angular distributions and forward-backward asymmetries are presented, of two-fermion events produced in e+e- collisions at centre-of-mass energies from 189 to 209 GeV at LEP, measured with the ALEPH detector. Results for e+e-, μ+μ-, τ+τ-, qq̄, bb̄ and cc̄ production are in agreement with the standard model predictions. Constraints are set on scenarios of new physics such as four-fermion contact interactions, leptoquarks, Z′ bosons, TeV-scale quantum gravity and R-parity violating squarks and sneutrinos.

Cross sections for inclusive direct photon production in π−p, π+p, and pp collisions at 300 GeV/c are measured at transverse momenta pT up to 7 GeV/c (xT=0.6). For π−p→γX also the rapidity distribution is presented. The cross-section ratio σ(π−p→γX)/σ(π+p→γX) is found to be 1 at pT=4 GeV/c and rises with increasing pT. This observation signals the occurrence of valence-quark–antiquark annihilation. The results are in good agreement with QCD predictions.Received 19 December 1986DOI:https://doi.org/10.1103/PhysRevD.36.8©1987 American Physical Society

Inelastic cross sections at 60 and 200 GeV/nucleon are determined in a streamer chamber for 16O on several nuclear targets. Charged particle multiplicity distributions for inelastic and central collisions are studied and compared with theoretical predictions. The inelastic cross section exhibit a geometrical dependence on nuclear radii. The multiplicity data are governed by the collision geometry. They are consistent with a picture of superposition of independent nucleon-nucleus interactions.

The aim of this observational preliminary trial was to estimate the association between the most common polymorphism of LH (LH-beta variant: v-betaLH), with different profiles of ovarian response to recombinant human FSH (rhFSH). A total of 60 normogonadotrophic patients undergoing a gonadotrophin-releasing hormone analogue long down-regulation protocol followed by stimulation with recombinant human FSH (rhFSH) for IVF/intracytoplasmic sperm injection, and in whom at least five oocytes were retrieved were retrospectively included. On the basis of the total rhFSH consumption, patients were divided into three groups: Group A: 22 women requiring a cumulative dose of rhFSH >3500 IU; Group B: 15 patients requiring 2000-3500 IU; Group C (control): 23 women requiring <2000 IU. The presence of v-betaLH was evaluated using specific immunoassays. Peak oestradiol concentrations were significantly lower in Group A when compared with both groups B (P < 0.05) and C (P < 0.001). Group A had a significantly lower (P < 0.05) number of oocytes retrieved (7.3 +/- 1.5, 11.7 +/- 2.4 and 14.7 +/- 4.1 in the three groups, respectively). Seven carriers (31.8%) of v-betaLH were found in Group A, whereas only one variant (6.7%) was observed in Group B; no variant was detected in Group C. These preliminary results suggest that v-betaLH is more frequent in women with ovarian resistance to rhFSH.

We report on the activity of CERN and INFN-LNF groups on the development of large area GEM detectors. The two groups work together within the RD51 Collaboration, to aim at the development of Micro-pattern Gas detectors technologies. The vast request for large area foils by the GEM community has driven a change in the manufacturing procedure by the TS-DEM-PMT laboratory, needed to overcome the previous size limitation of 450×450mm2. Now a single-mask technology is used allowing foils to be made as large as 450×2000mm2. The limitation in the short size, due to the definite width of the raw material, can be overcome by splicing more foils together. A 10×10cm2 GEM detector with the new single-mask foil has been tested with X-rays and the results are shown. Possible future applications for large area GEM are the TOTEM experiment upgrade at CERN, and the KLOE-2 experiment at the Dafne Φ-factory in Frascati.

The status of the R&D on the Cylindrical-GEM (CGEM) detector foreseen as inner tracker for KLOE-2, the upgrade of the KLOE experiment at the DAΦNE φ-factory, is presented. The R&D includes several activities: (i) the construction and complete characterization of the full-size CGEM prototype, equipped with 650μm pitch 1-D longitudinal strips; (ii) the study of the 2-D readout with XV patterned strips and operation in magnetic field (up to 1.5 T), performed with small planar prototypes in a dedicated test at the H4-SPS beam facility; (iii) the characterization of the single-mask GEM technology for the realization of large-area GEM foils.

We have studied the vector to pseudoscalar conversion decay phi -&gt; eta e+e-, with eta -&gt; pi0pi0pi0, with the KLOE detector at DAPHNE. The data set of 1.7 fb-1 of e+e- collisions at sqrt(s)~Mphi contains a clear conversion decay signal of ~31,000 events from which we measured a value of BR(phi -&gt; eta e+e-)=(1.075+-0.007+-0.038)x10-4. The same sample is used to determine the transition form factor by a fit to the e+e- invariant mass spectrum, obtaining b(phi eta) =(1.17 +- 0.10 + 0.07) GeV-2, that improves by a factor of five the precision of the previous measurement and is in good agreement with VMD expectations.

A study of scaling violations in fragmentation functions performed by the ALEPH collaboration at LEP is presented. Data samples enriched in uds, c, b and gluon jets, respectively, together with measurements of the longitudinal and transverse inclusive cross sections are used to extract the fragmentation function for the gluon and for each flavour. The measurements are compared to data from experiments at energies between 22 GeV and 91 GeV and scaling violations consistent with QCD predictions are observed. From this, a measurement of the strong coupling constant αs(Mz) = 0.126 ±0.009 is obtained.

Searches for supersymmetric particles produced in e+e− collisions at centre-of-mass energies of 130 and 136 GeV have been performed in a data sample of 5.7 pb−1 collected in the autumn of 1995 by the ALEPH detector at LEP. No candidate events were found, allowing limits to be set on the masses and production cross-sections of scalar leptons, scalar tops, charginos and neutralinos. The domains previously excluded at LEP1 are substantially extended. For instance, masses of gaugino-like charginos smaller than 67.8 GeV/c2 are excluded at the 95% C.L. for scalar neutrino masses larger than 200 GeV/c2.

In 431 000 hadronicZ decays recorded with the ALEPH detector at LEP, the yields of electrons and muons in events with one or more prompt leptons have been analysed to give information on the production and decay of heavy quarks. The fractions of $$b\bar b$$ and $$c\bar c$$ events are measured to be 0.219±0.006±0.005 and 0.165±0.005±0.020, and the corresponding forward-backward asymmetries at theZ mass are measured to be 0.090±0.013±0.003 and 0.111±0.021±0.018, after QED and QCD corrections. Measurements for the semileptonic branching ratios BR $$(b \to \ell ^ - \bar vX)$$ and BR (b→cℓ+ vX) yield 0.114±0.003±0.004 and 0.082±0.003±0.012, respectively. The dilepton events enable measurement of theb mixing parameter, Χ=0.114±0.014±0.008. Results are also presented for the energy variation of the $$b\bar b$$ asymmetry and the parameters required to describe heavy quark fragmentation. From the asymmetry measurements, the effective electroweak mixing angle is sin2θ eff =0.2333±0.0022.

Searches for pair production of squarks, sleptons, charginos, and neutralinos are performed with the data collected by the ALEPH detector at LEP at centre-of-mass energies from 188.6 to 201.6 GeV. No evidence for any such signals is observed in a total integrated luminosity of about 410pb-1. The negative results of the searches are translated into exclusion domains in the space of the relevant MSSM parameters, which improve significantly on the constraints set previously. Under the assumptions of gaugino and sfermion mass unification, these results allow a 95% C.L. lower limit of 37GeV/c2 to be set on the mass of the lightest neutralino for any tan beta and sfermion mass. Additional constraints in the MSSM parameter space are derived from the negative results of ALEPH searches for Higgs bosons. The results are also interpreted in the framework of minimal supergravity.

We assessed the effectiveness of intravesical bacillus Calmette-Guerin (BCG) for high risk transitional cell carcinoma of the bladder.A total of 51 patients with stage T1, grade 3 disease was treated with weekly instillations of 75 mg. Pasteur strain BCG for 6 weeks after transurethral resection for bladder cancer. An additional induction course was given to patients with relapse. Tumor-free patients followed a maintenance course with monthly instillations for 12 months.After the initial induction course 37 of 51 patients (72.5%) remained tumor-free. A second induction course was necessary in 13 patients. After 1 or 2 induction courses 44 of 51 patients (86.3%) were tumor-free. The maintenance course was administered to 44 patients, with 41 remaining tumor-free. After a median followup of 33 months (range 3 to 63) 28 patients (54.9%) were disease-free, 12 (23.5%) had recurrent tumors and 7 (13.7%) had progression. The risk of treatment failure was significantly greater for solid than papillary tumors (p = 0.0006), recurrent than primary tumors (p = 0.0052) and coexisting carcinoma in situ (p = 0.124) in multivariate analysis, and for early recurrence (p = 0.0001) in univariate analysis only. The drug was well tolerated with few side effects.Our data suggest that this low dose Pasteur BCG regimen is effective in the treatment of high risk superficial bladder cancer. Some tumor characteristics, such as solid appearance, coexisting carcinoma in situ, history of superficial transitional cell carcinoma and early relapse after the initial induction course, seem to be negative prognostic factors.

Exotic hadrons made of five quarks (pentaquarks) are searched for in hadronic Z decays collected by the ALEPH detector at LEP. No significant signal is observed. At 95% C.L., upper limits are set on the production rates N of such particles and their charge-conjugate state per Z decay: NΘ(1535)+⋅BR(Θ(1535)+→pKS0)<6.2×10−4,NΞ(1862)−−⋅BR(Ξ(1862)−−→Ξ−π−)<4.5×10−4,NΞ(1862)0⋅BR(Ξ(1862)0→Ξ−π+)<8.9×10−4,NΘc(3100)0⋅BR(Θc(3100)0→D*−p)<6.3×10−4,NΘc(3100)0⋅BR(Θc(3100)0→D−p)<31×10−4.

Using 106 000 hadronic events obtained with the ALEPH detector at LEP at energies close to the Z resonance peak, the strong coupling constant αs is measured by an analysis of energy-energy correlations (EEC) and the global event shape variables thrust, C-parameter and oblateness. It is shown that the theoretical uncertainties can be significantly reduced if the final state particles are first combined in clusters using a minimum scaled invariant mass cut, Ycut, before these variables are computed. The combined result from all shape variables of pre-clustered events is αs(MZ2 = 0.117±0.005 for a renormalization scale μ=12MZ. For μ values between MZ and the b-quark mass, the result changes by −0.009+0.006.

Limits on Z decay branching ratios into neutralinos are reported. They were obtained from searches for monojets, acoplanar jets, acoplanar lepton pairs, single photons and acoplanar photon pairs as signaturs for the reactions e+e- → χχ′ and e+e- → χχ′, where χ is the lightest neutralino and χ′ any heavier one. The data sample used for these searches corresponds to about 23 000 events of Z decay into multihadrons, collected at LEP by the ALEPH detector for centre of mass energies at and near the Z peak. The results obtained are used to restrict the parameter space of the minimal supersymmetric standard model.

The CMS Barrel resistive plate chambers quality tests are performed at three different sites (Bari, Pavia and Sofia), where equivalent software and hardware tools are used. Data from the first 210 detectors are available for a comprehensive analysis. The paper describes the general experimental set-up, the test procedure and the cosmic muon test results. The muon trajectory reconstruction algorithm, used for precise studies, is presented. The criteria to accept or reject a detector are also given. The CMS final-design chambers show an average efficiency greater than 95%.

In a sample of 190 000 hadronic Z decays, three signals of charm production are observed: two from the exclusive decays D° →K−π+andD∗+→D°π+→K−π+π+ and one in the transverse-momentum distribution of soft hadrons relative to the nearest jet. The features of these signals are in good agreement with expectations based on the standard model and previous measurements of the branching fractions. The number of D∗±→K±π±π± per hadronic decay of the Z is measured to be (5.11±0.34) × 10−3, and the branching ratio B(D0 → K−π+) is (3.62 ± 0.34 ± 0.44)%. Charm hadronization has been studied. The average fraction of the beam energy carried by the D∗ meson is found to be 〈XE〉c = 0.504−0.017+0.013±0.008, and implications of the measurements on the pseudoscalar-to-vector production ratio of charmed mesons are discussed.

Hyperhomocysteinemia has been described as a risk factor for unexplained recurrent pregnancy loss. Increased levels of homocysteine may be due to inadequate dietary intake of folate and vitamin B12 and inherited defects within the methionine-homocysteine pathway such as MTHFR C677T gene polymorphism. However, the association between hyperhomocysteinemia and sterility problems have been underlined only for recurrent pregnancy loss while a relationship between hyperhomocysteinemia and female sterility is still matter of discussion.This study sought to find out a possible relationship between sterility (primary sterility or secondary sterility due to recurrent pregnancy loss) and homocysteine metabolism.We selected 20 patients with recurrent pregnancy loss, 20 patients with unexplained female sterility and 20 healthy women as control group. Several whole blood samples were collected by venipuncture. Firstly homocysteinemia and other related variables were tested (i.e. folate and vitamin B12 levels); thereafter DNA was extracted by a further whole blood sample collected in EDTA in order to screen MTHFR C677T gene polymorphism. Statistical analysis was performed by chi square test; differences were considered to be significant if p < 0.05.The median fasting total plasma homocysteine concentration was 19.2 +/- 6.14 microM for patients with recurrent pregnancy loss, while was 21.05 +/- 8.78 microM for patients with unexplained sterility, vs 7.85 +/- 3.31 microM of control group (p < 0.05). Fifteen patients with unexplained female sterility showed MTHFR C677T homozigosity vs 17 with recurrent pregnancy loss and 3 in the control group (p < 0.05). On the other hand no significant differences were found in the levels of vitamin B 12 in the three groups, while reduced folate concentrations were found in women with unexplained female sterility and recurrent pregnancy loss (p < 0.05 vs control group.MTHFR C677T gene polymorphism is frequent in the studied populations. These data raise questions on the role of the homocysteine metabolism in sterility problems. Even though increased homocysteine (i.e. > 15 microM) and MTHFR C677T homozigosity have already been described as risk factors for recurrent pregnancy loss, few studies evaluated their role in women with unexplained sterility. Further studies on larger series are needed to better understand the role of homocysteine metabolism, including folate metabolism, in this clinical setting.

LH plays a key role in the intermediate-late phases of folliculogenesis. Although ovarian stimulation is efficiently achieved in most cases by the administration of exogenous FSH alone, specific subgroups of women may benefit from LH activity supplementation during ovarian stimulation. Some authors have found improved outcome with LH activity supplementation in advanced reproductive age women. Experience suggests that in about 10-12% of young normogonadotrophic patients treated with a gonadotrophin-releasing hormone agonist (GnRH-a) long protocol plus recombinant FSH human (r-hFSH), a 'steady response' is observed. In this subgroup of women, a higher number of oocytes is retrieved when daily LH activity supplementation is given from stimulation day 8, if compared with the standard FSH dose increase. Another subgroup of patients who may benefit from LH activity supplementation are those at risk for poor ovarian response treated with GnRH antagonist. Recent data demonstrate that in these women, when GnRH is administered in a flexible protocol, the concomitant addition of recombinant human LH improves the number of mature oocytes retrieved, when compared with the standard GnRH-a flare-up protocol. Thus, well calibrated LH administration improves the ovarian outcome in patients >35 years, in those showing an initial abnormal ovarian response to r-hFSH monotherapy, and in 'low prognosis' women treated with GnRH antagonists.

We have carried out a new direct search for the CP violating decay KS→3π0 with 1.7 fb−1 of e+e− collisions collected by the KLOE detector at the Φ-factory DAΦNE. We have searched for this decay in a sample of about 5.9×108 KSKL events tagging the KS by means of the KL interaction in the calorimeter and requiring six prompt photons. With respect to our previous search, the analysis has been improved by increasing of a factor four the tagged sample and by a more effective background rejection of fake KS tags and spurious clusters. We find no candidates in data and simulated background samples, while we expect 0.12 standard model events. Normalizing to the number of KS→2π0 events in the same sample, we set the upper limit on BR(KS→3π0)⩽2.6×10−8 at 90% C.L., five times lower than the previous limit. We also set the upper limit on the η000 parameter, |η000|⩽0.0088 at 90% C.L., improving by a factor two the latest direct measurement.

The ratio Rη=Γ(η→π+π−γ)/Γ(η→π+π−π0) has been measured by analysing 22 million ϕ→ηγ decays collected by the KLOE experiment at DAΦNE, corresponding to an integrated luminosity of 558 pb−1. The η→π+π−γ proceeds both via the ρ resonant contribution, and possibly a non-resonant direct term, connected to the box anomaly. Our result, Rη=0.1856±0.0005stat±0.0028syst, points out a sizable contribution of the direct term to the total width. The di-pion invariant mass for the η→π+π−γ decay could be described in a model-independent approach in terms of a single free parameter, α. The determined value of the parameter α is α=(1.32±0.08stat−0.09syst+0.10±0.02theo)GeV−2.

We searched for evidence of a Higgsstrahlung process in a secluded sector, leading to a final state with a dark photon U and a dark Higgs boson h′, with the KLOE detector at DAΦNE. We investigated the case of h′ lighter than U, with U decaying into a muon pair and h′ producing a missing energy signature. We found no evidence of the process and set upper limits to its parameters in the range 2mμ<mU<1000MeV, mh′<mU.

We have measured the running of the effective QED coupling constant $\alpha(s)$ in the time-like region $0.6<\sqrt s< 0.975$ GeV with the KLOE detector at DA$\Phi$NE using the Initial State Radiation process $e^+e^-\to\mu^+ \mu^-\gamma$. It represents the first measurement of the running of $\alpha(s)$ in this energy region. Our results show a more than 5$\sigma$ significance of the hadronic contribution to the running of $\alpha(s)$, which is the strongest direct evidence both in time- and space-like regions achieved in a single measurement. By using the $e^+e^-\to\pi^+\pi^-$ cross section measured by KLOE, the real and imaginary part of the shift $\Delta\alpha(s)$ has been extracted. By a fit of the real part of $\Delta\alpha(s)$ and assuming the lepton universality the branching ratio $BR(\omega\to\mu^+\mu^-) = (6.6\pm1.4_{stat}\pm1.7_{syst})\cdot 10^{-5} $ has been determined.

A novel version of the front-end electronics for the CMS Resistive Plate Chambers is described. It is based on a new front-end ASIC, designed and manufactured in the 0.8μm BiCMOS technology by Austria Mikro Systeme. The main improvements with respect to the previous version (Loddo et al., Proceedings of the Fourth International Workshop on Resistive Plate Chambers and related Detectors, Napoli, 15–16 October 1997) [1] concern the input impedance, the threshold uniformity and the timing performance. Simulation and test results will be shown, together with a brief description of the automatic test system for both front-end chip and board.

A model to simulate the avalanche formation process and the induced signal in a Resistive Plate Chamber is presented. A first investigation of the effects of various parameters on the performance of this detector is reported.

The results of searches for selectrons, charginos and neutralinos performed with the data collected by the ALEPH detector at LEP at centre-of-mass energies up to 209 GeV are interpreted in the framework of the Minimal Supersymmetric extension of the Standard Model with R-parity conservation. Under the assumptions of gaugino and sfermion mass unification and no sfermion mixing, an absolute lower limit of 73 GeV/c2 is set on the mass of the lighter selectron ẽR at the 95% confidence level. Similarly, limits on the masses of the heavier selectron ẽL and of the sneutrino ν̃e are set at 107 and 84 GeV/c2, respectively. Additional constraints are derived from the results of the searches for Higgs bosons. The results are also interpreted in the framework of minimal supergravity.

The decay B0 -> J/psi K0_S is reconstructed with J/psi -> e+ e- or mu+ mu- and K0_S -> pi+ pi-. From the full ALEPH dataset at LEP1 of about 4 million hadronic Z decays, 23 candidates are selected with an estimated purity of 71%. They are used to measure the CP asymmetry of this decay, given by sin 2beta in the Standard Model, with the result sin 2beta = 0.84 +0.82-1.04 +-0.16. This is combined with existing measurements from other experiments, and increases the confidence level that CP violation has been observed in this channel to 98%.

Single top production via the flavour changing neutral current reactions e+e- -> \bar{t}c, \bar{t}u is searched for within the 214 pb-1 of data collected by ALEPH at centre-of-mass energies between 204 and 209 GeV. No deviation from the Standard Model expectation is observed and upper limits on the single top production cross sections are derived. The combination with data collected at lower centre-of-mass energies yields an upper limit on the branching ratio BR(t -> Zc)+BR(t -> Zu) 14%, for BR(t -> \gamma c)+BR(t -> \gamma u)= 0 and mt=174 GeV/c2.

Quark and gluon jets with the same energy, 24 GeV, are compared in symmetric three-jet configurations from hadronic Z decays observed by the ALEPH detector. Jets are defined using the Durham algorithm. Gluon jets are identified using an anti-tag on b jets, based on a track impact parameter method. The comparison of gluon and mixed flavour quark jets shows that gluon jets have a softer fragmentation function, a larger angular width and a higher particle multiplicity, Evidence is presented which shows that the corresponding differences between gluon and b jets are significantly smaller. In a statistically limited comparison the multiplicity in c jets was found to be comparable with that observed for the jets of mixed quark flavour.

A search for pair-produced charged Higgs bosons in decays of the Z0 has been performed using the ALEPH detector at LEP for the decay channels H+H− → ντντ, H+H− → ντ cs and H+H− → cs cs. Searches for two additional decay channels in which cs is replaced by cb were also performed. With 1.17 pb−1 of integrated luminosity, corresponding to about 25 000 hadronic decays of the Z0, the charged Higgs has been excluded at 95% CL in the mass range 7.6 to 43.0 GeV for BR[H± → ντ] = 100%, 8.3 to 40.6 GeV for BR[H±→ντ] = BR[H±→cs] = 50%, and 14.4 to 35.4 GeV for BR[H±→cs] = 100% . With cs replaced by cb, the charged Higgs has been excluded at 95% CL in the mass range 12.0 to 40.7 GeV for BR[H±→ντ] = BR[H±→cb] = 50%, and 16.2 to 35.7 GeV for BR[H±→cb] = 100%.

B0B0 oscillation is studied using almost a million hadronic Z decays collected by the ALEPH experiment at LEP. Events are selected with two leptons present, on opposite sides of the event and with high transverse momentum. The leptons are expected to be dominantly from b decays; a topological vertexing technique is applied to measure the decay length of the b hadrons, and their momentum is determined using an energy-flow method. The fraction of events in which the leptons have the same charge is studied as a function of the measured decay time, and clear evidence is seen for the time-dependent nature of Bd0Bd0 mixing. The frequency measured for the oscillation corresponds to a mass difference for the Bd0 mass eigenstates Δmd = (3.3−0.4+0.5 ± 0.7) × 10−4 eV/c2. Allowing a second frequency component for the Bs0 a high value for Δms is favoured, leading to the limit Δms > 12 × 10−4 eV/c2 (95% CL), from which (Δm/Γ)s > 2.0 is derived.

From a sample of 150 000 hadronic Z decays collected with the ALEPH detector at LEP, events containing prompt leptons are used to measure the forward-backward asymmetries for the channels Z→bb and Z→cc, giving the results AFBb=0.126±0.028±0.012 and AFBc=0.064±0.039±0.030. These asymmetries correspond to the value of effective electroweak mixing angle at the Z mass sin2θW(mZ2) = 0.2262±0.0053.

LH plays a key role in the intermediate-late phases of folliculogenesis. Although ovarian stimulation is efficiently achieved in most cases by the administration of exogenous FSH alone, specific subgroups of women may benefit from LH activity supplementation during ovarian stimulation. Some authors have found improved outcome with LH activity supplementation in advanced reproductive age women. Experience suggests that in about 10-12% of young normogonadotrophic patients treated with a gonadotrophin-releasing hormone agonist (GnRH-a) long protocol plus recombinant FSH human (r-hFSH), a 'steady response' is observed. In this subgroup of women, a higher number of oocytes is retrieved when daily LH activity supplementation is given from stimulation day 8, if compared with the standard FSH dose increase. Another subgroup of patients who may benefit from LH activity supplementation are those at risk for poor ovarian response treated with GnRH antagonist. Recent data demonstrate that in these women, when GnRH is administered in a flexible protocol, the concomitant addition of recombinant human LH improves the number of mature oocytes retrieved, when compared with the standard GnRH-a flare-up protocol. Thus, well calibrated LH administration improves the ovarian outcome in patients >35 years, in those showing an initial abnormal ovarian response to r-hFSH monotherapy, and in 'low prognosis' women treated with GnRH antagonists.

A search has been made for a very light Higgs boson in the processes e+e- → e+e-H and e+e- →μ+μ-H using data collected by ALEPH at the LEP e+e- collider at centre of mass energies close to the Z peak. The mass range between 0 and 57 MeV is unambigously excluded at the 95% confidence level. If we combine this with our previously published analysis, the complete range from 0 to 24 GeV is excluded at 95% CL. The search is extended to light Higgs bosons of the minimal supersymmetric standard model, with the result that all possibilities of coupling are excluded for Higgs masses below 3 GeV.

A significant charge asymmetry is observed in the hadronic Z decays with the ALEPH detector at LEP. The asymmetry expressed in terms of the difference in momentum weighted charges in the two event hemispheres is measured to be <Qforward>−<Qbackward>= −0.0084±0.0015 (stat.) ±0.0004 (exp. sys.). In the framework of the standard model this can be interpreted as a measurement of the effective electroweak mixing angle, sin2Ow (Mz2=0.2300±0.0034 (stat.) ±0.0010 (exp. sys.) ±0.0038 (theor. sys.) or of the ratio of the vector to axual- vector coupling costants of the electron, gvegAe=+0.073±0.024.

The formation of highly reactive compounds in the gas mixture during Resistive Plate Chambers (RPCs) operation at the CERN Gamma Irradiation Facility (GIF) is studied. Results from two different types of chambers are discussed: 50 × 50 cm2 RPC prototypes and two final CMS-RB1 chambers. The RB1 detectors were also connected to a closed loop gas system. Gas composition, possible additional impurities as well as fluoride ions have been monitored in different gamma irradiation conditions both in open and closed loop mode. The chemical composition of the RPC electrode surface has also been analyzed using an electron microscope equipped with an EDS/X-ray.

The production of neutral strange particlesK s o , Λ and % MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaacciGaf83MdW% Kbaebaaaa!3780! $$\bar \Lambda $$ has been studied in 60 and 200 GeV per nucleon OAu and pAu collisions with the streamer chamber vertex spectrometer of the NA35 experiment at the CERN-SPS accelerator. Ratios of neutral strange particle production to negatively charged particle production in selected regions of phase space were measured to be the same in OAu and pAu reactions. The rates of strange particle production in central OAu collisions are about a factor of 16 higher than in pAu collisions when compared in the same regions of phase space. If an enhancement of strange particle production in OAu collisions relative to pAu collisions is considered to be a signature for quark-gluon plasma formation, no evidence supporting it is observed. The experimental results are compared to the Lund FRITIOF model.