The production of muons from heavy flavour decays is measured at forward rapidity in proton-proto... more The production of muons from heavy flavour decays is measured at forward rapidity in proton-proton collisions at √ s = 7 TeV collected with the ALICE experiment at the LHC. The analysis is carried out on a data sample corresponding to an integrated luminosity L int = 16.5 nb −1 . The transverse momentum and rapidity differential production cross sections of muons from heavy flavour decays are measured in the rapidity range 2.5 < y < 4, over the transverse momentum range 2 < p t < 12 GeV/c. The results are compared to predictions based on perturbative QCD calculations.
... Oil on Water RACHID CHEBBI, SAMI A. ABD ELRAHMAN AND HASSAN K. AHMED Department of Chemical a... more ... Oil on Water RACHID CHEBBI, SAMI A. ABD ELRAHMAN AND HASSAN K. AHMED Department of Chemical and Petroleum Engineering, United Arab Emirates University, Al Ain, United Arab Emirates ... (2002) studied spreading in the presence of a con-tinuous oil ...
The inclusive transverse momentum (p T ) distributions of primary charged particles are measured ... more The inclusive transverse momentum (p T ) distributions of primary charged particles are measured in the pseudo-rapidity range |η| < 0.8 as a function of event centrality in Pb-Pb collisions at √ s NN = 2.76 TeV with ALICE at the LHC. The data are presented in the p T range 0.15 < p T < 50 GeV/c for nine centrality intervals from 70-80% to 0-5%. The results in Pb-Pb are presented in terms of the nuclear modification factor R AA using a pp reference spectrum measured at the same collision energy. We observe that the suppression of high-p T particles strongly depends on event centrality. The yield is most suppressed in central collisions (0-5%) with R AA ≈ 0.13 at p T = 6-7 GeV/c. Above p T = 7 GeV/c, there is a significant rise in the nuclear modification factor, which reaches R AA ≈ 0.4 for p T > 30 GeV/c. In peripheral collisions (70-80%), only moderate suppression (R AA = 0.6-0.7) and a weak p T dependence is observed. The measured nuclear modification factors are compared to other measurements and model calculations.
A search is reported for the pair production of a new quark, b ′ , with at least one b ′ decaying... more A search is reported for the pair production of a new quark, b ′ , with at least one b ′ decaying to a Z boson and a bottom quark. The data, corresponding to 2.0 fb −1 of integrated luminosity, were collected from pp collisions at √ s = 7 TeV with the ATLAS detector at the CERN Large Hadron Collider. Using events with a b-tagged jet and a Z boson reconstructed from opposite-charge electrons, the mass distribution of large transverse momentum b ′ candidates is tested for an enhancement. No evidence for a b ′ signal is detected in the observed mass distribution, resulting in the exclusion at 95% confidence level of b ′ quarks with masses m b ′ < 400 GeV that decay entirely via b ′ → Z + b. In the case of a vector-like singlet b ′ mixing solely with the third Standard Model generation, masses m b ′ < 358 GeV are excluded. (c)
This paper presents a search for the t-channel exchange of an R-parity violating scalar top quark... more This paper presents a search for the t-channel exchange of an R-parity violating scalar top quark (t) in the e ± µ ∓ continuum using 2.1 fb −1 of data collected by the ATLAS detector in √ s = 7 TeV pp collisions at the Large Hadron Collider. Data are found to be consistent with the expectation from the Standard Model backgrounds. Limits on R-parity-violating couplings at 95% C.L. are calculated as a function of the scalar top mass (mt). The upper limits on the production cross section for pp → eµX, through the t-channel exchange of a scalar top quark, ranges from 170 fb for mt = 95 GeV to 30 fb for mt = 1000 GeV.
Nous présentons dans ce papier, une méthode de dimensionnement optimal du générateur photovoltaïq... more Nous présentons dans ce papier, une méthode de dimensionnement optimal du générateur photovoltaïque et du banc de batteries dans un système hybride de production d'électricité (éolienphotovoltaïque) totalement autonome. Pour une charge et une probabilité de perte d'énergie données sous le critère d'un prix minimum du système, un nombre optimal de batteries et de modules photovoltaïques a été calculé. Ainsi, à partir de données horaires de l'irradiation solaire, de la température ambiante et de la vitesse du vent, nous avons calculé la puissance horaire produite par l'aérogénérateur et par le générateur photovoltaïque sur une période d'analyse d'une année. Ces données sont issues de mesures au centre de Bouzaréah. Un profil de consommation type a été adopté. Il correspond au profil rencontré généralement dans les sites isolés.
The effect of event background fluctuations on charged particle jet reconstruction in Pb-Pb colli... more The effect of event background fluctuations on charged particle jet reconstruction in Pb-Pb collisions at √ s NN = 2.76 TeV has been measured with the ALICE experiment. The main sources of nonstatistical fluctuations are characterized based purely on experimental data with an unbiased method, as well as by using single high p t particles and simulated jets embedded into real Pb-Pb events and reconstructed with the anti-k t jet finder. The influence of a low transverse momentum cut-off on particles used in the jet reconstruction is quantified by varying the minimum track p t between 0.15 GeV/c and 2 GeV/c. For embedded jets reconstructed from charged particles with p t > 0.15 GeV/c, the uncertainty in the reconstructed jet transverse momentum due to the heavy-ion background is measured to be 11.3 GeV/c (standard deviation) for the 10% most central Pb-Pb collisions, slightly larger than the value of 11.0 GeV/c measured using the unbiased method. For a higher particle transverse momentum threshold of 2 GeV/c, which will generate a stronger bias towards hard fragmentation in the jet finding process, the standard deviation of the fluctuations in the reconstructed jet transverse momentum is reduced to 4.8-5.0 GeV/c for the 10% most central events. A non-Gaussian tail of the momentum uncertainty is observed and its impact on the reconstructed jet spectrum is evaluated for varying particle momentum thresholds, by folding the measured fluctuations with steeply falling spectra.
The polymorphism at codon 72 of the TP53 gene has been extensively studied for its involvement in... more The polymorphism at codon 72 of the TP53 gene has been extensively studied for its involvement in cancerogenesis and loss of heterozygosity (LOH) detection. Usually, the exon 4 of the TP53 gene is amplified by polymerase chain reaction (PCR) on DNA extracted from blood and tumor tissues, then digested by AccII. In the case of heterozygosity, the comparison of AccII profile from blood and tumor DNA PCR products allowed the identification of a potential LOH in the TP53 locus. This method can be hindered by a partial AccII digestion and/or DNA contamination of non-tumor cells. To circumvent these problems, we have developed a new approach by using the AccII restriction site between exon 4 and exon 6. The PCR amplification of exon 4-6, followed by AccII digestion allowed us to detect without ambiguity any LOH case.
The centrality dependence of the charged-particle multiplicity density at mid-rapidity in Pb-Pb c... more The centrality dependence of the charged-particle multiplicity density at mid-rapidity in Pb-Pb collisions at √ s NN = 2.76 TeV is presented. The charged-particle density normalized per participating nucleon pair increases by about a factor of two from peripheral (70-80%) to central (0-5%) collisions. The centrality dependence is found to be similar to that observed at lower collision energies. The data are compared with models based on different mechanisms for particle production in nuclear collisions.
This paper is dedicated to the memory of our ATLAS colleagues who did not live to see the full im... more This paper is dedicated to the memory of our ATLAS colleagues who did not live to see the full impact and significance of their contributions to the experiment.
The production of muons from heavy flavour decays is measured at forward rapidity in proton-proto... more The production of muons from heavy flavour decays is measured at forward rapidity in proton-proton collisions at √ s = 7 TeV collected with the ALICE experiment at the LHC. The analysis is carried out on a data sample corresponding to an integrated luminosity L int = 16.5 nb −1 . The transverse momentum and rapidity differential production cross sections of muons from heavy flavour decays are measured in the rapidity range 2.5 < y < 4, over the transverse momentum range 2 < p t < 12 GeV/c. The results are compared to predictions based on perturbative QCD calculations.
... Oil on Water RACHID CHEBBI, SAMI A. ABD ELRAHMAN AND HASSAN K. AHMED Department of Chemical a... more ... Oil on Water RACHID CHEBBI, SAMI A. ABD ELRAHMAN AND HASSAN K. AHMED Department of Chemical and Petroleum Engineering, United Arab Emirates University, Al Ain, United Arab Emirates ... (2002) studied spreading in the presence of a con-tinuous oil ...
The inclusive transverse momentum (p T ) distributions of primary charged particles are measured ... more The inclusive transverse momentum (p T ) distributions of primary charged particles are measured in the pseudo-rapidity range |η| < 0.8 as a function of event centrality in Pb-Pb collisions at √ s NN = 2.76 TeV with ALICE at the LHC. The data are presented in the p T range 0.15 < p T < 50 GeV/c for nine centrality intervals from 70-80% to 0-5%. The results in Pb-Pb are presented in terms of the nuclear modification factor R AA using a pp reference spectrum measured at the same collision energy. We observe that the suppression of high-p T particles strongly depends on event centrality. The yield is most suppressed in central collisions (0-5%) with R AA ≈ 0.13 at p T = 6-7 GeV/c. Above p T = 7 GeV/c, there is a significant rise in the nuclear modification factor, which reaches R AA ≈ 0.4 for p T > 30 GeV/c. In peripheral collisions (70-80%), only moderate suppression (R AA = 0.6-0.7) and a weak p T dependence is observed. The measured nuclear modification factors are compared to other measurements and model calculations.
A search is reported for the pair production of a new quark, b ′ , with at least one b ′ decaying... more A search is reported for the pair production of a new quark, b ′ , with at least one b ′ decaying to a Z boson and a bottom quark. The data, corresponding to 2.0 fb −1 of integrated luminosity, were collected from pp collisions at √ s = 7 TeV with the ATLAS detector at the CERN Large Hadron Collider. Using events with a b-tagged jet and a Z boson reconstructed from opposite-charge electrons, the mass distribution of large transverse momentum b ′ candidates is tested for an enhancement. No evidence for a b ′ signal is detected in the observed mass distribution, resulting in the exclusion at 95% confidence level of b ′ quarks with masses m b ′ < 400 GeV that decay entirely via b ′ → Z + b. In the case of a vector-like singlet b ′ mixing solely with the third Standard Model generation, masses m b ′ < 358 GeV are excluded. (c)
This paper presents a search for the t-channel exchange of an R-parity violating scalar top quark... more This paper presents a search for the t-channel exchange of an R-parity violating scalar top quark (t) in the e ± µ ∓ continuum using 2.1 fb −1 of data collected by the ATLAS detector in √ s = 7 TeV pp collisions at the Large Hadron Collider. Data are found to be consistent with the expectation from the Standard Model backgrounds. Limits on R-parity-violating couplings at 95% C.L. are calculated as a function of the scalar top mass (mt). The upper limits on the production cross section for pp → eµX, through the t-channel exchange of a scalar top quark, ranges from 170 fb for mt = 95 GeV to 30 fb for mt = 1000 GeV.
Nous présentons dans ce papier, une méthode de dimensionnement optimal du générateur photovoltaïq... more Nous présentons dans ce papier, une méthode de dimensionnement optimal du générateur photovoltaïque et du banc de batteries dans un système hybride de production d'électricité (éolienphotovoltaïque) totalement autonome. Pour une charge et une probabilité de perte d'énergie données sous le critère d'un prix minimum du système, un nombre optimal de batteries et de modules photovoltaïques a été calculé. Ainsi, à partir de données horaires de l'irradiation solaire, de la température ambiante et de la vitesse du vent, nous avons calculé la puissance horaire produite par l'aérogénérateur et par le générateur photovoltaïque sur une période d'analyse d'une année. Ces données sont issues de mesures au centre de Bouzaréah. Un profil de consommation type a été adopté. Il correspond au profil rencontré généralement dans les sites isolés.
The effect of event background fluctuations on charged particle jet reconstruction in Pb-Pb colli... more The effect of event background fluctuations on charged particle jet reconstruction in Pb-Pb collisions at √ s NN = 2.76 TeV has been measured with the ALICE experiment. The main sources of nonstatistical fluctuations are characterized based purely on experimental data with an unbiased method, as well as by using single high p t particles and simulated jets embedded into real Pb-Pb events and reconstructed with the anti-k t jet finder. The influence of a low transverse momentum cut-off on particles used in the jet reconstruction is quantified by varying the minimum track p t between 0.15 GeV/c and 2 GeV/c. For embedded jets reconstructed from charged particles with p t > 0.15 GeV/c, the uncertainty in the reconstructed jet transverse momentum due to the heavy-ion background is measured to be 11.3 GeV/c (standard deviation) for the 10% most central Pb-Pb collisions, slightly larger than the value of 11.0 GeV/c measured using the unbiased method. For a higher particle transverse momentum threshold of 2 GeV/c, which will generate a stronger bias towards hard fragmentation in the jet finding process, the standard deviation of the fluctuations in the reconstructed jet transverse momentum is reduced to 4.8-5.0 GeV/c for the 10% most central events. A non-Gaussian tail of the momentum uncertainty is observed and its impact on the reconstructed jet spectrum is evaluated for varying particle momentum thresholds, by folding the measured fluctuations with steeply falling spectra.
The polymorphism at codon 72 of the TP53 gene has been extensively studied for its involvement in... more The polymorphism at codon 72 of the TP53 gene has been extensively studied for its involvement in cancerogenesis and loss of heterozygosity (LOH) detection. Usually, the exon 4 of the TP53 gene is amplified by polymerase chain reaction (PCR) on DNA extracted from blood and tumor tissues, then digested by AccII. In the case of heterozygosity, the comparison of AccII profile from blood and tumor DNA PCR products allowed the identification of a potential LOH in the TP53 locus. This method can be hindered by a partial AccII digestion and/or DNA contamination of non-tumor cells. To circumvent these problems, we have developed a new approach by using the AccII restriction site between exon 4 and exon 6. The PCR amplification of exon 4-6, followed by AccII digestion allowed us to detect without ambiguity any LOH case.
The centrality dependence of the charged-particle multiplicity density at mid-rapidity in Pb-Pb c... more The centrality dependence of the charged-particle multiplicity density at mid-rapidity in Pb-Pb collisions at √ s NN = 2.76 TeV is presented. The charged-particle density normalized per participating nucleon pair increases by about a factor of two from peripheral (70-80%) to central (0-5%) collisions. The centrality dependence is found to be similar to that observed at lower collision energies. The data are compared with models based on different mechanisms for particle production in nuclear collisions.
This paper is dedicated to the memory of our ATLAS colleagues who did not live to see the full im... more This paper is dedicated to the memory of our ATLAS colleagues who did not live to see the full impact and significance of their contributions to the experiment.
Uploads
Papers by rachid samy