2,209 research outputs found
Measurement of forward neutral pion transverse momentum spectra for = 7TeV proton-proton collisions at LHC
The inclusive production rate of neutral pions in the rapidity range greater
than has been measured by the Large Hadron Collider forward (LHCf)
experiment during LHC \,TeV proton-proton collision operation in
early 2010. This paper presents the transverse momentum spectra of the neutral
pions. The spectra from two independent LHCf detectors are consistent with each
other and serve as a cross check of the data. The transverse momentum spectra
are also compared with the predictions of several hadronic interaction models
that are often used for high energy particle physics and for modeling
ultra-high-energy cosmic-ray showers.Comment: 18 Pages, 10 figures, submitted to Phys. Rev.
The performance of the LHCf detector for hadronic showers
The Large Hadron Collider forward (LHCf) experiment has been designed to use
the LHC to benchmark the hadronic interaction models used in cosmic-ray
physics. The LHCf experiment measures neutral particles emitted in the very
forward region of LHC collisions. In this paper, the performances of the LHCf
detectors for hadronic showers was studied with MC simulations and beam tests.
The detection efficiency for neutrons is from 60% to 70% above 500 GeV. The
energy resolutions are about 40% and the position resolution is 0.1 to 1.3mm
depend on the incident energy for neutrons. The energy scale determined by the
MC simulations and the validity of the MC simulations were examined using 350
GeV proton beams at the CERN-SPS.Comment: 15pages, 19 figure
Measurement of zero degree single photon energy spectra for sqrt(s) = 7TeV proton-proton collisions at LHC
In early 2010, the Large Hadron Collider forward (LHCf) experiment measured
very forward neutral particle spectra in LHC proton-proton collisions. From a
limited data set taken under the best beam conditions (low beam-gas background
and low occurance of pile-up events), the single photon spectra at sqrt(s)=7TeV
and pseudo-rapidity (eta) ranges from 8.81 to 8.99 and from 10.94 to infinity
were obtained for the first time and are reported in this paper. The spectra
from two independent LHCf detectors are consistent with one another and serve
as a cross check of the data. The photon spectra are also compared with the
predictions of several hadron interaction models that are used extensively for
modeling ultra high energy cosmic ray showers. Despite conservative estimates
for the systematic errors, none of the models agree perfectly with the
measurements. A notable difference is found between the data and the DPMJET
3.04 and PYTHIA 8.145 hadron interaction models above 2TeV where the models
predict higher photon yield than the data. The QGSJET II-03 model predicts
overall lower photon yield than the data, especially above 2TeV in the rapidity
range 8.81<eta<8.99
Developing a High Resolution ZDC for the EIC
The Electron Ion Collider offers the opportunity to make un-paralleled multidimen- sional measurements of the spin structure of the proton and nuclei, as well as a study of the onset of partonic saturation at small Bjorken-x [1]. An important requirement of the physics program is the tagging of spectator neutrons and the identification of forward photons. We propose to design and build a Zero Degree Calorimeter, or ZDC, to measure photons and neutrons with excellent energy & position resolution
First results from LHCf for forward physics in âs = 7TeV proton-proton interactions
The LHCf Collaboration has completed the first step of its scheduled physics program for the study of emission of neutral particles in the forward region of proton-proton (pp) interactions at LHC. Between 2009 and 2010 the LHCf
experiment has successfully taken data at 900 GeV and 7TeV total energy in the center-of-mass frame of reference (CM). After a short presentation of the experimental apparatus, the results for the Îł-ray spectrum at âs = 7TeV are presented in this paper
Sinteza i bioloĆĄko vrednovanje novih derivata 2-fenil-benzimidazol-1-acetamida kao potencijalnih anthelmintika
The present study describes synthesis of a series of 2-phenyl benzimidazole-1-acetamide derivatives and their evaluation for anthelmintic activity using Indian adult earthworms, Pheretima posthuma. The structure of the title compounds was elucidated by elemental analysis and spectral data. The compounds 4-({[2-(4-nitrophenyl)-1H-benzimidazol-1-yl]acetyl}amino) benzoic acid (3a), N-ethyl-2-[2-(4-nitrophenyl)-1H-benzimidazol-1-yl] acetamide (3c), N-benzyl-2-[2-(4-nitrophenyl)-1H-benzimidazol-1-yl] acetamide (3d), N-(4-hydroxyphenyl)-2-[2-(4-nitrophenyl)-1H-benzimidazol-1-yl] acetamide (3f), 2-[2-(4-nitrophenyl)-1H-benzimidazol-1-yl]-N-phenylacetamide (3h), 2-[2-(4-chlorophenyl)-1H-benzimidazol-1-yl]-N\u27-phenylacetohydrazide (3k), 2-[2-(4-chlorophenyl)-1H-benzimidazol-1-yl]-N-(4-nitrophenyl) acetamide (3n) and 2-[2-(4-chlorophenyl)-1H-benzimidazol-1-yl]-N-phenylacetamide (3q) were better to paralyze worms whereas N-ethyl-2-[2-(4-nitrophenyl)-1H-benzimidazol-1-yl] acetamide (3c), N-(4-nitrophenyl)-2-[2-(4-nitrophenyl)-1H-benzimidazol-1yl] acetamide (3e), 4-({[2-(4-chlorophenyl)-1H-benzimidazol-1-yl] acetyl} amino) benzoic acid (3j), 2-[2-(4-chlorophenyl)-1H-benzimidazol-1-yl]-N-ethylacetamide (3l) and 2-[2-(4-chlorophenyl)-1H-benzimidazol-1-yl]-N-phenylacetamide (3q) were better to cause death of worms compared to the anthelmintic drug albendazole.U radu je opisana sinteza derivata 2-fenil-benzimidazol-1-acetamida i ispitivanje njihovog anthelmintiÄkog djelovanja na odrasle indijske gliste, Pheretima posthuma. Struktura sintetiziranih spojeva odreÄena je elementarnom analizom i spektroskopskim metodama. Spojevi 4-({[2-(4-nitrofenil)-1H-benzimidazol-1-il]acetil}amino) benzojeva kiselina (3a), N-etil-2-[2-(4-nitrofenil)-1H-benzimidazol-1-il] acetamid (3c), N-benzil-2-[2-(4-nitrofenil)-1H-benzimidazol-1-il] acetamid (3d), N-(4-hidroksifenil)-2-[2-(4-nitrofenil)-1H-benzimidazol-1-il] acetamid (3f), 2-[2-(4-nitrofenil)-1H-benzimidazol-1-il]-N-fenilacetamid (3h), 2-[2-(4-klorfenil)-1H-benzimidazol-1-il]-N\u27-fenilacetohidrazid (3k), 2-[2-(4-klorfenil)-1H-benzimidazol-1-il]-N-(4-nitrofenil) acetamid (3n) i 2-[2-(4-klorfenil)-1H-benzimidazol-1-il]-N-fenilacetamid (3q) jaÄe paraliziraju gliste, a N-etil-2-[2-(4-nitrofenil)-1H-benzimidazol-1-il] acetamid (3c), 2-[2-(4-nitrofenil)-1H-benzimidazol-1-il]-N-fenilacetamid (3h), 4-({[2-(4-klorfenil)-1H-benzimidazol-1-il]acetil}amino) benzojeva kiselina (3j), 2-[2-(4-klorfenil)-1H-benzimidazol-1-il]-N-etilacetamid (3l) i 2-[2-(4-klorfenil)-1H-benzimidazol-1-il]-N-fenilacetamid (3q) uÄinkovitije usmrÄuju gliste nego anthelmintik albendazol
Nasopharyngeal pneumococcal carriage in South Asian infants:Results of observational cohort studies in vaccinated and unvaccinated populations
BACKGROUND: Nasopharyngeal pneumococcal carriage (NPC) is a prerequisite for invasive pneumococcal disease and reduced carriage of vaccine serotypes is a marker for the protection offered by the pneumococcal conjugate vaccine (PCV). The present study reports NPC during the first year of life in a vaccinated (with PCV10) cohort in Bangladesh and an unvaccinated cohort in India. METHODS: A total of 450 and 459 infants were recruited from India and Bangladesh respectively within 0-7 days after birth. Nasopharyngeal swabs were collected at baseline, 18 and 36 weeks after birth. The swabs were processed for pneumococcal culture and identification of serotypes by the Quellung test and polymerase chain reaction (PCR). An identical protocol was applied at both sites. RESULTS: Prevalence of NPC was 48% in the Indian and 54.8% in the Bangladeshi cohort at 18 weeks. It increased to 53% and 64.8% respectively at 36 weeks. The average prevalence of vaccine serotypes was higher in the Indian cohort (17.8% vs 9.8% for PCV-10 and 26.1% vs17.6% for PCV-13) with 6A, 6B, 19F, 23F, and 19A as the common serotypes. On the other hand, the prevalence of non-vaccine serotypes was higher (43.6% vs 27.1% for non-PCV13) in the Bangladeshi cohort with 34, 15B, 17F, and 35B as the common serotypes. Overcrowding was associated with increased risk of pneumococcal carriage. The present PCV-13 vaccine would cover 28%-30% and 47%-48% serotypes in the Bangladeshi and Indian cohorts respectively. CONCLUSIONS: South Asian infants get colonised with pneumococci early in infancy; predominantly vaccine serotypes in PCV naĂŻve population (India) and non-vaccine serotypes in the vaccinated population (Bangladesh). These local findings are important to inform the public health policy and the development of higher valent pneumococcal vaccines
Results from the LHCf experiment
LHCf is an experiment designed to study the very forward emission of neutral particles produced in collisions at the LHC. Its results can be used to calibrate the hadron interaction models of the Monte Carlo codes which allow the
interpretation of energy spectrum and composition of high-energy cosmic rays as measured by air shower ground detectors. The experiment has already completed taking data in proton-proton collisions at âs = 900 GeV and at âs = 7TeV during 2009 and 2010. The detectors are now being upgraded and they will be installed again in the LHC tunnel for proton-ion collisions and for operation with protons at
âs = 14TeV. In this paper results and comparisons with the predictions obtained from Monte Carlo simulations will be reported
Comparison of hadron interaction models with measurement of forward spectra by the LHCf apparatus
The LHCf experiment is a forward experiment of LHC. The two
LHCf detectors, each composed of a pair of sampling and imaging calorimeters, have been installed at the forward region of IP1 to measure energy and transverse momentum spectra of neutral particles emitted in the very forward region of LHC collisions (η > 8.4). The operation at 900 GeV and 7TeV pp collisions has been completed in the middle of July 2010. We present some preliminary results in this
paper
Forward photon energy spectrum at LHC 7 TeV p-p collisions measured by LHCf
Abstract The LHCf experiment is one of the LHC forward experiments. The aim is to measure the energy and the transverse momentum spectra of photons, neutrons and Ï 0 's at the very forward region (the pseudo-rapidity range of η > 8.4 ), which should be critical data to calibrate hadron interaction models used in the air shower simulations. LHCf successfully operated at s = 900 GeV and s = 7 TeV protonâproton collisions in 2009 and 2010. We present the first physics result, single photon energy spectra at s = 7 TeV protonâproton collisions and the pseudo-rapidity ranges of η > 10.94 and 8.81 η 8.9 . The obtained spectra were compared with the predictions by several hadron interaction models and the models do not reproduce the experimental results perfectly
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