Ayman Mahrous

Prof. Ayman Mahrous

orcid

Research Focus & Metrics

Academic Career Length

32Years (1995-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 September 2012 in Physics Letters B
Verified
Journal Article
Open access
SCS. Chatrchyan
S. Chatrchyan
VKV. Khachatryan
V. Khachatryan
ASA.M. Sirunyan
A.M. Sirunyan
ATA. Tumasyan
A. Tumasyan
WAW. Adam
W. Adam
DWD. Wenman
D. Wenman
Results are presented from searches for the standard model Higgs boson in proton-proton collisions at root s = 7 and 8 TeV in the Compact Muon Solenoid experiment at the LHC, using data samples corresponding to integrated luminosities of up to 5.1 fb(-1) at 7 TeV and 5.3 fb(-1) at 8 TeV. The search is performed in five decay modes: gamma gamma, ZZ, W+W-, tau(+)tau(-), and b (b) over bar. An excess of events is observed above the expected background, with a local significance of 5.0 standard deviations, at a mass near 125 GeV, signalling the production of a new particle. The expected significance for a standard model Higgs boson of that mass is 5.8 standard deviations. The excess is most significant in the two decay modes with the best mass resolution, gamma gamma and ZZ; a fit to these signals gives a mass of 125.3 +/- 0.4(stat.) +/- 0.5(syst.) GeV. The decay to two photons indicates that the new particle is a boson with spin different from one.BMWF ; FWF ; FNRS ; FWO ; CNPq ; CAPES ; FAPERJ ; FAPESP ; MEYS ; CERN ; CAS ; MoST ; NSFC ; COLCIENCIAS ; MSES ; RPF ; MoER ; SF0690030s09 ; ERDF ; Academy of Finland ; MEC ; HIP ; CEA ; CNRS/IN2P3 ; BMBF ; DFG ; HGF ; GSRT ; OTKA ; NKTH ; DAE ; DST ; IPM ; SFI ; INFN ; NRF ; WCU ; LAS ; CINVESTAV ; CONACYT ; SEP ; UASLP-FAI ; MSI ; PAEC ; MSHE ; NSC ; FCT ; JINR ; MON ; RosAtom ; RAS ; RFBR ; MSTD ; SEIDI ; CPAN ; Swiss Funding Agencies ; NSC ; ThEPCenter ; IPST ; NSTDA ; TUBITAK ; TAEK ; NASU ; STFC ; University of California Institute for Mexico and the United States ; the Marie-Curie programme and the European Research Council and EPLANET ; DOE and NSF ; the Leventis Foundation ; the A. P. Sloan Foundation ; the Alexander von Humboldt Foundation ; the Belgian Federal Science Policy Office ; the Fonds pour la Formation à la Recherche dans l’Industrie et dans l’Agriculture ; the Agentschap voor Innovatie door Wetenschap en Technologie ; the Ministry of Education, Youth and Sports of Czech Republic ; the Agence Nationale de la Recherche ANR-12-JS05-002-01 ; the Council of Science and Industrial Research, India; the Compagnia di San Paolo ; the HOMING PLUS programme of Foundation for Polish Science, cofinanced by EU ; Regional Development Fund

17 March 2016 in The European Physical Journal C
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Journal Article
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CCCMS Collaboration
CMS Collaboration
VKV. Khachatryan
V. Khachatryan
ASA. M. Sirunyan
A. M. Sirunyan
ATA. Tumasyan
A. Tumasyan
WAW. Adam
W. Adam
NWN. Woods
N. Woods
New sets of parameters (“tunes”) for the underlying-event (UE) modelling of the pythia8, pythia6 and herwig++Monte Carlo event generators are constructed using different parton distribution...

1 January 2013 in Physics Letters B
Verified
Journal Article
Open access
SCS. Chatrchyan
S. Chatrchyan
VKV. Khachatryan
V. Khachatryan
ASA.M. Sirunyan
A.M. Sirunyan
ATA. Tumasyan
A. Tumasyan
WAW. Adam
W. Adam
JSJ. Swanson
J. Swanson
Results on two-particle angular correlations for charged particles emitted in pPb collisions at a nucleon-nucleon center-of-mass energy of 5.02 TeV are presented. The analysis uses two million collisions collected with the CMS detector at the LHC. The correlations are studied over a broad range of pseudorapidity, eta, and full azimuth, phi, as a function of charged particle multiplicity and particle transverse momentum, p(T). In high-multiplicity events, a long-range (2 < vertical bar Delta eta vertical bar < 4), near-side (Delta phi approximate to 0) structure emerges in the two-particle Delta eta-Delta phi correlation functions. This is the first observation of such correlations in proton-nucleus collisions, resembling the ridge-like correlations seen in high-multiplicity pp collisions at root s = 7 TeV and in AA collisions over a broad range of center-of-mass energies. The correlation strength exhibits a pronounced maximum in the range of p(T) = 1-1.5 GeV/c and an approximately linear increase with charged particle multiplicity for high-multiplicity events. These observations are qualitatively similar to those in pp collisions when selecting the same observed particle multiplicity, while the overall strength of the correlations is significantly larger in pPb collisions.BMWF ; FWF ; FNRS ; FWO ; CNPq ; CAPES ; FAPERJ ; FAPESP ; MES ; CERN ; CAS ; MoST ; NSFC ; COLCIENCIAS ; MSES ; RPF ; MoER ; ERDF ; Academy of Finland ; MEC ; HIP ; CEA ; CNRS ; BMBF ; DFG ; HGF ; GSRT ; OTKA ; NKTH ; DAE ; DST ; IPM ; SFI ; INFN ; NRF ; WCU ; LAS ; CINVESTAV ; CONACYT ; UASLP-FAI ; MSI ; PAEC ; MSHE ; NSC ; FCT ; JINR ; MON ; RosAtom ; RAS ; RFBR ; MESTD ; SEIDI ; CPAN ; Swiss Funding Agencies ; NSC ; ThEPCenter ; IPST ; STAR ; NSTDA ; TUBITAK ; TAEK ; NASU ; STFC ; DOE ; NSF

1 July 2013 in Physics Letters B
Verified
Journal Article
Open access
SCS. Chatrchyan
S. Chatrchyan
VKV. Khachatryan
V. Khachatryan
ASA.M. Sirunyan
A.M. Sirunyan
ATA. Tumasyan
A. Tumasyan
WAW. Adam
W. Adam
JSJ. Swanson
J. Swanson
Measurements of two- and four-particle angular correlations for charged particles emitted in pPb collisions are presented over a wide range in pseudorapidity and full azimuth. The data, corresponding to an integrated luminosity of approximately 31 nb−1, were collected during the 2013 LHC pPb run at a nucleon–nucleon center-of-mass energy of 5.02 TeV by the CMS experiment. The results are compared to 2.76 TeV semi-peripheral PbPb collision data, collected during the 2011 PbPb run, covering a similar range of particle multiplicities. The observed correlations are characterized by the near-side (|Δϕ|≈0) associated pair yields and the azimuthal anisotropy Fourier harmonics (vn). The second-order (v2) and third-order (v3) anisotropy harmonics are extracted using the two-particle azimuthal correlation technique. A four-particle correlation method is also applied to obtain the value of v2 and further explore the multi-particle nature of the correlations. Both associated pair yields and anisotropy harmonics are studied as a function of particle multiplicity and transverse momentum. The associated pair yields, the four-particle v2, and the v3 become apparent at about the same multiplicity. A remarkable similarity in the v3 signal as a function of multiplicity is observed between the pPb and PbPb systems. Predictions based on the color glass condensate and hydrodynamic models are compared to the experimental resultsThe Austrian Federal Ministry of Science and Research and the Austrian Science Fund ; the Belgian Fonds de la Recherche Scientifique, and Fonds voor Wetenschappelijk Onderzoek ; the Brazilian Funding Agencies ; the Bulgarian Ministry of Education and Science; CERN ; the Chinese Academy of Sciences, Ministry of Science and Technology, and National Natural Science Foundation of China ; the Colombian Funding Agency ; the Croatian Ministry of Science, Education and Sport ; the Research Promotion Foundation, Cyprus; the Ministry of Education and Research ; and European Regional Development Fund, Estonia; the Academy of Finland, Finnish Ministry of Education and Culture, and Helsinki Institute of Physics; the Institut National de Physique Nucleaire et de Physique des Particules/CNRS, and Commissariat a l’Energie Atomique et aux Energies Alternatives/CEA, France; the Bundesministerium fur Bildung und Forschung, Deutsche Forschungsgemeinschaft, and Helmholtz-Gemeinschaft Deutscher Forschungszentren, Germany; the General Secretariat for Research and Technology, Greece; the National Scientific Research Foundation, and National Office for Research and Technology, Hungary; the Department of Atomic Energy and the Department of Science and Technology, India; the Institute for Studies in Theoretical Physics and Mathematics, Iran; the Science Foundation, Ireland; the Istituto Nazionale di Fisica Nucleare, Italy; the Korean Ministry of Education, Science and Technology and the World Class University program of NRF, Republic of Korea; the Lithuanian Academy of Sciences; the Mexican Funding Agencies ; the Ministry of Business, Innovation and Employment, New Zealand; the Pakistan Atomic Energy Commission; the Ministry of Science and Higher Education and the National Science Centre, Poland; the Fundac¸ao para a Ciencia e a Tecnologia, Portugal; JINR, Dubna; the Ministry of Education and Science of the Russian Federation, the Federal Agency of Atomic Energy of the Russian Federation, Russian Academy of Sciences, and the Russian Foundation for Basic Research; the Ministry of Education, Science and Technological Development of Serbia; the Secretaria de Estado de Investigacio´n, Desarrollo e Innovacion and Programa Consolider-Ingenio 2010, Spain; the Swiss Funding Agencies ; the National Science Council, Taipei; the Thailand Center of Excellence in Physics, the Institute for the Promotion of Teaching Science and Technology of Thailand, Special Task Force for Activating Research and the National Science and Technology Development Agency of Thailand ; the Scientific and Technical Research Council of Turkey and Turkish Atomic Energy Authority ; the Science and Technology Facilities Council UK; the U.S. Department of Energy and the U.S. National Science Foundation ; European Union ; the Leventis Foundation ; the A. P. Sloan Foundation ; the Alexander von Humboldt Foundation ; the Belgian Federal Science Policy Office ; the Fonds pour la Formation a` la Recherche dans l’Industrie et dans l’Agriculture (FRIA-Belgium); the Agentschap voor Innovatie door Wetenschap en Technologie (IWTBelgium); the Ministry of Education Youth and Sports (MEYS) of Czech Republic; the Council of Science and Industrial Research India; the Compagnia di San Paolo (Torino); the HOMING PLUS program of Foundation for Polish Science cofinanced by EU Regional Development Fund; and the Thalis and Aristeia programs cofinanced by EU-ESF and the Greek NSRF.

1 July 2003 in Astroparticle Physics
Verified
Journal Article
Closed access
MTM. Takeda
M. Takeda
NSN. Sakaki
N. Sakaki
KHK. Honda
K. Honda
MCM. Chikawa
M. Chikawa
MFM. Fukushima
M. Fukushima
HYH. Yoshii
H. Yoshii

22 May 2014 in Journal of High Energy Physics
Verified
Journal Article
Open access
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SCS. Chatrchyan
S. Chatrchyan
TCThe CMS collaboration
The CMS collaboration
VKV. Khachatryan
V. Khachatryan
ASA.M. Sirunyan
A.M. Sirunyan
ATA. Tumasyan
A. Tumasyan
NWN. Woods
N. Woods
A search for a standard model Higgs boson decaying into a pair of τ leptons is performed using events recorded by the CMS experiment at the LHC in 2011 and 2012. The dataset corresponds to an integrated luminosity of 4.9 fb−1 at a centre-of-mass energy of 7 TeV and 19.7 fb−1 at 8 TeV. Each τ lepton decays hadronically or leptonically to an electron or a muon, leading to six different final states for the τ -lepton pair, all considered in this analysis. An excess of events is observed over the expected background contributions, with a local significance larger than 3 standard deviations for m H values between 115 and 130 GeV. The best fit of the observed H → τ τ signal cross section times branching fraction for m H = 125 GeV is 0.78 ± 0.27 times the standard model expectation. These observations constitute evidence for the 125 GeV Higgs boson decaying to a pair of τ leptons. Open image in new window