Author
German Martinez
Other affiliations: University of Maryland, College Park, École des mines de Nantes, CERN ...read more
Bio: German Martinez is an academic researcher from Florida State University. The author has contributed to research in topics: Large Hadron Collider & Lepton. The author has an hindex of 141, co-authored 1476 publications receiving 107887 citations. Previous affiliations of German Martinez include University of Maryland, College Park & École des mines de Nantes.
Topics: Large Hadron Collider, Lepton, Standard Model, Higgs boson, Boson
Papers published on a yearly basis
Papers
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TL;DR: In this paper, a measurement of direct photons in p+p collisions at root s = 200 GeV is presented, where a photon excess above background from pi(0)->gamma+gamma, eta ->gamma +gamma and other decays is observed in the transverse momentum range 5.5 < p(T)< 7 GeV/c.
Abstract: A measurement of direct photons in p+p collisions at root s=200 GeV is presented. A photon excess above background from pi(0)->gamma+gamma, eta ->gamma+gamma and other decays is observed in the transverse momentum range 5.5 < p(T)< 7 GeV/c. The result is compared to a next-to-leading-order perturbative QCD calculation. Within errors, good agreement is found between the QCD calculation and the measured result.
43 citations
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TL;DR: In this paper, a search for the decays of heavy exotic long-lived particles (LLPs) that are produced in proton-proton collisions at a center-of-mass energy of 13 TeV at the CERN LHC and come to rest in the CMS detector is presented.
Abstract: A search is presented for the decays of heavy exotic long-lived particles (LLPs) that are produced in proton-proton collisions at a center-of-mass energy of 13 TeV at the CERN LHC and come to rest in the CMS detector. Their decays would be visible during periods of time well separated from proton-proton collisions. Two decay scenarios of stopped LLPs are explored: a hadronic decay detected in the calorimeter and a decay into muons detected in the muon system. The calorimeter (muon) search covers a period of sensitivity totaling 721 (744) hours in 38.6 (39.0) fb−1 of data collected by the CMS detector in 2015 and 2016. The results are interpreted in several scenarios that predict LLPs. Production cross section limits are set as a function of the mean proper lifetime and the mass of the LLPs, for lifetimes between 100 ns and 10 days. These are the most stringent limits to date on the mass of hadronically decaying stopped LLPs, and this is the first search at the LHC for stopped LLPs that decay to muons.
43 citations
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TL;DR: In this paper, the authors presented the search for the production of a Higgs boson in association with a single top quark, using data collected in proton-proton collisions at a center-of-mass energy of 8 TeV corresponding to an integrated luminosity of 19.7 inverse femtobarns.
Abstract: This paper presents the search for the production of a Higgs boson in association with a single top quark, using data collected in proton-proton collisions at a center-of-mass energy of 8 TeV corresponding to an integrated luminosity of 19.7 inverse femtobarns. The search exploits a variety of Higgs boson decay modes resulting in final states with photons, bottom quarks, and multiple charged leptons, including tau leptons, and employs a variety of multivariate techniques to maximize sensitivity to the signal. The analysis is optimized for the opposite sign of the Yukawa coupling to that in the standard model and corresponding to a large enhancement of the signal cross section. In the absence of an excess of candidate signal events over the background predictions, 95% confidence level observed (expected) upper limits on anomalous tHq production are set, ranging between 600 (450) fb and 1000 (700) fb depending on the assumed diphoton branching fraction of the Higgs boson. This is the first time that results on anomalous tHq production have been reported.
43 citations
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Vardan Khachatryan1, Albert M. Sirunyan1, Armen Tumasyan1, Wolfgang Adam2 +2354 more•Institutions (189)
TL;DR: Kachatryan et al. as mentioned in this paper acknowledge the enduring support for the construction and operation of the LHC and the CMS detector provided by the following funding agencies: theAustrian Federal Ministry of Science, Research and Development, and the Austrian Science Fund; the Belgian National Research Institute, and Fondation National de la Recherche Scientifique, and Wetenschappelijk Onderzoek; the Brazilian Funding Agencies (CNPq, CAPES, FAPERJ, andFAPESP); the Bulgarian Ministry of Education and Science
Abstract: we acknowledge the enduring support for the construction
and operation of the LHC and the CMS detector
provided by the following funding agencies: the
Austrian Federal Ministry of Science, Research and
Economy and the Austrian Science Fund; the Belgian
Fonds de la Recherche Scientifique, and Fonds voor
Wetenschappelijk Onderzoek; the Brazilian Funding
Agencies (CNPq, CAPES, FAPERJ, and FAPESP); 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 (COLCIENCIAS);
the Croatian Ministry of Science, Education and Sport, and
the Croatian Science Foundation; the Research Promotion
Foundation, Cyprus; the Ministry of Education and
Research, Estonian Research Council via IUT23-4 and
IUT23-6 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 Innovation Office, 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 Ministry of Science, ICT and Future
Planning, and National Research Foundation (NRF),
Republic of Korea; the Lithuanian Academy of Sciences;
the Ministry of Education, and University of Malaya
(Malaysia); the Mexican Funding Agencies (BUAP,
CINVESTAV, CONACYT, LNS, SEP, and UASLP-FAI);
V. KHACHATRYAN et al. PHYSICAL REVIEW D 94, 072002 (2016)
072002-12
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 Center, Poland; the Fundacao 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 Investigacion,
Desarrollo e Innovacion and Programa Consolider-
Ingenio 2010, Spain; the Swiss Funding Agencies (ETH
Board, ETH Zurich, PSI, SNF, UniZH, Canton Zurich, and
SER); the Ministry of Science and Technology, 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 National Academy of Sciences of Ukraine,
and State Fund for Fundamental Researches, Ukraine; the
Science and Technology Facilities Council, UK; the US
Department of Energy, and the US National Science
Foundation. Individuals have received support from the
Marie-Curie program and the European Research Council
and EPLANET (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 (IWT-Belgium); the Ministry of Education,
Youth and Sports (MEYS) of the Czech Republic; the
Council of Science and Industrial Research, India; the
HOMING PLUS program of the Foundation for Polish
Science, cofinanced from European Union, Regional
Development Fund; the Mobility Plus program of the
Ministry of Science and Higher Education (Poland); the
OPUS program of the National Science Center (Poland);
MIUR project 20108T4XTM (Italy); the Thalis and
Aristeia programs cofinanced by EU-ESF and the Greek
NSRF; the National Priorities Research Program by Qatar
National Research Fund; the Rachadapisek Sompot Fund
for Postdoctoral Fellowship, Chulalongkorn University
(Thailand); the Chulalongkorn Academic into Its 2nd
Century Project Advancement Project (Thailand); and
the Welch Foundation, Contract No. C-1845.
43 citations
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Vardan Khachatryan, Albert M. Sirunyan, Armen Tumasyan, Wolfgang Adam1 +2370 more•Institutions (186)
TL;DR: The decorrelation in the azimuthal angle between the most forward and the most backward jets (Mueller-Navelet jets) is measured in data collected in pp collisions with the CMS detector at the LHC at s=7, compared to predictions of various Monte Carlo event generators and to analytical predictions based on the DGLAP and BFKL parton evolution schemes.
Abstract: The decorrelation in the azimuthal angle between the most forward and the most backward jets (Mueller-Navelet jets) is measured in data collected in pp collisions with the CMS detector at the LHC at sqrt(s) = 7 TeV. The measurement is presented in the form of distributions of azimuthal-angle differences, Delta(phi), between the Mueller-Navelet jets, the average cosines of (pi-Delta(phi)), 2(pi-Delta(phi)), and 3(pi-Delta(phi)), and ratios of these cosines. The jets are required to have transverse momenta, pT, in excess of 35 GeV and rapidities, |y|, of less than 4.7. The results are presented as a function of the rapidity separation, Delta(y), between the Mueller-Navelet jets, reaching Delta(y) up to 9.4 for the first time. The results are compared to predictions of various Monte Carlo event generators and to analytical predictions based on the DGLAP and BFKL parton evolution schemes.
43 citations
Cited by
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TL;DR: There is, I think, something ethereal about i —the square root of minus one, which seems an odd beast at that time—an intruder hovering on the edge of reality.
Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.
Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …
33,785 citations
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TL;DR: In this article, the authors present a cosmological analysis based on full-mission Planck observations of temperature and polarization anisotropies of the cosmic microwave background (CMB) radiation.
Abstract: This paper presents cosmological results based on full-mission Planck observations of temperature and polarization anisotropies of the cosmic microwave background (CMB) radiation. Our results are in very good agreement with the 2013 analysis of the Planck nominal-mission temperature data, but with increased precision. The temperature and polarization power spectra are consistent with the standard spatially-flat 6-parameter ΛCDM cosmology with a power-law spectrum of adiabatic scalar perturbations (denoted “base ΛCDM” in this paper). From the Planck temperature data combined with Planck lensing, for this cosmology we find a Hubble constant, H0 = (67.8 ± 0.9) km s-1Mpc-1, a matter density parameter Ωm = 0.308 ± 0.012, and a tilted scalar spectral index with ns = 0.968 ± 0.006, consistent with the 2013 analysis. Note that in this abstract we quote 68% confidence limits on measured parameters and 95% upper limits on other parameters. We present the first results of polarization measurements with the Low Frequency Instrument at large angular scales. Combined with the Planck temperature and lensing data, these measurements give a reionization optical depth of τ = 0.066 ± 0.016, corresponding to a reionization redshift of . These results are consistent with those from WMAP polarization measurements cleaned for dust emission using 353-GHz polarization maps from the High Frequency Instrument. We find no evidence for any departure from base ΛCDM in the neutrino sector of the theory; for example, combining Planck observations with other astrophysical data we find Neff = 3.15 ± 0.23 for the effective number of relativistic degrees of freedom, consistent with the value Neff = 3.046 of the Standard Model of particle physics. The sum of neutrino masses is constrained to ∑ mν < 0.23 eV. The spatial curvature of our Universe is found to be very close to zero, with | ΩK | < 0.005. Adding a tensor component as a single-parameter extension to base ΛCDM we find an upper limit on the tensor-to-scalar ratio of r0.002< 0.11, consistent with the Planck 2013 results and consistent with the B-mode polarization constraints from a joint analysis of BICEP2, Keck Array, and Planck (BKP) data. Adding the BKP B-mode data to our analysis leads to a tighter constraint of r0.002 < 0.09 and disfavours inflationarymodels with a V(φ) ∝ φ2 potential. The addition of Planck polarization data leads to strong constraints on deviations from a purely adiabatic spectrum of fluctuations. We find no evidence for any contribution from isocurvature perturbations or from cosmic defects. Combining Planck data with other astrophysical data, including Type Ia supernovae, the equation of state of dark energy is constrained to w = −1.006 ± 0.045, consistent with the expected value for a cosmological constant. The standard big bang nucleosynthesis predictions for the helium and deuterium abundances for the best-fit Planck base ΛCDM cosmology are in excellent agreement with observations. We also constraints on annihilating dark matter and on possible deviations from the standard recombination history. In neither case do we find no evidence for new physics. The Planck results for base ΛCDM are in good agreement with baryon acoustic oscillation data and with the JLA sample of Type Ia supernovae. However, as in the 2013 analysis, the amplitude of the fluctuation spectrum is found to be higher than inferred from some analyses of rich cluster counts and weak gravitational lensing. We show that these tensions cannot easily be resolved with simple modifications of the base ΛCDM cosmology. Apart from these tensions, the base ΛCDM cosmology provides an excellent description of the Planck CMB observations and many other astrophysical data sets.
10,728 citations
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TL;DR: In this paper, a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) is presented.
Abstract: Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These
9,929 citations
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TL;DR: In this article, a search for the Standard Model Higgs boson in proton-proton collisions with the ATLAS detector at the LHC is presented, which has a significance of 5.9 standard deviations, corresponding to a background fluctuation probability of 1.7×10−9.
9,282 citations