scispace - formally typeset
Search or ask a question
Author

German Martinez

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.


Papers
More filters
Journal ArticleDOI
Albert M. Sirunyan1, Armen Tumasyan1, Wolfgang Adam, Federico Ambrogi  +2382 moreInstitutions (212)
TL;DR: In this paper, the authors measured the fiducial and differential production cross sections of the Higgs boson in proton-proton collisions at 13 TeV using events where a Higgs particle decays into a pair of W bosons that subsequently decay into a final state with an electron, a muon, and a couple of neutrinos.
Abstract: Measurements of the fiducial inclusive and differential production cross sections of the Higgs boson in proton-proton collisions at $ \sqrt{s} $ = 13 TeV are performed using events where the Higgs boson decays into a pair of W bosons that subsequently decay into a final state with an electron, a muon, and a pair of neutrinos. The analysis is based on data collected with the CMS detector at the LHC during 2016–2018, corresponding to an integrated luminosity of 137 fb$^{−1}$. Production cross sections are measured as a function of the transverse momentum of the Higgs boson and the associated jet multiplicity. The Higgs boson signal is extracted and simultaneously unfolded to correct for selection efficiency and resolution effects using maximum-likelihood fits to the observed distributions in data. The integrated fiducial cross section is measured to be 86.5 ± 9.5 fb, consistent with the Standard Model expectation of 82.5 ± 4.2 fb. No significant deviation from the Standard Model expectations is observed in the differential measurements.[graphic not available: see fulltext]

20 citations

Journal ArticleDOI
Albert M. Sirunyan1, Armen Tumasyan1, Wolfgang Adam, Federico Ambrogi  +2251 moreInstitutions (156)
TL;DR: This analysis differs from previous searches for new physics in the top quark sector by explicitly separating t W from t t ¯ events and exploiting the specific sensitivity of the t W process to new physics.
Abstract: A search for new physics in top quark production is performed in proton-proton collisions at 13 TeV. The data set corresponds to an integrated luminosity of 35.9 fb(-1) collected in 2016 with the CMS detector. Events with two opposite-sign isolated leptons (electrons or muons), and b quark jets in the final state are selected. The search is sensitive to new physics in top quark pair production and in single top quark production in association with a W boson. No significant deviation from the standard model expectation is observed. Results are interpreted in the framework of effective field theory and constraints on the relevant effective couplings are set, one at a time, using a dedicated multivariate analysis. This analysis differs from previous searches for new physics in the top quark sector by explicitly separating tW from t (t) over bar events and exploiting the specific sensitivity of the tW process to new physics.

20 citations

Journal ArticleDOI
Vardan Khachatryan1, Albert M. Sirunyan1, Armen Tumasyan1, Wolfgang Adam  +2261 moreInstitutions (148)
TL;DR: The number of observed candidate events is found to agree with the expected contributions from standard model processes, and the result is interpreted in the mass parameter space of fourteen simplified supersymmetric models that assume the pair production of gluinos or squarks and a range of decay modes.
Abstract: A search for new phenomena is performed in final states containing one or more jets and an imbalance in transverse momentum in pp collisions at a centre-of-mass energy of 13[Formula: see text]. The analysed data sample, recorded with the CMS detector at the CERN LHC, corresponds to an integrated luminosity of 2.3[Formula: see text]. Several kinematic variables are employed to suppress the dominant background, multijet production, as well as to discriminate between other standard model and new physics processes. The search provides sensitivity to a broad range of new-physics models that yield a stable weakly interacting massive particle. The number of observed candidate events is found to agree with the expected contributions from standard model processes, and the result is interpreted in the mass parameter space of fourteen simplified supersymmetric models that assume the pair production of gluinos or squarks and a range of decay modes. For models that assume gluino pair production, masses up to 1575 and 975[Formula: see text] are excluded for gluinos and neutralinos, respectively. For models involving the pair production of top squarks and compressed mass spectra, top squark masses up to 400[Formula: see text] are excluded.

20 citations

Journal Article
TL;DR: In this paper, Aggarwal et al. presented the Central Pb+Pb Collisions at 158 A GeV/c M.Aggarwal, 1 A. Agnihotri, 2 Z. Ahammed, 3 A.S.Ahammed and A.C.R.
Abstract: Three-Pion Interferometry Results from Central Pb+Pb Collisions at 158 A GeV/c M.M. Aggarwal, 1 A. Agnihotri, 2 Z. Ahammed, 3 A.L.S. Angelis, 4 V. Antonenko, 5 V. Arefiev, 6 V. Astakhov, 6 V. Avdeitchikov, 6 T.C. Awes, 7 P.V.K.S. Baba, 8 S.K. Badyal, 8 C. Barlag, 9 S. Bathe, 9 B. Batiounia, 6 T. Bernier, 10 K.B. Bhalla, 2 V.S. Bhatia, 1 C. Blume, 9 R. Bock, 11 E.-M. Bohne, 9 Z. B¨ r¨ cz, 9 D. Bucher, 9 o o 12 H. B¨ sching, 9 L. Carlen, 13 V. Chalyshev, 6 S. Chattopadhyay, 3 R. Cherbatchev, 5 T. Chujo, 14 A. Buijs, u 9 A.C. Das, 3 M.P. Decowski, 18 H. Delagrange, 10 V. Djordjadze, 6 P. Donni, 4 I. Doubovik, 5 A. Claussen, S. Dutt, 8 M.R. Dutta Majumdar, 3 K. El Chenawi, 13 S. Eliseev, 15 K. Enosawa, 14 P. Foka, 4 S. Fokin, 5 M.S. Ganti, 3 S. Garpman, 13 O. Gavrishchuk, 6 F.J.M. Geurts, 12 T.K. Ghosh, 16 R. Glasow, 9 S. K.Gupta, 2 B. Guskov, 6 H. ˚ .Gustafsson, 13 H. H.Gutbrod, 10 R. Higuchi, 14 I. Hrivnacova, 15 M. Ippolitov, 5 H. Kalechofsky, 4 A R. Kamermans, 12 K.-H. Kampert, 9 K. Karadjev, 5 K. Karpio, 17 S. Kato, 14 S. Kees, 9 C. Klein-B¨ sing, 9 o 9 B. W. Kolb, 11 I. Kosarev, 6 I. Koutcheryaev, 5 T. Kr¨ mpel, 9 A. Kugler, 15 P. Kulinich, 18 S. Knoche, u M. Kurata, 14 K. Kurita, 14 N. Kuzmin, 6 I. Langbein, 11 A. Lebedev, 5 Y.Y. Lee, 11 H. L¨ hner, 16 L. Luquin, 10 o 19 V. Manko, 5 M. Martin, 4 G. Mart´ 10 A. Maximov, 6 G. Mgebrichvili, 5 Y. Miake, 14 D.P. Mahapatra, inez, 8 G.C. Mishra, 19 Y. Miyamoto, 14 B. Mohanty, 19 M.-J. Mora, 10 D. Morrison, 20 D. S. Mukhopadhyay, 3 Md.F. Mir, H. Naef, 4 B. K. Nandi, 19 S. K. Nayak, 10 T. K. Nayak, 3 S. Neumaier, 11 A. Nianine, 5 V. Nikitine, 6 S. Nikolaev, 5 P. Nilsson, 13 S. Nishimura, 14 P. Nomokonov, 6 J. Nystrand, 13 F.E. Obenshain, 20 A. Oskarsson, 13 I. Otterlund, 13 M. Pachr, 15 S. Pavliouk, 6 T. Peitzmann, 9 V. Petracek, 15 W. Pinganaud, 10 F. Plasil, 7 U. von Poblotzki, 9 M.L. Purschke, 11 J. Rak, 15 R. Raniwala, 2 S. Raniwala, 2 V.S. Ramamurthy, 19 N.K. Rao, 8 F. Retiere, 10 K. Reygers, 9 G. Roland, 18 L. Rosselet, 4 I. Roufanov, 6 C. Roy, 10 J.M. Rubio, 4 H. Sako, 14 S.S. Sambyal, 8 R. Santo, 9 S. Sato, 14 H. Schlagheck, 9 H.-R. Schmidt, 11 Y. Schutz, 10 G. Shabratova, 6 T.H. Shah, 8 I. Sibiriak, 5 T. Siemiarczuk, 17 D. Silvermyr, 13 B.C. Sinha, 3 N. Slavine, 6 K. S¨ derstr¨ m, 13 o o N. Solomey, 4 S.P. Sorensen, 7,20 P. Stankus, 7 G. Stefanek, 17 P. Steinberg, 18 E. Stenlund, 13 D. St¨ ken, 9 u M. Sumbera, 15 T. Svensson, 13 M.D. Trivedi, 3 A. Tsvetkov, 5 L. Tykarski, 17 J. Urbahn, 11 E.C.v.d. Pijll, 12 N.v. Eijndhoven, 12 G.J.v. Nieuwenhuizen, 18 A. Vinogradov, 5 Y.P. Viyogi, 3 A. Vodopianov, 6 S. V¨ r¨ s, 4 o o B. Wyslouch, 18 K. Yagi, 14 Y. Yokota, 14 G.R. Young 7 (WA98 collaboration) University of Panjab, Chandigarh 160014, India University of Rajasthan, Jaipur 302004, Rajasthan, India 3 Variable Energy Cyclotron Centre, Calcutta 700 064, India 4 University of Geneva, CH-1211 Geneva 4,Switzerland 5 RRC Kurchatov Institute, RU-123182 Moscow, Russia 6 Joint Institute for Nuclear Research, RU-141980 Dubna, Russia 7 Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6372, USA 8 University of Jammu, Jammu 180001, India 9 University of M¨ nster, D-48149 M¨ nster, Germany u u 10 SUBATECH, Ecole des Mines, Nantes, France

20 citations

Journal ArticleDOI
Vardan Khachatryan1, Albert M. Sirunyan1, Armen Tumasyan1, Wolfgang Adam  +2320 moreInstitutions (193)
TL;DR: In this article, cross sections for the production of a Z boson in association with jets in proton-proton collisions at a centre-of-mass energy of √s=8 TeV are measured using a data sample collected by the CMS experiment at the LHC corresponding to 19.6 fb^(−1).
Abstract: Cross sections for the production of a Z boson in association with jets in proton-proton collisions at a centre-of-mass energy of √s=8 TeV are measured using a data sample collected by the CMS experiment at the LHC corresponding to 19.6 fb^(−1). Differential cross sections are presented as functions of up to three observables that describe the jet kinematics and the jet activity. Correlations between the azimuthal directions and the rapidities of the jets and the Z boson are studied in detail. The predictions of a number of multileg generators with leading or next-to-leading order accuracy are compared with the measurements. The comparison shows the importance of including multi-parton contributions in the matrix elements and the improvement in the predictions when next-to-leading order terms are included.

20 citations


Cited by
More filters
Journal ArticleDOI

[...]

08 Dec 2001-BMJ
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

Journal ArticleDOI
Peter A. R. Ade1, Nabila Aghanim2, Monique Arnaud3, M. Ashdown4  +334 moreInstitutions (82)
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

Journal ArticleDOI
01 Apr 1988-Nature
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

Journal ArticleDOI
Georges Aad1, T. Abajyan2, Brad Abbott3, Jalal Abdallah4  +2964 moreInstitutions (200)
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