Author
J. E. Ramirez
Other affiliations: University of Puerto Rico at Mayagüez
Bio: J. E. Ramirez is an academic researcher from University of Puerto Rico. The author has contributed to research in topics: Branching fraction & Production (computer science). The author has an hindex of 34, co-authored 184 publications receiving 9345 citations. Previous affiliations of J. E. Ramirez include University of Puerto Rico at Mayagüez.
Papers
More filters
TL;DR: The Compact Muon Solenoid (CMS) detector at the Large Hadron Collider (LHC) at CERN as mentioned in this paper was designed to study proton-proton (and lead-lead) collisions at a centre-of-mass energy of 14 TeV (5.5 TeV nucleon-nucleon) and at luminosities up to 10(34)cm(-2)s(-1)
Abstract: The Compact Muon Solenoid (CMS) detector is described. The detector operates at the Large Hadron Collider (LHC) at CERN. It was conceived to study proton-proton (and lead-lead) collisions at a centre-of-mass energy of 14 TeV (5.5 TeV nucleon-nucleon) and at luminosities up to 10(34)cm(-2)s(-1) (10(27)cm(-2)s(-1)). At the core of the CMS detector sits a high-magnetic-field and large-bore superconducting solenoid surrounding an all-silicon pixel and strip tracker, a lead-tungstate scintillating-crystals electromagnetic calorimeter, and a brass-scintillator sampling hadron calorimeter. The iron yoke of the flux-return is instrumented with four stations of muon detectors covering most of the 4 pi solid angle. Forward sampling calorimeters extend the pseudo-rapidity coverage to high values (vertical bar eta vertical bar <= 5) assuring very good hermeticity. The overall dimensions of the CMS detector are a length of 21.6 m, a diameter of 14.6 m and a total weight of 12500 t.
5,193 citations
29 Mar 2012
TL;DR: In this article, the authors reported results from searches for the standard model Higgs boson in proton-proton collisions at square root(s) = 7 TeV in five decay modes: gamma pair, b-quark pair, tau lepton pair, W pair, and Z pair.
Abstract: Combined results are reported from searches for the standard model Higgs boson in proton-proton collisions at sqrt(s)=7 TeV in five Higgs boson decay modes: gamma pair, b-quark pair, tau lepton pair, W pair, and Z pair. The explored Higgs boson mass range is 110-600 GeV. The analysed data correspond to an integrated luminosity of 4.6-4.8 inverse femtobarns. The expected excluded mass range in the absence of the standard model Higgs boson is 118-543 GeV at 95% CL. The observed results exclude the standard model Higgs boson in the mass range 127-600 GeV at 95% CL, and in the mass range 129-525 GeV at 99% CL. An excess of events above the expected standard model background is observed at the low end of the explored mass range making the observed limits weaker than expected in the absence of a signal. The largest excess, with a local significance of 3.1 sigma, is observed for a Higgs boson mass hypothesis of 124 GeV. The global significance of observing an excess with a local significance greater than 3.1 sigma anywhere in the search range 110-600 (110-145) GeV is estimated to be 1.5 sigma (2.1 sigma). More data are required to ascertain the origin of this excess.
786 citations
University of Rochester1, Southern Methodist University2, Syracuse University3, Vanderbilt University4, Wayne State University5, Carleton University6, Carnegie Mellon University7, University of Chicago8, Cornell University9, University of Florida10, George Mason University11, University of Illinois at Urbana–Champaign12, Indiana University13, University of Kansas14, Luther College15, University of Minnesota16, Northwestern University17, University at Albany, SUNY18, University of Oklahoma19, University of Pittsburgh20, University of Puerto Rico21, Purdue University22, Rensselaer Polytechnic Institute23
TL;DR: In this article, a search has been made for the new resonance $Y(4260)$ recently reported by the BABAR Collaboration, and a good quality fit to our data is obtained with a single resonance.
Abstract: Using $13.3\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ of ${e}^{+}{e}^{\ensuremath{-}}$ collision data taken in the $\ensuremath{\Upsilon}(1S\ensuremath{-}4S)$ region with the CLEO III detector at the CESR collider, a search has been made for the new resonance $Y(4260)$ recently reported by the BABAR Collaboration. The production of $Y(4260)$ in initial state radiation (ISR), and its decay into ${\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}J/\ensuremath{\psi}$, are confirmed. A good quality fit to our data is obtained with a single resonance. We determine $M(Y(4260))=({4284}_{\ensuremath{-}16}^{+17}(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}4(\mathrm{syst}))\text{ }\text{ }\mathrm{MeV}/{c}^{2}$, $\ensuremath{\Gamma}(Y(4260))=({73}_{\ensuremath{-}25}^{+39}(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}5(\mathrm{syst}))\text{ }\text{ }\mathrm{MeV}/{c}^{2}$, and ${\ensuremath{\Gamma}}_{ee}(Y(4260))\ifmmode\times\else\texttimes\fi{}\mathcal{B}(Y(4260)\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}J/\ensuremath{\psi})=({8.9}_{\ensuremath{-}3.1}^{+3.9}(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}1.8(\mathrm{syst}))\text{ }\text{ }\mathrm{eV}/{c}^{2}$.
176 citations
Southern Methodist University1, Syracuse University2, Vanderbilt University3, Wayne State University4, Carleton University5, Carnegie Mellon University6, University of Bonn7, University of Chicago8, Cornell University9, University of Florida10, George Mason University11, University of Illinois at Urbana–Champaign12, Indiana University13, University of Kansas14, Luther College15, University of Minnesota16, Northwestern University17, University at Albany, SUNY18, University of Oklahoma19, University of Pittsburgh20, University of Puerto Rico at Mayagüez21, Purdue University22, Rensselaer Polytechnic Institute23, University of Rochester24
TL;DR: In this paper, the CLEO detector operating at the CESR e+e- collider at 3.97-4.26 GeV was used to investigate 15 charmonium decay modes of the psi(4040), psi(4160), and Y(4260) resonances.
Abstract: Using data collected with the CLEO detector operating at the CESR e+e- collider at sqrt[s]=3.97-4.26 GeV, we investigate 15 charmonium decay modes of the psi(4040), psi(4160), and Y(4260) resonances. We confirm, at 11 sigma significance, the BABAR Y(4260)-->pi+pi- J/psi discovery, make the first observation of Y(4260)--> pi(0)pi(0) J/psi (5.1 sigma), and find the first evidence for Y(4260)-->K+K- J/psi(3.7 sigma). We measure e+e- cross sections at sqrt[s]=4.26 GeV as sigma(pi+pi- J/psi)=58(+12)(-10)+/-4 pb, sigma(pi(0)pi(0) J/psi)=23(+12)(-8)+/-1 pb, and sigma(K+K- J/psi)=9(+9)(-5)+/-1 pb, in which the uncertainties are statistical and systematic, respectively. Upper limits are placed on other decay rates from all three resonances.
166 citations
01 Jan 2004
TL;DR: This paper proposes the existence of bound (mass below thresh-old for strong decay) multiquark states including QQqq states and the H di-hyperon based on calculations using the bag model.
Abstract: 1 IntroductionNearly 30 years ago Jaffe proposed the existence of bound (mass below thresh-old for strong decay) multiquark states including QQqq states and the H di-hyperon [1] based on calculations using the bag model [2]. As the years passedand no convincing evidence for non mesonic and non baryonic states was foundthe field languished.
126 citations
Cited by
More filters
Journal Article•
28,685 citations
TL;DR: This biennial Review summarizes much of particle physics, using data from previous editions.
12,798 citations
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
TL;DR: In this paper, results from searches for the standard model Higgs boson in proton-proton collisions at 7 and 8 TeV in the CMS experiment at the LHC, using data samples corresponding to integrated luminosities of up to 5.8 standard deviations.
8,857 citations