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David d'Enterria

Publications and source records attributed to David d'Enterria.

At least 109 records · Page 6Linked to original sources

Study of Higgs boson production and its b-bbar decay in gamma-gamma processes in proton-nucleus collisions at the LHC

We explore for the first time the possibilities to measure an intermediate-mass (mH = 115-140 GeV/c^2) Standard-Model Higgs boson in electromagnetic proton-lead (pPb) interactions at the CERN Large Hadron Collider (LHC) via its b-bbar decay. Using equivalent Weizsaecker-Williams photon fluxes and Higgs effective field theory for the coupling gamma-gamma --> H, we obtain a leading-order cross section of the order of 0.3 pb for exclusive Higgs production in elastic (pPb --> gamma-gamma --> p H Pb) and semielastic (pPb --> gamma-gamma --> Pb H X) processes at sqrt(s) = 8.8 TeV. After applying various kinematics cuts to remove the main backgrounds (gamma-gamma --> b-bbar and misidentified gamma-gamma-->q-qbar events), we find that a Higgs boson with mH = 120 GeV/c^2 could be observed in the b-bbar channel with a 3sigma-significance integrating 300 pb^-1 with an upgraded pA luminosity of 10^31 cm^-2s^-1. We also provide for the first time semielastic Higgs cross sections, along with elastic t-tbar cross sections, for electromagnetic pp, pA and AA collisions at the LHC.

hep-ph↗

Forward jets physics in ATLAS, CMS and LHCb

The capabilities of the ATLAS, CMS and LHCb detectors to reconstruct jets at forward rapidities (|η|> 3) in p-p collisions at the CERN Large Hadron Collider are reviewed. The QCD and Higgs physics motivations for such measurements are summarised. Details are given on studies that provide information on the parton structure and evolution at small values of fractional momenta in the proton.

hep-ex↗

Higgs and Beyond the Standard Model physics with the FP420 detector at the LHC

The physics case of the FP420 R&D project aiming at the installation of proton detectors in the LHC tunnel at 420 m from the ATLAS and CMS interaction points, is presented. The motivations of the measurements accessible with FP420 -- exclusive Higgs production (pp --> p H p) and photon-induced processes (pp --> p gamma p --> p X p, pp --> p gamma gamma p --> p X p, where X is sensitive to new physics) -- are outlined.

hep-ex↗

Jet quenching

We present a comprehensive review of the physics of hadron and jet production at large transverse momentum in high-energy nucleus-nucleus collisions. Emphasis is put on experimental and theoretical "jet quenching" observables that provide direct information on the (thermo)dynamical properties of hot and dense QCD matter.

nucl-ex↗

Jet quenching in QCD matter: from RHIC to LHC

The current experimental and theoretical status of hadron and jet production at large transverse momentum in high-energy nucleus-nucleus collisions is summarised. The most important RHIC results are compared to theoretical parton energy loss predictions providing direct information on the (thermo)dynamical properties of hot and dense QCD matter. Prospects for the LHC are also outlined.

nucl-ex↗

Low-x QCD studies with forward jets in proton-proton collisions at sqrt{s} = 14 TeV in CMS

Forward (di)jet measurements are a useful tool to constrain the Parton Distribution Functions (PDFs) at low values of parton momentum fraction x, and to study the possible onset of BFKL or gluon saturation QCD evolutions in the proton. We present studies of jet reconstruction capabilities in the CMS Hadron Forward (HF) calorimeter (3<|eta|<5). The expected sensitivity of the inclusive forward jet p_T spectrum to the proton PDF, as well as the azimuthal decorrelation of Mueller-Navelet jets with a large rapidity separation are presented for p-p collisions at sqrt{s} = 14 TeV.

hep-ex↗

Single inclusive pion pT-spectra in proton-proton collisions at sqrt(s) = 22.4GeV: data versus perturbative QCD calculations

We compare the inclusive transverse momentum spectra of single pions above pT = 3 GeV/c measured in proton-proton (p-p) collisions at sqrt(s) = 21.7 - 23.8 GeV, with next-to-leading order (NLO) perturbative QCD (pQCD) predictions using recent parametrizations of the parton densities and parton-to-pion fragmentation functions. Although the dependence on the theoretical scales is large, the calculations can reproduce the experimental results both in magnitude and shape. Based on the existing data and on a pQCD $\sqrt{s}$-rescaling of the measured spectra, we provide a practical parametrization of the baseline p-p pion transverse momentum spectrum to be compared to nucleus-nucleus collisions data at sqrt(s_NN) = 22.4 GeV.

hep-ph↗

Forward Physics at the LHC: within and beyond the Standard Model

We review the detection capabilities in the forward direction of the various LHC experiments together with the associated physics programme. A selection of measurements accessible with near-beam instrumentation in various sectors (and extensions) of the Standard Model (SM) is outlined, including QCD (diffractive and elastic scattering, low-x parton dynamics, hadronic Monte Carlos for cosmic-rays), electroweak processes in gamma-gamma interactions, and Higgs physics (vector-boson-fusion and central exclusive production).

hep-ex↗

Low-x QCD studies with forward jets in proton-proton collisions at 14 TeV

The Large Hadron Collider will provide hadronic collisions at energies in the multi-TeV range, never explored before. The parton fractional momenta probed at such energies can be as low as x~2p_T/\sqrt(s) e^(-y)~10^-5 at large rapidities y, opening up attractive opportunities for low-x QCD studies. The combination of the CMS HF (3$<|η|<$5) and CASTOR (5.1<|η|<6.6) calorimeters allows one, in particular, to reconstruct very forward jets. We present generator-level studies of the CMS capabilities to measure the single inclusive forward jet spectrum and forward-backward (Mueller-Navelet) dijets in p-p collisions at 14 TeV. Both observables are sensitive to low-x gluon densities and non-linear QCD evolution.

hep-ex↗

High-density QCD with CMS at the LHC

The capabilities of the CMS experiment to explore the rich heavy-ion physics programme offered by the CERN Large Hadron Collider (LHC) are summarised. Various representative measurements in Pb-Pb collisions at sqrt(s) = 5.5 TeV are covered. These include "bulk" observables (charged hadron multiplicity, low-pT inclusive hadron spectra and elliptic flow) which provide information on the collective properties of the system; as well as perturbative processes (high-pT hadrons, jets, gamma-jet and quarkonium production) which yield "tomographic" information of the densest phases of the reaction.

nucl-ex↗

Quarkonia Photoproduction at Nucleus Colliders

Exclusive photoproduction of heavy quarkonia in high-energy ultraperipheral ion-ion interactions (gamma A --> V A, where V = J/Psi,Upsilon and the nucleus A remains intact) offers a useful means to constrain the small-x nuclear gluon density. We discuss preliminary results on J/Psi photoproduction in Au-Au collisions at RHIC energies, as well as full simulation-reconstruction studies of photo-produced Upsilon's in Pb-Pb interactions at the LHC.

nucl-ex↗

Forward Physics at the LHC

Small-angle detectors at the LHC give access to a broad physics programme within and beyond the Standard Model (SM). We review the capabilities of ALICE, ATLAS, CMS, LHCb, LHCf and TOTEM for forward physics studies in various sectors: soft and hard diffractive processes, exclusive Higgs production, low-x QCD, ultra-high-energy cosmic-rays, and electro-weak measurements.

hep-ex↗

Experimental tests of small-x QCD

Current and future experimental studies of the high-energy limit of QCD, dominated by non-linear gluon dynamics in the low-x sector of the hadron wavefunctions, are presented. Results at HERA (proton) and RHIC (nucleus) pointing to the possible onset of parton saturation phenomena, and perspectives at the LHC and new proposed DIS facilities are outlined.

hep-ex↗

Quark-Gluon Matter

A concise review of the experimental and phenomenological progress in high-energy heavy-ion physics over the past few years is presented. Emphasis is put on measurements at BNL-RHIC and CERN-SPS which provide information on fundamental properties of QCD matter at extreme values of temperature, density and low-x. The new opportunities accessible at the LHC, which may help clarify some of the current open issues, are also outlined.

nucl-ex↗

Small-x QCD studies with CMS at the LHC

The capabilities of the CMS experiment to study the low-x parton structure and QCD evolution in the proton and the nucleus at LHC energies are presented through four different measurements, to be carried out in Pb-Pb at sqrt(s_NN) = 5.5 TeV: (i) the charged hadron rapidity density $dN_{ch}/dη$ and (ii) the ultraperipheral (photo)production of Upsilon; and in p-p at sqrt(s) = 14 TeV: (iii) inclusive forward jets and (iv) Mueller-Navelet dijets (separated by $Deltaη\gtrsim$ 8).

hep-ex↗