175 research outputs found
Energy loss and thermalization of heavy quarks in a strongly-coupled plasma
Using the AdS/CFT correspondence, we compute the medium-induced energy loss
of a decelerating heavy quark moving through a strongly-coupled supersymmetric
Yang Mills plasma. In the regime where the deceleration is small, a
perturbative calculation is possible and we obtain the first two corrections to
the energy-loss rate of a heavy quark with constant velocity. The
thermalization of the heavy quark is also discussed.Comment: 4 pages, no figures, Proceedings of the 21st International Conference
on Ultra-Relativistic Nucleus Nucleus Collisions (QM09), Knoxville, USA,
March 30-April 4 200
Hanbury-Brown-Twiss measurements at large rapidity separations, or can we measure the proton radius in p-A collisions?
We point out that current calculations of inclusive two-particle correlations
in p-A collisions based on the Color Glass Condensate approach exhibit a
contribution from Hanbury-Brown-Twiss correlations. These HBT correlations are
quite distinct from the standard ones, in that they are apparent for particles
widely separated in rapidity. The transverse size of the emitter which is
reflected in these correlations is the gluonic size of the proton. This raises
an interesting possibility of measuring the proton size directly by the HBT
effect of particle pairs produced in p-A collisions.Comment: 11 pages, 3 eps figures; v2: comments, discussions, references and
acknowledgements added, conclusions unchanged, final versio
Massive quarks in NLO dipole factorization for DIS : Transverse photon
We calculate the light-cone wave functions for the QCD Fock components in a transverse virtual photon necessary for applications at next-to-leading order (NLO) in the QCD coupling, including quark masses. We present a detailed calculation of both the one-loop wave function for the quark-antiquark Fock component and the tree-level wave function for the quark-antiquark-gluon Fock component. The quark masses are renormalized in the pole mass scheme, satisfying constraints from the requirement of Lorentz invariance. In particular the quark Pauli form factor at NLO is recovered from the on-shell limit of the quark-antiquark Fock component. We use our result to calculate the next-to-leading-order correction to the high energy deep inelastic scattering (DIS) transverse structure function on a dense target in the dipole factorization framework. Together with our earlier result for longitudinal photons, this completes the calculation of the total deep inelastic scattering cross section in the dipole picture with massive quarks at next-to-leading order, enabling a comparison with experimental data.Peer reviewe
Massive Quarks at One Loop in the Dipole Picture of Deep Inelastic Scattering
We calculate the light cone wave functions for a virtual photon to split into quark-antiquark states, including for the first time quark masses at one loop accuracy. These wave functions can be used to calculate cross sections for several precision probes of perturbative gluon saturation at the Electron-Ion Collider. Using these wave functions we derive, for the first time, the dipole picture deep inelastic scattering cross sections at one loop for longitudinal and transverse virtual photons including quark masses. The quark masses are renormalized in the pole mass scheme, satisfying constraints from the requirement of Lorentz invariance of the quark Dirac and Pauli form factors.Peer reviewe
Diffractive deep inelastic scattering at NLO in the dipole picture : The q¯qg contribution
Publisher Copyright: © 2022 authors.We calculate the contribution from the qq¯g state production to the diffractive cross sections in deep inelastic scattering at high energy. The obtained cross section is finite by itself and a part of the full next-to-leading order result for the diffractive structure functions. We perform the calculation in exact kinematics in the eikonal limit, and show that the previously known high-Q2 and large MX2 results for the structure functions can be extracted from our results in the appropriate limits. We furthermore discuss the steps required to obtain the full next-to-leading order results for the structure functions.Peer reviewe
Shock wave collisions in AdS5: approximate numerical solutions
We numerically study the evolution of a boost-invariant N=4 SYM medium using
AdS/CFT. We consider a toy model for the collision of gravitational shock
waves, finding that the energy density first increases, reaches a maximum and
then starts to decrease, matching hydrodynamics for late times. For the initial
conditions we consider, the hydrodynamic scale governing the late time
behaviour is to very good approximation determined by the area of the black
hole horizon at initial times. Our results provide a toy model for the early
time evolution of the bulk system in heavy-ion collisions at RHIC and the LHC.Comment: 29 pages, 9 figure
Diffractive structure function in the dipole picture
We calculate the contribution from the component of a virtual
photon state to the small- diffractive cross section in deep inelastic
scattering in the saturation regime. The obtained cross section is finite by
itself and a part of the full next-to-leading order result. We perform the
calculation in exact kinematics in the eikonal limit, and show that the
previously known high virtuality and large invariant mass results
for the structure functions can be extracted. We furthermore discuss the steps
required to obtain the full next-to-leading order result.Comment: 6 pages, 1 figure. Presented by T.L. at "Diffraction and Low-x 2022,"
Corigliano Calabro, Italy, September 24-40, 202
Diffractive Deep Inelastic Scattering in the Dipole Picture at Next-to-Leading Order
We calculate the contribution from the state production to the
diffractive cross sections in deep inelastic scattering at high energy. The
obtained cross section is finite by itself, and consists a part of the full
next-to-leading order result for the diffractive structure functions. Our
calculation for the diffractive structure functions is performed using exact
kinematics, under the shockwave approximation of the scattering process. Once
the calculation is completed, we show that the previously known behaviour at
the high- and large- regime can be extracted from our results by
taking the appropriate limits. Furthermore, we discuss the steps required to
obtain the complete next-to-leading order results for the structure functions
in the color glass condensate (CGC) formalism, and the application of these
results to phenomenology.Comment: DIS2023, talk by HH; 5 pages, 3 figure
Universality of traveling waves with QCD running coupling
``Geometric scaling'', i.e. the dependence of DIS cross-sections on the ratio
Q/Q_S, where Q_S(Y) is the rapidity-dependent \saturation scale, can be
theoretically obtained from universal ``traveling wave'' solutions of the
nonlinear Balitsky-Kovchegov (BK) QCD evolution equation at fixed coupling. We
examine the similar mean-field predictions beyond leading-logarithmic order,
including running QCD coupling.Comment: 4 pages, 3 figures,, Invited talk given at the DIS 2007 Conference,
Munich, Germany, April 2007; Change of titl
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