Measurement of the Charm Structure Function and Its Role in Scale Noninvariance

Clark, A. R.; Johnson, K. J.; Kerth, L. T.; Loken, S.; Markiewicz, T. W.; Meyers, P. D.; Smith, W. H.; Strovink, M.; Wenzel, W. A.; Johnson, R.P.; Moore, C. D.; Mugge, M.; Shafer, Robert E.; Gollin, G. D.; Shoemaker, F. C.; Surko, P.

doi:10.1103/physrevlett.45.1465

Cited by 19 publications

(4 citation statements)

References 14 publications

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“…Moreover, the EMC analysis has been done at the leading order of QCD, clearly insufficient for accurate conclusions at NNLO. Despite the tensions 9 stated between the EMC measurement and its contemporary experiments in the case of inclusive DIS [89,96,97,105] and semi-inclusive charm DIS production cross sections [41,106], 10 various 9 See, for example, discussions in the early CTEQ analyses [103,104]. 10 Keep in mind that EMC employed non-identical detection techniques in the measurement of the inclusive structure functions F2 [105] and semi-inclusive F studies [107][108][109][110][111] have interpreted the excess seen in a few high-x bins of the EMC F 2c (x, Q) data as evidence for some nonperturbative charm contribution, while yet other studies concluded the opposite [31,33,34].…”

Section: A Global Analysis Including the Emc Charm Dis Measurementsmentioning

confidence: 99%

“…Moreover, the EMC analysis has been done at the leading order of QCD, clearly insufficient for accurate conclusions at NNLO. Despite the tensions 9 stated between the EMC measurement and its contemporary experiments in the case of inclusive DIS [89,96,97,105] and semi-inclusive charm DIS production cross sections [41,106] 10 , various studies [107][108][109][110][111] have interpreted the excess seen in a few high-x bins of the EMC F 2c (x, Q) data as evidence for some nonperturbative charm contribution, while yet other studies concluded the opposite [31,33,34]. Our special series of the CT14 IC fits included the EMC F 2c (x, Q) data to investigate the above conclusion.…”

Section: F a Global Analysis Including The Emc Charm Dis Measurementsmentioning

confidence: 99%

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CT14 intrinsic charm parton distribution functions from CTEQ-TEA global analysis

Hou

Dulat

Gao

et al. 2018

J. High Energ. Phys.

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Abstract:We investigate the possibility of a (sizable) nonperturbative contribution to the charm parton distribution function (PDF) in a nucleon, theoretical issues arising in its interpretation, and its potential impact on LHC scattering processes. The "fitted charm" PDF obtained in various QCD analyses contains a process-dependent component that is partly traced to power-suppressed radiative contributions in DIS and is generally different at the LHC. We discuss separation of the universal component of the nonperturbative charm from the rest of the radiative contributions and estimate its magnitude in the CT14 global QCD analysis at the next-to-next-to leading order in the QCD coupling strength, including the latest experimental data from HERA and the Large Hadron Collider. Models for the nonperturbative charm PDF are examined as a function of the charm quark mass and other parameters. The prospects for testing these models in the associated production of a Z boson and a charm jet at the LHC are studied under realistic assumptions, including effects of the final-state parton showering.

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Section: A Global Analysis Including the Emc Charm Dis Measurementsmentioning

confidence: 99%

“…Moreover, the EMC analysis has been done at the leading order of QCD, clearly insufficient for accurate conclusions at NNLO. Despite the tensions 9 stated between the EMC measurement and its contemporary experiments in the case of inclusive DIS [89,96,97,105] and semi-inclusive charm DIS production cross sections [41,106] 10 , various studies [107][108][109][110][111] have interpreted the excess seen in a few high-x bins of the EMC F 2c (x, Q) data as evidence for some nonperturbative charm contribution, while yet other studies concluded the opposite [31,33,34]. Our special series of the CT14 IC fits included the EMC F 2c (x, Q) data to investigate the above conclusion.…”

Section: F a Global Analysis Including The Emc Charm Dis Measurementsmentioning

confidence: 99%

CT14 intrinsic charm parton distribution functions from CTEQ-TEA global analysis

Hou

Dulat

Gao

et al. 2018

J. High Energ. Phys.

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“…62 Our data extend into the kinematic region known to contain scaling violations due to the crossing of the charm threshold. 49 We have made no detailed attempt to correct for this, but rather try removing the region in question and observe the effect. Before the interpolation to x bin centers, we eliminate all measurements with x < 0.15.…”

Section: Systematic Uncertaintiesmentioning

confidence: 99%

Measurement of the nucleon structure function using high energy muons

Meyers¹

1983

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“…An exception is the "target mass correction" which can be taken into account 51 by replacing the variable Our data extend into the kinematic region known to contain scaling violations due x with to the crossing of the charm threshold. 33 We have made no detailed attempt to correct e = 2x 1 + .j1 + 4x2M~jQ2.…”

Section: Dortmund-heidelberg-saclay (Cdhs) Neutrino Collaboration 18 mentioning

confidence: 99%

Measurement of the nucleon structure function in iron using 215- and 93-GeV muons

Meyers¹,

Clark

Johnson

et al. 1986

Phys. Rev. D

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We have measured the inclusive deep inelastic scattering of muons on nucleons in iron using beams of 93 and 215GeV muons. To perform this measurement, we have built and operated the Multimuon Spectrometer (MMS) in the muon beam at Fermilab. Using the known form of the radiativelycorrected electromagnetic cross section, we extract the struc- A. KinematicsThe Feynman diagram for deep inelastic lepton-hadron scattering in the lowest order of QED is shown in Fig. 1, together with a summary of our kinematical notation. To this order, the process is described as the exchange of one virtual photon. QED allows us to calculate unambiguously what happens at the leptonic (upper) vertex. The goal of our experiment is to uncover what happens in the region surrounding the hadronic vertex.We will be studying inclusive scattering, p.N -+ p.X, with no reference to any particular hadronic final state. This means that the only relevant 4-vectors at the hadronic vertex are p and q, and the only Lorentz-invariant quantities are q 2 and p · q (and p 2 = MJ.). While isolating the hadronic vertex is a productive move toward understanding the scattering process, experimentally it is imp_ortant to note that these quantities can be measured 3 ' < using only the initial and final muons:Q 2 = -q 2 = 4EE'sin 2 ~. where E, E', and 9 are the initial and final muon energies and the muon scattering angle as measured in the laboratory frame (the target rest frame). Terms containing the lepton mass have been neglected. Another useful quantity is the invariant mass of the hadronic final state: W 2 = (p + q) 2 = MJ. + 2MNv-Q 2 • The elastic limit is W 2 = MJ. or Q 2 = 2MNV. Resonances appear at fixed W 2 near this limit. Figure 2 shows the region of the Q 2 -v plane accessible to inelastic scattering at fixed incident energy E.It is convenient to describe another set of variables that are Q 2 and v scaled by their maximum values, neglecting lepton masses:v = Q 2 j2MNE = xy. B. Cross section and structure functionsBy demanding Lorentz covariance and gauge invariance we can translate 7 • 8 the diagram of Fig. 1 directly into an expression for the spin-averaged inclusive cross section:dQ2dv-~ 2Wl(Q ,v)sm 2 + W2 (Q 2 ,v)cos 2 2 ], (3) in terms of the two unknown "structure functions" wl and w2. scalar functions that describe the hadronic electromagnetic current. We treat the incident muon as a source of virtual photons and write the cross section as where T and L refer to transversely and longitudinally polarized virtual ph'?tons and K is a flux factor. Defining R = uL/uT we can eliminate W 1 in favor of R in the cross section Eq. 3. The advantages of this substitution will be described in the next section where it is shown that for some cases of interest R is expected to be small. For now we record the cross section in its new form, The approximate form comes from taking the Bjorken limit where energies (E,Q 2 ,v)-+ oo with x and y-finite. 10 In the kinematic region covered by our data, making such an approximation has a maximum effect of < ! % on our ...

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Measurement of the Charm Structure Function and Its Role in Scale Noninvariance

Cited by 19 publications

References 14 publications

CT14 intrinsic charm parton distribution functions from CTEQ-TEA global analysis

CT14 intrinsic charm parton distribution functions from CTEQ-TEA global analysis

Measurement of the nucleon structure function using high energy muons

Measurement of the nucleon structure function in iron using 215- and 93-GeV muons

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