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1812.03905
Sergiy Akkelin
S.V. Akkelin
Quasi equilibrium state of expanding quantum fields and two-pion Bose-Einstein correlations in $pp$ collisions at the LHC
20 pages, accepted for publication
Eur. Phys. J. A (2019) 55: 78
10.1140/epja/i2019-12755-9
null
hep-ph hep-ex nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We argue that the two-particle momentum correlation functions of high-multiplicity $p+p$ collisions at the LHC provide a signal for a ground state structure of a quasi equilibrium state of the longitudinally boost-invariant expanding quantum field which lies in the future light cone of a collision. The physical picture is that pions are produced by the expanding quantum emitter with two different scales approximately attributed to the expanding ideal gas in local equilibrium state and ground-state condensate. Specifically, we show that the effect of suppressing the two-particle Bose-Einstein momentum correlation functions increases with increasing transverse momentum of a like-sign pion pair due to different momentum-dependence of the corresponding particle emission regions.
[ { "created": "Mon, 10 Dec 2018 16:26:21 GMT", "version": "v1" }, { "created": "Wed, 27 Mar 2019 17:54:31 GMT", "version": "v2" }, { "created": "Fri, 17 May 2019 12:44:15 GMT", "version": "v3" } ]
2019-05-24
[ [ "Akkelin", "S. V.", "" ] ]
We argue that the two-particle momentum correlation functions of high-multiplicity $p+p$ collisions at the LHC provide a signal for a ground state structure of a quasi equilibrium state of the longitudinally boost-invariant expanding quantum field which lies in the future light cone of a collision. The physical picture is that pions are produced by the expanding quantum emitter with two different scales approximately attributed to the expanding ideal gas in local equilibrium state and ground-state condensate. Specifically, we show that the effect of suppressing the two-particle Bose-Einstein momentum correlation functions increases with increasing transverse momentum of a like-sign pion pair due to different momentum-dependence of the corresponding particle emission regions.
hep-ph/0206295
Christian Weiss
C. Weiss (Regensburg University)
Proton-antiproton annihilation into two photons at large s
6 pages, 3 figures, uses ws-procs9x6.cls. Talk presented at the Workshop on Exclusive Processes at High Momentum Transfer, Jefferson Lab, Newport News, VA, May 15-18, 2002
null
10.1142/9789812776211_0032
null
hep-ph
null
Exclusive proton-antiproton annihilation into two photons can be viewed as the Compton process in the crossed channel. At large s (~10 GeV^2) and |t|,|u| s this process can be described by a generalized partonic picture, analogous to the 'soft mechanism' in wide-angle real Compton scattering. The two photons are emitted in the annihilation of a single fast quark and antiquark ('handbag graph'). The transition of the p-pbar system to a q-qbar pair through soft interactions is described by double distributions, which can be related to the timelike proton elastic form factors as well as, by crossing symmetry, to the usual quark--antiquark distributions in the nucleon. We estimate that this reaction should be observable with reasonable statistics at the proposed 1.5..15 GeV high-luminosity antiproton storage ring (HESR) at GSI.
[ { "created": "Fri, 28 Jun 2002 16:14:01 GMT", "version": "v1" } ]
2017-08-23
[ [ "Weiss", "C.", "", "Regensburg University" ] ]
Exclusive proton-antiproton annihilation into two photons can be viewed as the Compton process in the crossed channel. At large s (~10 GeV^2) and |t|,|u| s this process can be described by a generalized partonic picture, analogous to the 'soft mechanism' in wide-angle real Compton scattering. The two photons are emitted in the annihilation of a single fast quark and antiquark ('handbag graph'). The transition of the p-pbar system to a q-qbar pair through soft interactions is described by double distributions, which can be related to the timelike proton elastic form factors as well as, by crossing symmetry, to the usual quark--antiquark distributions in the nucleon. We estimate that this reaction should be observable with reasonable statistics at the proposed 1.5..15 GeV high-luminosity antiproton storage ring (HESR) at GSI.
hep-ph/0210237
Christian Weiss
C. Weiss (Regensburg University)
Twist-3 effects in deeply virtual Compton scattering made simple
4 pages, 3 figures, uses ws-p8-50x6-00.cls . Proceedings of the Baryons 2002 Conference, Jefferson Lab, Newport News, VA, March 3-8, 2002
null
10.1142/9789812704887_0044
null
hep-ph
null
We show that electromagnetic gauge invariance requires a 'spin rotation' of the quarks in the usual twist-2 contribution to the amplitude for deeply virtual Compton scattering. This rotation is equivalent to the inclusion of certain kinematical twist-3 (Wandzura-Wilczek type) terms, which have been derived previously using other methods. The new representation of the twist-3 terms is very compact and allows for a simple physical interpretation.
[ { "created": "Wed, 16 Oct 2002 18:10:59 GMT", "version": "v1" } ]
2017-08-23
[ [ "Weiss", "C.", "", "Regensburg University" ] ]
We show that electromagnetic gauge invariance requires a 'spin rotation' of the quarks in the usual twist-2 contribution to the amplitude for deeply virtual Compton scattering. This rotation is equivalent to the inclusion of certain kinematical twist-3 (Wandzura-Wilczek type) terms, which have been derived previously using other methods. The new representation of the twist-3 terms is very compact and allows for a simple physical interpretation.
2407.13506
Yehonatan Viernik
Yuval Grossman, Yosef Nir, Matthias Neubert, Yogev Shpilman and Yehonatan Viernik
$B_{s}^0\to K^0\overline{K}{}^0$ beyond the Standard Model
16 pages, 3 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Within the Standard Model, the branching fraction of the $B_s\to K^0\overline{K}{}^0$ decay is related to other decay rates and CP asymmetries through the approximate $SU(3)$ flavor symmetry of the strong interactions. Three such relations were shown to be violated at a level of about $3\sigma$ each. By means of a systematic search for new physics explanations of these puzzles, we find that possible solutions are highly fine-tuned and rather implausible.
[ { "created": "Thu, 18 Jul 2024 13:39:50 GMT", "version": "v1" } ]
2024-07-19
[ [ "Grossman", "Yuval", "" ], [ "Nir", "Yosef", "" ], [ "Neubert", "Matthias", "" ], [ "Shpilman", "Yogev", "" ], [ "Viernik", "Yehonatan", "" ] ]
Within the Standard Model, the branching fraction of the $B_s\to K^0\overline{K}{}^0$ decay is related to other decay rates and CP asymmetries through the approximate $SU(3)$ flavor symmetry of the strong interactions. Three such relations were shown to be violated at a level of about $3\sigma$ each. By means of a systematic search for new physics explanations of these puzzles, we find that possible solutions are highly fine-tuned and rather implausible.
hep-ph/0510164
Roberto Contino
Kaustubh Agashe, Roberto Contino
The Minimal Composite Higgs Model and Electroweak Precision Tests
v2: an estimate of Delta rho added in the conclusions for the case of a different realization of custodial symmetry, plus a few extra comments and a reference; v3: a few typos corrected, some important changes in sections 2 and 4, a reference added. Conclusions unchanged. Version published in NPB
Nucl.Phys.B742:59-85,2006
10.1016/j.nuclphysb.2006.02.011
null
hep-ph
null
A complete analysis of the electroweak precision observables is performed within a recently proposed minimal composite Higgs model, realized as a 5-dimensional warped compactification. In particular, we compute Z->bb and the one-loop correction to the rho parameter. We find that oblique data can be easily reproduced without a significant amount of tuning in the parameters of the model, while Z->bb imposes a stronger constraint. As a consequence of the latter, some of the new fermionic resonances must have mass around 4 TeV, which corresponds to an electroweak fine tuning of a few percent. Other resonances, such as Z', can be lighter in sizeable portions of the parameter space. We discuss in detail the origin of the Z->bb constraint and we suggest several possible avenues beyond the minimal model for weakening it.
[ { "created": "Wed, 12 Oct 2005 19:53:31 GMT", "version": "v1" }, { "created": "Fri, 28 Oct 2005 20:27:50 GMT", "version": "v2" }, { "created": "Thu, 16 Mar 2006 16:43:26 GMT", "version": "v3" } ]
2011-05-05
[ [ "Agashe", "Kaustubh", "" ], [ "Contino", "Roberto", "" ] ]
A complete analysis of the electroweak precision observables is performed within a recently proposed minimal composite Higgs model, realized as a 5-dimensional warped compactification. In particular, we compute Z->bb and the one-loop correction to the rho parameter. We find that oblique data can be easily reproduced without a significant amount of tuning in the parameters of the model, while Z->bb imposes a stronger constraint. As a consequence of the latter, some of the new fermionic resonances must have mass around 4 TeV, which corresponds to an electroweak fine tuning of a few percent. Other resonances, such as Z', can be lighter in sizeable portions of the parameter space. We discuss in detail the origin of the Z->bb constraint and we suggest several possible avenues beyond the minimal model for weakening it.
0705.2277
Qi-Shu Yan
Sukanta Dutta, Kaoru Hagiwara, Qi-Shu Yan, Kentaroh Yoshida
Constraints on the electroweak chiral Lagrangian from the precision data
One more reference is included. Typoes are removed. The version to appear at Nucl. Phys. B
Nucl.Phys.B790:111-137,2008
10.1016/j.nuclphysb.2007.08.017
null
hep-ph
null
In the framework of the effective field theory method, we use the experimental data and the perturbative unitarity bounds to determine the values and uncertainty of all the 11 chiral coefficients ($\al_i, i=0, ..., 10$) of the standard electroweak chiral Lagrangian. Up to linear terms in $\al_i$, we provide the one-loop renormalization group equations of all the chiral coefficients, which are calculated in the Feynman-'t Hooft gauge using the modified minimal subtraction scheme. With the improved renormalization group equations to sum over the logarithmic corrections, we analyze the current experimental uncertainty of oblique correction parameters, $S(\Lambda)$ and $T(\Lambda)$. We find that, due to the large uncertainty in the triple gauge-boson coupling measurements, the parameter space of positive $S(\Lambda)$ for $\Lambda > 1$ TeV is still allowed by the current experimental data. $T(\Lambda)$ tends to increase with $\Lambda$ even in the presence of the operators that contribute to the triple and quartic gauge-boson couplings.
[ { "created": "Wed, 16 May 2007 04:21:07 GMT", "version": "v1" }, { "created": "Sat, 13 Oct 2007 14:48:51 GMT", "version": "v2" } ]
2008-11-26
[ [ "Dutta", "Sukanta", "" ], [ "Hagiwara", "Kaoru", "" ], [ "Yan", "Qi-Shu", "" ], [ "Yoshida", "Kentaroh", "" ] ]
In the framework of the effective field theory method, we use the experimental data and the perturbative unitarity bounds to determine the values and uncertainty of all the 11 chiral coefficients ($\al_i, i=0, ..., 10$) of the standard electroweak chiral Lagrangian. Up to linear terms in $\al_i$, we provide the one-loop renormalization group equations of all the chiral coefficients, which are calculated in the Feynman-'t Hooft gauge using the modified minimal subtraction scheme. With the improved renormalization group equations to sum over the logarithmic corrections, we analyze the current experimental uncertainty of oblique correction parameters, $S(\Lambda)$ and $T(\Lambda)$. We find that, due to the large uncertainty in the triple gauge-boson coupling measurements, the parameter space of positive $S(\Lambda)$ for $\Lambda > 1$ TeV is still allowed by the current experimental data. $T(\Lambda)$ tends to increase with $\Lambda$ even in the presence of the operators that contribute to the triple and quartic gauge-boson couplings.
2210.12992
Ju-Jun Xie
Xin Zhu, Hao-Nan Wang, De-Min Li, En Wang, Li-Sheng Geng, and Ju-Jun Xie
Further understanding the nature of $a_0(1710)$ in the $D^+_s \to \pi^0 K^+ K^0_S$ decay
8 pages, 8 figures
null
null
null
hep-ph hep-ex nucl-ex nucl-th
http://creativecommons.org/licenses/by/4.0/
Based on our previous work about the role of $a_0(1710)$ in the $D_s^+\to\pi^+K_S^0K_S^0$ decay [Phy. Rev. D 105, 116010 (2022)], we perform a further theoretical study of $a_0(1710)^+$ in the process $D^+_s \to \pi^0 a_0(1710)^+ \to \pi^0 K^+ K^0_S$. In addition to $a_0(1710)$, the contributions of $K^*$ and $a_0(980)$ are also taken into account. Firstly, we consider the contributions from the tree diagrams of $K^{*+} \to K^+\pi^0$ and $\bar{K}^{*0} \to \pi^0 \bar{K}^0$. Secondly, we describe the final state interaction of $K\bar{K}$ in the chiral unitary approach to study the contribution of $a_0(980)$, while the $a_0(1710)$ state is dynamically generated from the $K^*\bar{K}^*$ interaction, and then decays into $K^+\bar{K}^0$. Since the final $K^+ K_S^0$ state is in pure isospin $I=1$, the $D_s^+\to\pi^0K^+K_s^0$ decay is an ideal process to study the $a_0(1710)^+$ and $a_0(980)^+$ resonances. Based on our theoretical calculations, it is found that the recent experimental measurements on the $K^+K^0_S$, $\pi^0K^+$, and $\pi^0 K_S^0$ invariant mass distributions can be well reproduced, which supports the molecular $K^*\bar{K}^*$ nature of the scalar $a_0(1710)$ resonance.
[ { "created": "Mon, 24 Oct 2022 07:28:23 GMT", "version": "v1" } ]
2022-10-25
[ [ "Zhu", "Xin", "" ], [ "Wang", "Hao-Nan", "" ], [ "Li", "De-Min", "" ], [ "Wang", "En", "" ], [ "Geng", "Li-Sheng", "" ], [ "Xie", "Ju-Jun", "" ] ]
Based on our previous work about the role of $a_0(1710)$ in the $D_s^+\to\pi^+K_S^0K_S^0$ decay [Phy. Rev. D 105, 116010 (2022)], we perform a further theoretical study of $a_0(1710)^+$ in the process $D^+_s \to \pi^0 a_0(1710)^+ \to \pi^0 K^+ K^0_S$. In addition to $a_0(1710)$, the contributions of $K^*$ and $a_0(980)$ are also taken into account. Firstly, we consider the contributions from the tree diagrams of $K^{*+} \to K^+\pi^0$ and $\bar{K}^{*0} \to \pi^0 \bar{K}^0$. Secondly, we describe the final state interaction of $K\bar{K}$ in the chiral unitary approach to study the contribution of $a_0(980)$, while the $a_0(1710)$ state is dynamically generated from the $K^*\bar{K}^*$ interaction, and then decays into $K^+\bar{K}^0$. Since the final $K^+ K_S^0$ state is in pure isospin $I=1$, the $D_s^+\to\pi^0K^+K_s^0$ decay is an ideal process to study the $a_0(1710)^+$ and $a_0(980)^+$ resonances. Based on our theoretical calculations, it is found that the recent experimental measurements on the $K^+K^0_S$, $\pi^0K^+$, and $\pi^0 K_S^0$ invariant mass distributions can be well reproduced, which supports the molecular $K^*\bar{K}^*$ nature of the scalar $a_0(1710)$ resonance.
hep-ph/0112150
Barry R. Holstein
Barry R. Holstein
Allowed Eta Decay Modes and Chiral Symmetry
Contribution to Eta Physics Handbook, Workshop on Eta Physics, Uppsala 2001, 28 page latex file with 9 figures
Phys.Scripta T99:55-67,2002
10.1238/Physica.Topical.099a00055
null
hep-ph
null
Recently, the development of chiral perturbation theory has allowed the generation of rigorous low energy theorems for various hadronic processes based only on the chiral invariance of the underlying QCD Lagrangian. Such techniques are highly developed and well tested in the domain of pionic and kaonic reactions. In this note we point out that with the addition of a few additional and reasonable assumptions similar predictive power is available for processes involving the eta meson.
[ { "created": "Tue, 11 Dec 2001 08:16:53 GMT", "version": "v1" } ]
2011-07-19
[ [ "Holstein", "Barry R.", "" ] ]
Recently, the development of chiral perturbation theory has allowed the generation of rigorous low energy theorems for various hadronic processes based only on the chiral invariance of the underlying QCD Lagrangian. Such techniques are highly developed and well tested in the domain of pionic and kaonic reactions. In this note we point out that with the addition of a few additional and reasonable assumptions similar predictive power is available for processes involving the eta meson.
hep-ph/0608250
Andreas Ipp
Andreas Ipp
The pressure of deconfined QCD for all temperatures and quark chemical potentials
4 pages, 5 figures, to appear in the proceedings of Strong and Electroweak Matter 2006 (SEWM), BNL, May 2006
Nucl.Phys.A785:182-185,2007
10.1016/j.nuclphysa.2006.11.124
ECT*-06-12
hep-ph
null
A new method for the evaluation of the perturbative expansion of the QCD pressure is presented which is valid for all temperatures and quark chemical potentials in the deconfined phase, and worked out up to and including order g^4. This new approach unifies several distinct perturbative approaches to the equation of state, and agrees with dimensional reduction, HDL and HTL resummation schemes, and the zero-temperature result in their respective ranges of validity.
[ { "created": "Tue, 22 Aug 2006 15:35:06 GMT", "version": "v1" } ]
2008-11-26
[ [ "Ipp", "Andreas", "" ] ]
A new method for the evaluation of the perturbative expansion of the QCD pressure is presented which is valid for all temperatures and quark chemical potentials in the deconfined phase, and worked out up to and including order g^4. This new approach unifies several distinct perturbative approaches to the equation of state, and agrees with dimensional reduction, HDL and HTL resummation schemes, and the zero-temperature result in their respective ranges of validity.
0803.1424
Joachim Kopp
Evgeny Kh. Akhmedov, Joachim Kopp, Manfred Lindner
Comment on 'Time-energy uncertainty relations for neutrino oscillations and the Mossbauer neutrino experiment'
LaTeX, 6 pages, no figures; v2 has been extended compared to v1 and matches the published version; title changed in journal
J.Phys.G36:078001,2009
10.1088/0954-3899/36/7/078001
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the implications of the time-energy uncertainty relation to recoillessly emitted and captured neutrinos (Mossbauer neutrinos) and show that it does not preclude oscillations of these neutrinos, contrary to a recent claim (J. Phys. G35 (2008) 095003, arXiv:0803.0527).
[ { "created": "Mon, 10 Mar 2008 14:28:53 GMT", "version": "v1" }, { "created": "Fri, 1 May 2009 16:32:18 GMT", "version": "v2" } ]
2009-05-01
[ [ "Akhmedov", "Evgeny Kh.", "" ], [ "Kopp", "Joachim", "" ], [ "Lindner", "Manfred", "" ] ]
We discuss the implications of the time-energy uncertainty relation to recoillessly emitted and captured neutrinos (Mossbauer neutrinos) and show that it does not preclude oscillations of these neutrinos, contrary to a recent claim (J. Phys. G35 (2008) 095003, arXiv:0803.0527).
2003.11821
Priyotosh Bandyopadhyay
Shilpa Jangid, Priyotosh Bandyopadhyay
Distinguishing Inert Higgs Doublet and Inert Triplet Scenarios
41 pages, 32 figures and 5 tables, citations added EPJC accepted version
null
10.1140/epjc/s10052-020-8271-5
IITH-PH-0002/20
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this article we consider a comparative study between Type-I 2HDM and $Y=0$, $SU(2)$ triplet extensions having one $Z_2$-odd doublet and triplet that render the desired dark matter(DM). For the inert doublet model (IDM) either a neutral scalar or pseudoscalar can be the DM, whereas for inert triplet model (ITM) it is a CP-even scalar. The bounds from perturbativity and vacuum stability are studied for both the scenarios by calculating the two-loop beta functions. While the quartic couplings are restricted to $0.1-0.2$ for a Planck scale perturbativity for IDM, these are much relaxed ($0.8$ ) for ITM. The RG-improved potentials by Coleman-Weinberg show the regions of stability, meta-stability and instability of the electroweak vacuum. The constraints coming from DM relic, the direct and indirect experiments like XENON1T, LUX and H.E.S.S., Fermi-LAT allow the DM mass $\gtrsim 700, \,1176$ GeV for IDM, ITM respectively. Though mass-splitting among $Z_2$-odd particles in IDM is a possibility for ITM we have to rely on loop-corrections. The phenomenological signatures at the LHC show that the mono-lepton plus missing energy with prompt and displaced decays in the case of IDM and ITM can distinguish such scenarios at the LHC along with other complementary modes.
[ { "created": "Thu, 26 Mar 2020 10:30:51 GMT", "version": "v1" }, { "created": "Thu, 2 Apr 2020 16:12:42 GMT", "version": "v2" }, { "created": "Wed, 22 Jul 2020 18:18:30 GMT", "version": "v3" } ]
2020-08-26
[ [ "Jangid", "Shilpa", "" ], [ "Bandyopadhyay", "Priyotosh", "" ] ]
In this article we consider a comparative study between Type-I 2HDM and $Y=0$, $SU(2)$ triplet extensions having one $Z_2$-odd doublet and triplet that render the desired dark matter(DM). For the inert doublet model (IDM) either a neutral scalar or pseudoscalar can be the DM, whereas for inert triplet model (ITM) it is a CP-even scalar. The bounds from perturbativity and vacuum stability are studied for both the scenarios by calculating the two-loop beta functions. While the quartic couplings are restricted to $0.1-0.2$ for a Planck scale perturbativity for IDM, these are much relaxed ($0.8$ ) for ITM. The RG-improved potentials by Coleman-Weinberg show the regions of stability, meta-stability and instability of the electroweak vacuum. The constraints coming from DM relic, the direct and indirect experiments like XENON1T, LUX and H.E.S.S., Fermi-LAT allow the DM mass $\gtrsim 700, \,1176$ GeV for IDM, ITM respectively. Though mass-splitting among $Z_2$-odd particles in IDM is a possibility for ITM we have to rely on loop-corrections. The phenomenological signatures at the LHC show that the mono-lepton plus missing energy with prompt and displaced decays in the case of IDM and ITM can distinguish such scenarios at the LHC along with other complementary modes.
hep-ph/9908345
Z. Hioki
Zenro Hioki
Probing Anomalous Top-Couplings at Polarized Linear Collider
6 pages, Latex, Talk at the fourth International Workshops on Linear Colliders (LCWS99), April 28 - May 5, 1999, Sitges, Barcelona, Spain. Report-no was corrected (TOKUSHIMA 99-01 --> 99-02)
null
null
TOKUSHIMA 99-02
hep-ph
null
The energy spectra of the lepton(s) in eebar --> ttbar --> l^{+-}X/ l^+l^- X' at next linear colliders (NLC) are analyzed a model-independent way for arbitrary longitudinal beam polarizations as a general test of possible anomalous top-quark couplings.
[ { "created": "Fri, 13 Aug 1999 05:07:56 GMT", "version": "v1" }, { "created": "Sun, 22 Aug 1999 07:26:58 GMT", "version": "v2" } ]
2007-05-23
[ [ "Hioki", "Zenro", "" ] ]
The energy spectra of the lepton(s) in eebar --> ttbar --> l^{+-}X/ l^+l^- X' at next linear colliders (NLC) are analyzed a model-independent way for arbitrary longitudinal beam polarizations as a general test of possible anomalous top-quark couplings.
1909.08954
Michael Klasen
V. Guzey, M. Klasen
Inclusive and diffractive dijet photoproduction in UPCs at the LHC in NLO QCD
7 pages, 5 figures, 1 table. Proceedings of the EPS Conference on High-Energy Physics (EPS-HEP 2019), Ghent, Belgium
null
null
MS-TP-19-25
hep-ph hep-ex nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a next-to-leading order QCD calculation of inclusive dijet photoproduction in ultraperipheral Pb-Pb collisions at the LHC and show that the results agree very well with various kinematic distributions measured by the ATLAS collaboration. The effect of including these data in nCTEQ or EPPS16 nuclear parton density functions (nPDFs) is then studied using the Bayesian reweighting technique. For an assumed total error of 5\% on the final data, its inclusion would lead to a significant reduction of the nPDF uncertainties of up to a factor of two at small values of the parton momentum fraction. As an outlook, we discuss future analyes of diffractive nPDFs, which are so far completely unknown.
[ { "created": "Thu, 19 Sep 2019 13:06:08 GMT", "version": "v1" } ]
2019-09-20
[ [ "Guzey", "V.", "" ], [ "Klasen", "M.", "" ] ]
We present a next-to-leading order QCD calculation of inclusive dijet photoproduction in ultraperipheral Pb-Pb collisions at the LHC and show that the results agree very well with various kinematic distributions measured by the ATLAS collaboration. The effect of including these data in nCTEQ or EPPS16 nuclear parton density functions (nPDFs) is then studied using the Bayesian reweighting technique. For an assumed total error of 5\% on the final data, its inclusion would lead to a significant reduction of the nPDF uncertainties of up to a factor of two at small values of the parton momentum fraction. As an outlook, we discuss future analyes of diffractive nPDFs, which are so far completely unknown.
1906.09028
Narayan Rana
Ajjath A H, Pulak Banerjee, Amlan Chakraborty, Prasanna K. Dhani, Pooja Mukherjee, Narayan Rana, V. Ravindran
NNLO QCD$\oplus$QED corrections to Higgs production in bottom quark annihilation
18 pages, 7 figures, 5 tables
Phys. Rev. D 100, 114016 (2019)
10.1103/PhysRevD.100.114016
IMSc/2019/05/05, PSI-PR-19-12, TIF-UNIMI-2019-7
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present next-to-next-to leading order (NNLO) quantum electrodynamics (QED) corrections to the production of the Higgs boson in bottom quark annihilation at the Large Hadron Collider (LHC) in the five flavor scheme. We have systematically included the NNLO corrections resulting from the interference of quantum chromodynamics (QCD) and QED interactions. We have investigated the infrared (IR) structure of the bottom quark form factor up to two loop level in QED and in QCD$\times$QED using K+G equation. We find that the IR poles in the form factor are controlled by the universal cusp, collinear and soft anomalous dimensions. In addition, we derive the QED as well as QCD$\times$QED contributions to soft distribution function as well as to the ultraviolet renormalization constant of the bottom Yukawa coupling up to second order in strong coupling and fine structure constant. Finally, we report our findings on the numerical impact of the NNLO results from QED and QCD$\times$QED at the LHC energies taking into account the dominant NNLO QCD corrections.
[ { "created": "Fri, 21 Jun 2019 09:40:28 GMT", "version": "v1" } ]
2019-12-18
[ [ "H", "Ajjath A", "" ], [ "Banerjee", "Pulak", "" ], [ "Chakraborty", "Amlan", "" ], [ "Dhani", "Prasanna K.", "" ], [ "Mukherjee", "Pooja", "" ], [ "Rana", "Narayan", "" ], [ "Ravindran", "V.", "" ] ]
We present next-to-next-to leading order (NNLO) quantum electrodynamics (QED) corrections to the production of the Higgs boson in bottom quark annihilation at the Large Hadron Collider (LHC) in the five flavor scheme. We have systematically included the NNLO corrections resulting from the interference of quantum chromodynamics (QCD) and QED interactions. We have investigated the infrared (IR) structure of the bottom quark form factor up to two loop level in QED and in QCD$\times$QED using K+G equation. We find that the IR poles in the form factor are controlled by the universal cusp, collinear and soft anomalous dimensions. In addition, we derive the QED as well as QCD$\times$QED contributions to soft distribution function as well as to the ultraviolet renormalization constant of the bottom Yukawa coupling up to second order in strong coupling and fine structure constant. Finally, we report our findings on the numerical impact of the NNLO results from QED and QCD$\times$QED at the LHC energies taking into account the dominant NNLO QCD corrections.
2107.02074
Bikash Thapa
Bikash Thapa, Ng. K. Francis
Resonant leptogenesis and TM$_1$ mixing in minimal Type-I seesaw model with S$_4$ symmetry
19 pages, 7 figures, 2 tables
null
10.1140/epjc/s10052-021-09859-2
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
We present an S$_4$ flavour symmetric model within a minimal seesaw framework resulting in mass matrices that leads to TM$_1$ mixing. Minimal seesaw is realized by adding two right-handed neutrinos to the Standard Model. The model predicts Normal Hierarchy (NH) for neutrino masses. Using the constrained six-dimensional parameter space, we have evaluated the effective Majorana neutrino mass, which is the parameter of interest in neutrinoless double beta decay experiments. The possibility of explaining baryogenesis via resonant leptogenesis is also examined within the model. A non-zero, resonantly enhanced CP asymmetry generated from the decay of right-handed neutrinos at the TeV scale is studied, considering flavour effects. The evolution of lepton asymmetry is discussed by solving the set of Boltzmann equations numerically and obtain the value of baryon asymmetry to be $\lvert \eta_B \rvert = 6.3 \times 10^{-10}$.
[ { "created": "Mon, 5 Jul 2021 15:13:31 GMT", "version": "v1" } ]
2021-12-22
[ [ "Thapa", "Bikash", "" ], [ "Francis", "Ng. K.", "" ] ]
We present an S$_4$ flavour symmetric model within a minimal seesaw framework resulting in mass matrices that leads to TM$_1$ mixing. Minimal seesaw is realized by adding two right-handed neutrinos to the Standard Model. The model predicts Normal Hierarchy (NH) for neutrino masses. Using the constrained six-dimensional parameter space, we have evaluated the effective Majorana neutrino mass, which is the parameter of interest in neutrinoless double beta decay experiments. The possibility of explaining baryogenesis via resonant leptogenesis is also examined within the model. A non-zero, resonantly enhanced CP asymmetry generated from the decay of right-handed neutrinos at the TeV scale is studied, considering flavour effects. The evolution of lepton asymmetry is discussed by solving the set of Boltzmann equations numerically and obtain the value of baryon asymmetry to be $\lvert \eta_B \rvert = 6.3 \times 10^{-10}$.
hep-ph/9704279
Yuly Shabelsky
M. G. Ryskin and Yu. M. Shabelski
$\sigma_L/\sigma_T$ in the $\rho^0$ - meson diffractive electroproproduction
9 pages, Latex + 2 figures, epsfig.sty
null
null
null
hep-ph
null
The background due to the direct diffractive dissociation of the photon into the $\pi^+\pi^-$-pair to the "elastic" diffractive $\rho^0$-meson production in electron-proton collisions is calculated. At large $Q^2$ the interference between resonant and non-resonant $\pi^+ \pi^-$ production changes the $\sigma^L/\sigma^T$ ratio with the mass of the $2\pi$ (i.e. $\rho^0$-meson) state.
[ { "created": "Thu, 10 Apr 1997 09:04:20 GMT", "version": "v1" } ]
2016-09-06
[ [ "Ryskin", "M. G.", "" ], [ "Shabelski", "Yu. M.", "" ] ]
The background due to the direct diffractive dissociation of the photon into the $\pi^+\pi^-$-pair to the "elastic" diffractive $\rho^0$-meson production in electron-proton collisions is calculated. At large $Q^2$ the interference between resonant and non-resonant $\pi^+ \pi^-$ production changes the $\sigma^L/\sigma^T$ ratio with the mass of the $2\pi$ (i.e. $\rho^0$-meson) state.
hep-ph/0409062
Mikko Laine
M. Laine
Mesonic correlators in hot QCD
10 pages, to appear in the Proceedings of SEWM04, Helsinki, Finland, 16-19 June 2004
null
10.1142/9789812702159_0007
null
hep-ph
null
Certain spacelike mesonic correlation lengths serve as interesting theoretical probes for the reliability of perturbation theory in high-temperature QCD, are directly sensitive to chiral symmetry restoration and to the axial anomaly, and might also have indirect phenomenological signatures in idealised heavy ion collision experiments. I review here the weak-coupling predictions for some of these correlation lengths, to be compared with results from lattice Monte Carlo simulations.
[ { "created": "Mon, 6 Sep 2004 18:35:22 GMT", "version": "v1" } ]
2017-08-23
[ [ "Laine", "M.", "" ] ]
Certain spacelike mesonic correlation lengths serve as interesting theoretical probes for the reliability of perturbation theory in high-temperature QCD, are directly sensitive to chiral symmetry restoration and to the axial anomaly, and might also have indirect phenomenological signatures in idealised heavy ion collision experiments. I review here the weak-coupling predictions for some of these correlation lengths, to be compared with results from lattice Monte Carlo simulations.
2009.10725
Tom Tong
Graham D. Kribs, Xiaochuan Lu, Adam Martin, and Tom Tong
Custodial Symmetry (Violation) in SMEFT
35 pages + appendices, 7 tables
Phys. Rev. D 104, 056006 (2021)
10.1103/PhysRevD.104.056006
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate precision observables sensitive to custodial symmetric/violating UV physics beyond the Standard Model. We use the SMEFT framework which in general includes non-oblique corrections that requires a generalization of the Peskin-Takeuchi $T$ parameter to unambiguously detect custodial symmetry/violation. We take a first step towards constructing a SMEFT reparameterization-invariant replacement, that we call $\mathscr{T}$, valid at least for tree-level custodial violating contributions. We utilize a new custodial basis of $\nu$SMEFT (SMEFT augmented by right-handed neutrinos) which explicitly identifies the global $SU(2)_R$ symmetries of the Higgs and fermion sectors, that in turn permits easy identification of higher-dimensional operators that are custodial preserving or violating. We carefully consider equation-of-motion redundancies that cause custodial symmetric operators in one basis to be equivalent to a set of custodial symmetric and/or violating operators in another basis. Utilizing known results about tree/loop operator generation, we demonstrate that the basis-dependent appearance of custodial-violating operators does not invalidate our $\mathscr{T}$ parameter at tree-level. We illustrate our results with several UV theory examples, demonstrating that $\mathscr{T}$ faithfully identifies custodial symmetry violation, while $T$ can fail.
[ { "created": "Tue, 22 Sep 2020 18:00:00 GMT", "version": "v1" }, { "created": "Mon, 26 Oct 2020 06:27:03 GMT", "version": "v2" } ]
2021-09-15
[ [ "Kribs", "Graham D.", "" ], [ "Lu", "Xiaochuan", "" ], [ "Martin", "Adam", "" ], [ "Tong", "Tom", "" ] ]
We investigate precision observables sensitive to custodial symmetric/violating UV physics beyond the Standard Model. We use the SMEFT framework which in general includes non-oblique corrections that requires a generalization of the Peskin-Takeuchi $T$ parameter to unambiguously detect custodial symmetry/violation. We take a first step towards constructing a SMEFT reparameterization-invariant replacement, that we call $\mathscr{T}$, valid at least for tree-level custodial violating contributions. We utilize a new custodial basis of $\nu$SMEFT (SMEFT augmented by right-handed neutrinos) which explicitly identifies the global $SU(2)_R$ symmetries of the Higgs and fermion sectors, that in turn permits easy identification of higher-dimensional operators that are custodial preserving or violating. We carefully consider equation-of-motion redundancies that cause custodial symmetric operators in one basis to be equivalent to a set of custodial symmetric and/or violating operators in another basis. Utilizing known results about tree/loop operator generation, we demonstrate that the basis-dependent appearance of custodial-violating operators does not invalidate our $\mathscr{T}$ parameter at tree-level. We illustrate our results with several UV theory examples, demonstrating that $\mathscr{T}$ faithfully identifies custodial symmetry violation, while $T$ can fail.
hep-ph/0607080
Evangelos Matsinos
E. Matsinos, W.S. Woolcock, G.C. Oades, G. Rasche and A. Gashi
Phase-shift analysis of low-energy $\pi^{\pm}p$ elastic-scattering data
43 pages, 6 figures
Nucl.Phys.A778:95-123,2006
10.1016/j.nuclphysa.2006.07.040
null
hep-ph
null
Using electromagnetic corrections previously calculated by means of a potential model, we have made a phase-shift analysis of the $\pi^\pm p$ elastic-scattering data up to a pion laboratory kinetic energy of 100 MeV. The hadronic interaction was assumed to be isospin invariant. We found that it was possible to obtain self-consistent databases by removing very few measurements. A pion-nucleon model was fitted to the elastic-scattering database obtained after the removal of the outliers. The model-parameter values showed an impressive stability when the database was subjected to different criteria for the rejection of experiments. Our result for the pseudovector $\pi N N$ coupling constant (in the standard form) is $0.0733 \pm 0.0014$. The six hadronic phase shifts up to 100 MeV are given in tabulated form. We also give the values of the s-wave scattering lengths and the p-wave scattering volumes. Big differences in the s-wave part of the interaction were observed when comparing our hadronic phase shifts with those of the current GWU solution. We demonstrate that the hadronic phase shifts obtained from the analysis of the elastic-scattering data cannot reproduce the measurements of the $\pi^- p$ charge-exchange reaction, thus corroborating past evidence that the hadronic interaction violates isospin invariance. Assuming the validity of the result obtained within the framework of chiral perturbation theory, that the mass difference between the $u$- and the $d$-quark has only a very small effect on the isospin invariance of the purely hadronic interaction, the isospin-invariance violation revealed by the data must arise from the fact that we are dealing with a hadronic interaction which still contains residual effects of electromagnetic origin.
[ { "created": "Fri, 7 Jul 2006 12:45:31 GMT", "version": "v1" }, { "created": "Tue, 25 Jul 2006 11:58:03 GMT", "version": "v2" } ]
2008-11-26
[ [ "Matsinos", "E.", "" ], [ "Woolcock", "W. S.", "" ], [ "Oades", "G. C.", "" ], [ "Rasche", "G.", "" ], [ "Gashi", "A.", "" ] ]
Using electromagnetic corrections previously calculated by means of a potential model, we have made a phase-shift analysis of the $\pi^\pm p$ elastic-scattering data up to a pion laboratory kinetic energy of 100 MeV. The hadronic interaction was assumed to be isospin invariant. We found that it was possible to obtain self-consistent databases by removing very few measurements. A pion-nucleon model was fitted to the elastic-scattering database obtained after the removal of the outliers. The model-parameter values showed an impressive stability when the database was subjected to different criteria for the rejection of experiments. Our result for the pseudovector $\pi N N$ coupling constant (in the standard form) is $0.0733 \pm 0.0014$. The six hadronic phase shifts up to 100 MeV are given in tabulated form. We also give the values of the s-wave scattering lengths and the p-wave scattering volumes. Big differences in the s-wave part of the interaction were observed when comparing our hadronic phase shifts with those of the current GWU solution. We demonstrate that the hadronic phase shifts obtained from the analysis of the elastic-scattering data cannot reproduce the measurements of the $\pi^- p$ charge-exchange reaction, thus corroborating past evidence that the hadronic interaction violates isospin invariance. Assuming the validity of the result obtained within the framework of chiral perturbation theory, that the mass difference between the $u$- and the $d$-quark has only a very small effect on the isospin invariance of the purely hadronic interaction, the isospin-invariance violation revealed by the data must arise from the fact that we are dealing with a hadronic interaction which still contains residual effects of electromagnetic origin.
hep-ph/9705371
Akihiro Murayama
Akihiro Murayama (Department of Physics, Faculty of Education, Shizuoka University)
Some Advantages of SUSY SU(4) x SU(2)_L x SU(2)_R Model in String Derived SO(10) GUTs
10 pages, Latex
Int.J.Mod.Phys. A13 (1998) 4257-4264
10.1142/S0217751X98002043
SH-97-01
hep-ph
null
A D-parity violated SUSY SU(4) x SU(2) _ L x SU(2)_R gauge model with the Higgs sector 2{(4,1,2)+(4-bar,1, 2)}+(1,2,2)+some(1,1,1)'s is shown to have the following advantages: (i) It is the simplest and almost unique solution that satisfies M_X = M_{string} ~0.6 x 10^{18} GeV and M_{INT} ~ 5 x10^{11} GeV in superstring derived SUSY SO(10) GUTs. (ii) The proton is stable enough by the automatic "doublet-triplet splitting" closely connected with the D-parity violation. (iii) The minimization of SUSY one-loop effective potential in a toy model suggests that the SO(10) gauge theory tends to break dynamically down to the SU(4) x SU(2)_ L x SU(2)_R model.
[ { "created": "Wed, 21 May 1997 08:51:22 GMT", "version": "v1" } ]
2009-10-30
[ [ "Murayama", "Akihiro", "", "Department of Physics, Faculty of Education,\n Shizuoka University" ] ]
A D-parity violated SUSY SU(4) x SU(2) _ L x SU(2)_R gauge model with the Higgs sector 2{(4,1,2)+(4-bar,1, 2)}+(1,2,2)+some(1,1,1)'s is shown to have the following advantages: (i) It is the simplest and almost unique solution that satisfies M_X = M_{string} ~0.6 x 10^{18} GeV and M_{INT} ~ 5 x10^{11} GeV in superstring derived SUSY SO(10) GUTs. (ii) The proton is stable enough by the automatic "doublet-triplet splitting" closely connected with the D-parity violation. (iii) The minimization of SUSY one-loop effective potential in a toy model suggests that the SO(10) gauge theory tends to break dynamically down to the SU(4) x SU(2)_ L x SU(2)_R model.
1702.00016
Francesco D'Eramo
Francesco D'Eramo, Bradley J. Kavanagh, Paolo Panci
Probing Leptophilic Dark Sectors with Hadronic Processes
11 pages, 4 figures, version published in Physics Letters B
Phys.Lett. B771 (2017) 339-348
10.1016/j.physletb.2017.05.063
SCIPP 17/01, CERN-TH-2017-016
hep-ph astro-ph.CO hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study vector portal dark matter models where the mediator couples only to leptons. In spite of the lack of tree-level couplings to colored states, radiative effects generate interactions with quark fields that could give rise to a signal in current and future experiments. We identify such experimental signatures: scattering of nuclei in dark matter direct detection; resonant production of lepton-antilepton pairs at the Large Hadron Collider; and hadronic final states in dark matter indirect searches. Furthermore, radiative effects also generate an irreducible mass mixing between the vector mediator and the $Z$ boson, severely bounded by ElectroWeak Precision Tests. We use current experimental results to put bounds on this class of models, accounting for both radiatively induced and tree-level processes. Remarkably, the former often overwhelm the latter.
[ { "created": "Tue, 31 Jan 2017 19:00:05 GMT", "version": "v1" }, { "created": "Thu, 8 Jun 2017 13:46:13 GMT", "version": "v2" } ]
2017-06-09
[ [ "D'Eramo", "Francesco", "" ], [ "Kavanagh", "Bradley J.", "" ], [ "Panci", "Paolo", "" ] ]
We study vector portal dark matter models where the mediator couples only to leptons. In spite of the lack of tree-level couplings to colored states, radiative effects generate interactions with quark fields that could give rise to a signal in current and future experiments. We identify such experimental signatures: scattering of nuclei in dark matter direct detection; resonant production of lepton-antilepton pairs at the Large Hadron Collider; and hadronic final states in dark matter indirect searches. Furthermore, radiative effects also generate an irreducible mass mixing between the vector mediator and the $Z$ boson, severely bounded by ElectroWeak Precision Tests. We use current experimental results to put bounds on this class of models, accounting for both radiatively induced and tree-level processes. Remarkably, the former often overwhelm the latter.
1608.05370
Natsumi Nagata
John Ellis, Jason L. Evans, Azar Mustafayev, Natsumi Nagata, and Keith A. Olive
The Super-GUT CMSSM Revisited
30 pages, 6 figures; version published in EPJC
Eur. Phys. J. C76, 592 (2016)
10.1140/epjc/s10052-016-4437-6
KCL-PH-TH/2016-52, CERN-PH-TH/2016-185, KIAS-P16059, UMN-TH-3601/16, FTPI-MINN-16/23
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We revisit minimal supersymmetric SU(5) grand unification (GUT) models in which the soft supersymmetry-breaking parameters of the minimal supersymmetric Standard Model (MSSM) are universal at some input scale, $M_{in}$, above the supersymmetric gauge coupling unification scale, $M_{GUT}$. As in the constrained MSSM (CMSSM), we assume that the scalar masses and gaugino masses have common values, $m_0$ and $m_{1/2}$ respectively, at $M_{in}$, as do the trilinear soft supersymmetry-breaking parameters $A_0$. Going beyond previous studies of such a super-GUT CMSSM scenario, we explore the constraints imposed by the lower limit on the proton lifetime and the LHC measurement of the Higgs mass, $m_h$. We find regions of $m_0$, $m_{1/2}$, $A_0$ and the parameters of the SU(5) superpotential that are compatible with these and other phenomenological constraints such as the density of cold dark matter, which we assume to be provided by the lightest neutralino. Typically, these allowed regions appear for $m_0$ and $m_{1/2}$ in the multi-TeV region, for suitable values of the unknown SU(5) GUT-scale phases and superpotential couplings, and with the ratio of supersymmetric Higgs vacuum expectation values $\tan \beta \lesssim 6$.
[ { "created": "Thu, 18 Aug 2016 18:43:45 GMT", "version": "v1" }, { "created": "Fri, 11 Nov 2016 14:43:38 GMT", "version": "v2" } ]
2016-11-14
[ [ "Ellis", "John", "" ], [ "Evans", "Jason L.", "" ], [ "Mustafayev", "Azar", "" ], [ "Nagata", "Natsumi", "" ], [ "Olive", "Keith A.", "" ] ]
We revisit minimal supersymmetric SU(5) grand unification (GUT) models in which the soft supersymmetry-breaking parameters of the minimal supersymmetric Standard Model (MSSM) are universal at some input scale, $M_{in}$, above the supersymmetric gauge coupling unification scale, $M_{GUT}$. As in the constrained MSSM (CMSSM), we assume that the scalar masses and gaugino masses have common values, $m_0$ and $m_{1/2}$ respectively, at $M_{in}$, as do the trilinear soft supersymmetry-breaking parameters $A_0$. Going beyond previous studies of such a super-GUT CMSSM scenario, we explore the constraints imposed by the lower limit on the proton lifetime and the LHC measurement of the Higgs mass, $m_h$. We find regions of $m_0$, $m_{1/2}$, $A_0$ and the parameters of the SU(5) superpotential that are compatible with these and other phenomenological constraints such as the density of cold dark matter, which we assume to be provided by the lightest neutralino. Typically, these allowed regions appear for $m_0$ and $m_{1/2}$ in the multi-TeV region, for suitable values of the unknown SU(5) GUT-scale phases and superpotential couplings, and with the ratio of supersymmetric Higgs vacuum expectation values $\tan \beta \lesssim 6$.
2012.12847
Sven Fabian
Sven Fabian, Florian Goertz and Yun Jiang
Dark Matter and Nature of Electroweak Phase Transition with an Inert Doublet
18 pages, 7 figures, 2 tables; v2: Matches version published in JCAP
null
10.1088/1475-7516/2021/09/011
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We provide a comprehensive and up-to-date analysis of the prospects to realize Dark Matter (DM) in the Inert Doublet Model, while simultaneously enhancing the Electroweak Phase Transition (EWPhT) such as to allow for electroweak baryogenesis. Instead of focusing on certain aspects or mass hierarchies, we perform extensive, yet fine-grained, parameter space scans, where we analyze the nature of the EWPhT in both the light and the heavy DM regions, confronting it with the amount of DM potentially residing in the lightest inert-doublet state. Thereby, we point out a viable region where a non-trivial two-step EWPhT can appear, without being in conflict with direct-detection bounds, which could leave interesting imprints in gravitational wave signatures. We propose new benchmarks with this feature as well as update benchmarks with a strong first-order transition in the light of new XENON1T limits. Moreover, taking into account these latest bounds as well as relevant collider constraints, we envisage a new region for light DM with a small mass splitting, lifting the usual assumption of exact degeneracy of the new non-DM scalars, such as to avoid collider bounds while providing a fair DM abundance over a rather large DM mass range. This follows from a detailed survey of the impact of co-annihilations on the abundance, dissecting the various channels.
[ { "created": "Wed, 23 Dec 2020 18:14:44 GMT", "version": "v1" }, { "created": "Tue, 19 Oct 2021 14:56:36 GMT", "version": "v2" } ]
2021-10-20
[ [ "Fabian", "Sven", "" ], [ "Goertz", "Florian", "" ], [ "Jiang", "Yun", "" ] ]
We provide a comprehensive and up-to-date analysis of the prospects to realize Dark Matter (DM) in the Inert Doublet Model, while simultaneously enhancing the Electroweak Phase Transition (EWPhT) such as to allow for electroweak baryogenesis. Instead of focusing on certain aspects or mass hierarchies, we perform extensive, yet fine-grained, parameter space scans, where we analyze the nature of the EWPhT in both the light and the heavy DM regions, confronting it with the amount of DM potentially residing in the lightest inert-doublet state. Thereby, we point out a viable region where a non-trivial two-step EWPhT can appear, without being in conflict with direct-detection bounds, which could leave interesting imprints in gravitational wave signatures. We propose new benchmarks with this feature as well as update benchmarks with a strong first-order transition in the light of new XENON1T limits. Moreover, taking into account these latest bounds as well as relevant collider constraints, we envisage a new region for light DM with a small mass splitting, lifting the usual assumption of exact degeneracy of the new non-DM scalars, such as to avoid collider bounds while providing a fair DM abundance over a rather large DM mass range. This follows from a detailed survey of the impact of co-annihilations on the abundance, dissecting the various channels.
1703.05977
Alexander Huss
James Currie, Thomas Gehrmann, Alexander Huss, Jan Niehues
NNLO QCD corrections to jet production in deep inelastic scattering
86 pages, 16 figures, 7 tables. v2: fix of an implementational error; figures and discussion changed accordingly
null
10.1007/JHEP07(2017)018
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Hadronic jets in deeply inelastic electron-proton collisions are produced by the scattering of a parton from the proton with the virtual gauge boson mediating the interaction. The HERA experiments have performed precision measurements of inclusive single jet production and di-jet production in the Breit frame, which provide important constraints on the strong coupling constant and on parton distributions in the proton. We describe the calculation of the next-to-next-to-leading order (NNLO) QCD corrections to these processes, and assess their size and impact. A detailed comparison with data from the H1 and ZEUS experiments highlights that inclusive single jet production displays a better perturbative convergence than di-jet production. We also observe that the event selection cuts in some of the di-jet measurements of both H1 and ZEUS induce an infrared sensitivity that destabilises the perturbative stability of the predictions. Our results open up new opportunities for QCD precision studies with jet production observables in deep inelastic scattering.
[ { "created": "Fri, 17 Mar 2017 11:51:26 GMT", "version": "v1" }, { "created": "Mon, 2 Nov 2020 10:41:52 GMT", "version": "v2" } ]
2020-11-03
[ [ "Currie", "James", "" ], [ "Gehrmann", "Thomas", "" ], [ "Huss", "Alexander", "" ], [ "Niehues", "Jan", "" ] ]
Hadronic jets in deeply inelastic electron-proton collisions are produced by the scattering of a parton from the proton with the virtual gauge boson mediating the interaction. The HERA experiments have performed precision measurements of inclusive single jet production and di-jet production in the Breit frame, which provide important constraints on the strong coupling constant and on parton distributions in the proton. We describe the calculation of the next-to-next-to-leading order (NNLO) QCD corrections to these processes, and assess their size and impact. A detailed comparison with data from the H1 and ZEUS experiments highlights that inclusive single jet production displays a better perturbative convergence than di-jet production. We also observe that the event selection cuts in some of the di-jet measurements of both H1 and ZEUS induce an infrared sensitivity that destabilises the perturbative stability of the predictions. Our results open up new opportunities for QCD precision studies with jet production observables in deep inelastic scattering.
hep-ph/9403246
"V. A." Khoze
V.S. Fadin, V.A. Khoze and M.I. Kotsky
Top quark polarization as a probe of $t\bar{t}$ threshold dynamics
21 pages. Figures available upon request
Z.Phys. C64 (1994) 45-56
10.1007/BF01557234
null
hep-ph
null
We study the spin properties of top quarks produced in collisions of polarized photons in the threshold region. For a relatively heavy top quark the influence of non-perturbative effects is small and its polarization parameters can be predicted in perturbative QCD. The measurements of the top polarization may allow a novel test of QCD in the $t\bar{t}$ system. In particular, they may provide a new way to determine the precise value of $\alpha_s$ and to study the properties of the top quark.
[ { "created": "Tue, 8 Mar 1994 21:10:12 GMT", "version": "v1" } ]
2009-10-28
[ [ "Fadin", "V. S.", "" ], [ "Khoze", "V. A.", "" ], [ "Kotsky", "M. I.", "" ] ]
We study the spin properties of top quarks produced in collisions of polarized photons in the threshold region. For a relatively heavy top quark the influence of non-perturbative effects is small and its polarization parameters can be predicted in perturbative QCD. The measurements of the top polarization may allow a novel test of QCD in the $t\bar{t}$ system. In particular, they may provide a new way to determine the precise value of $\alpha_s$ and to study the properties of the top quark.
2101.12574
Ji Xu
De-Min Li, Xi-Ruo Zhang, Ye Xing, Ji Xu
Weak decays of doubly heavy baryons: four-body nonleptonic decay channels
15 pages, 3 figures and 3 tables
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The LHCb Collaboration announced the observation of doubly charmed baryon through $\Xi_{c c}^{++} \rightarrow \Lambda_{c}^{+} K^{-} \pi^{+} \pi^{+}$ in 2017. Since then, a series of studies of doubly heavy baryons have been presented. $\Xi_{cc}^{++}$ was discovered through nonleptonic four-body decay mode, and experimental data has indicated that the decay modes of $\Xi_{c c}^{++}$ are not saturated by two and three-body intermediate states. In this work, we analyze the four-body weak decays of doubly heavy baryons $\Xi_{cc}^{++}, \Xi_{cc}^+$, and $\Omega_{cc}^+$. Decay amplitudes for various channels are parametrized in terms of SU(3) irreducible amplitudes. We point out that branching fractions for Cabibbo-allowed processes $\Xi_{cc}^{+}\to\Lambda_c^+\pi^+ \pi^0 K^-$, $\Omega_{cc}^{+}\to\Lambda_c^+\pi^+ \overline K^0 K^-$ would be helpful to search for $\Xi_{cc}^+$ and $\Omega_{cc}^+$ in future measurements at experimental facilities like LHC, Belle II, and CEPC.
[ { "created": "Fri, 29 Jan 2021 13:43:18 GMT", "version": "v1" } ]
2021-02-01
[ [ "Li", "De-Min", "" ], [ "Zhang", "Xi-Ruo", "" ], [ "Xing", "Ye", "" ], [ "Xu", "Ji", "" ] ]
The LHCb Collaboration announced the observation of doubly charmed baryon through $\Xi_{c c}^{++} \rightarrow \Lambda_{c}^{+} K^{-} \pi^{+} \pi^{+}$ in 2017. Since then, a series of studies of doubly heavy baryons have been presented. $\Xi_{cc}^{++}$ was discovered through nonleptonic four-body decay mode, and experimental data has indicated that the decay modes of $\Xi_{c c}^{++}$ are not saturated by two and three-body intermediate states. In this work, we analyze the four-body weak decays of doubly heavy baryons $\Xi_{cc}^{++}, \Xi_{cc}^+$, and $\Omega_{cc}^+$. Decay amplitudes for various channels are parametrized in terms of SU(3) irreducible amplitudes. We point out that branching fractions for Cabibbo-allowed processes $\Xi_{cc}^{+}\to\Lambda_c^+\pi^+ \pi^0 K^-$, $\Omega_{cc}^{+}\to\Lambda_c^+\pi^+ \overline K^0 K^-$ would be helpful to search for $\Xi_{cc}^+$ and $\Omega_{cc}^+$ in future measurements at experimental facilities like LHC, Belle II, and CEPC.
2205.01118
Andrzej Buras
Andrzej J. Buras
On the Standard Model Predictions for Rare K and B Decay Branching Ratios: 2022
Some polemic statements removed and new arguments for the strategy given, new references added, results in (16) updated and few misprints removed. Conclusions unchanged
null
null
null
hep-ph hep-ex hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this decade one expects a very significant progress in measuring the branching ratios for several rare $K$ and $B$ decays, in particular for the decays $K^+\to\pi^+\nu\bar\nu$, $K_L\to\pi^0\nu\bar\nu$, $B_s\to\mu^+\mu^+$ and $B_d\to\mu^+\mu^+$. On the theory side a very significant progress on calculating these branching ratios has been achieved in the last thirty years culminating recently in rather precise SM predictions for them. It is then unfortunate that some papers still cite the results for $K^+\to\pi^+\nu\bar\nu$ and $K_L\to\pi^0\nu\bar\nu$ presented by us in 2015. They are clearly out of date. Similar comments apply to predictions for $B_{s,d}\to\mu^+\mu^-$. In this note I want to stress again that, in view of the tensions between various determinations of $V_{cb}$ in tree-level decays, presently, the only trustable SM predictions for the branching ratios in question can be obtained by eliminating their dependence on the CKM parameters with the help of $|\varepsilon_K|$, $\Delta M_s$, $\Delta M_d$ and $S_{\psi K_S}$, evaluated in the SM. In this context I am astonished by statements made by some computer code practitioners that setting in this strategy these four $\Delta F=2$ observables to their experimental values is an assumption. The goal of this strategy is not to make an overall SM fit but to predict the SM branching ratios. In the SM there are no new physics (NP) contributions to $\Delta F=2$ transitions and no assumption on the absence of NP is needed. Moreover, presently NP is not required to describe simultaneously the very precise data on $|\varepsilon_K|$, $\Delta M_s$, $\Delta M_d$ and $S_{\psi K_S}$. This strategy for obtaining true SM predictions for rare decay branching ratios is moreover not polluted by hadronic uncertainies and observed anomalies in semi-leptonic decays used often in global analyses as stressed recently in (arxiv: 2209.03968).
[ { "created": "Mon, 2 May 2022 18:00:02 GMT", "version": "v1" }, { "created": "Mon, 19 Sep 2022 12:12:00 GMT", "version": "v2" } ]
2022-09-20
[ [ "Buras", "Andrzej J.", "" ] ]
In this decade one expects a very significant progress in measuring the branching ratios for several rare $K$ and $B$ decays, in particular for the decays $K^+\to\pi^+\nu\bar\nu$, $K_L\to\pi^0\nu\bar\nu$, $B_s\to\mu^+\mu^+$ and $B_d\to\mu^+\mu^+$. On the theory side a very significant progress on calculating these branching ratios has been achieved in the last thirty years culminating recently in rather precise SM predictions for them. It is then unfortunate that some papers still cite the results for $K^+\to\pi^+\nu\bar\nu$ and $K_L\to\pi^0\nu\bar\nu$ presented by us in 2015. They are clearly out of date. Similar comments apply to predictions for $B_{s,d}\to\mu^+\mu^-$. In this note I want to stress again that, in view of the tensions between various determinations of $V_{cb}$ in tree-level decays, presently, the only trustable SM predictions for the branching ratios in question can be obtained by eliminating their dependence on the CKM parameters with the help of $|\varepsilon_K|$, $\Delta M_s$, $\Delta M_d$ and $S_{\psi K_S}$, evaluated in the SM. In this context I am astonished by statements made by some computer code practitioners that setting in this strategy these four $\Delta F=2$ observables to their experimental values is an assumption. The goal of this strategy is not to make an overall SM fit but to predict the SM branching ratios. In the SM there are no new physics (NP) contributions to $\Delta F=2$ transitions and no assumption on the absence of NP is needed. Moreover, presently NP is not required to describe simultaneously the very precise data on $|\varepsilon_K|$, $\Delta M_s$, $\Delta M_d$ and $S_{\psi K_S}$. This strategy for obtaining true SM predictions for rare decay branching ratios is moreover not polluted by hadronic uncertainies and observed anomalies in semi-leptonic decays used often in global analyses as stressed recently in (arxiv: 2209.03968).
hep-ph/9606440
Hyun-Chul Kim
Hyun-Chul Kim, Teruaki Watabe, and Klaus Goeke
Strange vector form factors of the nucleon in the SU(3) chiral quark-soliton model with the proper kaonic cloud
27 pages with 8 figures. RevTeX and epsfig.sty are used. Submitted to Nucl. Phys. A
Nucl.Phys. A616 (1997) 606-624
10.1016/S0375-9474(96)00486-1
RUB-TPII-11/95
hep-ph
null
The strange vector form factors are evaluated in the range between $Q^2=0$ and $Q^2=1\ \mbox{GeV}^2$ in the framework of the SU(3) chiral quark-soliton model (or semi-bosonized SU(3) Nambu-Jona-Lasinio model). The rotational $1/N_c$ and $m_s$ corrections are taken into account up to linear order. Taking care of a proper Yukawa-tail of the kaonic cloud, we get $\langle r^{2}\rangle^{\rm Sachs}_{s}=-0.095\; \mbox{fm}^2$ and $\mu_s = -0.68\;\mu_N$. The results are compared with several different models.
[ { "created": "Wed, 26 Jun 1996 12:41:38 GMT", "version": "v1" } ]
2009-10-28
[ [ "Kim", "Hyun-Chul", "" ], [ "Watabe", "Teruaki", "" ], [ "Goeke", "Klaus", "" ] ]
The strange vector form factors are evaluated in the range between $Q^2=0$ and $Q^2=1\ \mbox{GeV}^2$ in the framework of the SU(3) chiral quark-soliton model (or semi-bosonized SU(3) Nambu-Jona-Lasinio model). The rotational $1/N_c$ and $m_s$ corrections are taken into account up to linear order. Taking care of a proper Yukawa-tail of the kaonic cloud, we get $\langle r^{2}\rangle^{\rm Sachs}_{s}=-0.095\; \mbox{fm}^2$ and $\mu_s = -0.68\;\mu_N$. The results are compared with several different models.
2401.14904
Xiaopeng Wang
Jingxuan Chen, Xiaopeng Wang, Yanbing Cai, Xurong Chen and Qian Wang
An analysis of the gluon distribution with next-to-leading order splitting function in small-$x$
14 pages, 3 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
An approximated solution for gluon distribution from DGLAP evolution equations with NLO splitting function in the small-$x$ limit is presented. We first obtain the simplified forms of LO and NLO splitting functions in the small-$x$ limit. With these approximated splitting functions, we obtain the analytical gluon distribution by using the Mellin transform. The free parameters in the boundary conditions are obtained by fitting the CJ15 gluon distribution data. We find that the asymptotic behavior of gluon distribution are consistent with the CJ15 data, however, the NLO results with the consideration of ``ladder'' structure of gluon emission are slightly better than those from LO. These results indicate that the corrections from NLO is significant and is necessary for a better description of the behavior of the gluon distribution in small-$x$ region. In addition, we investigate the DGLAP evolution of the proton structure function by using the analytical solution of the gluon distribution. The differential structure function shows that our results have a similar tendency with CJ15 at small-$x$.
[ { "created": "Fri, 26 Jan 2024 14:35:56 GMT", "version": "v1" } ]
2024-01-29
[ [ "Chen", "Jingxuan", "" ], [ "Wang", "Xiaopeng", "" ], [ "Cai", "Yanbing", "" ], [ "Chen", "Xurong", "" ], [ "Wang", "Qian", "" ] ]
An approximated solution for gluon distribution from DGLAP evolution equations with NLO splitting function in the small-$x$ limit is presented. We first obtain the simplified forms of LO and NLO splitting functions in the small-$x$ limit. With these approximated splitting functions, we obtain the analytical gluon distribution by using the Mellin transform. The free parameters in the boundary conditions are obtained by fitting the CJ15 gluon distribution data. We find that the asymptotic behavior of gluon distribution are consistent with the CJ15 data, however, the NLO results with the consideration of ``ladder'' structure of gluon emission are slightly better than those from LO. These results indicate that the corrections from NLO is significant and is necessary for a better description of the behavior of the gluon distribution in small-$x$ region. In addition, we investigate the DGLAP evolution of the proton structure function by using the analytical solution of the gluon distribution. The differential structure function shows that our results have a similar tendency with CJ15 at small-$x$.
0711.2728
Peihong Gu
Jitesh R. Bhatt, Pei-Hong Gu, Utpal Sarkar, Santosh K. Singh
Left-Right Symmetric Model of Neutrino Dark Energy
4 pages. Revised version. Accepted by PLB
Phys.Lett.B663:83-85,2008
10.1016/j.physletb.2008.03.059
null
hep-ph
null
We implemented the neutrino dark energy proposal in a left-right symmetric model. Unlike earlier models of mass varying neutrinos, in the present model the mass parameter that depends on the scalar field (acceleron) remains very light naturally. The required neutrino masses then predicts the U(1)_R breaking scale to be in the TeV range, providing new signals for LHC. Compared to all other neutrino dark energy proposals, this model has the added advantage that it can also be embedded into a grand unified theory. In this scenario leptogenesis occurs through decays of scalars at very high energy.
[ { "created": "Sun, 18 Nov 2007 09:16:04 GMT", "version": "v1" }, { "created": "Wed, 2 Apr 2008 10:35:47 GMT", "version": "v2" } ]
2008-11-26
[ [ "Bhatt", "Jitesh R.", "" ], [ "Gu", "Pei-Hong", "" ], [ "Sarkar", "Utpal", "" ], [ "Singh", "Santosh K.", "" ] ]
We implemented the neutrino dark energy proposal in a left-right symmetric model. Unlike earlier models of mass varying neutrinos, in the present model the mass parameter that depends on the scalar field (acceleron) remains very light naturally. The required neutrino masses then predicts the U(1)_R breaking scale to be in the TeV range, providing new signals for LHC. Compared to all other neutrino dark energy proposals, this model has the added advantage that it can also be embedded into a grand unified theory. In this scenario leptogenesis occurs through decays of scalars at very high energy.
hep-ph/0608015
Valery Lyubovitskij
Amand Faessler, Thomas Gutsche, Barry R. Holstein, Valery E. Lyubovitskij, Diana Nicmorus, Kem Pumsa-ard
Light baryon magnetic moments and N -> Delta gamma transition in a Lorentz covariant chiral quark approach
29 pages, 10 figures, accepted for publication in Phys. Rev. D
Phys.Rev. D74 (2006) 074010
10.1103/PhysRevD.74.074010
null
hep-ph
null
We calculate magnetic moments of light baryons and N -> Delta gamma transition characteristics using a manifestly Lorentz covariant chiral quark approach for the study of baryons as bound states of constituent quarks dressed by a cloud of pseudoscalar mesons.
[ { "created": "Wed, 2 Aug 2006 07:05:49 GMT", "version": "v1" }, { "created": "Thu, 21 Sep 2006 15:46:07 GMT", "version": "v2" } ]
2007-05-23
[ [ "Faessler", "Amand", "" ], [ "Gutsche", "Thomas", "" ], [ "Holstein", "Barry R.", "" ], [ "Lyubovitskij", "Valery E.", "" ], [ "Nicmorus", "Diana", "" ], [ "Pumsa-ard", "Kem", "" ] ]
We calculate magnetic moments of light baryons and N -> Delta gamma transition characteristics using a manifestly Lorentz covariant chiral quark approach for the study of baryons as bound states of constituent quarks dressed by a cloud of pseudoscalar mesons.
hep-ph/0201265
Sergio Scopetta
Sergio Scopetta (Perugia) and Vicente Vento (Valencia)
Generalized parton distributions in constituent quark models
19 pages, 8 figures, discussion of the Isgur and Karl model added, NLO QCD evolution evaluated, references and figures added
Eur.Phys.J. A16 (2003) 527-535
null
FTUV-02-0108; IFIC-02-10
hep-ph nucl-th
null
An approach is proposed to calculate Generalized Parton Distributions (GPDs) in a Constituent Quark Model (CQM) scenario. These off-diagonal distributions are obtained from momentum space wave functions to be evaluated in a given non relativistic or relativized CQM. The general relations linking the twist-two GPDs to the form factors and to the leading twist quark densities are consistently recovered from our expressions. Results for the leading twist, unpolarized GPD, H, in a simple harmonic oscillator model, as well as in the Isgur and Karl model, are shown to have the general behavior found in previous estimates. NLO evolution of the obtained distributions, from the low momentum scale of the model up to the experimental one, is also shown. Further natural applications of the proposed formalism are addressed.
[ { "created": "Tue, 29 Jan 2002 11:57:27 GMT", "version": "v1" }, { "created": "Tue, 1 Oct 2002 13:54:16 GMT", "version": "v2" } ]
2007-05-23
[ [ "Scopetta", "Sergio", "", "Perugia" ], [ "Vento", "Vicente", "", "Valencia" ] ]
An approach is proposed to calculate Generalized Parton Distributions (GPDs) in a Constituent Quark Model (CQM) scenario. These off-diagonal distributions are obtained from momentum space wave functions to be evaluated in a given non relativistic or relativized CQM. The general relations linking the twist-two GPDs to the form factors and to the leading twist quark densities are consistently recovered from our expressions. Results for the leading twist, unpolarized GPD, H, in a simple harmonic oscillator model, as well as in the Isgur and Karl model, are shown to have the general behavior found in previous estimates. NLO evolution of the obtained distributions, from the low momentum scale of the model up to the experimental one, is also shown. Further natural applications of the proposed formalism are addressed.
1406.2081
Xiaojia Li
Lipei Du, Xiaojia Li and Da-Xin Zhang
Connection between proton decay suppression and seesaw mechanism in supersymmetric SO(10) models
11 pages, no figure. Several minor corrections
JHEP10(2014)036
10.1007/JHEP10(2014)036
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a mechanism to suppress proton decay induced by dimension-5 operators in a supersymmetric SO(10) model. Proton lifetime is directly connected with the intermediate vacuum expectation value which is responsible for the seesaw mechanism. The model shows many consistencies with the present theoretical results such as the components of the two Higgs doublets in the minimal supersymmetric standard model.
[ { "created": "Mon, 9 Jun 2014 05:45:30 GMT", "version": "v1" }, { "created": "Thu, 11 Sep 2014 12:36:26 GMT", "version": "v2" } ]
2014-10-14
[ [ "Du", "Lipei", "" ], [ "Li", "Xiaojia", "" ], [ "Zhang", "Da-Xin", "" ] ]
We propose a mechanism to suppress proton decay induced by dimension-5 operators in a supersymmetric SO(10) model. Proton lifetime is directly connected with the intermediate vacuum expectation value which is responsible for the seesaw mechanism. The model shows many consistencies with the present theoretical results such as the components of the two Higgs doublets in the minimal supersymmetric standard model.
hep-ph/0302070
Dmitri Kuzmenko
Yu.S.Kalashnikova and D.S.Kuzmenko (ITEP, Moscow)
Adiabatic potentials and spectra of heavy hybrid mesons
7 pages, 2 figures, talk at the NPD-2002 Conference, December 2-6, ITEP, Moscow, one reference added
Phys.Atom.Nucl. 67 (2004) 538-542; Yad.Fiz. 67 (2004) 556-560
10.1134/1.1690061
null
hep-ph hep-lat
null
Using the QCD string approach the adiabatic potentials and spectra of b\bar b-hybrid mesons are calculated. The results are compared to lattice studies.
[ { "created": "Mon, 10 Feb 2003 22:21:54 GMT", "version": "v1" }, { "created": "Mon, 31 Mar 2003 11:20:10 GMT", "version": "v2" } ]
2009-11-10
[ [ "Kalashnikova", "Yu. S.", "", "ITEP, Moscow" ], [ "Kuzmenko", "D. S.", "", "ITEP, Moscow" ] ]
Using the QCD string approach the adiabatic potentials and spectra of b\bar b-hybrid mesons are calculated. The results are compared to lattice studies.
hep-ph/0608200
Jungil Lee
Geoffrey T. Bodwin (Argonne), Eric Braaten (Ohio State U.), Jungil Lee, Chaehyun Yu (Korea U.)
Exclusive Two-Vector-Meson Production from e^+ e^- Annihilation
22 pages. 3 figures, 5 tables, Minor corrections. Version published in Phys. Rev. D
Phys.Rev.D74:074014,2006
10.1103/PhysRevD.74.074014
ANL-HEP-PR-06-57
hep-ph
null
The exclusive production of pairs of vector mesons with J^{PC} = 1^{--} in e^+ e^- collisions can proceed through e^+ e^- annihilation into two virtual photons. At energies much greater than the meson masses, the cross section is dominated by the independent fragmentation of the virtual photons into the vector mesons. The fragmentation approximation is used to calculate the cross sections and angular distributions for pairs of vector mesons that can be produced at the B factories. The predicted cross sections for rho^0 + rho^0 and rho^0 + phi production agree with recent measurements by the BaBar Collaboration. For the production of two charmonium vector mesons, the nonfragmentation corrections to the cross sections are calculated by using the NRQCD factorization formalism. The predicted cross sections for J/psi + J/psi and J/psi + psi(2S) production are compatible with upper limits set by the Belle Collaboration.
[ { "created": "Fri, 18 Aug 2006 07:39:31 GMT", "version": "v1" }, { "created": "Wed, 25 Oct 2006 09:27:27 GMT", "version": "v2" } ]
2008-11-26
[ [ "Bodwin", "Geoffrey T.", "", "Argonne" ], [ "Braaten", "Eric", "", "Ohio State U." ], [ "Lee", "Jungil", "", "Korea U." ], [ "Yu", "Chaehyun", "", "Korea U." ] ]
The exclusive production of pairs of vector mesons with J^{PC} = 1^{--} in e^+ e^- collisions can proceed through e^+ e^- annihilation into two virtual photons. At energies much greater than the meson masses, the cross section is dominated by the independent fragmentation of the virtual photons into the vector mesons. The fragmentation approximation is used to calculate the cross sections and angular distributions for pairs of vector mesons that can be produced at the B factories. The predicted cross sections for rho^0 + rho^0 and rho^0 + phi production agree with recent measurements by the BaBar Collaboration. For the production of two charmonium vector mesons, the nonfragmentation corrections to the cross sections are calculated by using the NRQCD factorization formalism. The predicted cross sections for J/psi + J/psi and J/psi + psi(2S) production are compatible with upper limits set by the Belle Collaboration.
hep-ph/9503235
'Peter Lipa'
Martin Greiner, Jens Giesemann, Peter Lipa and Peter Carruthers
Wavelet correlations in hierarchical branching processes
31 pages, latex, 10 figures (available from authors).
Z.Phys. C69 (1996) 305-322
null
HEPHY-PUB 618/95, AZPH-TH/95-03
hep-ph
null
A study of correlations in tractable multiparticle cascade models in terms of wavelets reveals many promising features. The selfsimilar construction of the wavelet basis functions and their multiscale localization properties provide a new approach to the statistical analysis and analytical control of hierarchically organized branching processes. The exact analytical solution of several discrete models shows that the wavelet transformation supresses redundancy in the correlation information. Wavelet correlations can be naturally interpreted as correlations between structures (clumps) living on different scales.
[ { "created": "Sat, 4 Mar 1995 22:15:22 GMT", "version": "v1" } ]
2016-09-01
[ [ "Greiner", "Martin", "" ], [ "Giesemann", "Jens", "" ], [ "Lipa", "Peter", "" ], [ "Carruthers", "Peter", "" ] ]
A study of correlations in tractable multiparticle cascade models in terms of wavelets reveals many promising features. The selfsimilar construction of the wavelet basis functions and their multiscale localization properties provide a new approach to the statistical analysis and analytical control of hierarchically organized branching processes. The exact analytical solution of several discrete models shows that the wavelet transformation supresses redundancy in the correlation information. Wavelet correlations can be naturally interpreted as correlations between structures (clumps) living on different scales.
1006.1885
Mihailo Backovic
Mihailo Backovic and John P. Ralston
Relic Abundance Predicts Universal Mass-Width Relations for Dark Matter Interactions
9 pages, 11 figures
null
null
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We find new and universal relations for the properties of dark matter particles consistent with standard relic abundances. Analysis is based on first characterizing the $s$-channel resonant annihilation process in great detail, keeping track of all velocity-dependence, the presence of multiple scales and treating each physical regime above, below, and close to thresholds separately. The resonant regime as well as extension to include non-resonant processes are then reduced to analytic formulas and inequalities that describe the full range of multi-dimensional numerical work. These results eliminate the need to recompute relic abundance model by model, and reduce calculations to verifying certain scale and parameter combinations are consistent. Remarkably simple formulas describe the relation between the total width of an $s$-channel intermediate particle, the masses and the couplings involved. Eliminating the width in terms of the mass produces new consistency relations between dark matter masses and the intermediate masses. The formulas are general enough to test directly whether new particles can be identified as dark matter. Resonance mass and total width are quantities directly observable at accelerators such as the LHC, and will be sufficient to establish whether new discoveries are consistent with the cosmological bounds on dark matter.
[ { "created": "Wed, 9 Jun 2010 19:32:41 GMT", "version": "v1" } ]
2010-06-10
[ [ "Backovic", "Mihailo", "" ], [ "Ralston", "John P.", "" ] ]
We find new and universal relations for the properties of dark matter particles consistent with standard relic abundances. Analysis is based on first characterizing the $s$-channel resonant annihilation process in great detail, keeping track of all velocity-dependence, the presence of multiple scales and treating each physical regime above, below, and close to thresholds separately. The resonant regime as well as extension to include non-resonant processes are then reduced to analytic formulas and inequalities that describe the full range of multi-dimensional numerical work. These results eliminate the need to recompute relic abundance model by model, and reduce calculations to verifying certain scale and parameter combinations are consistent. Remarkably simple formulas describe the relation between the total width of an $s$-channel intermediate particle, the masses and the couplings involved. Eliminating the width in terms of the mass produces new consistency relations between dark matter masses and the intermediate masses. The formulas are general enough to test directly whether new particles can be identified as dark matter. Resonance mass and total width are quantities directly observable at accelerators such as the LHC, and will be sufficient to establish whether new discoveries are consistent with the cosmological bounds on dark matter.
hep-ph/0205066
Nobuchika Okada
Takeshi Fukuyama and Nobuchika Okada
Neutrino oscillation data versus minimal supersymmetric SO(10) model
18 pages, 3 figures. Some numerical errors in the version published in JHEP have been corrected: the mass eigenvalue M_{R_i}, and <m_nu>_ee and epsilon in Table 3
JHEP 0211:011,2002
10.1088/1126-6708/2002/11/011
UMD-PP-02-048
hep-ph
null
We reconsider the minimal supersymmetric SO(10) model, where only one {\bf 10} and one $\bar{\bf 126}$ Higgs multiplets have Yukawa couplings with matter multiplets. The model is generalized to include CP-violating phases, and examined how well its predictions can meet the current neutrino oscillation data. Using the electroweak scale data about six quark masses, three angles and one CP-phase in the Cabibbo-Kobayashi-Maskawa matrix and three charged-lepton masses and given $\tan \beta$ (the ratio of vacuum expectation values of a pair of Higgs doublets), we obtain the Pontecorvo-Maki-Nakagawa-Sakata matrix and the ratio, $\Delta m_\odot^2/\Delta m_\oplus^2 $, as functions of only one free parameter in the model. In our analysis, one-loop renormalization group equations for the gauge couplings, the Yukawa couplings and the effective dimension-five operator are used to connect the data between the electroweak scale and the grand unification scale. Fixing the free parameter appropriately, we find, for example, $\sin^2 2 \theta_{12} \sim 0.72$, $\sin^2 2 \theta_{23} \sim 0.90$, $\sin^2 2 \theta_{13} \sim 0.16$ and $\Delta m_\odot^2/\Delta m_\oplus^2 \sim 0.19$ with $\tan \beta = 45$, which are in agreement with the current neutrino oscillation data.
[ { "created": "Tue, 7 May 2002 20:31:23 GMT", "version": "v1" }, { "created": "Fri, 18 Apr 2003 02:19:09 GMT", "version": "v2" } ]
2010-04-06
[ [ "Fukuyama", "Takeshi", "" ], [ "Okada", "Nobuchika", "" ] ]
We reconsider the minimal supersymmetric SO(10) model, where only one {\bf 10} and one $\bar{\bf 126}$ Higgs multiplets have Yukawa couplings with matter multiplets. The model is generalized to include CP-violating phases, and examined how well its predictions can meet the current neutrino oscillation data. Using the electroweak scale data about six quark masses, three angles and one CP-phase in the Cabibbo-Kobayashi-Maskawa matrix and three charged-lepton masses and given $\tan \beta$ (the ratio of vacuum expectation values of a pair of Higgs doublets), we obtain the Pontecorvo-Maki-Nakagawa-Sakata matrix and the ratio, $\Delta m_\odot^2/\Delta m_\oplus^2 $, as functions of only one free parameter in the model. In our analysis, one-loop renormalization group equations for the gauge couplings, the Yukawa couplings and the effective dimension-five operator are used to connect the data between the electroweak scale and the grand unification scale. Fixing the free parameter appropriately, we find, for example, $\sin^2 2 \theta_{12} \sim 0.72$, $\sin^2 2 \theta_{23} \sim 0.90$, $\sin^2 2 \theta_{13} \sim 0.16$ and $\Delta m_\odot^2/\Delta m_\oplus^2 \sim 0.19$ with $\tan \beta = 45$, which are in agreement with the current neutrino oscillation data.
hep-ph/0105090
Yi Liao
Harald Grosse (ITP, Wien) and Yi Liao (ITP, Leipzig)
Pair Production of Neutral Higgs Bosons through Noncommutative QED Interactions at Linear Colliders
12 pages, 3 figures using axodraw.sty; v2: proof version in Phys. Rev. D, minor rewording
Phys.Rev.D64:115007,2001
10.1103/PhysRevD.64.115007
LU-ITP 2001/019
hep-ph hep-th
null
We study the feasibility of detecting noncommutative (NC) QED through neutral Higgs boson (H) pair production at linear colliders (LC). This is based on the assumption that H interacts directly with photon in NCQED as suggested by symmetry considerations and strongly hinted by our previous study on \pi^0-photon interactions. We find the following striking features as compared to the standard model (SM) result: (1) generally larger cross sections for an NC scale of order 1 TeV; (2) completely different dependence on initial beam polarizations; (3) distinct distributions in the polar and azimuthal angles; and (4) day-night asymmetry due to the Earth's rotation. These will help to separate NC signals from those in the SM or other new physics at LC. We emphasize the importance of treating properly the Lorentz noninvariance problem and show how the impact of the Earth's rotation can be used as an advantage for our purpose of searching for NC signals.
[ { "created": "Thu, 10 May 2001 12:15:52 GMT", "version": "v1" }, { "created": "Fri, 12 Oct 2001 16:16:47 GMT", "version": "v2" } ]
2014-11-17
[ [ "Grosse", "Harald", "", "ITP, Wien" ], [ "Liao", "Yi", "", "ITP, Leipzig" ] ]
We study the feasibility of detecting noncommutative (NC) QED through neutral Higgs boson (H) pair production at linear colliders (LC). This is based on the assumption that H interacts directly with photon in NCQED as suggested by symmetry considerations and strongly hinted by our previous study on \pi^0-photon interactions. We find the following striking features as compared to the standard model (SM) result: (1) generally larger cross sections for an NC scale of order 1 TeV; (2) completely different dependence on initial beam polarizations; (3) distinct distributions in the polar and azimuthal angles; and (4) day-night asymmetry due to the Earth's rotation. These will help to separate NC signals from those in the SM or other new physics at LC. We emphasize the importance of treating properly the Lorentz noninvariance problem and show how the impact of the Earth's rotation can be used as an advantage for our purpose of searching for NC signals.
hep-ph/0506322
Mikhail Vysotsky
M.I.Vysotsky
B-> rho pi, rho rho, pi pi: hunting for alpha
16 pages. Recent Belle results on CP asymmetries in B_d(\bar{B}_d)-->rho^+ rho^- decays are taken into account. Version to be published in Yad.Fiz
Phys.Atom.Nucl. 69 (2006) 679-685
10.1134/S1063778806040119
null
hep-ph hep-ex
null
We determine the domains of the values of unitarity triangle angle alpha, allowed by the charmless strangeless B_d (\bar B_d) decays.
[ { "created": "Thu, 30 Jun 2005 13:51:20 GMT", "version": "v1" }, { "created": "Wed, 28 Sep 2005 08:51:56 GMT", "version": "v2" } ]
2009-11-11
[ [ "Vysotsky", "M. I.", "" ] ]
We determine the domains of the values of unitarity triangle angle alpha, allowed by the charmless strangeless B_d (\bar B_d) decays.
2403.05618
Joschka Birk
Joschka Birk, Anna Hallin, Gregor Kasieczka
OmniJet-$\alpha$: The first cross-task foundation model for particle physics
null
null
null
null
hep-ph cs.LG hep-ex physics.data-an
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Foundation models are multi-dataset and multi-task machine learning methods that once pre-trained can be fine-tuned for a large variety of downstream applications. The successful development of such general-purpose models for physics data would be a major breakthrough as they could improve the achievable physics performance while at the same time drastically reduce the required amount of training time and data. We report significant progress on this challenge on several fronts. First, a comprehensive set of evaluation methods is introduced to judge the quality of an encoding from physics data into a representation suitable for the autoregressive generation of particle jets with transformer architectures (the common backbone of foundation models). These measures motivate the choice of a higher-fidelity tokenization compared to previous works. Finally, we demonstrate transfer learning between an unsupervised problem (jet generation) and a classic supervised task (jet tagging) with our new OmniJet-$\alpha$ model. This is the first successful transfer between two different and actively studied classes of tasks and constitutes a major step in the building of foundation models for particle physics.
[ { "created": "Fri, 8 Mar 2024 19:00:01 GMT", "version": "v1" } ]
2024-03-12
[ [ "Birk", "Joschka", "" ], [ "Hallin", "Anna", "" ], [ "Kasieczka", "Gregor", "" ] ]
Foundation models are multi-dataset and multi-task machine learning methods that once pre-trained can be fine-tuned for a large variety of downstream applications. The successful development of such general-purpose models for physics data would be a major breakthrough as they could improve the achievable physics performance while at the same time drastically reduce the required amount of training time and data. We report significant progress on this challenge on several fronts. First, a comprehensive set of evaluation methods is introduced to judge the quality of an encoding from physics data into a representation suitable for the autoregressive generation of particle jets with transformer architectures (the common backbone of foundation models). These measures motivate the choice of a higher-fidelity tokenization compared to previous works. Finally, we demonstrate transfer learning between an unsupervised problem (jet generation) and a classic supervised task (jet tagging) with our new OmniJet-$\alpha$ model. This is the first successful transfer between two different and actively studied classes of tasks and constitutes a major step in the building of foundation models for particle physics.
hep-ph/0410249
Helmut Eberl Dr.
H. Eberl, M. Beccaria, F.M. Renard, C. Verzegnassi
Supersymmetry Tests from a Combined Analysis of Chargino, Neutralino, and Charged Higgs Boson Pair Production at a 1 TeV Linear Collider
5 pages, 3 figures, talk given by H. Eberl at the 12th International Conference on Supersymmetry and Unification of Fundamental Interactions (SUSY 2004), Tsukuba, Japan, June 17-23, 2004
null
null
HEPHY-PUB 795/04, PM-04/34
hep-ph
null
We consider the production of chargino, neutralino and charged Higgs boson pairs at future linear colliders for c. m. energies in the one TeV range within the MSSM. We compute the leading (double) and next-to leading (linear) supersymmetric logarithmic terms of the so-called "Sudakov expansion" at one-loop level. We show that a combined analysis of the slopes of the chargino, neutralino, and charged Higgs boson pair production cross sections would offer a simple possibility for determining \tan\beta for large (\gsim 10) values, and the parameters M_1, M_2, and \mu. This test could provide a strong consistency check of the considered supersymmetric model.
[ { "created": "Mon, 18 Oct 2004 12:22:08 GMT", "version": "v1" } ]
2007-05-23
[ [ "Eberl", "H.", "" ], [ "Beccaria", "M.", "" ], [ "Renard", "F. M.", "" ], [ "Verzegnassi", "C.", "" ] ]
We consider the production of chargino, neutralino and charged Higgs boson pairs at future linear colliders for c. m. energies in the one TeV range within the MSSM. We compute the leading (double) and next-to leading (linear) supersymmetric logarithmic terms of the so-called "Sudakov expansion" at one-loop level. We show that a combined analysis of the slopes of the chargino, neutralino, and charged Higgs boson pair production cross sections would offer a simple possibility for determining \tan\beta for large (\gsim 10) values, and the parameters M_1, M_2, and \mu. This test could provide a strong consistency check of the considered supersymmetric model.
1412.8386
Francesco Vissani
Francesco Vissani
Neutrino Sources and Properties
16 pages, 8 figures, 1 summary table
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this lecture, prepared for PhD students, basic considerations on neutrino interactions, properties and sites of production are overviewed. The detailed content is as follows: Sect. 1, Weak interactions and neutrinos: Fermi coupling; definition of neutrinos; global numbers. Sect. 2, A list of neutrino sources: Explanatory note and examples (solar pp- and supernova-neutrinos). Sect. 3, Neutrinos oscillations: Basic formalism (Pontecorvo); matter effect (Mikheev, Smirnov, Wolfenstein); status of neutrino masses and mixings. Sect. 4, Modifying the standard model to include neutrinos masses: The fermions of the standard model; one additional operator in the standard model (Weinberg); implications. One summary table and several exercises offer the students occasions to check, consolidate and extend their understanding; the brief reference list includes historical and review papers and some entry points to active research in neutrino physics.
[ { "created": "Mon, 29 Dec 2014 16:45:59 GMT", "version": "v1" }, { "created": "Tue, 19 May 2015 16:18:20 GMT", "version": "v2" } ]
2015-05-20
[ [ "Vissani", "Francesco", "" ] ]
In this lecture, prepared for PhD students, basic considerations on neutrino interactions, properties and sites of production are overviewed. The detailed content is as follows: Sect. 1, Weak interactions and neutrinos: Fermi coupling; definition of neutrinos; global numbers. Sect. 2, A list of neutrino sources: Explanatory note and examples (solar pp- and supernova-neutrinos). Sect. 3, Neutrinos oscillations: Basic formalism (Pontecorvo); matter effect (Mikheev, Smirnov, Wolfenstein); status of neutrino masses and mixings. Sect. 4, Modifying the standard model to include neutrinos masses: The fermions of the standard model; one additional operator in the standard model (Weinberg); implications. One summary table and several exercises offer the students occasions to check, consolidate and extend their understanding; the brief reference list includes historical and review papers and some entry points to active research in neutrino physics.
1801.03582
Gang Li
Yawei Zhang and Gang Li
Exploring the $\Upsilon(4S,5S,6S) \to h_b(1P)\eta$ hidden-bottom hadronic transitions
11 pages, 3 figures
Phys. Rev. D 97, 014018 (2018)
10.1103/PhysRevD.97.014018
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recently, Belle Collaboration has reported the measurement of the spin-flipping transition $\Upsilon(4S) \to h_b(1P)\eta$ with an unexpectedly large branching ratio: $\mathcal{B}(\Upsilon(4S) \to h_b(1P)\eta) =(2.18\pm 0.11\pm 0.18)\times 10^{-3}$. Such a large branching fraction contradicts with the anticipated suppression for the spin flip. In this work, we examine the effects induced by intermediate bottomed meson loops and point out that these effects are significantly important. Using the effective Lagrangian approach (ELA), we find the experimental data on $\Upsilon(4S) \to h_b(1P)\eta$ can be accommodated with the reasonable inputs. We then explore the decays $\Upsilon(5S,6S)\to h_b(1P)\eta$ and find that these two channels also have sizable branching fractions. We also calculate these these processes in the framework of nonrelativistic effective field theory (NREFT). For the decays $\Upsilon(4S) \to h_b(1P) \eta$, the NREFT results are at the same order of magnitude but smaller than the ELA results by a factor of $2$ to $5$. For the decays $\Upsilon(5S, 6S) \to h_b(1P) \eta$ the NREFT results are smaller than the ELA results by approximately one order of magnitude. We suggest future experiment Belle-II to search for the $\Upsilon(5S, 6S)\to h_b(1P) \eta$ decays which will be helpful to understand the transition mechanism.
[ { "created": "Wed, 10 Jan 2018 23:22:30 GMT", "version": "v1" } ]
2018-01-31
[ [ "Zhang", "Yawei", "" ], [ "Li", "Gang", "" ] ]
Recently, Belle Collaboration has reported the measurement of the spin-flipping transition $\Upsilon(4S) \to h_b(1P)\eta$ with an unexpectedly large branching ratio: $\mathcal{B}(\Upsilon(4S) \to h_b(1P)\eta) =(2.18\pm 0.11\pm 0.18)\times 10^{-3}$. Such a large branching fraction contradicts with the anticipated suppression for the spin flip. In this work, we examine the effects induced by intermediate bottomed meson loops and point out that these effects are significantly important. Using the effective Lagrangian approach (ELA), we find the experimental data on $\Upsilon(4S) \to h_b(1P)\eta$ can be accommodated with the reasonable inputs. We then explore the decays $\Upsilon(5S,6S)\to h_b(1P)\eta$ and find that these two channels also have sizable branching fractions. We also calculate these these processes in the framework of nonrelativistic effective field theory (NREFT). For the decays $\Upsilon(4S) \to h_b(1P) \eta$, the NREFT results are at the same order of magnitude but smaller than the ELA results by a factor of $2$ to $5$. For the decays $\Upsilon(5S, 6S) \to h_b(1P) \eta$ the NREFT results are smaller than the ELA results by approximately one order of magnitude. We suggest future experiment Belle-II to search for the $\Upsilon(5S, 6S)\to h_b(1P) \eta$ decays which will be helpful to understand the transition mechanism.
1712.06147
Antonio Pich
Hector Gisbert and Antonio Pich
Direct CP violation in $K^0\to\pi\pi$: Standard Model Status
45 pages, 4 figures
null
10.1088/1361-6633/aac18e
IFIC/17-56, FTUV/17-1218
hep-ph hep-ex hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In 1988 the NA31 experiment presented the first evidence of direct CP violation in the $K^0\to\pi\pi$ decay amplitudes. A clear signal with a $7.2\,\sigma$ statistical significance was later established with the full data samples from the NA31, E731, NA48 and KTeV experiments, confirming that CP violation is associated with a $\Delta S=1$ quark transition, as predicted by the Standard Model. However, the theoretical prediction for the measured ratio $\varepsilon'/\varepsilon$ has been a subject of strong controversy along the years. Although the underlying physics was already clarified in 2001, the recent release of improved lattice data has revived again the theoretical debate. We review the current status, discussing in detail the different ingredients that enter into the calculation of this observable and the reasons why seemingly contradictory predictions were obtained in the past by several groups. An update of the Standard Model prediction is presented and the prospects for future improvements are analysed. Taking into account all known short-distance and long-distance contributions, one obtains $\mbox{Re}\left(\varepsilon'/\varepsilon\right) = (15 \pm 7)\cdot 10^{-4}$, in good agreement with the experimental measurement.
[ { "created": "Sun, 17 Dec 2017 17:18:54 GMT", "version": "v1" } ]
2018-07-25
[ [ "Gisbert", "Hector", "" ], [ "Pich", "Antonio", "" ] ]
In 1988 the NA31 experiment presented the first evidence of direct CP violation in the $K^0\to\pi\pi$ decay amplitudes. A clear signal with a $7.2\,\sigma$ statistical significance was later established with the full data samples from the NA31, E731, NA48 and KTeV experiments, confirming that CP violation is associated with a $\Delta S=1$ quark transition, as predicted by the Standard Model. However, the theoretical prediction for the measured ratio $\varepsilon'/\varepsilon$ has been a subject of strong controversy along the years. Although the underlying physics was already clarified in 2001, the recent release of improved lattice data has revived again the theoretical debate. We review the current status, discussing in detail the different ingredients that enter into the calculation of this observable and the reasons why seemingly contradictory predictions were obtained in the past by several groups. An update of the Standard Model prediction is presented and the prospects for future improvements are analysed. Taking into account all known short-distance and long-distance contributions, one obtains $\mbox{Re}\left(\varepsilon'/\varepsilon\right) = (15 \pm 7)\cdot 10^{-4}$, in good agreement with the experimental measurement.
2003.02667
Nobuchika Okada
Nobuchika Okada, Satomi Okada, Qaisar Shafi
Light $Z^\prime$ and Dark Matter from U(1)$_X$ Gauge Symmetry
18 pages, 4 figures, new references added, typos corrected
null
10.1016/j.physletb.2020.135845
null
hep-ph astro-ph.CO hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider a U(1)$_X$ gauge symmetry extension of the Standard Model (SM) with a $Z^\prime$-portal Majorana fermion dark matter that allows for a relatively light gauge boson $Z^\prime$ with mass of 10 MeV$-$ a few GeV and a much heavier dark matter through the freeze-in mechanism. In a second scenario the roles are reversed, and the dark matter mass, in the keV range or so, lies well below the $Z^\prime$ mass, say, $\sim 1$ GeV. We outline the parameter space that can be explored for these two scenarios at the future Lifetime Frontier experiments including Belle-II, FASER, LDMX and SHiP.
[ { "created": "Wed, 4 Mar 2020 06:43:48 GMT", "version": "v1" }, { "created": "Thu, 19 Mar 2020 18:37:29 GMT", "version": "v2" } ]
2020-10-28
[ [ "Okada", "Nobuchika", "" ], [ "Okada", "Satomi", "" ], [ "Shafi", "Qaisar", "" ] ]
We consider a U(1)$_X$ gauge symmetry extension of the Standard Model (SM) with a $Z^\prime$-portal Majorana fermion dark matter that allows for a relatively light gauge boson $Z^\prime$ with mass of 10 MeV$-$ a few GeV and a much heavier dark matter through the freeze-in mechanism. In a second scenario the roles are reversed, and the dark matter mass, in the keV range or so, lies well below the $Z^\prime$ mass, say, $\sim 1$ GeV. We outline the parameter space that can be explored for these two scenarios at the future Lifetime Frontier experiments including Belle-II, FASER, LDMX and SHiP.
1810.03713
Howard Baer
Howard Baer, Vernon Barger and Dibyashree Sengupta
Gravity safe, electroweak natural axionic solution to strong CP and SUSY mu problems
14 pages including two .png figures
null
10.1016/j.physletb.2019.01.007
OU-HEP-180930
hep-ph astro-ph.CO hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Particle physics models with Peccei-Quinn (PQ) symmetry breaking as a consequence of supersymmetry (SUSY) breaking are attractive in that they solve the strong CP problem with a SUSY DFSZ-like axion, link the SUSY breaking and PQ breaking intermediate mass scales and can resolve the SUSY mu problem with a naturalness-required weak scale mu term whilst soft SUSY breaking terms inhabit the multi-TeV regime as required by LHC sparticle mass limits and the Higgs mass measurement. On the negative ledger, models based on global symmetries suffer a generic gravity spoliation problem. We present a model based on the discrete R-symmetry Z_{24}^R-- which may emerge from compactification of 10-d Lorentzian spacetime in string theory-- where the mu term and dangerous proton decay and R-parity violating operators are either suppressed or forbidden while a gravity-safe PQ symmetry emerges as an accidental approximate global symmetry leading to a solution to the strong CP problem and a weak-scale/natural value for the mu term.
[ { "created": "Mon, 8 Oct 2018 21:40:24 GMT", "version": "v1" } ]
2019-01-16
[ [ "Baer", "Howard", "" ], [ "Barger", "Vernon", "" ], [ "Sengupta", "Dibyashree", "" ] ]
Particle physics models with Peccei-Quinn (PQ) symmetry breaking as a consequence of supersymmetry (SUSY) breaking are attractive in that they solve the strong CP problem with a SUSY DFSZ-like axion, link the SUSY breaking and PQ breaking intermediate mass scales and can resolve the SUSY mu problem with a naturalness-required weak scale mu term whilst soft SUSY breaking terms inhabit the multi-TeV regime as required by LHC sparticle mass limits and the Higgs mass measurement. On the negative ledger, models based on global symmetries suffer a generic gravity spoliation problem. We present a model based on the discrete R-symmetry Z_{24}^R-- which may emerge from compactification of 10-d Lorentzian spacetime in string theory-- where the mu term and dangerous proton decay and R-parity violating operators are either suppressed or forbidden while a gravity-safe PQ symmetry emerges as an accidental approximate global symmetry leading to a solution to the strong CP problem and a weak-scale/natural value for the mu term.
2005.02273
Cheng-Jun Xia
Cheng-Jun Xia, Toshiki Maruyama, Nobutoshi Yasutake, Toshitaka Tatsumi, Hong Shen, and Hajime Togashi
Systematic study on the quark-hadron mixed phase in compact stars
null
Phys. Rev. D 102, 023031 (2020)
10.1103/PhysRevD.102.023031
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate systematically the quark-hadron mixed phase in dense stellar matter, and its influence on compact star structures. The properties of quark matter and hadronic matter are fixed based on various model predictions. Beside adopting constant values, the surface tension $\Sigma$ for the quark-hadron interface is estimated with the multiple reflection expansion method and equivparticle model. To fix the structures of quark-hadron pasta phases, a continuous dimensionality of the structure is adopted as proposed by Ravenhall, Pethick, and Wilson. The corresponding properties of hybrid stars are then obtained and confronted with pulsar observations. It is found that the correlation between radius and tidal deformability in traditional neutron stars preserves in hybrid stars. For those permitted by pulsar observations, in almost all cases the quark phase persists inside the most massive compact stars. The quark-hadron interface plays an important role on hybrid star structures once quark matter emerges. The surface tension $\Sigma$ estimated with various methods increases with density, which predicts stiffer EOSs for the quark-hadron mixed phase and increases the maximum mass of hybrid stars. The EOSs of hybrid star matter are well constrained at densities $n\lesssim 0.8$ fm${}^{-3}$, while larger uncertainty is expected at higher densities.
[ { "created": "Tue, 5 May 2020 15:07:49 GMT", "version": "v1" }, { "created": "Wed, 13 May 2020 01:29:59 GMT", "version": "v2" }, { "created": "Sat, 25 Jul 2020 00:27:36 GMT", "version": "v3" } ]
2020-07-29
[ [ "Xia", "Cheng-Jun", "" ], [ "Maruyama", "Toshiki", "" ], [ "Yasutake", "Nobutoshi", "" ], [ "Tatsumi", "Toshitaka", "" ], [ "Shen", "Hong", "" ], [ "Togashi", "Hajime", "" ] ]
We investigate systematically the quark-hadron mixed phase in dense stellar matter, and its influence on compact star structures. The properties of quark matter and hadronic matter are fixed based on various model predictions. Beside adopting constant values, the surface tension $\Sigma$ for the quark-hadron interface is estimated with the multiple reflection expansion method and equivparticle model. To fix the structures of quark-hadron pasta phases, a continuous dimensionality of the structure is adopted as proposed by Ravenhall, Pethick, and Wilson. The corresponding properties of hybrid stars are then obtained and confronted with pulsar observations. It is found that the correlation between radius and tidal deformability in traditional neutron stars preserves in hybrid stars. For those permitted by pulsar observations, in almost all cases the quark phase persists inside the most massive compact stars. The quark-hadron interface plays an important role on hybrid star structures once quark matter emerges. The surface tension $\Sigma$ estimated with various methods increases with density, which predicts stiffer EOSs for the quark-hadron mixed phase and increases the maximum mass of hybrid stars. The EOSs of hybrid star matter are well constrained at densities $n\lesssim 0.8$ fm${}^{-3}$, while larger uncertainty is expected at higher densities.
2107.06431
Yasuhito Sakaki
Akimasa Ishikawa, Yasuhito Sakaki, Yosuke Takubo
Search for axion-like particles with electron and positron beams at KEK Linac
13 pages, 4 figures
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a fixed-target experiment to search for Axion-like particles (ALPs) coupling to photons, which utilizes electron and positron beams available at KEK Linac. The sensitivity to ALP is evaluated for two shielding setups in conjunction with other beam dump experiments, fixed-target experiments, and $e^+e^-$ collider experiments. This study shows that the two setups can explore the gap between the search region excluded by the beam dump experiments and the $e^+e^-$ collider experiments.
[ { "created": "Wed, 14 Jul 2021 00:12:58 GMT", "version": "v1" }, { "created": "Tue, 10 Aug 2021 07:40:18 GMT", "version": "v2" } ]
2021-08-11
[ [ "Ishikawa", "Akimasa", "" ], [ "Sakaki", "Yasuhito", "" ], [ "Takubo", "Yosuke", "" ] ]
We propose a fixed-target experiment to search for Axion-like particles (ALPs) coupling to photons, which utilizes electron and positron beams available at KEK Linac. The sensitivity to ALP is evaluated for two shielding setups in conjunction with other beam dump experiments, fixed-target experiments, and $e^+e^-$ collider experiments. This study shows that the two setups can explore the gap between the search region excluded by the beam dump experiments and the $e^+e^-$ collider experiments.
0711.3590
Tobias Huber
G. Heinrich, T. Huber, D. Maitre
Master Integrals for Fermionic Contributions to Massless Three-Loop Form Factors
12 pages, 1 figure. References added and updated. Appendix on evaluation of Mellin-Barnes integrals added. Version to appear in PLB
Phys.Lett.B662:344-352,2008
10.1016/j.physletb.2008.03.028
null
hep-ph
null
In this letter we continue the calculation of master integrals for massless three-loop form factors by giving analytical results for those integrals which are relevant for the fermionic contributions proportional to N_F^2, N_F*N, and N_F/N. Working in dimensional regularisation, we express one of the integrals in a closed form which is exact to all orders in epsilon, containing Gamma-functions and hypergeometric functions of unit argument. In all other cases we derive multiple Mellin-Barnes representations from which the coefficients of the Laurent expansion in epsilon are extracted in an analytical form. To obtain the finite part of the three-loop quark and gluon form factors, all coefficients through transcendentality six in the Riemann zeta-function have to be included.
[ { "created": "Thu, 22 Nov 2007 14:38:28 GMT", "version": "v1" }, { "created": "Thu, 27 Mar 2008 15:48:05 GMT", "version": "v2" } ]
2008-11-26
[ [ "Heinrich", "G.", "" ], [ "Huber", "T.", "" ], [ "Maitre", "D.", "" ] ]
In this letter we continue the calculation of master integrals for massless three-loop form factors by giving analytical results for those integrals which are relevant for the fermionic contributions proportional to N_F^2, N_F*N, and N_F/N. Working in dimensional regularisation, we express one of the integrals in a closed form which is exact to all orders in epsilon, containing Gamma-functions and hypergeometric functions of unit argument. In all other cases we derive multiple Mellin-Barnes representations from which the coefficients of the Laurent expansion in epsilon are extracted in an analytical form. To obtain the finite part of the three-loop quark and gluon form factors, all coefficients through transcendentality six in the Riemann zeta-function have to be included.
1403.0412
Sona Pochybova
Sona Pochybova
On particle production in jets with quark-like and gluon-like fragmentation
5 pages, 4 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the $p/\pi$ ratio in jets produced in simulated proton-proton collisions at $\sqrt{s_{NN}}=7~\mathrm{TeV}$ using Pythia $6.4$ Monte-Carlo generator. We compare the $p/\pi$ ratio in the selected quark-like and gluon-like jets to a reference samples of quark- and gluon-jets tagged at Monte-Carlo level. We observe that the contamination in the selected jets significantly influences the observed ratios. This suggests, that the origin of the jet fixes the value of the $p/\pi$ ratio within the model that we use.
[ { "created": "Mon, 3 Mar 2014 12:39:52 GMT", "version": "v1" } ]
2014-03-04
[ [ "Pochybova", "Sona", "" ] ]
We study the $p/\pi$ ratio in jets produced in simulated proton-proton collisions at $\sqrt{s_{NN}}=7~\mathrm{TeV}$ using Pythia $6.4$ Monte-Carlo generator. We compare the $p/\pi$ ratio in the selected quark-like and gluon-like jets to a reference samples of quark- and gluon-jets tagged at Monte-Carlo level. We observe that the contamination in the selected jets significantly influences the observed ratios. This suggests, that the origin of the jet fixes the value of the $p/\pi$ ratio within the model that we use.
1606.04772
David d'Enterria
David d'Enterria
$\alpha_s$ review (2016)
4 pages, 2 figures. Minor changes. Version submitted to Proceedings Moriond QCD 2016
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The current world-average of the strong coupling at the Z pole mass, $\alpha_s(m^2_{Z}) = 0.1181 \pm 0.0013$, is obtained from a comparison of perturbative QCD calculations computed, at least, at next-to-next-to-leading-order accuracy, to a set of 6 groups of experimental observables: (i) lattice QCD "data", (ii) $\tau$ hadronic decays, (iii) proton structure functions, (iv) event shapes and jet rates in $e^+e^-$ collisions, (v) Z boson hadronic decays, and (vi) top-quark cross sections in p-p collisions. In addition, at least 8 other $\alpha_s$ extractions, usually with a lower level of theoretical and/or experimental precision today, have been proposed: pion, $\Upsilon$, W hadronic decays; soft and hard fragmentation functions; jets cross sections in pp, e-p and $\gamma$-p collisions; and photon F$_2$ structure function in $\gamma\,\gamma$ collisions. These 14 $\alpha_s$ determinations are reviewed, and the perspectives of reduction of their present uncertainties are discussed.
[ { "created": "Wed, 15 Jun 2016 14:05:28 GMT", "version": "v1" }, { "created": "Mon, 27 Jun 2016 23:53:03 GMT", "version": "v2" } ]
2016-06-29
[ [ "d'Enterria", "David", "" ] ]
The current world-average of the strong coupling at the Z pole mass, $\alpha_s(m^2_{Z}) = 0.1181 \pm 0.0013$, is obtained from a comparison of perturbative QCD calculations computed, at least, at next-to-next-to-leading-order accuracy, to a set of 6 groups of experimental observables: (i) lattice QCD "data", (ii) $\tau$ hadronic decays, (iii) proton structure functions, (iv) event shapes and jet rates in $e^+e^-$ collisions, (v) Z boson hadronic decays, and (vi) top-quark cross sections in p-p collisions. In addition, at least 8 other $\alpha_s$ extractions, usually with a lower level of theoretical and/or experimental precision today, have been proposed: pion, $\Upsilon$, W hadronic decays; soft and hard fragmentation functions; jets cross sections in pp, e-p and $\gamma$-p collisions; and photon F$_2$ structure function in $\gamma\,\gamma$ collisions. These 14 $\alpha_s$ determinations are reviewed, and the perspectives of reduction of their present uncertainties are discussed.
0801.2238
Efremov Anatoly
A.V. Efremov, K.Goeke and P.Schweitzer
Sivers and Collins Single Spin Asymmetries
9 pages, 23 eps figures. Talk at XII Workshop on High Energy Spin Physics (DSPIN-07), Dubna, Sept. 3-7, 2007 and at ASI - SYMMETRIES AND SPIN (SPIN-Praha-2007), Prague, July 8 - 14, 2007
Eur.Phys.J.ST162:1-11,2008
10.1140/epjst/e2008-00768-9
null
hep-ph
null
The Sivers and Collins asymmetries are the most prominent Single Spin Asymmetries (SSA)in Semi-Inclusive Deeply Inelastic Scattering (SIDIS)with transverse target polarization. In this talk we present our understanding of these phenomena.
[ { "created": "Tue, 15 Jan 2008 09:40:58 GMT", "version": "v1" }, { "created": "Mon, 21 Jan 2008 12:50:49 GMT", "version": "v2" } ]
2008-12-18
[ [ "Efremov", "A. V.", "" ], [ "Goeke", "K.", "" ], [ "Schweitzer", "P.", "" ] ]
The Sivers and Collins asymmetries are the most prominent Single Spin Asymmetries (SSA)in Semi-Inclusive Deeply Inelastic Scattering (SIDIS)with transverse target polarization. In this talk we present our understanding of these phenomena.
hep-ph/9610222
null
Jonathan L. Rosner (CERN and University of Chicago)
Top Quark Mass
61 pages, latex, 26 figures. Some typos corrected
NATO Adv.Study Inst.Ser.B Phys.363:43-103,1997
null
CERN-TH-96/245, EFI-96-34
hep-ph
null
The influence of the top quark mass on mixing processes and precise electroweak measurements is described. Experimental observation of the top quark in proton-antiproton collisions is discussed, and some brief remarks are made about electron-positron production. Some speculations are noted about the possible significance of the large top quark mass.
[ { "created": "Wed, 2 Oct 1996 20:50:48 GMT", "version": "v1" }, { "created": "Mon, 6 Jan 1997 16:03:10 GMT", "version": "v2" } ]
2014-11-17
[ [ "Rosner", "Jonathan L.", "", "CERN and University of Chicago" ] ]
The influence of the top quark mass on mixing processes and precise electroweak measurements is described. Experimental observation of the top quark in proton-antiproton collisions is discussed, and some brief remarks are made about electron-positron production. Some speculations are noted about the possible significance of the large top quark mass.
1905.00891
Yongchao Zhang
P. S. Bhupal Dev, Francesc Ferrer, Yiyang Zhang, Yongchao Zhang
Gravitational Waves from First-Order Phase Transition in a Simple Axion-Like Particle Model
30 pages, 11 figures, minor changes, version accepted by JCAP
JCAP 1911, 006 (2019)
10.1088/1475-7516/2019/11/006
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider a gauge-singlet complex scalar field $\Phi$ with a global $U(1)$ symmetry that is spontaneously broken at some high energy scale $f_a$. As a result, the angular part of the $\Phi$-field becomes an axion-like particle (ALP). We show that if the $\Phi$-field has a non-zero coupling $\kappa$ to the Standard Model Higgs boson, there exists a certain region in the $\left(f_a, \kappa\right)$ parameter space where the global $U(1)$ symmetry-breaking induces a strongly first order phase transition, thereby producing stochastic gravitational waves that are potentially observable in current and future gravitational-wave detectors. In particular, we find that future gravitational-wave experiments such as TianQin, BBO and Cosmic Explorer could probe a broad range of the energy scale $10^3 \, {\rm GeV} \lesssim f_a \lesssim 10^{8} \, {\rm GeV}$, independent of the ALP mass. Since all the ALP couplings to the Standard Model particles are proportional to inverse powers of the energy scale $f_a$ (up to model-dependent ${\cal O}(1)$ coefficients), the gravitational-wave detection prospects are largely complementary to the current laboratory, astrophysical and cosmological probes of the ALP scenarios.
[ { "created": "Thu, 2 May 2019 17:59:35 GMT", "version": "v1" }, { "created": "Wed, 23 Oct 2019 07:17:26 GMT", "version": "v2" } ]
2019-11-07
[ [ "Dev", "P. S. Bhupal", "" ], [ "Ferrer", "Francesc", "" ], [ "Zhang", "Yiyang", "" ], [ "Zhang", "Yongchao", "" ] ]
We consider a gauge-singlet complex scalar field $\Phi$ with a global $U(1)$ symmetry that is spontaneously broken at some high energy scale $f_a$. As a result, the angular part of the $\Phi$-field becomes an axion-like particle (ALP). We show that if the $\Phi$-field has a non-zero coupling $\kappa$ to the Standard Model Higgs boson, there exists a certain region in the $\left(f_a, \kappa\right)$ parameter space where the global $U(1)$ symmetry-breaking induces a strongly first order phase transition, thereby producing stochastic gravitational waves that are potentially observable in current and future gravitational-wave detectors. In particular, we find that future gravitational-wave experiments such as TianQin, BBO and Cosmic Explorer could probe a broad range of the energy scale $10^3 \, {\rm GeV} \lesssim f_a \lesssim 10^{8} \, {\rm GeV}$, independent of the ALP mass. Since all the ALP couplings to the Standard Model particles are proportional to inverse powers of the energy scale $f_a$ (up to model-dependent ${\cal O}(1)$ coefficients), the gravitational-wave detection prospects are largely complementary to the current laboratory, astrophysical and cosmological probes of the ALP scenarios.
hep-ph/0209265
Blazenka Melic
Blazenka Melic
Exclusive Nonleptonic B Decays from QCD Light-Cone Sum Rules
15 pages, 7 figures included, typos corrected, invited talk at Int. School "Heavy Quark Physics", May 27 - June 04 2002, JINR, Dubna, Russia; to be published in the Springer series Lecture Notes in Physics
Lect.Notes Phys. 647 (2004) 287-301
10.1007/b97728
WUE-ITP-2002-021
hep-ph
null
We are going to review recent advances in the theory of exclusive nonleptonic B decays. The emphasis is going to be on the factorization hypothesis and the role of nonfactorizable contributions for nonleptonic B decays. In particular, we will discuss in more detail calculations of nonfactorizable contributions in the QCD light-cone sum rule approach and their implications to the $B \to \pi \pi$ and $B \to J/\psi K$ decays.
[ { "created": "Mon, 23 Sep 2002 19:22:30 GMT", "version": "v1" }, { "created": "Wed, 25 Sep 2002 15:09:05 GMT", "version": "v2" } ]
2017-08-23
[ [ "Melic", "Blazenka", "" ] ]
We are going to review recent advances in the theory of exclusive nonleptonic B decays. The emphasis is going to be on the factorization hypothesis and the role of nonfactorizable contributions for nonleptonic B decays. In particular, we will discuss in more detail calculations of nonfactorizable contributions in the QCD light-cone sum rule approach and their implications to the $B \to \pi \pi$ and $B \to J/\psi K$ decays.
hep-ph/9902282
Mikko Laine
M. Laine (CERN)
Magnetic fields and the EW phase transition
5 pages. Talk given at SEWM'98, Dec.98, Copenhagen
null
null
null
hep-ph
null
We review the motivation for, lattice results on, and some implications of, external magnetic fields present at the time of the cosmological electroweak phase transition.
[ { "created": "Tue, 9 Feb 1999 15:47:02 GMT", "version": "v1" } ]
2007-05-23
[ [ "Laine", "M.", "", "CERN" ] ]
We review the motivation for, lattice results on, and some implications of, external magnetic fields present at the time of the cosmological electroweak phase transition.
0911.0206
Lisheng Geng
T. Branz, L.S. Geng, and E. Oset
Two-photon and one photon-one vector meson decay widths of the $f_0(1370)$, $f_2(1270)$, $f_0(1710)$, $f'_2(1525)$, and $K^*_2(1430)$
More discussions about the relation between qqbar states and dynamically generated states; version published in PRD.
Phys.Rev.D81:054037,2010
10.1103/PhysRevD.81.054037
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate the radiative decay widths, two-photon ($\gamma\gamma$) and one photon-one vector meson ($V\gamma$), of the dynamically generated resonances from vector meson-vector meson interaction in a unitary approach based on the hidden-gauge Lagrangians. In the present paper we consider the following dynamically generated resonances: $f_0(1370)$, $f_0(1710)$, $f_2(1270)$, $f_2'(1525)$, $K^*_2(1430)$, two strangeness=0 and isospin=1 states, and two strangeness=1 and isospin=1/2 states. For the $f_0(1370)$ and $f_2(1270)$ we reproduce the previous results for the two-photon decay widths and further calculate their one photon-one vector decay widths. For the $f_0(1710)$ and $f_2'(1525)$ the calculated two-photon decay widths are found to be consistent with data. The $\rho^0\gamma$, $\omega\gamma$ and $\phi\gamma$ decay widths of the $f_0(1370)$, $f_2(1270)$, $f_0(1710)$, $f'_2(1525)$ are compared with the results predicted by other approaches. The $K^{*+}\gamma$ and $K^{*0}\gamma$ decay rates of the $K^*_2(1430)$ are also calculated and compared with the results obtained in the framework of the covariant oscillator quark model. The results for the two states with strangeness=0, isospin=1 and two states with strangeness=1, isospin=1/2 are predictions that need to be tested by future experiments.
[ { "created": "Sun, 1 Nov 2009 21:20:34 GMT", "version": "v1" }, { "created": "Sun, 18 Apr 2010 10:18:00 GMT", "version": "v2" } ]
2010-04-21
[ [ "Branz", "T.", "" ], [ "Geng", "L. S.", "" ], [ "Oset", "E.", "" ] ]
We calculate the radiative decay widths, two-photon ($\gamma\gamma$) and one photon-one vector meson ($V\gamma$), of the dynamically generated resonances from vector meson-vector meson interaction in a unitary approach based on the hidden-gauge Lagrangians. In the present paper we consider the following dynamically generated resonances: $f_0(1370)$, $f_0(1710)$, $f_2(1270)$, $f_2'(1525)$, $K^*_2(1430)$, two strangeness=0 and isospin=1 states, and two strangeness=1 and isospin=1/2 states. For the $f_0(1370)$ and $f_2(1270)$ we reproduce the previous results for the two-photon decay widths and further calculate their one photon-one vector decay widths. For the $f_0(1710)$ and $f_2'(1525)$ the calculated two-photon decay widths are found to be consistent with data. The $\rho^0\gamma$, $\omega\gamma$ and $\phi\gamma$ decay widths of the $f_0(1370)$, $f_2(1270)$, $f_0(1710)$, $f'_2(1525)$ are compared with the results predicted by other approaches. The $K^{*+}\gamma$ and $K^{*0}\gamma$ decay rates of the $K^*_2(1430)$ are also calculated and compared with the results obtained in the framework of the covariant oscillator quark model. The results for the two states with strangeness=0, isospin=1 and two states with strangeness=1, isospin=1/2 are predictions that need to be tested by future experiments.
hep-ph/9903334
Yasunori Nomura
Yasunori Nomura and Takashi Sugimoto
Quark and Lepton Mass Matrices in the SO(10) Grand Unified Theory with Generation Flipping
28 pages, Latex
Phys.Rev.D61:093003,2000
10.1103/PhysRevD.61.093003
UT-840
hep-ph
null
We investigate the SO(10) grand unified model with generation flipping. The model contains one extra matter multiplet $\psi(10)$ and it mixes with the usual matter multiplets $\psi_i(16)$ when the SO(10) is broken down to SU(5). We find the parameter region of the model in which the observed quark masses and mixings are well reproduced. The resulting parameter region is consistent with the observation that only $\psi_i(16)$ have a source of hierarchies and indicates that the mixing between second and third generations tends to be large in the lepton sector, which is consistent with the observed maximal mixing of the atmospheric neutrino oscillation. We also show that the model can accommodate MSW and vacuum oscillation solutions to the solar neutrino deficit depending on the form of the Majorana mass matrix for the right-handed neutrinos.
[ { "created": "Fri, 12 Mar 1999 06:06:41 GMT", "version": "v1" }, { "created": "Tue, 10 Aug 1999 05:24:23 GMT", "version": "v2" }, { "created": "Wed, 19 Jan 2000 07:45:31 GMT", "version": "v3" } ]
2009-09-29
[ [ "Nomura", "Yasunori", "" ], [ "Sugimoto", "Takashi", "" ] ]
We investigate the SO(10) grand unified model with generation flipping. The model contains one extra matter multiplet $\psi(10)$ and it mixes with the usual matter multiplets $\psi_i(16)$ when the SO(10) is broken down to SU(5). We find the parameter region of the model in which the observed quark masses and mixings are well reproduced. The resulting parameter region is consistent with the observation that only $\psi_i(16)$ have a source of hierarchies and indicates that the mixing between second and third generations tends to be large in the lepton sector, which is consistent with the observed maximal mixing of the atmospheric neutrino oscillation. We also show that the model can accommodate MSW and vacuum oscillation solutions to the solar neutrino deficit depending on the form of the Majorana mass matrix for the right-handed neutrinos.
2202.04085
Hao Chen
Hao Chen, Ian Moult, Joshua Sandor and Hua Xing Zhu
Celestial Blocks and Transverse Spin in the Three-Point Energy Correlator
75 pages, 16 figures
null
10.1007/JHEP09(2022)199
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Quantitative theoretical techniques for understanding the substructure of jets at the LHC enable new insights into the dynamics of QCD, and novel approaches to search for new physics. Recently, there has been a program to reformulate jet substructure in terms of correlation functions, $\langle \mathcal{E}(\vec n_1) \mathcal{E}(\vec n_2) \cdots \mathcal{E}(\vec n_k) \rangle$, of light-ray operators, $\mathcal{E}(\vec n)$, allowing the application of techniques developed in the study of Conformal Field Theories (CFTs). In this paper we further develop these techniques in the particular context of the three-point correlator $\langle \mathcal{E}(\vec n_1) \mathcal{E}(\vec n_2) \mathcal{E}(\vec n_3) \rangle$, using recently computed perturbative data in both QCD and $\mathcal{N}=4$ sYM. We derive the celestial blocks appearing in the light-ray operator product expansion (OPE) of the three-point correlator, and use the Lorentzian inversion formula to extract the spectrum of light-ray operators appearing in the expansion, showing, in particular, that the OPE data is analytic in transverse spin. Throughout our presentation, we highlight the relation between the OPE approach, and more standard splitting function based approaches of perturbative QCD, emphasizing the utility of the OPE approach for incorporating symmetries in jet substructure calculations. We hope that our presentation introduces a number of new techniques to the jet substructure community, and also illustrates the phenomenological relevance of the study of light-ray operators in the OPE limit to the CFT community.
[ { "created": "Tue, 8 Feb 2022 19:00:01 GMT", "version": "v1" } ]
2022-10-19
[ [ "Chen", "Hao", "" ], [ "Moult", "Ian", "" ], [ "Sandor", "Joshua", "" ], [ "Zhu", "Hua Xing", "" ] ]
Quantitative theoretical techniques for understanding the substructure of jets at the LHC enable new insights into the dynamics of QCD, and novel approaches to search for new physics. Recently, there has been a program to reformulate jet substructure in terms of correlation functions, $\langle \mathcal{E}(\vec n_1) \mathcal{E}(\vec n_2) \cdots \mathcal{E}(\vec n_k) \rangle$, of light-ray operators, $\mathcal{E}(\vec n)$, allowing the application of techniques developed in the study of Conformal Field Theories (CFTs). In this paper we further develop these techniques in the particular context of the three-point correlator $\langle \mathcal{E}(\vec n_1) \mathcal{E}(\vec n_2) \mathcal{E}(\vec n_3) \rangle$, using recently computed perturbative data in both QCD and $\mathcal{N}=4$ sYM. We derive the celestial blocks appearing in the light-ray operator product expansion (OPE) of the three-point correlator, and use the Lorentzian inversion formula to extract the spectrum of light-ray operators appearing in the expansion, showing, in particular, that the OPE data is analytic in transverse spin. Throughout our presentation, we highlight the relation between the OPE approach, and more standard splitting function based approaches of perturbative QCD, emphasizing the utility of the OPE approach for incorporating symmetries in jet substructure calculations. We hope that our presentation introduces a number of new techniques to the jet substructure community, and also illustrates the phenomenological relevance of the study of light-ray operators in the OPE limit to the CFT community.
hep-ph/9510382
Udo Zueckert
U. Z\"uckert
Dynamical Interplay of Quarks and Solitonic Meson Clouds in Baryons
2 pages, postscript file submitted as uuencoded compressed file, talk given at the International School on Nuclear Physics, "Quarks in Hadrons and Nuclei", Erice, Sicily, Italy, September 19-27, 1995
Prog.Part.Nucl.Phys.36:177-178,1996
10.1016/0146-6410(96)00022-1
UNITU-THEP-16/1995
hep-ph
null
In the Nambu--Jona-Lasinio (NJL-) model baryons are considered either as quark-diquark-composites or as soliton configurations of mesons. The construction of a hybrid model, which possesses a dynamical interplay between both pictures, is presented. The Bethe-Salpeter equation for diquarks and the Faddeev equation for diquark-quark bound states in the background of a soliton configuration is solved.
[ { "created": "Tue, 24 Oct 1995 09:15:05 GMT", "version": "v1" } ]
2011-04-15
[ [ "Zückert", "U.", "" ] ]
In the Nambu--Jona-Lasinio (NJL-) model baryons are considered either as quark-diquark-composites or as soliton configurations of mesons. The construction of a hybrid model, which possesses a dynamical interplay between both pictures, is presented. The Bethe-Salpeter equation for diquarks and the Faddeev equation for diquark-quark bound states in the background of a soliton configuration is solved.
1309.4235
C\'edric Lorc\'e
E. Leader (Imperial Coll., London) and C. Lorce (Orsay, IPN and Liege, IFPA)
The angular momentum controversy: What's it all about and does it matter?
96 pages, 11 figures, 5 tables, review prepared for Physics Reports
null
10.1016/j.physrep.2014.02.010
null
hep-ph hep-ex hep-th nucl-th quant-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The general question, crucial to an understanding of the internal structure of the nucleon, of how to split the total angular momentum of a photon or gluon into spin and orbital contributions is one of the most important and interesting challenges faced by gauge theories like Quantum Electrodynamics and Quantum Chromodynamics. This is particularly challenging since all QED textbooks state that such an splitting cannot be done for a photon (and a fortiori for a gluon) in a gauge-invariant way, yet experimentalists around the world are engaged in measuring what they believe is the gluon spin! This question has been a subject of intense debate and controversy, ever since, in 2008, it was claimed that such a gauge-invariant split was, in fact, possible. We explain in what sense this claim is true and how it turns out that one of the main problems is that such a decomposition is not unique and therefore raises the question of what is the most natural or physical choice. The essential requirement of measurability does not solve the ambiguities and leads us to the conclusion that the choice of a particular decomposition is essentially a matter of taste and convenience. In this review, we provide a pedagogical introduction to the question of angular momentum decomposition in a gauge theory, present the main relevant decompositions and discuss in detail several aspects of the controversies regarding the question of gauge invariance, frame dependence, uniqueness and measurability. We stress the physical implications of the recent developments and collect into a separate section all the sum rules and relations which we think experimentally relevant. We hope that such a review will make the matter amenable to a broader community and will help to clarify the present situation.
[ { "created": "Tue, 17 Sep 2013 09:10:30 GMT", "version": "v1" } ]
2015-07-01
[ [ "Leader", "E.", "", "Imperial Coll., London" ], [ "Lorce", "C.", "", "Orsay, IPN and Liege,\n IFPA" ] ]
The general question, crucial to an understanding of the internal structure of the nucleon, of how to split the total angular momentum of a photon or gluon into spin and orbital contributions is one of the most important and interesting challenges faced by gauge theories like Quantum Electrodynamics and Quantum Chromodynamics. This is particularly challenging since all QED textbooks state that such an splitting cannot be done for a photon (and a fortiori for a gluon) in a gauge-invariant way, yet experimentalists around the world are engaged in measuring what they believe is the gluon spin! This question has been a subject of intense debate and controversy, ever since, in 2008, it was claimed that such a gauge-invariant split was, in fact, possible. We explain in what sense this claim is true and how it turns out that one of the main problems is that such a decomposition is not unique and therefore raises the question of what is the most natural or physical choice. The essential requirement of measurability does not solve the ambiguities and leads us to the conclusion that the choice of a particular decomposition is essentially a matter of taste and convenience. In this review, we provide a pedagogical introduction to the question of angular momentum decomposition in a gauge theory, present the main relevant decompositions and discuss in detail several aspects of the controversies regarding the question of gauge invariance, frame dependence, uniqueness and measurability. We stress the physical implications of the recent developments and collect into a separate section all the sum rules and relations which we think experimentally relevant. We hope that such a review will make the matter amenable to a broader community and will help to clarify the present situation.
hep-ph/0406248
Luciano Pandola
L. Pandola
Search for time modulations in the Gallex/GNO solar neutrino data
12 pages, 7 figures
Astropart.Phys.22:219-226,2004
10.1016/j.astropartphys.2004.07.007
null
hep-ph
null
The final data of the Gallex and GNO radiochemical experiments have been searched for possible time modulations of the solar neutrino capture rate using the Lomb-Scargle periodogram and the maximum likelihood methods. Both analyses, performed using the raw data, do not support the presence of a time variability with characteristic periods resembling those of rotation of the solar magnetic fields, as previously suggested in the literature by some authors. In this context, the potential sensitivity of the Lomb-Scargle method to radiochemical 71Ga data has also been explored with simulated data. This allowed to set an exclusion plot in the frequency/amplitude plane from the Gallex-GNO dataset.
[ { "created": "Wed, 23 Jun 2004 07:40:25 GMT", "version": "v1" } ]
2011-05-23
[ [ "Pandola", "L.", "" ] ]
The final data of the Gallex and GNO radiochemical experiments have been searched for possible time modulations of the solar neutrino capture rate using the Lomb-Scargle periodogram and the maximum likelihood methods. Both analyses, performed using the raw data, do not support the presence of a time variability with characteristic periods resembling those of rotation of the solar magnetic fields, as previously suggested in the literature by some authors. In this context, the potential sensitivity of the Lomb-Scargle method to radiochemical 71Ga data has also been explored with simulated data. This allowed to set an exclusion plot in the frequency/amplitude plane from the Gallex-GNO dataset.
hep-ph/0502161
Carl Albright
Carl H. Albright
Bounds on the Neutrino Mixing Angles and CP Phase for an SO(10) Model with Lopsided Mass Matrices
23 pages, 5 sets of scatterplots, successful leptogenesis with strongly correlated neutrino mixing parameters, published version with added references
Phys.Rev.D72:013001,2005; Erratum-ibid.D74:039903,2006
10.1103/PhysRevD.72.013001 10.1103/PhysRevD.74.039903
FERMILAB-Pub-05-021-T
hep-ph hep-ex
null
The bounds on the neutrino mixing angles and CP Dirac phase for an SO(10) model with lopsided mass matrices, arising from the presence of ${\bf 16}_H$ and $\bar{\bf 16}_H$ Higgs representations, are studied by variation of the one real and three unknown complex input parameters for the right-handed Majorana neutrino mass matrix. The scatter plots obtained favor nearly maximal atmospheric neutrino mixing, while the reactor neutrino mixing lies in the range $10^{-5} \lsim \sin^2 \theta_{13} \lsim 1 \times 10^{-2}$ with values greater than $10^{-3}$ most densely populated. A rather compelling scenario within the model follows, if we restrict the three unknown complex parameters to their imaginary axes and set two of them equal. We then find the scatter plots are reduced to narrow bands, as the mixing angles and CP phase become highly correlated and predictive. The bounds on the mixing angles and phase then become $0.45 \lsim \sin^2 \theta_{23} \lsim 0.55$, $0.38 \lsim \tan^2 \theta_{12} \lsim 0.50$, $0.002 \lsim \sin^2 \theta_{13} \lsim 0.003$, and $60^\circ \lsim \pm \delta_{CP} \lsim 85^\circ$. Moreover, successful leptogenesis and subsequent baryogenesis are also obtained, with $\eta_B$ increasing from $(2.7 to 6.3) \times 10^{-10}$ as $\sin^2 \theta_{23}$ increases from 0.45 to 0.55.
[ { "created": "Thu, 17 Feb 2005 20:16:51 GMT", "version": "v1" }, { "created": "Wed, 23 Feb 2005 20:46:21 GMT", "version": "v2" }, { "created": "Fri, 1 Apr 2005 17:01:50 GMT", "version": "v3" }, { "created": "Mon, 20 Jun 2005 19:31:32 GMT", "version": "v4" }, { "cr...
2014-11-18
[ [ "Albright", "Carl H.", "" ] ]
The bounds on the neutrino mixing angles and CP Dirac phase for an SO(10) model with lopsided mass matrices, arising from the presence of ${\bf 16}_H$ and $\bar{\bf 16}_H$ Higgs representations, are studied by variation of the one real and three unknown complex input parameters for the right-handed Majorana neutrino mass matrix. The scatter plots obtained favor nearly maximal atmospheric neutrino mixing, while the reactor neutrino mixing lies in the range $10^{-5} \lsim \sin^2 \theta_{13} \lsim 1 \times 10^{-2}$ with values greater than $10^{-3}$ most densely populated. A rather compelling scenario within the model follows, if we restrict the three unknown complex parameters to their imaginary axes and set two of them equal. We then find the scatter plots are reduced to narrow bands, as the mixing angles and CP phase become highly correlated and predictive. The bounds on the mixing angles and phase then become $0.45 \lsim \sin^2 \theta_{23} \lsim 0.55$, $0.38 \lsim \tan^2 \theta_{12} \lsim 0.50$, $0.002 \lsim \sin^2 \theta_{13} \lsim 0.003$, and $60^\circ \lsim \pm \delta_{CP} \lsim 85^\circ$. Moreover, successful leptogenesis and subsequent baryogenesis are also obtained, with $\eta_B$ increasing from $(2.7 to 6.3) \times 10^{-10}$ as $\sin^2 \theta_{23}$ increases from 0.45 to 0.55.
1008.0117
Yi Liao
Yi Liao (1 and 2 and 3), Guo-Zhu Ning (2), Lu Ren (2) ((1) CHEP, Peking U., (2) Nankai U., (3) Heidelberg U.)
Flavor Violating Transitions of Charged Leptons from a Seesaw Mechanism of Dimension Seven
v1: 25 pages, 8 figures; v2: proofread version for PRD. Included muon-electron conversion in nuclei at the referee's suggestion and added relevant refs accordingly; main conclusion not changed but bounds on tau lepton decays becoming more stringent; linguistic and editing corrections also made
Phys.Rev.D82:113003,2010
10.1103/PhysRevD.82.113003
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A mechanism has been suggested recently to generate the neutrino mass out of a dimension-seven operator. This is expected to relieve the tension between the occurrence of a tiny neutrino mass and the observability of other physics effects beyond it. Such a mechanism would inevitably entail lepton flavor violating effects. We study in this work the radiative and purely leptonic transitions of the light charged leptons. In so doing we make a systematic analysis of the flavor structure by providing a convenient parametrization of the mass matrices in terms of independent physical parameters and diagonalizing them explicitly. We illustrate our numerical results by sampling over two CP phases and one Yukawa coupling which are the essential parameters in addition to the heavy lepton mass. We find that with the stringent constraints coming from the muon decays and the muon-electron conversion in nuclei taken into account the decays of the tau lepton are severely suppressed in the majority of parameter space. There exist, however, small regions in which some tau decays can reach a level that is about 2 orders of magnitude below their current bounds.
[ { "created": "Sat, 31 Jul 2010 19:26:32 GMT", "version": "v1" }, { "created": "Wed, 1 Dec 2010 01:28:43 GMT", "version": "v2" } ]
2010-12-24
[ [ "Liao", "Yi", "", "1 and 2 and 3" ], [ "Ning", "Guo-Zhu", "" ], [ "Ren", "Lu", "" ] ]
A mechanism has been suggested recently to generate the neutrino mass out of a dimension-seven operator. This is expected to relieve the tension between the occurrence of a tiny neutrino mass and the observability of other physics effects beyond it. Such a mechanism would inevitably entail lepton flavor violating effects. We study in this work the radiative and purely leptonic transitions of the light charged leptons. In so doing we make a systematic analysis of the flavor structure by providing a convenient parametrization of the mass matrices in terms of independent physical parameters and diagonalizing them explicitly. We illustrate our numerical results by sampling over two CP phases and one Yukawa coupling which are the essential parameters in addition to the heavy lepton mass. We find that with the stringent constraints coming from the muon decays and the muon-electron conversion in nuclei taken into account the decays of the tau lepton are severely suppressed in the majority of parameter space. There exist, however, small regions in which some tau decays can reach a level that is about 2 orders of magnitude below their current bounds.
hep-ph/9507463
David Bowser-Chao
Ali Abbasabadi, David Bowser-Chao, Duane A. Dicus and Wayne W. Repko
Higgs-photon associated production at $e\bar{e}$ colliders
To appear in PRD. 18 pages latex, uses REVTEX; 5 postscript figures
Phys.Rev. D52 (1995) 3919-3928
10.1103/PhysRevD.52.3919
MSUHEP-41012
hep-ph
null
We present complete analytical expressions for the amplitudes of the process $e\bar{e}\rightarrow H\gamma$. The calculation is performed using nonlinear gauges, which significantly simplifies both the actual analytical calculation and the check of its gauge invariance. After comparing our results with a previous numerical calculation, we extend the range of Higgs masses and center of mass energies to those appropriate to LEP 200 and a future linear collider.
[ { "created": "Mon, 31 Jul 1995 20:07:52 GMT", "version": "v1" }, { "created": "Mon, 31 Jul 1995 20:23:43 GMT", "version": "v2" } ]
2009-10-28
[ [ "Abbasabadi", "Ali", "" ], [ "Bowser-Chao", "David", "" ], [ "Dicus", "Duane A.", "" ], [ "Repko", "Wayne W.", "" ] ]
We present complete analytical expressions for the amplitudes of the process $e\bar{e}\rightarrow H\gamma$. The calculation is performed using nonlinear gauges, which significantly simplifies both the actual analytical calculation and the check of its gauge invariance. After comparing our results with a previous numerical calculation, we extend the range of Higgs masses and center of mass energies to those appropriate to LEP 200 and a future linear collider.
hep-ph/0406127
Andrei Afanasev
Andrei Afanasev, N.P. Merenkov
Large Logarithms in the Beam Normal Spin Asymmetry of Elastic Electron--Proton Scattering
10 pages, 6 figures; typos fixed, a reference added
Phys.Rev.D70:073002,2004
10.1103/PhysRevD.70.073002
JLAB-PHY-04-238
hep-ph nucl-th
null
We study a parity-conserving single-spin beam asymmetry of elastic electron-proton scattering induced by an absorptive part of the two-photon exchange amplitude. It is demonstrated that excitation of inelastic hadronic intermediate states by the consecutive exchange of two photons leads to logarithmic and double-logarithmic enhancement due to contributions of hard collinear quasi-real photons. The asymmetry at small electron scattering angles is expressed in terms of the total photoproduction cross section on the proton, and is predicted to reach the magnitude of 20-30 parts per million. At these conditions and fixed 4-momentum transfers, the asymmetry is rising logarithmically with increasing electron beam energy, following the high-energy diffractive behavior of total photoproduction cross section on the proton.
[ { "created": "Thu, 10 Jun 2004 20:12:53 GMT", "version": "v1" }, { "created": "Sat, 12 Jun 2004 16:29:02 GMT", "version": "v2" } ]
2008-11-26
[ [ "Afanasev", "Andrei", "" ], [ "Merenkov", "N. P.", "" ] ]
We study a parity-conserving single-spin beam asymmetry of elastic electron-proton scattering induced by an absorptive part of the two-photon exchange amplitude. It is demonstrated that excitation of inelastic hadronic intermediate states by the consecutive exchange of two photons leads to logarithmic and double-logarithmic enhancement due to contributions of hard collinear quasi-real photons. The asymmetry at small electron scattering angles is expressed in terms of the total photoproduction cross section on the proton, and is predicted to reach the magnitude of 20-30 parts per million. At these conditions and fixed 4-momentum transfers, the asymmetry is rising logarithmically with increasing electron beam energy, following the high-energy diffractive behavior of total photoproduction cross section on the proton.
hep-ph/0605062
Horst Stoecker
Horst Stoecker
Stable TeV - Black Hole Remnants at the LHC: Discovery through Di-Jet Suppression, Mono-Jet Emission and a Supersonic Boom in the Quark-Gluon Plasma
21 pages, 9 figures. accepted for publication in International Journal of Modern Physics D, added content in Section 5
Int.J.Mod.Phys.D16:185-205,2007
10.1142/S0218271807009930
null
hep-ph astro-ph hep-ex nucl-ex nucl-th
null
The production of Large Extra Dimension (LXD) Black Holes (BHs), with a new, fundamental mass scale of $M_f = 1$ TeV, has been predicted to occur at the Large Hadron Collider, LHC, with the formidable rate of $10^8$ per year in p-p collisions at full energy, 14 TeV, and at full luminosity. We show that such LXD-BH formation will be experimentally observable at the LHC by the complete disappearance of all very high $p_t$ ($> 500$ GeV) back-to-back correlated Di-Jets of total mass $M > M_f = 1$ TeV. We suggest to complement this clear cut-off signal at $M > 2*500$ GeV in the di-jet-correlation function by detecting the subsequent, Hawking-decay products of the LXD-BHs, namely either multiple high energy ($> 100$ GeV) SM Mono-Jets (i.e. away-side jet missing), sprayed off the evaporating BHs isentropically into all directions or the thermalization of the multiple overlapping Hawking-radiation in a Heckler-Kapusta-Plasma. Microcanonical quantum statistical calculations of the Hawking evaporation process for these LXD-BHs show that cold black hole remnants (BHRs) of Mass $\sim M_f$ remain leftover as the ashes of these spectacular Di-Jet-suppressed events. Strong Di-Jet suppression is also expected with Heavy Ion beams at the LHC, due to Quark-Gluon-Plasma induced jet attenuation at medium to low jet energies, $p_t < 200$ GeV. The (Mono-)Jets in these events can be used to trigger for Tsunami-emission of secondary compressed QCD-matter at well defined Mach-angles, both at the trigger side and at the awayside (missing) jet. The Machshock-angles allow for a direct measurement of both the equation of state EoS and the speed of sound $c_s$ via supersonic bang in the "big bang" matter.
[ { "created": "Fri, 5 May 2006 14:32:24 GMT", "version": "v1" }, { "created": "Mon, 8 May 2006 09:32:57 GMT", "version": "v2" }, { "created": "Tue, 20 Jun 2006 11:52:10 GMT", "version": "v3" } ]
2008-11-26
[ [ "Stoecker", "Horst", "" ] ]
The production of Large Extra Dimension (LXD) Black Holes (BHs), with a new, fundamental mass scale of $M_f = 1$ TeV, has been predicted to occur at the Large Hadron Collider, LHC, with the formidable rate of $10^8$ per year in p-p collisions at full energy, 14 TeV, and at full luminosity. We show that such LXD-BH formation will be experimentally observable at the LHC by the complete disappearance of all very high $p_t$ ($> 500$ GeV) back-to-back correlated Di-Jets of total mass $M > M_f = 1$ TeV. We suggest to complement this clear cut-off signal at $M > 2*500$ GeV in the di-jet-correlation function by detecting the subsequent, Hawking-decay products of the LXD-BHs, namely either multiple high energy ($> 100$ GeV) SM Mono-Jets (i.e. away-side jet missing), sprayed off the evaporating BHs isentropically into all directions or the thermalization of the multiple overlapping Hawking-radiation in a Heckler-Kapusta-Plasma. Microcanonical quantum statistical calculations of the Hawking evaporation process for these LXD-BHs show that cold black hole remnants (BHRs) of Mass $\sim M_f$ remain leftover as the ashes of these spectacular Di-Jet-suppressed events. Strong Di-Jet suppression is also expected with Heavy Ion beams at the LHC, due to Quark-Gluon-Plasma induced jet attenuation at medium to low jet energies, $p_t < 200$ GeV. The (Mono-)Jets in these events can be used to trigger for Tsunami-emission of secondary compressed QCD-matter at well defined Mach-angles, both at the trigger side and at the awayside (missing) jet. The Machshock-angles allow for a direct measurement of both the equation of state EoS and the speed of sound $c_s$ via supersonic bang in the "big bang" matter.
1606.04186
Yohei Ema
Yohei Ema, Takeo Moroi
Early Decay of Peccei-Quinn Fermion and the IceCube Neutrino Events
20 pages, 2 figures; v2: references added; v3: version accepted for publication in PLB
null
10.1016/j.physletb.2016.09.048
UT-16-25
hep-ph astro-ph.CO astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
IceCube observed high-energy neutrino flux in the energy region from TeV to PeV. The decay of a massive long-lived particle in the early universe can be the origin of the IceCube neutrino events, which we call an "early decay scenario." In this paper, we construct a particle physics model that contains such a massive long-lived particle based on the Peccei-Quinn model. We calculate the present neutrino flux, taking account of realistic initial energy distributions of particles produced by the decay of the massive long-lived particle. We show that the early decay scenario naturally fits into the Peccei-Quinn model, and that the neutrino flux observed by IceCube can be explained in such a framework. We also see that, based on that model, a consistent cosmological history that explains the abundance of the massive long-lived particle is realized.
[ { "created": "Tue, 14 Jun 2016 01:18:34 GMT", "version": "v1" }, { "created": "Sun, 26 Jun 2016 21:17:26 GMT", "version": "v2" }, { "created": "Thu, 22 Sep 2016 05:03:16 GMT", "version": "v3" } ]
2016-10-05
[ [ "Ema", "Yohei", "" ], [ "Moroi", "Takeo", "" ] ]
IceCube observed high-energy neutrino flux in the energy region from TeV to PeV. The decay of a massive long-lived particle in the early universe can be the origin of the IceCube neutrino events, which we call an "early decay scenario." In this paper, we construct a particle physics model that contains such a massive long-lived particle based on the Peccei-Quinn model. We calculate the present neutrino flux, taking account of realistic initial energy distributions of particles produced by the decay of the massive long-lived particle. We show that the early decay scenario naturally fits into the Peccei-Quinn model, and that the neutrino flux observed by IceCube can be explained in such a framework. We also see that, based on that model, a consistent cosmological history that explains the abundance of the massive long-lived particle is realized.
1109.6819
Bronislav Zakharov
P.Aurenche and B.G.Zakharov
Jet color chemistry and anomalous baryon production in $AA$-collisions
20 pages, 4 figures, Eur.Phys.J. version
Eur.Phys.J. C71 (2011) 1829
10.1140/epjc/s10052-011-1829-5
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study anomalous high-$p_T$ baryon production in $AA$-collisions due to formation of the two parton collinear $gq$ system in the anti-sextet color state for quark jets and $gg$ system in the decuplet/anti-decuplet color states for gluon jets. Fragmentation of these states, which are absent for $NN$-collisions, after escaping from the quark-gluon plasma leads to baryon production. Our qualitative estimates show that this mechanism can be potentially important at RHIC and LHC energies.
[ { "created": "Fri, 30 Sep 2011 13:34:33 GMT", "version": "v1" }, { "created": "Fri, 30 Dec 2011 14:34:01 GMT", "version": "v2" } ]
2015-05-30
[ [ "Aurenche", "P.", "" ], [ "Zakharov", "B. G.", "" ] ]
We study anomalous high-$p_T$ baryon production in $AA$-collisions due to formation of the two parton collinear $gq$ system in the anti-sextet color state for quark jets and $gg$ system in the decuplet/anti-decuplet color states for gluon jets. Fragmentation of these states, which are absent for $NN$-collisions, after escaping from the quark-gluon plasma leads to baryon production. Our qualitative estimates show that this mechanism can be potentially important at RHIC and LHC energies.
hep-ph/0206179
Robert L. Thews
R. L. Thews (Department of Physics, University of Arizona)
Nonlinear Behavior of Quarkonium Formation and Deconfinement Signals
To appear in the proceedings of Pan American Advanced Studies Institute on New States of Matter in Hadronic Interactions (PASI 2002), Campos do Jordao, Brazil, 7-18 Jan 2002; American Institute of Physics 2002
AIP Conf.Proc. 631 (2002) 490-524
10.1063/1.1513696
null
hep-ph nucl-th
null
We anticipate new features of quarkonium production in heavy ion collisions at RHIC and LHC energies which differ from a straightforward extrapolation of results at CERN SPS energy. General arguments indicate that one may expect quarkonium formation rates to increase more rapidly with energy and centrality than the production rate of the heavy quarks which they contain. This is due to new formation mechanisms in which independently-produced quarks and antiquarks form a bound quarkonium state. This mechanism will depend quadratically on the total number of initially-produced heavy quark pairs, and becomes numerically significant only at RHIC and LHC energy. When viewed as a signal of color deconfinement, a transition from suppression to enhancement may be observed. Explicit model calculations are presented, in which one can follow striking variations of final quarkonium production within a range of parameter space.
[ { "created": "Wed, 19 Jun 2002 21:26:00 GMT", "version": "v1" } ]
2009-11-07
[ [ "Thews", "R. L.", "", "Department of Physics, University of Arizona" ] ]
We anticipate new features of quarkonium production in heavy ion collisions at RHIC and LHC energies which differ from a straightforward extrapolation of results at CERN SPS energy. General arguments indicate that one may expect quarkonium formation rates to increase more rapidly with energy and centrality than the production rate of the heavy quarks which they contain. This is due to new formation mechanisms in which independently-produced quarks and antiquarks form a bound quarkonium state. This mechanism will depend quadratically on the total number of initially-produced heavy quark pairs, and becomes numerically significant only at RHIC and LHC energy. When viewed as a signal of color deconfinement, a transition from suppression to enhancement may be observed. Explicit model calculations are presented, in which one can follow striking variations of final quarkonium production within a range of parameter space.
hep-ph/9808237
Yu-Qi Chen
Yu-Qi Chen
Solving the rho - pi puzzle by higher charmonium Fock states
11 pages, Talk given at 3rd Workshop on Continuous Advances in QCD (QCD 98), Minneapolis, MN, 16-19 Apr 1998
null
null
null
hep-ph hep-ex nucl-th
null
A new explanation for the longstanding puzzle of the tiny branching fraction of psi' --> rho pi relative to that for J/psi --> rho pi was proposed. In the case of J/psi, we argue that this decay is dominated by a higher Fock state in which the c cbar pair is in a color-octet ^3S_1 state and annihilates via the process c cbar --> q qbar. In the case of the psi', we argue that the probability for the c cbar c pair in this higher Fock state to be close enough to annihilate is suppressed by a dynamical effect related to the small energy gap between the mass of the psi' and the D Dbar threshold.
[ { "created": "Thu, 6 Aug 1998 03:11:05 GMT", "version": "v1" } ]
2007-05-23
[ [ "Chen", "Yu-Qi", "" ] ]
A new explanation for the longstanding puzzle of the tiny branching fraction of psi' --> rho pi relative to that for J/psi --> rho pi was proposed. In the case of J/psi, we argue that this decay is dominated by a higher Fock state in which the c cbar pair is in a color-octet ^3S_1 state and annihilates via the process c cbar --> q qbar. In the case of the psi', we argue that the probability for the c cbar c pair in this higher Fock state to be close enough to annihilate is suppressed by a dynamical effect related to the small energy gap between the mass of the psi' and the D Dbar threshold.
1008.5153
Clifford Cheung
Clifford Cheung and Yasunori Nomura
Singlet Portal to the Hidden Sector
12 pages, 5 figures
JHEP 1011:103,2010
10.1007/JHEP11(2010)103
UCB-PTH-10/16
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Ultraviolet physics typically induces a kinetic mixing between gauge singlets which is marginal and hence non-decoupling in the infrared. In singlet extensions of the minimal supersymmetric standard model, e.g. the next-to-minimal supersymmetric standard model, this furnishes a well motivated and distinctive portal connecting the visible sector to any hidden sector which contains a singlet chiral superfield. In the presence of singlet kinetic mixing, the hidden sector automatically acquires a light mass scale in the range 0.1 - 100 GeV induced by electroweak symmetry breaking. In theories with R-parity conservation, superparticles produced at the LHC invariably cascade decay into hidden sector particles. Since the hidden sector singlet couples to the visible sector via the Higgs sector, these cascades necessarily produce a Higgs boson in an order 0.01 - 1 fraction of events. Furthermore, supersymmetric cascades typically produce highly boosted, low-mass hidden sector singlets decaying visibly, albeit with displacement, into the heaviest standard model particles which are kinematically accessible. We study experimental constraints on this broad class of theories, as well as the role of singlet kinetic mixing in direct detection of hidden sector dark matter. We also present related theories in which a hidden sector singlet interacts with the visible sector through kinetic mixing with right-handed neutrinos.
[ { "created": "Mon, 30 Aug 2010 20:00:05 GMT", "version": "v1" } ]
2010-11-26
[ [ "Cheung", "Clifford", "" ], [ "Nomura", "Yasunori", "" ] ]
Ultraviolet physics typically induces a kinetic mixing between gauge singlets which is marginal and hence non-decoupling in the infrared. In singlet extensions of the minimal supersymmetric standard model, e.g. the next-to-minimal supersymmetric standard model, this furnishes a well motivated and distinctive portal connecting the visible sector to any hidden sector which contains a singlet chiral superfield. In the presence of singlet kinetic mixing, the hidden sector automatically acquires a light mass scale in the range 0.1 - 100 GeV induced by electroweak symmetry breaking. In theories with R-parity conservation, superparticles produced at the LHC invariably cascade decay into hidden sector particles. Since the hidden sector singlet couples to the visible sector via the Higgs sector, these cascades necessarily produce a Higgs boson in an order 0.01 - 1 fraction of events. Furthermore, supersymmetric cascades typically produce highly boosted, low-mass hidden sector singlets decaying visibly, albeit with displacement, into the heaviest standard model particles which are kinematically accessible. We study experimental constraints on this broad class of theories, as well as the role of singlet kinetic mixing in direct detection of hidden sector dark matter. We also present related theories in which a hidden sector singlet interacts with the visible sector through kinetic mixing with right-handed neutrinos.
1003.4521
German Calderon
G. Calderon
Branching ratios and CP asymmetries in charmless nonleptonic B decays to radially excited mesons
18 pages, 11 tables
Phys. Rev. D 86, 094022 (2012)
10.1103/PhysRevD.86.094022
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Nonleptonic two body B decays including radially excited $\pi(1300)$ or $\rho(1450)$ mesons in the final state are studied using the framework of generalized naive factorization approach. Branching ratios and CP asymmetries of $B\to P\pi(1300)$, $B\to V\pi(1300)$, $B\to P\rho(1450)$ and $B\to V\rho(1450)$ decays are calculated, where P and V stand for pseudoscalar and vector charmless mesons. Form factors for $B\to \pi(1300)$ and $B\to \rho(1450)$ transitions are estimated in the improved version of the Isgur-Scora-Grinstein-Wise quark model. In some processes, CP asymmetries of more than 10% and branching ratios of $10^{-5}$ order are found, which could be reached in experiments.
[ { "created": "Tue, 23 Mar 2010 20:25:45 GMT", "version": "v1" } ]
2013-08-06
[ [ "Calderon", "G.", "" ] ]
Nonleptonic two body B decays including radially excited $\pi(1300)$ or $\rho(1450)$ mesons in the final state are studied using the framework of generalized naive factorization approach. Branching ratios and CP asymmetries of $B\to P\pi(1300)$, $B\to V\pi(1300)$, $B\to P\rho(1450)$ and $B\to V\rho(1450)$ decays are calculated, where P and V stand for pseudoscalar and vector charmless mesons. Form factors for $B\to \pi(1300)$ and $B\to \rho(1450)$ transitions are estimated in the improved version of the Isgur-Scora-Grinstein-Wise quark model. In some processes, CP asymmetries of more than 10% and branching ratios of $10^{-5}$ order are found, which could be reached in experiments.
0807.4359
Farkhad Khalil-zade
O. B. Abdinov, F.T. Khalil-zade, S. S. Rzaeva
Electric Charge Quantization in Standard Model
4 pages
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the framework of Standard Model for the arbitrary values of Higgs and fermions fields hypercharges, taking into account parity invariance of electromagnetic interaction, expressions for the fermions charges, testifying the electric charge quantization are obtained. From the chiral anomalies cancellation condition within one family of leptons and quarks, numerical values of fermions charges, coinciding with standard values of charges have been obtained.
[ { "created": "Mon, 28 Jul 2008 05:38:26 GMT", "version": "v1" } ]
2008-07-29
[ [ "Abdinov", "O. B.", "" ], [ "Khalil-zade", "F. T.", "" ], [ "Rzaeva", "S. S.", "" ] ]
In the framework of Standard Model for the arbitrary values of Higgs and fermions fields hypercharges, taking into account parity invariance of electromagnetic interaction, expressions for the fermions charges, testifying the electric charge quantization are obtained. From the chiral anomalies cancellation condition within one family of leptons and quarks, numerical values of fermions charges, coinciding with standard values of charges have been obtained.
0903.0256
Yadong Yang
Yuan-Guo Xu, Ru-Min Wang and Ya-Dong Yang
B_s\to K^{(*)-}K^{(*)+}, K^{(*)-}\pi^{+}, K^{(*)-}\rho^{+} decays in R-parity violating supersymmetry
29 pages, 6 figures, to appear in PRD
Phys.Rev.D79:095017,2009
10.1103/PhysRevD.79.095017
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
With the first measurements of the branching ratios and the direct CP asymmetries of $B_s\to K^{-}K^{+}$, $K^{-}\pi^{+}$ decays by the CDF collaboration, we constrain the relevant parameter space of the Minimal Supersymmetric Standard Model with R-parity violation. Using the constrained R-parity violating couplings, we further examine their possible effects in $B_{s}\to K^{-*}\pi^{+}$, $K^{(*)-}\rho^{+}$ and $K^{(*)\pm}K^{(*)\mp}$ decays. We find that some branching ratios and CP asymmetries are very sensitive to the R-parity violating couplings. The direct longitudinal CP asymmetries of tree-dominated process $B_s\to K^{*-}\rho^{+}$ could be enlarged to $\sim 70%$ and the longitudinal polarizations of $B_s\to K^{*-}K^{*+}$, $K^{*-}\rho^{+}$ decays could be suppressed very much by the squark exchange couplings. Near future experiments at CERN LHC can test these predictions and shrink/reveal the parameter spaces of RPV SUSY.
[ { "created": "Mon, 2 Mar 2009 10:47:12 GMT", "version": "v1" }, { "created": "Fri, 8 May 2009 02:24:22 GMT", "version": "v2" } ]
2009-07-30
[ [ "Xu", "Yuan-Guo", "" ], [ "Wang", "Ru-Min", "" ], [ "Yang", "Ya-Dong", "" ] ]
With the first measurements of the branching ratios and the direct CP asymmetries of $B_s\to K^{-}K^{+}$, $K^{-}\pi^{+}$ decays by the CDF collaboration, we constrain the relevant parameter space of the Minimal Supersymmetric Standard Model with R-parity violation. Using the constrained R-parity violating couplings, we further examine their possible effects in $B_{s}\to K^{-*}\pi^{+}$, $K^{(*)-}\rho^{+}$ and $K^{(*)\pm}K^{(*)\mp}$ decays. We find that some branching ratios and CP asymmetries are very sensitive to the R-parity violating couplings. The direct longitudinal CP asymmetries of tree-dominated process $B_s\to K^{*-}\rho^{+}$ could be enlarged to $\sim 70%$ and the longitudinal polarizations of $B_s\to K^{*-}K^{*+}$, $K^{*-}\rho^{+}$ decays could be suppressed very much by the squark exchange couplings. Near future experiments at CERN LHC can test these predictions and shrink/reveal the parameter spaces of RPV SUSY.
1806.04844
Haiqing Zhou
Hong-Yu Chen, Hai-Qing Zhou
Two-photon exchange effects in $e^+e^- \rightarrow \pi^+\pi^-$ and time-like pion electromagnetic form factor
null
Phys. Rev. D 98, 054003 (2018)
10.1103/PhysRevD.98.054003
null
hep-ph hep-ex nucl-th
http://creativecommons.org/publicdomain/zero/1.0/
The two-photon-exchange (TPE) effects in the process $e^+e^- \rightarrow \pi^+\pi^-$ at large momentum transfer are discussed within the perturbative QCD (pQCD). The contributions from the twist-2 and twist-3 distribution amplitudes (DAs) of pion are considered in the estimation. Different with the results under the one-photon-exchange (OPE) approximation, the TPE effects result in an asymmetry of the differential cross section on the scattering angle. The precise measurement of this asymmetry by the further experiment is an precise test of pQCD at large momentum transfer. The time-like electromagnetic form factor of pion at the leading order of pQCD is re-discussed and the comparison of our results with those in the references are presented.
[ { "created": "Wed, 13 Jun 2018 04:52:15 GMT", "version": "v1" } ]
2018-09-12
[ [ "Chen", "Hong-Yu", "" ], [ "Zhou", "Hai-Qing", "" ] ]
The two-photon-exchange (TPE) effects in the process $e^+e^- \rightarrow \pi^+\pi^-$ at large momentum transfer are discussed within the perturbative QCD (pQCD). The contributions from the twist-2 and twist-3 distribution amplitudes (DAs) of pion are considered in the estimation. Different with the results under the one-photon-exchange (OPE) approximation, the TPE effects result in an asymmetry of the differential cross section on the scattering angle. The precise measurement of this asymmetry by the further experiment is an precise test of pQCD at large momentum transfer. The time-like electromagnetic form factor of pion at the leading order of pQCD is re-discussed and the comparison of our results with those in the references are presented.
hep-ph/0603177
Carlo Oleari
Barbara Jager, Carlo Oleari and Dieter Zeppenfeld
Next-to-leading order QCD corrections to W+W- production via vector-boson fusion
29 pages, 14 figures
JHEP0607:015,2006
10.1088/1126-6708/2006/07/015
null
hep-ph
null
Vector-boson fusion processes constitute an important class of reactions at hadron colliders, both for signals and backgrounds of new physics in the electroweak interactions. We consider what is commonly referred to as W+W- production via vector-boson fusion (with subsequent leptonic decay of the Ws), or, more precisely, e+ nu_e mu- nubar_mu + 2 jets production in proton-proton scattering, with all resonant and non-resonant Feynman diagrams and spin correlations of the final-state leptons included, in the phase-space regions which are dominated by t-channel electroweak-boson exchange. We compute the next-to-leading order QCD corrections to this process, at order alpha^6 alpha_s. The QCD corrections are modest, changing total cross sections by less than 10%. Remaining scale uncertainties are below 2%. A fully-flexible next-to-leading order partonic Monte Carlo program allows to demonstrate these features for cross sections within typical vector-boson-fusion acceptance cuts. Modest corrections are also found for distributions.
[ { "created": "Wed, 22 Mar 2006 16:48:00 GMT", "version": "v1" } ]
2009-11-11
[ [ "Jager", "Barbara", "" ], [ "Oleari", "Carlo", "" ], [ "Zeppenfeld", "Dieter", "" ] ]
Vector-boson fusion processes constitute an important class of reactions at hadron colliders, both for signals and backgrounds of new physics in the electroweak interactions. We consider what is commonly referred to as W+W- production via vector-boson fusion (with subsequent leptonic decay of the Ws), or, more precisely, e+ nu_e mu- nubar_mu + 2 jets production in proton-proton scattering, with all resonant and non-resonant Feynman diagrams and spin correlations of the final-state leptons included, in the phase-space regions which are dominated by t-channel electroweak-boson exchange. We compute the next-to-leading order QCD corrections to this process, at order alpha^6 alpha_s. The QCD corrections are modest, changing total cross sections by less than 10%. Remaining scale uncertainties are below 2%. A fully-flexible next-to-leading order partonic Monte Carlo program allows to demonstrate these features for cross sections within typical vector-boson-fusion acceptance cuts. Modest corrections are also found for distributions.
1610.09618
Giampiero Passarino
Giampiero Passarino (Turin U. & INFN, Turin)
Field reparametrization in effective field theories
15 pages, 11 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Debate topic for Effective Field Theory (EFT) is the choice of a "basis" for $\mrdim = 6$ operators Clearly all bases are equivalent as long as they are a "basis", containing a minimal set of operators after the use of equations of motion and respecting gauge invariance. From a more formal point of view a basis is characterized by its closure with respect to renormalization. Equivalence of bases should always be understood as a statement for the S-matrix and not for the Lagrangian, as dictated by the equivalence theorem. Any phenomenological approach that misses one of these ingredients is still acceptable for a preliminar analysis, as long as it does not pretend to be an EFT. Here we revisit the equivalence theorem and its consequences for EFT when two sets of higher dimensional operators are connected by a set of non-linear, noninvariant, field reparametrizations.
[ { "created": "Sun, 30 Oct 2016 08:59:14 GMT", "version": "v1" } ]
2016-11-01
[ [ "Passarino", "Giampiero", "", "Turin U. & INFN, Turin" ] ]
Debate topic for Effective Field Theory (EFT) is the choice of a "basis" for $\mrdim = 6$ operators Clearly all bases are equivalent as long as they are a "basis", containing a minimal set of operators after the use of equations of motion and respecting gauge invariance. From a more formal point of view a basis is characterized by its closure with respect to renormalization. Equivalence of bases should always be understood as a statement for the S-matrix and not for the Lagrangian, as dictated by the equivalence theorem. Any phenomenological approach that misses one of these ingredients is still acceptable for a preliminar analysis, as long as it does not pretend to be an EFT. Here we revisit the equivalence theorem and its consequences for EFT when two sets of higher dimensional operators are connected by a set of non-linear, noninvariant, field reparametrizations.
1206.2549
Pere Masjuan
P. Masjuan
\gamma*\gamma \rightarrow \pi^0 transition form factor at low-energies from a model-independent approach
9 pages, 5 figures. Matches version published in PRD
Phys. Rev., D86, 094021 (2012)
10.1103/PhysRevD.86.094021
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The recent measured \gamma*\gamma \rightarrow \pi^0 transition form factor in the space-like region by the Belle Collaboration together with the previous published results by CLEO, CELLO and BABAR collaborations are analyzed using the mathematical theory of Pad\'e Approximants which provides a good and systematic description of the low energy region exemplified here with the extraction of the slope a_{\pi} and curvature b_{\pi} of the form factor in a model-independent way. The impact of them on the pion exchange contribution to the hadronic light-by-light scattering part of the anomalous magnetic moment a_{\mu} is also discussed.
[ { "created": "Tue, 12 Jun 2012 14:46:12 GMT", "version": "v1" }, { "created": "Mon, 19 Nov 2012 09:53:11 GMT", "version": "v2" } ]
2013-05-30
[ [ "Masjuan", "P.", "" ] ]
The recent measured \gamma*\gamma \rightarrow \pi^0 transition form factor in the space-like region by the Belle Collaboration together with the previous published results by CLEO, CELLO and BABAR collaborations are analyzed using the mathematical theory of Pad\'e Approximants which provides a good and systematic description of the low energy region exemplified here with the extraction of the slope a_{\pi} and curvature b_{\pi} of the form factor in a model-independent way. The impact of them on the pion exchange contribution to the hadronic light-by-light scattering part of the anomalous magnetic moment a_{\mu} is also discussed.
1502.08041
Massimo Bianchi Prof
Andrea Addazi and Massimo Bianchi
Neutron Majorana mass from Exotic Instantons in a Pati-Salam model
21 pages, 3 figures
null
null
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show how exotic stringy instantons can generate an effective interaction between color diquark sextets in a Pati-Salam model, inducing a Majorana mass term for the neutron. In particular, we discuss a simple quiver theory for a Pati-Salam like model, as an example in which the calculations of exotic instantons' effects are simple and controllable. We discuss some different possibilities in order to generate $n-\bar{n}$ oscillation testable in the next generation of experiments, Majorana mass matrices for neutrini and a Post-Sphaleron Baryogenesis scenario. Connections with Dark Matter issues and the Higgs mass Hierarchy problem are discussed, in view of implications for LHC and rare processes physics. The model may be viewed as a completion of Left-Right symmetry, alternative to a GUT-inspired scenario. Combined measures in Neutron-Antineutron physics, FCNC, LHC, Dark Matter could rule out the proposed model or uncover aspects of physics at the Planck scale!
[ { "created": "Fri, 27 Feb 2015 20:08:06 GMT", "version": "v1" } ]
2015-03-02
[ [ "Addazi", "Andrea", "" ], [ "Bianchi", "Massimo", "" ] ]
We show how exotic stringy instantons can generate an effective interaction between color diquark sextets in a Pati-Salam model, inducing a Majorana mass term for the neutron. In particular, we discuss a simple quiver theory for a Pati-Salam like model, as an example in which the calculations of exotic instantons' effects are simple and controllable. We discuss some different possibilities in order to generate $n-\bar{n}$ oscillation testable in the next generation of experiments, Majorana mass matrices for neutrini and a Post-Sphaleron Baryogenesis scenario. Connections with Dark Matter issues and the Higgs mass Hierarchy problem are discussed, in view of implications for LHC and rare processes physics. The model may be viewed as a completion of Left-Right symmetry, alternative to a GUT-inspired scenario. Combined measures in Neutron-Antineutron physics, FCNC, LHC, Dark Matter could rule out the proposed model or uncover aspects of physics at the Planck scale!
hep-ph/0007332
A. K. Chaudhuri
A. K. Chaudhuri
Phase transition in linear sigma model and disoriented chiral condensate
6 pages including 4 figures
null
null
null
hep-ph
null
We have investigated the phase transition and disoriented chiral condensate domain formation in linear sigma model. Solving the equation of motion for the sigma model fields in contact with a heat bath, we have shown that the fields undergo phase transition above a certain critical temperature(T_c). It was also shown that when the fields thermalised at temperature above T_c are cooled down sufficiently rapidly, disoriented chiral condensate domains are formed quite late in the evolution.
[ { "created": "Fri, 28 Jul 2000 11:24:22 GMT", "version": "v1" } ]
2007-05-23
[ [ "Chaudhuri", "A. K.", "" ] ]
We have investigated the phase transition and disoriented chiral condensate domain formation in linear sigma model. Solving the equation of motion for the sigma model fields in contact with a heat bath, we have shown that the fields undergo phase transition above a certain critical temperature(T_c). It was also shown that when the fields thermalised at temperature above T_c are cooled down sufficiently rapidly, disoriented chiral condensate domains are formed quite late in the evolution.
hep-ph/0306196
Yurii Surovtsev
Yu.S. Surovtsev, D. Krupa and M. Nagy
Mesons of the $f_0$-family in the processes $\pi\pi\to\pi\pi,K\bar{K},\eta\eta$ up to 1.9 GeV
8 pages, LaTex; Talk at the XVI Int'l Baldin Seminar on High Energy Physics Problems "Relativistic Nuclear Physics and Quantum Chromodynamics" (Dubna, 10-15 June, 2002) and at Int. Conf. "Hadron Structure' 02" (Herl'any, Slovak Republic, 22-29 September 2002)
null
null
null
hep-ph
null
In combined 2- and 3-channel analyses of experimental data on the coupled processes $\pi\pi\to\pi\pi,K\bar{K},\eta\eta$ in the channel with $I^GJ^{PC}=0^+0^{++}$, various scenarios of these reactions(with different numbers of resonances) are considered. In a model-independent approach, confirmation of the $\sigma$-meson below 1 GeV and definite indications of the QCD nature of other $f_0$ resonances are obtained. The conclusion on the linear realization of chiral symmetry is drawn.
[ { "created": "Sat, 21 Jun 2003 14:50:21 GMT", "version": "v1" } ]
2007-05-23
[ [ "Surovtsev", "Yu. S.", "" ], [ "Krupa", "D.", "" ], [ "Nagy", "M.", "" ] ]
In combined 2- and 3-channel analyses of experimental data on the coupled processes $\pi\pi\to\pi\pi,K\bar{K},\eta\eta$ in the channel with $I^GJ^{PC}=0^+0^{++}$, various scenarios of these reactions(with different numbers of resonances) are considered. In a model-independent approach, confirmation of the $\sigma$-meson below 1 GeV and definite indications of the QCD nature of other $f_0$ resonances are obtained. The conclusion on the linear realization of chiral symmetry is drawn.
1109.5181
Kevin Dusling
Kevin Dusling, Thomas Schaefer
Bulk viscosity, particle spectra and flow in heavy-ion collisions
null
null
10.1103/PhysRevC.85.044909
null
hep-ph nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the effects of bulk viscosity on pT spectra and elliptic flow in heavy ion collisions. For this purpose we compute the dissipative correction df to the single particle distribution functions in leading-log QCD, and in several simplified models. We consider, in particular, the relaxation time approximation and a kinetic model for the hadron resonance gas. We implement these distribution functions in a hydrodynamic simulation of Au + Au collisions at RHIC. We find significant corrections due to bulk viscosity in hadron pT spectra and the differential elliptic flow parameter v2(pT). These corrections are dominated by viscous corrections to the distribution function. We find that the relation between df and the bulk viscosity is different in the quark gluon plasma and hadronic phases. Reliable bounds on the bulk viscosity require accurate calculations of df in a hadronic resonance gas. Based on v2 spectra at RHIC we conservatively estimate zeta/s <= 0.05 near freeze-out. We also find that effects of the bulk viscosity on the pT integrated v2 are small.
[ { "created": "Fri, 23 Sep 2011 20:00:05 GMT", "version": "v1" }, { "created": "Wed, 11 Jan 2012 17:03:30 GMT", "version": "v2" } ]
2013-05-30
[ [ "Dusling", "Kevin", "" ], [ "Schaefer", "Thomas", "" ] ]
We study the effects of bulk viscosity on pT spectra and elliptic flow in heavy ion collisions. For this purpose we compute the dissipative correction df to the single particle distribution functions in leading-log QCD, and in several simplified models. We consider, in particular, the relaxation time approximation and a kinetic model for the hadron resonance gas. We implement these distribution functions in a hydrodynamic simulation of Au + Au collisions at RHIC. We find significant corrections due to bulk viscosity in hadron pT spectra and the differential elliptic flow parameter v2(pT). These corrections are dominated by viscous corrections to the distribution function. We find that the relation between df and the bulk viscosity is different in the quark gluon plasma and hadronic phases. Reliable bounds on the bulk viscosity require accurate calculations of df in a hadronic resonance gas. Based on v2 spectra at RHIC we conservatively estimate zeta/s <= 0.05 near freeze-out. We also find that effects of the bulk viscosity on the pT integrated v2 are small.
1602.04635
Kazimierz Bodek
Kazimierz Bodek
Beta-Decay Correlations in the LHC Era
8 pages, 2 figures, presented at Jagiellonian Symposium of Fundamental and Applied Subatomic Physics, Cracow, 2015
Acta Phys. Pol. B. 47, 349 (2016)
10.5506/APhysPolB.47.349
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Neutron and nuclear beta decay correlation coefficients are linearly sensitive to the exotic scalar and tensor interactions that are not included in the Standard Model. The proposed experiment will measure simultaneously 11 neutron correlation coefficients ($a$, $A$, $B$, $D$, $H$, $L$, $N$, $R$, $S$, $U$, $V$) where 5 of them ($H$, $L$, $S$, $U$, $V$) were never addressed before. Silicon pixel detectors are considered as promising alternative to multi-wire gas chambers devoted for electron tracking in the original setup. The expected sensitivity limits for $\epsilon_S$ and $\epsilon_T$ -- EFT parameters describing the scalar and tensor contributions to be extracted from the transverse electron polarization related coefficients $H$, $L$, $N$, $R$, $S$, $U$, $V$ are discussed.
[ { "created": "Mon, 15 Feb 2016 11:31:27 GMT", "version": "v1" }, { "created": "Wed, 17 Feb 2016 21:55:03 GMT", "version": "v2" } ]
2016-02-19
[ [ "Bodek", "Kazimierz", "" ] ]
Neutron and nuclear beta decay correlation coefficients are linearly sensitive to the exotic scalar and tensor interactions that are not included in the Standard Model. The proposed experiment will measure simultaneously 11 neutron correlation coefficients ($a$, $A$, $B$, $D$, $H$, $L$, $N$, $R$, $S$, $U$, $V$) where 5 of them ($H$, $L$, $S$, $U$, $V$) were never addressed before. Silicon pixel detectors are considered as promising alternative to multi-wire gas chambers devoted for electron tracking in the original setup. The expected sensitivity limits for $\epsilon_S$ and $\epsilon_T$ -- EFT parameters describing the scalar and tensor contributions to be extracted from the transverse electron polarization related coefficients $H$, $L$, $N$, $R$, $S$, $U$, $V$ are discussed.
1104.4776
Pedro Schwaller
Qing-Hong Cao, Marcela Carena, Stefania Gori, Arjun Menon, Pedro Schwaller, Carlos E.M. Wagner, Lian-Tao Wang
W plus two jets from a quasi-inert Higgs doublet
15 pages, 4 figures
null
10.1007/JHEP08(2011)002
EFI-11-11, ANL-HEP-PR-11-28, FERMILAB-PUB-11-189-T
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We show that, the result recently reported by the CDF collaboration showing an excess in the invariant mass distribution of jet pairs produced in association with a W-boson can be explained by a simple extension of the Standard Model (SM) with an additional quasi-inert Higgs doublet. The two additional neutral Higgs states H^0 and A^0 have a mass of about 150 GeV and decay into a pair of jets. W^\pm H^0/A^0 pairs are produced from the decay of the heavier charged Higgs boson H^\pm. Depending on the precise masses of the neutral and charged Higgs bosons, the model is shown to be in agreement with constraints from electroweak precision tests and from flavor physics for a broad range of the Standard Model-like Higgs mass from 100 GeV to several hundreds of GeV. Other possible signals of this model at the Tevatron and the LHC are discussed.
[ { "created": "Mon, 25 Apr 2011 19:16:19 GMT", "version": "v1" } ]
2015-03-19
[ [ "Cao", "Qing-Hong", "" ], [ "Carena", "Marcela", "" ], [ "Gori", "Stefania", "" ], [ "Menon", "Arjun", "" ], [ "Schwaller", "Pedro", "" ], [ "Wagner", "Carlos E. M.", "" ], [ "Wang", "Lian-Tao", "" ] ]
We show that, the result recently reported by the CDF collaboration showing an excess in the invariant mass distribution of jet pairs produced in association with a W-boson can be explained by a simple extension of the Standard Model (SM) with an additional quasi-inert Higgs doublet. The two additional neutral Higgs states H^0 and A^0 have a mass of about 150 GeV and decay into a pair of jets. W^\pm H^0/A^0 pairs are produced from the decay of the heavier charged Higgs boson H^\pm. Depending on the precise masses of the neutral and charged Higgs bosons, the model is shown to be in agreement with constraints from electroweak precision tests and from flavor physics for a broad range of the Standard Model-like Higgs mass from 100 GeV to several hundreds of GeV. Other possible signals of this model at the Tevatron and the LHC are discussed.
1102.0643
Konstantin Kouzakov
Konstantin A. Kouzakov, Alexander I. Studenikin, and Mikhail B. Voloshin
On neutrino-atom scattering in searches for neutrino magnetic moments
1 page, to appear in Nuclear Physics B Proceedings Supplement 2011 (Proceedings of the XXIV International Conference on Neutrino Physics and Astrophysics, Athens, June 14-19, 2010)
null
10.1016/j.nuclphysbps.2012.09.133
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the experimental searches for neutrino magnetic moments using germanium detectors one studies the ionization channel in the neutrino-atom scattering. We find that the so-called stepping approximation to the neutrino-impact ionization is exact in the semiclassical limit, and that the deviations from this approximation are very small.
[ { "created": "Thu, 3 Feb 2011 10:52:31 GMT", "version": "v1" } ]
2015-05-27
[ [ "Kouzakov", "Konstantin A.", "" ], [ "Studenikin", "Alexander I.", "" ], [ "Voloshin", "Mikhail B.", "" ] ]
In the experimental searches for neutrino magnetic moments using germanium detectors one studies the ionization channel in the neutrino-atom scattering. We find that the so-called stepping approximation to the neutrino-impact ionization is exact in the semiclassical limit, and that the deviations from this approximation are very small.
hep-ph/9610339
Plamen Krastev
P.I. Krastev (Inst. for Advanced Study)
Time-Variations of Solar Neutrino Signals
4 pages, 2 figures, LATEX, uses sprocl.sty (included) talk presented at the DPF '96 meeting, Minneapolis, MN, August 10 - 15, 1996
null
null
null
hep-ph astro-ph
null
The most popular solutions of the solar neutrino problem which assume massive neutrinos predict varying with time signals in the solar neutrino detectors. The variations represent a distinctive feature of these solutions and do not depend on the theoretically predicted total flux of neutrinos from the Sun. The sensitivity of SuperKamiokande and SNO to day-night variations due to regeneration in the Earth is estimated.
[ { "created": "Sun, 13 Oct 1996 17:43:19 GMT", "version": "v1" } ]
2007-05-23
[ [ "Krastev", "P. I.", "", "Inst. for Advanced Study" ] ]
The most popular solutions of the solar neutrino problem which assume massive neutrinos predict varying with time signals in the solar neutrino detectors. The variations represent a distinctive feature of these solutions and do not depend on the theoretically predicted total flux of neutrinos from the Sun. The sensitivity of SuperKamiokande and SNO to day-night variations due to regeneration in the Earth is estimated.
0812.0270
Rodion Kolevatov
Rodion Kolevatov and Urs Achim Wiedemann
Varying and inverting the mass hierarchy in collisional energy loss
10 pages, 3 figures
null
null
CERN-PH-TH/2008-235
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Heavy ion collisions at RHIC and at the LHC give access to the medium-induced suppression patterns of heavy-flavored single inclusive hadron spectra at high transverse momentum. This opens novel opportunities for a detailed characterization of the medium produced in the collision. In this note, we point out that the capacity of a QCD medium to absorb the recoil of a partonic projectile is an independent signature, which may differ for different media at the same density. In particular, while the mass hierarchy (i.e., the projectile mass dependence) of radiative energy loss depends solely on a property of the projectile, the mass hierarchy of collisional energy loss depends significantly on properties of the medium. By varying these properties in a class of models, we find that the mass hierarchy of collisional parton energy loss can be modified considerably and can even be inverted, compared to that of radiative parton energy loss. This may help to disentangle the relative strengths of radiative and collisional contributions to jet quenching, and it may be employed to constrain properties of the produced QCD medium beyond its density.
[ { "created": "Mon, 1 Dec 2008 12:00:08 GMT", "version": "v1" } ]
2008-12-02
[ [ "Kolevatov", "Rodion", "" ], [ "Wiedemann", "Urs Achim", "" ] ]
Heavy ion collisions at RHIC and at the LHC give access to the medium-induced suppression patterns of heavy-flavored single inclusive hadron spectra at high transverse momentum. This opens novel opportunities for a detailed characterization of the medium produced in the collision. In this note, we point out that the capacity of a QCD medium to absorb the recoil of a partonic projectile is an independent signature, which may differ for different media at the same density. In particular, while the mass hierarchy (i.e., the projectile mass dependence) of radiative energy loss depends solely on a property of the projectile, the mass hierarchy of collisional energy loss depends significantly on properties of the medium. By varying these properties in a class of models, we find that the mass hierarchy of collisional parton energy loss can be modified considerably and can even be inverted, compared to that of radiative parton energy loss. This may help to disentangle the relative strengths of radiative and collisional contributions to jet quenching, and it may be employed to constrain properties of the produced QCD medium beyond its density.
1711.10840
Stefano Carrazza
Stefano Carrazza
Machine learning challenges in theoretical HEP
7 pages, 3 figures, in proceedings of the 18th International Workshop on Advanced Computing and Analysis Techniques in Physics Research (ACAT 2017)
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In these proceedings we perform a brief review of machine learning (ML) applications in theoretical High Energy Physics (HEP-TH). We start the discussion by defining and then classifying machine learning tasks in theoretical HEP. We then discuss some of the most popular and recent published approaches with focus on a relevant case study topic: the determination of parton distribution functions (PDFs) and related tools. Finally, we provide an outlook about future applications and developments due to the synergy between ML and HEP-TH.
[ { "created": "Wed, 29 Nov 2017 13:24:38 GMT", "version": "v1" }, { "created": "Tue, 16 Jan 2018 20:50:05 GMT", "version": "v2" } ]
2018-01-18
[ [ "Carrazza", "Stefano", "" ] ]
In these proceedings we perform a brief review of machine learning (ML) applications in theoretical High Energy Physics (HEP-TH). We start the discussion by defining and then classifying machine learning tasks in theoretical HEP. We then discuss some of the most popular and recent published approaches with focus on a relevant case study topic: the determination of parton distribution functions (PDFs) and related tools. Finally, we provide an outlook about future applications and developments due to the synergy between ML and HEP-TH.
1810.05618
Robert Ziegler
Marcin Badziak, Nishita Desai, Cyril Hugonie, Robert Ziegler
Extended Gauge Mediation in the NMSSM with Displaced LHC Signals
12 pages
null
10.1140/epjc/s10052-019-6590-1
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyze models of extended Gauge Mediation in the context of the NMSSM, concentrating on supersymmetric spectra with light gluinos, low fine-tuning and decays of the lightest neutralino leading to displaced vertices. While the minimal scenario has rather heavy gluinos as a result of restrictions from the Higgs sector, we propose two new models in which the gluino can be as light as allowed by direct searches at the LHC, with a mass of about 1.7 TeV and 2.0 TeV, respectively. Both models have a tuning of a few permille, and lead to an interesting phenomenology due to a light singlet sector. A singlet state at around 98 GeV can account for the LEP excess, while the singlino has a mass of the order of 100 GeV and decays to b-jets and the gravitino, with decay lengths of a few cm.
[ { "created": "Fri, 12 Oct 2018 17:26:52 GMT", "version": "v1" } ]
2019-02-20
[ [ "Badziak", "Marcin", "" ], [ "Desai", "Nishita", "" ], [ "Hugonie", "Cyril", "" ], [ "Ziegler", "Robert", "" ] ]
We analyze models of extended Gauge Mediation in the context of the NMSSM, concentrating on supersymmetric spectra with light gluinos, low fine-tuning and decays of the lightest neutralino leading to displaced vertices. While the minimal scenario has rather heavy gluinos as a result of restrictions from the Higgs sector, we propose two new models in which the gluino can be as light as allowed by direct searches at the LHC, with a mass of about 1.7 TeV and 2.0 TeV, respectively. Both models have a tuning of a few permille, and lead to an interesting phenomenology due to a light singlet sector. A singlet state at around 98 GeV can account for the LEP excess, while the singlino has a mass of the order of 100 GeV and decays to b-jets and the gravitino, with decay lengths of a few cm.
2203.16583
Marek Karliner
Nora Brambilla, Hua-Xing Chen, Angelo Esposito, Jacopo Ferretti, Anthony Francis, Feng-Kun Guo, Christoph Hanhart, Atsushi Hosaka, Robert L. Jaffe, Marek Karliner, Richard Lebed, Randy Lewis, Luciano Maiani, Nilmani Mathur, Ulf-G. Mei{\ss}ner, Alessandro Pilloni, Antonio Davide Polosa, Sasa Prelovsek, Jean-Marc Richard, Veronica Riquer, Mitja Rosina, Jonathan L. Rosner, Elena Santopinto, Eric S. Swanson, Adam P. Szczepaniak, Sachiko Takeuchi, Makoto Takizawa, Frank Wilczek, Yasuhiro Yamaguchi, Bing-Song Zou
Substructure of Multiquark Hadrons (Snowmass 2021 White Paper)
47 pages, 10 figures. Corresponding authors: Marek Karliner, Elena Santopinto
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In recent years there has been a rapidly growing body of experimental evidence for existence of exotic, multiquark hadrons, i.e. mesons which contain additional quarks, beyond the usual quark-antiquark pair and baryons which consist of more than three quarks. In all cases with robust evidence they contain at least one heavy quark Q=c or b, the majority including two heavy quarks. Two key theoretical questions have been triggered by these discoveries: (a) how are quarks organized inside these multiquark states -- as compact objects with all quarks within one confinement volume, interacting via color forces, perhaps with an important role played by diquarks, or as deuteron-like hadronic molecules, bound by light-meson exchange? (b) what other multiquark states should we expect? The two questions are tightly intertwined. Each of the interpretations provides a natural explanation of parts of the data, but neither explains all of the data. It is quite possible that both kinds of structures appear in Nature. It may also be the case that certain states are superpositions of the compact and molecular configurations. This Whitepaper brings together contributions from many leading practitioners in the field, representing a wide spectrum of theoretical interpretations. We discuss the importance of future experimental and phenomenological work, which will lead to better understandingof multiquark phenomena in QCD.
[ { "created": "Wed, 30 Mar 2022 18:14:13 GMT", "version": "v1" } ]
2022-04-01
[ [ "Brambilla", "Nora", "" ], [ "Chen", "Hua-Xing", "" ], [ "Esposito", "Angelo", "" ], [ "Ferretti", "Jacopo", "" ], [ "Francis", "Anthony", "" ], [ "Guo", "Feng-Kun", "" ], [ "Hanhart", "Christoph", "" ], ...
In recent years there has been a rapidly growing body of experimental evidence for existence of exotic, multiquark hadrons, i.e. mesons which contain additional quarks, beyond the usual quark-antiquark pair and baryons which consist of more than three quarks. In all cases with robust evidence they contain at least one heavy quark Q=c or b, the majority including two heavy quarks. Two key theoretical questions have been triggered by these discoveries: (a) how are quarks organized inside these multiquark states -- as compact objects with all quarks within one confinement volume, interacting via color forces, perhaps with an important role played by diquarks, or as deuteron-like hadronic molecules, bound by light-meson exchange? (b) what other multiquark states should we expect? The two questions are tightly intertwined. Each of the interpretations provides a natural explanation of parts of the data, but neither explains all of the data. It is quite possible that both kinds of structures appear in Nature. It may also be the case that certain states are superpositions of the compact and molecular configurations. This Whitepaper brings together contributions from many leading practitioners in the field, representing a wide spectrum of theoretical interpretations. We discuss the importance of future experimental and phenomenological work, which will lead to better understandingof multiquark phenomena in QCD.
hep-ph/9312359
Arkady Vainshtein
I.I.Bigi, M.A.Shifman, N.G.Uraltsev, A.I.Vainshtein
On the Motion of Heavy Quarks inside Hadrons: Universal Distributions and Inclusive Decays
34 pages, Latex, 4 figures. Some clarifying comments and postscript files of figures are added
Int.J.Mod.Phys. A9 (1994) 2467-2504
10.1142/S0217751X94000996
null
hep-ph
null
In previous papers we have pointed out that there exists a QCD analog of the phenomenological concept of the so called Fermi motion for the heavy quark inside a hadron. Here we show in a more detailed way how this comes about and we analyze the limitations of this concept. Non-perturbative as well as perturbative aspects are included. We emphasize both the similarities and the differences to the well-known treatment of deep inelastic lepton-nucleon scattering. We derive a model-independent {\em lower} bound on the kinetic energy of the heavy quark inside the hadron.
[ { "created": "Fri, 31 Dec 1993 05:45:29 GMT", "version": "v1" }, { "created": "Fri, 7 Jan 1994 08:46:01 GMT", "version": "v2" } ]
2009-10-22
[ [ "Bigi", "I. I.", "" ], [ "Shifman", "M. A.", "" ], [ "Uraltsev", "N. G.", "" ], [ "Vainshtein", "A. I.", "" ] ]
In previous papers we have pointed out that there exists a QCD analog of the phenomenological concept of the so called Fermi motion for the heavy quark inside a hadron. Here we show in a more detailed way how this comes about and we analyze the limitations of this concept. Non-perturbative as well as perturbative aspects are included. We emphasize both the similarities and the differences to the well-known treatment of deep inelastic lepton-nucleon scattering. We derive a model-independent {\em lower} bound on the kinetic energy of the heavy quark inside the hadron.
hep-ph/9803390
Baldicchi Massimiliano
M. Baldicchi and G.M. Prosperi
Regge trajectories and quarkonium spectrum from a first principle Salpeter equation
18 pages, 3 figures, revtex.sty
Phys.Lett. B436 (1998) 145-152
10.1016/S0370-2693(98)00830-2
Milano preprint IFUM 606/FT
hep-ph
null
We compute the heavy-heavy, light-light and light-heavy quarkonium spectrum starting from a first principle Salpeter equation obtained in a preceding paper. We neglect spin-orbit structures and exclude from our treatment the light pseudoscalar states which in principle would require the use of the full Bethe-Salpeter equation due to the chiral symmetry breaking problem. For the rest we find an overall good agreement with the experimental data. In particular for the light-light case we find straight Regge trajectories with the right slope and intercepts. The strong coupling constant $\alpha_s$, the string tension $\sigma$ occurring in the potential and the heavy quark masses are taken from the heavy quarkonium semirelativistic fit with only a small rearrangement. The light quark masses are set equal to baricentral value of the current quark masses as reported by the particle data group. For what concerns the light-light and the light-heavy systems the calculation is essentially parameter free.
[ { "created": "Thu, 19 Mar 1998 16:14:57 GMT", "version": "v1" }, { "created": "Fri, 20 Mar 1998 15:46:23 GMT", "version": "v2" } ]
2009-10-31
[ [ "Baldicchi", "M.", "" ], [ "Prosperi", "G. M.", "" ] ]
We compute the heavy-heavy, light-light and light-heavy quarkonium spectrum starting from a first principle Salpeter equation obtained in a preceding paper. We neglect spin-orbit structures and exclude from our treatment the light pseudoscalar states which in principle would require the use of the full Bethe-Salpeter equation due to the chiral symmetry breaking problem. For the rest we find an overall good agreement with the experimental data. In particular for the light-light case we find straight Regge trajectories with the right slope and intercepts. The strong coupling constant $\alpha_s$, the string tension $\sigma$ occurring in the potential and the heavy quark masses are taken from the heavy quarkonium semirelativistic fit with only a small rearrangement. The light quark masses are set equal to baricentral value of the current quark masses as reported by the particle data group. For what concerns the light-light and the light-heavy systems the calculation is essentially parameter free.
2112.08724
Anna Sch\"afer
Anna Sch\"afer, Iurii Karpenko, Xiang-Yu Wu, Jan Hammelmann, Hannah Elfner
Particle production in a hybrid approach for a beam energy scan of Au+Au/Pb+Pb collisions between $\sqrt{s_\mathrm{NN}}$ = 4.3 GeV and $\sqrt{s_\mathrm{NN}}$ = 200.0 GeV
null
null
10.1140/epja/s10050-022-00872-x
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Heavy-ion collisions at varying collision energies provide access to different regions of the QCD phase diagram. In particular collisions at intermediate energies are promising candidates to experimentally identify the postulated first order phase transition and critical end point. While heavy-ion collisions at low and high collision energies are theoretically well described by transport approaches and hydrodynamics+transport hybrid approaches, respectively, intermediate energy collisions remain a challenge. In this work, a modular hybrid approach, the SMASH-vHLLE-hybrid coupling 3+1D viscous hydrodynamics (vHLLE) to hadronic transport (SMASH), is introduced. It is validated and subsequently applied in Au+Au/Pb+Pb collisions between $\sqrt{s_\mathrm{NN}}$ = 4.3 GeV and $\sqrt{s_\mathrm{NN}}$ = 200.0 GeV to study the rapidity and transverse mass distributions of identified particles as well as excitation functions for $\mathrm{dN}/\mathrm{d}y|_{y = 0}$ and $\langle p_\mathrm{T} \rangle$. A good agreement with experimental measurements is obtained, including the baryon stopping dynamics. The transition from a Gaussian rapidity spectrum of protons at lower energies to the double-hump structure at high energies is reproduced. The centrality and energy dependence of charged particle $v_2$ is also described reasonably well. This work serves as a basis for further studies, e.g. systematic investigations of different equations of state or transport coefficients.
[ { "created": "Thu, 16 Dec 2021 09:22:03 GMT", "version": "v1" }, { "created": "Sun, 22 Jan 2023 09:29:12 GMT", "version": "v2" } ]
2023-01-24
[ [ "Schäfer", "Anna", "" ], [ "Karpenko", "Iurii", "" ], [ "Wu", "Xiang-Yu", "" ], [ "Hammelmann", "Jan", "" ], [ "Elfner", "Hannah", "" ] ]
Heavy-ion collisions at varying collision energies provide access to different regions of the QCD phase diagram. In particular collisions at intermediate energies are promising candidates to experimentally identify the postulated first order phase transition and critical end point. While heavy-ion collisions at low and high collision energies are theoretically well described by transport approaches and hydrodynamics+transport hybrid approaches, respectively, intermediate energy collisions remain a challenge. In this work, a modular hybrid approach, the SMASH-vHLLE-hybrid coupling 3+1D viscous hydrodynamics (vHLLE) to hadronic transport (SMASH), is introduced. It is validated and subsequently applied in Au+Au/Pb+Pb collisions between $\sqrt{s_\mathrm{NN}}$ = 4.3 GeV and $\sqrt{s_\mathrm{NN}}$ = 200.0 GeV to study the rapidity and transverse mass distributions of identified particles as well as excitation functions for $\mathrm{dN}/\mathrm{d}y|_{y = 0}$ and $\langle p_\mathrm{T} \rangle$. A good agreement with experimental measurements is obtained, including the baryon stopping dynamics. The transition from a Gaussian rapidity spectrum of protons at lower energies to the double-hump structure at high energies is reproduced. The centrality and energy dependence of charged particle $v_2$ is also described reasonably well. This work serves as a basis for further studies, e.g. systematic investigations of different equations of state or transport coefficients.
1811.12738
Zhou Rui
Zhou Rui, Ya-Qian Li, Jie Zhang
Isovector scalar $a_0(980)$ and $a_0(1450)$ resonances in the $B\rightarrow \psi (K\bar{K},\pi\eta) $ decays
10 pages, 2 figures, 2 tables
Phys. Rev. D 99, 093007 (2019)
10.1103/PhysRevD.99.093007
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present an analysis of two isovector scalar resonant contributions to the $B$ decays into charmonia plus $K\bar K$ or $\pi\eta$ pair in the perturbative QCD approach. The Flatt\'{e} model for the $a_0(980)$ resonance and the Breit Wigner formula for the $a_0(1450)$ resonance are adopted to parametrize the timelike form factors in the dimeson distribution amplitudes, which capture the important final state interactions in these processes. The predicted distribution in the $K^+K^-$ invariant mass as well as its integrated branching ratio for the $a_0(980)$ resonance in the $B^0\rightarrow J/\psi K^+K^-$ mode agree well with the current available experimental data. The obtained branching ratio of the quasi-two-body decay $B^0\rightarrow J/\psi a_0(980)(\rightarrow \pi^0\eta)$ can reach the order of $10^{-6}$, letting the corresponding measurement appear feasible. For the $a_0(1450)$ component, our results could be tested by further experiments in the LHCb and Belle II. We also discuss some theoretical uncertainties in detail in our calculation.
[ { "created": "Fri, 30 Nov 2018 11:34:51 GMT", "version": "v1" }, { "created": "Mon, 20 May 2019 13:36:02 GMT", "version": "v2" } ]
2019-05-29
[ [ "Rui", "Zhou", "" ], [ "Li", "Ya-Qian", "" ], [ "Zhang", "Jie", "" ] ]
We present an analysis of two isovector scalar resonant contributions to the $B$ decays into charmonia plus $K\bar K$ or $\pi\eta$ pair in the perturbative QCD approach. The Flatt\'{e} model for the $a_0(980)$ resonance and the Breit Wigner formula for the $a_0(1450)$ resonance are adopted to parametrize the timelike form factors in the dimeson distribution amplitudes, which capture the important final state interactions in these processes. The predicted distribution in the $K^+K^-$ invariant mass as well as its integrated branching ratio for the $a_0(980)$ resonance in the $B^0\rightarrow J/\psi K^+K^-$ mode agree well with the current available experimental data. The obtained branching ratio of the quasi-two-body decay $B^0\rightarrow J/\psi a_0(980)(\rightarrow \pi^0\eta)$ can reach the order of $10^{-6}$, letting the corresponding measurement appear feasible. For the $a_0(1450)$ component, our results could be tested by further experiments in the LHCb and Belle II. We also discuss some theoretical uncertainties in detail in our calculation.
0805.3063
Ali N. Khorramian
Ali N. Khorramian and S. Atashbar Tehrani
NNLO QCD contributions to the flavor non-singlet sector of ${\bf {F_2(x,Q^2)}}$
29 pages, 8 figures
Phys.Rev.D78:074019,2008
10.1103/PhysRevD.78.074019
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present the results of our QCD analysis for nonsinglet unpolarized quark distributions and structure function $F_2(x,Q^2)$. New parameterizations are derived for the nonsinglet quark distributions for the kinematic wide range of $x$ and $Q^2$. The analysis is based on the Jacobi polynomials expansion of the structure function. The higher twist contributions of proton and deuteron structure function are obtained in the large $x$ region. Our calculations for nonsinglet unpolarized quark distribution functions based on the Jacobi polynomials method are in good agreement with the other theoretical models. The values of $\Lambda_{QCD}$ and $\alpha_s(M_z^2)$ are determined.
[ { "created": "Tue, 20 May 2008 12:32:23 GMT", "version": "v1" }, { "created": "Thu, 25 Dec 2008 06:57:46 GMT", "version": "v2" } ]
2008-12-25
[ [ "Khorramian", "Ali N.", "" ], [ "Tehrani", "S. Atashbar", "" ] ]
We present the results of our QCD analysis for nonsinglet unpolarized quark distributions and structure function $F_2(x,Q^2)$. New parameterizations are derived for the nonsinglet quark distributions for the kinematic wide range of $x$ and $Q^2$. The analysis is based on the Jacobi polynomials expansion of the structure function. The higher twist contributions of proton and deuteron structure function are obtained in the large $x$ region. Our calculations for nonsinglet unpolarized quark distribution functions based on the Jacobi polynomials method are in good agreement with the other theoretical models. The values of $\Lambda_{QCD}$ and $\alpha_s(M_z^2)$ are determined.
hep-ph/9507439
Fritz Dejongh
F. DeJongh (Fermilab) and P. Sphicas (Massachusetts Institute of Technology)
Extracting $\alpha$ from the CP Asymmetry in $B^0 \to \pi^+ \pi^-$ Decays
18 pages latex, 9 eps files
Phys.Rev. D53 (1996) 4930-4936
10.1103/PhysRevD.53.4930
FERMILAB-PUB-95/179-E and LNS-95-157
hep-ph
null
The extraction of the CKM angle $\alpha$ from the asymmetry in $B^0 \to \pi^+\pi^-$ vs ${\bar B^0} \to \pi^+\pi^-$ suffers from a currently unknown penguin contribution. Experimentally, one can determine the magnitude and phase of the CP asymmetry from a time-dependent analysis of tagged events, and the average rate for $B^0$ and $\bar{B}^0$ decays to $\pi^+\pi^-$ from untagged events. These measurements, together with the magnitudes and relative phase of the tree and penguin diagrams, can in principle completely determine $\alpha$, free of discrete ambiguities. We perform an error analysis on $\alpha$ given assumptions on the values and uncertainties of both the measurements and theoretical inputs.
[ { "created": "Thu, 27 Jul 1995 21:41:53 GMT", "version": "v1" } ]
2009-10-28
[ [ "DeJongh", "F.", "", "Fermilab" ], [ "Sphicas", "P.", "", "Massachusetts Institute of\n Technology" ] ]
The extraction of the CKM angle $\alpha$ from the asymmetry in $B^0 \to \pi^+\pi^-$ vs ${\bar B^0} \to \pi^+\pi^-$ suffers from a currently unknown penguin contribution. Experimentally, one can determine the magnitude and phase of the CP asymmetry from a time-dependent analysis of tagged events, and the average rate for $B^0$ and $\bar{B}^0$ decays to $\pi^+\pi^-$ from untagged events. These measurements, together with the magnitudes and relative phase of the tree and penguin diagrams, can in principle completely determine $\alpha$, free of discrete ambiguities. We perform an error analysis on $\alpha$ given assumptions on the values and uncertainties of both the measurements and theoretical inputs.
hep-ph/9905217
Adrian Dumitru
Adrian Dumitru (Yale University)
Calculation of the expansion rate of the three-volume measure in high-energy heavy-ion collisions
10 Pages REVTEX, 4 Figures; Title slightly modified, 2 new figures
Phys.Lett. B463 (1999) 138
10.1016/S0370-2693(99)01018-7
YRHI-99-29
hep-ph astro-ph nucl-th
null
In ultrarelativistic heavy-ion collisions the local three-volume measure is expanding in the longitudinal and transverse directions. This is similar to the Hubble-expansion of the universe, except that the former is not locally isotropic. As an example the expansion rate is calculated assuming that the energy-momentum tensor in the central region is that of an ideal fluid, undergoing Bjorken flow in longitudinal direction, and with initial conditions as expected for BNL-RHIC energy. While the longitudinal expansion of three-volume is independent of the energy density of the fluid, in case of 3+1 dimensional expansion the form of the hydrodynamical solution (rarefaction wave or deflagration shock) affects the three-volume expansion rate on the hadronization hypersurface. As a consequence the average expansion rate on that surface depends on the transverse size of the system. This may reflect in an impact-parameter dependence of the formation probability of light nuclei and of the freeze-out temperature of the strong interactions in the system.
[ { "created": "Mon, 3 May 1999 23:33:14 GMT", "version": "v1" }, { "created": "Tue, 24 Aug 1999 09:31:07 GMT", "version": "v2" } ]
2009-10-31
[ [ "Dumitru", "Adrian", "", "Yale University" ] ]
In ultrarelativistic heavy-ion collisions the local three-volume measure is expanding in the longitudinal and transverse directions. This is similar to the Hubble-expansion of the universe, except that the former is not locally isotropic. As an example the expansion rate is calculated assuming that the energy-momentum tensor in the central region is that of an ideal fluid, undergoing Bjorken flow in longitudinal direction, and with initial conditions as expected for BNL-RHIC energy. While the longitudinal expansion of three-volume is independent of the energy density of the fluid, in case of 3+1 dimensional expansion the form of the hydrodynamical solution (rarefaction wave or deflagration shock) affects the three-volume expansion rate on the hadronization hypersurface. As a consequence the average expansion rate on that surface depends on the transverse size of the system. This may reflect in an impact-parameter dependence of the formation probability of light nuclei and of the freeze-out temperature of the strong interactions in the system.
hep-ph/9404344
Renard Fernand Michel
G.J. Gounaris, J. Layssac, F.M. Renard
Higgs Production in $SU(2)_c$ Symmetric Interactions
19 pages, 13 figures available by air mail upon request, (e-mail renard@lpmsun2.lpm.univ-montp2.fr PM/94-13, THES-TP-94/03
Z.Phys. C65 (1995) 245-254; Erratum-ibid. C67 (1995) 542
10.1007/BF01571880
null
hep-ph
null
We study the sensitivity of Higgs production and decay processes to the $SU(2)_c$ symmetric couplings $O_W$ and $O_{UW}$. Remarkable results are obtained in the case of $\gamma \gamma \to H$ and for certain ratios of Higgs decay widths. We also discuss and complete previous results on unitarity constraints for such couplings.
[ { "created": "Wed, 27 Apr 1994 11:11:32 GMT", "version": "v1" } ]
2009-10-28
[ [ "Gounaris", "G. J.", "" ], [ "Layssac", "J.", "" ], [ "Renard", "F. M.", "" ] ]
We study the sensitivity of Higgs production and decay processes to the $SU(2)_c$ symmetric couplings $O_W$ and $O_{UW}$. Remarkable results are obtained in the case of $\gamma \gamma \to H$ and for certain ratios of Higgs decay widths. We also discuss and complete previous results on unitarity constraints for such couplings.