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hep-ph/9807255
Gianni Salme' -Sanita'
F.M. Lev (JINR-Dubna), E. Pace (Rome University), G. Salme` (INFN-Rome)
Electromagnetic and weak current operators for interacting systems within the front-form dynamics
40 pages, submitted to Nucl. Phys. A
Nucl.Phys. A641 (1998) 229-259
10.1016/S0375-9474(98)00469-2
INFN 1214/98
hep-ph nucl-th
null
Electromagnetic and weak current operators for interacting systems should properly commute with the Poincar\'e generators and satisfy Hermiticity. The electromagnetic current should also satisfy ${\cal P}$ and ${\cal T}$ covariance and continuity equation. We show that in front-form dynamics the current can be constructed from auxiliary operators, defined in a Breit frame where initial and final three-momenta of the system are directed along the $z$ axis. Poincar\'e covariance constraints reduce for auxiliary operators to the ones imposed only by kinematical rotations around the $z$ axis; while Hermiticity requires a suitable behaviour of the auxiliary operators under rotations by $\pi$ around the $x$ or $y$ axes. Applications to deep inelastic structure functions and electromagnetic form factors are discussed. Elastic and transition form factors can be extracted without any ambiguity and in the elastic case the continuity equation is automatically satisfied, once Poincar\'e, ${\cal P}$ and ${\cal T}$ covariance, together with Hermiticity, are imposed.
[ { "created": "Mon, 6 Jul 1998 12:54:07 GMT", "version": "v1" } ]
2016-09-06
[ [ "Lev", "F. M.", "", "JINR-Dubna" ], [ "Pace", "E.", "", "Rome University" ], [ "Salme`", "G.", "", "INFN-Rome" ] ]
Electromagnetic and weak current operators for interacting systems should properly commute with the Poincar\'e generators and satisfy Hermiticity. The electromagnetic current should also satisfy ${\cal P}$ and ${\cal T}$ covariance and continuity equation. We show that in front-form dynamics the current can be constructed from auxiliary operators, defined in a Breit frame where initial and final three-momenta of the system are directed along the $z$ axis. Poincar\'e covariance constraints reduce for auxiliary operators to the ones imposed only by kinematical rotations around the $z$ axis; while Hermiticity requires a suitable behaviour of the auxiliary operators under rotations by $\pi$ around the $x$ or $y$ axes. Applications to deep inelastic structure functions and electromagnetic form factors are discussed. Elastic and transition form factors can be extracted without any ambiguity and in the elastic case the continuity equation is automatically satisfied, once Poincar\'e, ${\cal P}$ and ${\cal T}$ covariance, together with Hermiticity, are imposed.
hep-ph/9709492
Alexander Kusenko
Alexander Kusenko and Mikhail Shaposhnikov (CERN)
Supersymmetric Q-balls as dark matter
16 pages, 3 figures (epsf); replaced with a final version, to appear in Phys. Lett. B (references added)
Phys.Lett.B418:46-54,1998
10.1016/S0370-2693(97)01375-0
CERN-TH/97-259
hep-ph astro-ph gr-qc hep-th
null
Supersymmetric extensions of the standard model generically contain stable non-topological solitons, Q-balls, which carry baryon or lepton number. We show that large Q-balls can be copiously produced in the early universe, can survive until the present time, and can contribute to dark matter.
[ { "created": "Mon, 29 Sep 1997 13:38:43 GMT", "version": "v1" }, { "created": "Thu, 9 Oct 1997 22:35:08 GMT", "version": "v2" }, { "created": "Thu, 30 Oct 1997 09:32:37 GMT", "version": "v3" } ]
2011-05-05
[ [ "Kusenko", "Alexander", "", "CERN" ], [ "Shaposhnikov", "Mikhail", "", "CERN" ] ]
Supersymmetric extensions of the standard model generically contain stable non-topological solitons, Q-balls, which carry baryon or lepton number. We show that large Q-balls can be copiously produced in the early universe, can survive until the present time, and can contribute to dark matter.
0905.3259
Yuming Wang
Run-Hui Li, Cai-Dian Lu and Yu-Ming Wang
Exclusive $B_s$ decays to the charmed mesons $D_s^+(1968,2317)$ in the standard model
21 pages, 3 figures
Phys.Rev.D80:014005,2009
10.1103/PhysRevD.80.014005
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The transition form factors of $\bar B_s^0\to D_{s}^+(2317)$ and $\bar B_s^0\to D_s^+(1968)$ at large recoil region are investigated in the light cone sum rules approach, where the heavy quark effective theory is adopted to describe the form factors at small recoil region. With the form factors obtained, we carry out a detailed analysis on both the semileptonic decays $\bar B_s^0\to D_s^+(1968,2317) l \bar{\nu}_l$ and nonleptonic decays $B_s \to D_s^+(1968,2317) M$ with $M$ being a light meson or a charmed meson under the factorization approach. Our results show that the branching fraction of $\bar B_s^0\to D_s^+(2317) \mu \bar{\nu}_\mu$ is around $2.3 \times 10^{-3}$, which should be detectable with ease at the Tevatron and LHC. It is also found that the branching fractions of $\bar B_s^0\to D_s^+(1968) l \bar{\nu}_l$ are almost one order larger than those of the corresponding $B_s^0\to D_s^+(2317) l \bar{\nu}_l$ decays. The consistency of predictions for $B_s \to D_s^+(1968,2317) L$ ($L$ denotes a light meson) in the factorization assumption and $k_T$ factorization also supports the success of color transparency mechanism in the color allowed decay modes. Most two-charmed meson decays of $B_s$ meson possess quite large branching ratios that are accessible in the experiments. These channels are of great importance to explore the hadronic structure of charmed mesons as well as the nonperturbative dynamics of QCD.
[ { "created": "Wed, 20 May 2009 09:37:39 GMT", "version": "v1" } ]
2009-08-25
[ [ "Li", "Run-Hui", "" ], [ "Lu", "Cai-Dian", "" ], [ "Wang", "Yu-Ming", "" ] ]
The transition form factors of $\bar B_s^0\to D_{s}^+(2317)$ and $\bar B_s^0\to D_s^+(1968)$ at large recoil region are investigated in the light cone sum rules approach, where the heavy quark effective theory is adopted to describe the form factors at small recoil region. With the form factors obtained, we carry out a detailed analysis on both the semileptonic decays $\bar B_s^0\to D_s^+(1968,2317) l \bar{\nu}_l$ and nonleptonic decays $B_s \to D_s^+(1968,2317) M$ with $M$ being a light meson or a charmed meson under the factorization approach. Our results show that the branching fraction of $\bar B_s^0\to D_s^+(2317) \mu \bar{\nu}_\mu$ is around $2.3 \times 10^{-3}$, which should be detectable with ease at the Tevatron and LHC. It is also found that the branching fractions of $\bar B_s^0\to D_s^+(1968) l \bar{\nu}_l$ are almost one order larger than those of the corresponding $B_s^0\to D_s^+(2317) l \bar{\nu}_l$ decays. The consistency of predictions for $B_s \to D_s^+(1968,2317) L$ ($L$ denotes a light meson) in the factorization assumption and $k_T$ factorization also supports the success of color transparency mechanism in the color allowed decay modes. Most two-charmed meson decays of $B_s$ meson possess quite large branching ratios that are accessible in the experiments. These channels are of great importance to explore the hadronic structure of charmed mesons as well as the nonperturbative dynamics of QCD.
1707.00725
Cristian Caniu Barros
Enrico Bertuzzo, Cristian J. Caniu Barros and Giovanni Grilli di Cortona
MeV Dark Matter: Model Independent Bounds
19 pages, 2 figures. A few clarifications added, matches version published in JHEP
null
10.1007/JHEP09(2017)116
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We use the framework of dark matter effective field theories to study the complementarity of bounds for a dark matter particle with mass in the MeV range. Taking properly into account the mixing between operators induced by the renormalization group running, we impose experimental constraints coming from the CMB, BBN, LHC, LEP, direct detection experiments and meson decays. In particular, we focus on the case of a vector coupling between the dark matter and the standard model fermions, and study to which extent future experiments can hope to probe regions of parameters space which are not already ruled out by current data.
[ { "created": "Mon, 3 Jul 2017 18:40:21 GMT", "version": "v1" }, { "created": "Tue, 11 Jul 2017 02:08:31 GMT", "version": "v2" }, { "created": "Mon, 4 Sep 2017 13:59:22 GMT", "version": "v3" } ]
2017-10-25
[ [ "Bertuzzo", "Enrico", "" ], [ "Barros", "Cristian J. Caniu", "" ], [ "di Cortona", "Giovanni Grilli", "" ] ]
We use the framework of dark matter effective field theories to study the complementarity of bounds for a dark matter particle with mass in the MeV range. Taking properly into account the mixing between operators induced by the renormalization group running, we impose experimental constraints coming from the CMB, BBN, LHC, LEP, direct detection experiments and meson decays. In particular, we focus on the case of a vector coupling between the dark matter and the standard model fermions, and study to which extent future experiments can hope to probe regions of parameters space which are not already ruled out by current data.
1008.3263
Mikko Laine
M. Laine, M. Vepsalainen, A. Vuorinen
Ultraviolet asymptotics of scalar and pseudoscalar correlators in hot Yang-Mills theory
27 pages. v2: minor improvements, published version
JHEP 1010:010,2010
10.1007/JHEP10(2010)010
null
hep-ph hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Inspired by recent lattice measurements, we determine the short-distance (a << r << 1/pi T) as well as large-frequency (1/a >> omega >> pi T) asymptotics of scalar (trace anomaly) and pseudoscalar (topological charge density) correlators at 2-loop order in hot Yang-Mills theory. The results are expressed in the form of an Operator Product Expansion. We confirm and refine the determination of a number of Wilson coefficients; however some discrepancies with recent literature are detected as well, and employing the correct values might help, on the qualitative level, to understand some of the features observed in the lattice measurements. On the other hand, the Wilson coefficients show slow convergence and it appears uncertain whether this approach can lead to quantitative comparisons with lattice data. Nevertheless, as we outline, our general results might serve as theoretical starting points for a number of perhaps phenomenologically more successful lines of investigation.
[ { "created": "Thu, 19 Aug 2010 10:26:55 GMT", "version": "v1" }, { "created": "Mon, 11 Oct 2010 08:04:58 GMT", "version": "v2" } ]
2010-12-09
[ [ "Laine", "M.", "" ], [ "Vepsalainen", "M.", "" ], [ "Vuorinen", "A.", "" ] ]
Inspired by recent lattice measurements, we determine the short-distance (a << r << 1/pi T) as well as large-frequency (1/a >> omega >> pi T) asymptotics of scalar (trace anomaly) and pseudoscalar (topological charge density) correlators at 2-loop order in hot Yang-Mills theory. The results are expressed in the form of an Operator Product Expansion. We confirm and refine the determination of a number of Wilson coefficients; however some discrepancies with recent literature are detected as well, and employing the correct values might help, on the qualitative level, to understand some of the features observed in the lattice measurements. On the other hand, the Wilson coefficients show slow convergence and it appears uncertain whether this approach can lead to quantitative comparisons with lattice data. Nevertheless, as we outline, our general results might serve as theoretical starting points for a number of perhaps phenomenologically more successful lines of investigation.
2104.14707
Chul Kim
Lin Dai, Chul Kim, Adam K. Leibovich
Heavy quark jet production near threshold
36 pages, 11 figures; matches the version to be published
null
10.1007/JHEP09(2021)148
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we study the fragmentation of a heavy quark into a jet near threshold, meaning that final state jet carries most of the energy of the fragmenting heavy quark. Using the heavy quark fragmentation function, we simultaneously resum large logarithms of the jet radius $R$ and $1-z$, where $z$ is the ratio of the jet energy to the initiating heavy quark energy. There are numerically significant corrections to the leading order rate due to this resummation. We also investigate the heavy quark fragmentation to a groomed jet, using the soft drop grooming algorithm as an example. In order to do so, we introduce a collinear-ultrasoft mode sensitive to the grooming region determined by the algorithm's $z_{\mathrm{cut}}$ parameter. This allows us to resum large logarithms of $z_{\mathrm{cut}}/(1-z)$, again leading to large numerical corrections near the endpoint. A nice feature of the analysis of the heavy quark fragmenting to a groomed jet is the heavy quark mass $m$ renders the algorithm infrared finite, allowing a perturbative calculation. We analyze this for $E_JR \sim m$ and $E_JR\gg m$, where $E_J$ is the jet energy. To do the latter case, we introduce an ultracollinear-soft mode, allowing us to resum large logarithms of $E_JR/m$. Finally, as an application we calculate the rate for $e^+e^-$ collisions to produce a heavy quark jet in the endpoint region, where we show that grooming effects have a sizable contribution near the endpoint.
[ { "created": "Fri, 30 Apr 2021 00:53:40 GMT", "version": "v1" }, { "created": "Wed, 15 Sep 2021 02:26:20 GMT", "version": "v2" } ]
2021-10-13
[ [ "Dai", "Lin", "" ], [ "Kim", "Chul", "" ], [ "Leibovich", "Adam K.", "" ] ]
In this paper, we study the fragmentation of a heavy quark into a jet near threshold, meaning that final state jet carries most of the energy of the fragmenting heavy quark. Using the heavy quark fragmentation function, we simultaneously resum large logarithms of the jet radius $R$ and $1-z$, where $z$ is the ratio of the jet energy to the initiating heavy quark energy. There are numerically significant corrections to the leading order rate due to this resummation. We also investigate the heavy quark fragmentation to a groomed jet, using the soft drop grooming algorithm as an example. In order to do so, we introduce a collinear-ultrasoft mode sensitive to the grooming region determined by the algorithm's $z_{\mathrm{cut}}$ parameter. This allows us to resum large logarithms of $z_{\mathrm{cut}}/(1-z)$, again leading to large numerical corrections near the endpoint. A nice feature of the analysis of the heavy quark fragmenting to a groomed jet is the heavy quark mass $m$ renders the algorithm infrared finite, allowing a perturbative calculation. We analyze this for $E_JR \sim m$ and $E_JR\gg m$, where $E_J$ is the jet energy. To do the latter case, we introduce an ultracollinear-soft mode, allowing us to resum large logarithms of $E_JR/m$. Finally, as an application we calculate the rate for $e^+e^-$ collisions to produce a heavy quark jet in the endpoint region, where we show that grooming effects have a sizable contribution near the endpoint.
2005.00763
Aleksey Pivovarov
M. K. Volkov, A. A. Pivovarov, K. Nurlan
On the mixing angle of the vector mesons $\omega(782)$ and $\phi(1020)$
null
null
10.1142/S0217732320502004
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In the present work, the mixing angle of the vector $\omega(782)$ and $\phi(1020)$ mesons is estimated in the framework of Nambu--Jona-Lasinio model. The decay $\phi \to \pi^{0} \gamma$ is considered as a basic process to determine this angle. The obtained value is compared with the results of the other authors. Besides, the width of the decay $\phi \to 3\pi$ and the cross-section of the process $e^{+}e^{-} \to \pi^{0} \phi$ are calculated by using this angle.
[ { "created": "Sat, 2 May 2020 09:33:44 GMT", "version": "v1" } ]
2020-08-26
[ [ "Volkov", "M. K.", "" ], [ "Pivovarov", "A. A.", "" ], [ "Nurlan", "K.", "" ] ]
In the present work, the mixing angle of the vector $\omega(782)$ and $\phi(1020)$ mesons is estimated in the framework of Nambu--Jona-Lasinio model. The decay $\phi \to \pi^{0} \gamma$ is considered as a basic process to determine this angle. The obtained value is compared with the results of the other authors. Besides, the width of the decay $\phi \to 3\pi$ and the cross-section of the process $e^{+}e^{-} \to \pi^{0} \phi$ are calculated by using this angle.
1512.03003
Jeremie Quevillon
Aleksandra Drozd, John Ellis, J\'er\'emie Quevillon and Tevong You
The Universal One-Loop Effective Action
30 pages, v2 contains additional comments and corrects typos, version accepted for publication in JHEP
null
10.1007/JHEP03(2016)180
KCL-PH-TH/2015-54, LCTS/2015-42, CERN-PH-TH/2015-284, Cavendish-HEP-15/12, DAMTP-2015-88
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present the universal one-loop effective action for all operators of dimension up to six obtained by integrating out massive, non-degenerate multiplets. Our general expression may be applied to loops of heavy fermions or bosons, and has been checked against partial results available in the literature. The broad applicability of this approach simplifies one-loop matching from an ultraviolet model to a lower-energy effective field theory (EFT), a procedure which is now reduced to the evaluation of a combination of matrices in our universal expression, without any loop integrals to evaluate. We illustrate the relationship of our results to the Standard Model (SM) EFT, using as an example the supersymmetric stop and sbottom squark Lagrangian and extracting from our universal expression the Wilson coefficients of dimension-six operators composed of SM fields.
[ { "created": "Wed, 9 Dec 2015 19:29:31 GMT", "version": "v1" }, { "created": "Mon, 7 Mar 2016 13:45:17 GMT", "version": "v2" } ]
2016-04-20
[ [ "Drozd", "Aleksandra", "" ], [ "Ellis", "John", "" ], [ "Quevillon", "Jérémie", "" ], [ "You", "Tevong", "" ] ]
We present the universal one-loop effective action for all operators of dimension up to six obtained by integrating out massive, non-degenerate multiplets. Our general expression may be applied to loops of heavy fermions or bosons, and has been checked against partial results available in the literature. The broad applicability of this approach simplifies one-loop matching from an ultraviolet model to a lower-energy effective field theory (EFT), a procedure which is now reduced to the evaluation of a combination of matrices in our universal expression, without any loop integrals to evaluate. We illustrate the relationship of our results to the Standard Model (SM) EFT, using as an example the supersymmetric stop and sbottom squark Lagrangian and extracting from our universal expression the Wilson coefficients of dimension-six operators composed of SM fields.
0906.3637
T. Lappi
T. Lappi, H. Kowalski, C. Marquet and R. Venugopalan
Diffractive structure functions in nuclei
5 pages, 3 figures, talk at "DIS 2009", Madrid, Spain, 26-30 Apr 2009
null
10.3360/dis.2009.36
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We calculate proton and nuclear diffractive structure functions in the IPsat (Kowalski-Teaney) dipole model. This parametrization has previously been shown to provide good agreement with inclusive F_2 measurements and exclusive vector meson measurements at HERA. We discuss how the impact parameter dependence crucially affects our analysis, in particular for small beta.
[ { "created": "Fri, 19 Jun 2009 10:36:13 GMT", "version": "v1" } ]
2009-11-12
[ [ "Lappi", "T.", "" ], [ "Kowalski", "H.", "" ], [ "Marquet", "C.", "" ], [ "Venugopalan", "R.", "" ] ]
We calculate proton and nuclear diffractive structure functions in the IPsat (Kowalski-Teaney) dipole model. This parametrization has previously been shown to provide good agreement with inclusive F_2 measurements and exclusive vector meson measurements at HERA. We discuss how the impact parameter dependence crucially affects our analysis, in particular for small beta.
2406.19970
Frank E. Taylor
Frank E. Taylor
A determination of FL at xmin with HERA data
42 pages, 13 figures
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
It is well known that there are persistent statistical tensions with the standard model in the low Q2 HERA deep inelastic scattering neutral current data characterized by a turn-over of F2(x, Q2) at low x and low Q2. One important experimental signature that sheds light on this low Q2 region is the determination of the longitudinal structure function FL(x, Q2). This paper describes a novel method to determine FL based on an extrapolation of the reduced NC cross section at fixed s and Q to the minimum value of x given by Q2/s. At this kinematic point, the reduced cross section equals 2xF1 = F2 - FL so that a determination of both this value and the value of F2, determines FL. Since the polarization of the exchanged photon is transverse at this kinematic point, we expect FL to be small because its dominate gluon component is strongly suppressed. Surprisingly, we find FL at low Q2 to be much larger than expectation and observe that both FL and F2 at x = Q2/s show several properties consistent with the dipole picture. We discuss the statistical as well as chief systematic errors of our method and we tabulate our determinations of F2, 2xF1 and FL in the Appendix.
[ { "created": "Fri, 28 Jun 2024 14:57:49 GMT", "version": "v1" }, { "created": "Mon, 1 Jul 2024 10:39:03 GMT", "version": "v2" } ]
2024-07-02
[ [ "Taylor", "Frank E.", "" ] ]
It is well known that there are persistent statistical tensions with the standard model in the low Q2 HERA deep inelastic scattering neutral current data characterized by a turn-over of F2(x, Q2) at low x and low Q2. One important experimental signature that sheds light on this low Q2 region is the determination of the longitudinal structure function FL(x, Q2). This paper describes a novel method to determine FL based on an extrapolation of the reduced NC cross section at fixed s and Q to the minimum value of x given by Q2/s. At this kinematic point, the reduced cross section equals 2xF1 = F2 - FL so that a determination of both this value and the value of F2, determines FL. Since the polarization of the exchanged photon is transverse at this kinematic point, we expect FL to be small because its dominate gluon component is strongly suppressed. Surprisingly, we find FL at low Q2 to be much larger than expectation and observe that both FL and F2 at x = Q2/s show several properties consistent with the dipole picture. We discuss the statistical as well as chief systematic errors of our method and we tabulate our determinations of F2, 2xF1 and FL in the Appendix.
2302.08998
Barbara Skrzypek
Barbara Skrzypek and Carlos A. Arg\"uelles
Lorentz Violation in Neutrino Oscillations using IceCube Atmospheric Neutrino Interferometry
null
null
null
null
hep-ph hep-ex
http://creativecommons.org/licenses/by/4.0/
Lorentz invariance is a fundamental symmetry of spacetime underpinning the Standard Model (SM) and our understanding of high-energy phenomena in particle physics. However, beyond the quantum gravity scale, we expect the SM to be replaced with a more fundamental, covariant theory giving a quantum description of gravity. The effective theory arising from this theory can break Lorentz invariance and thus predicts observables that exhibit low-energy manifestations of Lorentz violation. In particular, these observables could be a subleading contribution to neutrino oscillations and could therefore explain anomalous flavor measurements. The Standard Model Extension (SME) formalism describing such an effective theory predicts terms whose characteristic oscillation length becomes significant at atmospheric neutrino energies accessible by the IceCube Neutrino Observatory. We descibe past measurements and efforts to extend these using ten years of data along with a new energy reconstruction to study $\nu_{\mu}$ disappearance.
[ { "created": "Fri, 17 Feb 2023 17:05:00 GMT", "version": "v1" } ]
2023-02-20
[ [ "Skrzypek", "Barbara", "" ], [ "Argüelles", "Carlos A.", "" ] ]
Lorentz invariance is a fundamental symmetry of spacetime underpinning the Standard Model (SM) and our understanding of high-energy phenomena in particle physics. However, beyond the quantum gravity scale, we expect the SM to be replaced with a more fundamental, covariant theory giving a quantum description of gravity. The effective theory arising from this theory can break Lorentz invariance and thus predicts observables that exhibit low-energy manifestations of Lorentz violation. In particular, these observables could be a subleading contribution to neutrino oscillations and could therefore explain anomalous flavor measurements. The Standard Model Extension (SME) formalism describing such an effective theory predicts terms whose characteristic oscillation length becomes significant at atmospheric neutrino energies accessible by the IceCube Neutrino Observatory. We descibe past measurements and efforts to extend these using ten years of data along with a new energy reconstruction to study $\nu_{\mu}$ disappearance.
hep-ph/9602318
Sven Heinemeyer
S. Heinemeyer, W. Hollik
The decay $h^0 \to A^0A^0$: a complete 1-loop calculation in the MSSM
25 pages, LaTex, 10 figures included. Complete ps-file also available via WWW at http://itpaxp1.physik.uni-karlsruhe.de/prep/prep.html
Nucl.Phys. B474 (1996) 32-56
10.1016/0550-3213(96)00278-7
KA-TP-17-1995
hep-ph
null
In the minimal supersymmetric standard model the decay $h^0 \to A^0A^0$ of the light neutral scalar $h^0$ is kinematically allowed for low values of $\tan\beta$ when radiative corrections to the neutral Higgs masses are taken into account. The width of this decay mode is revisited on the basis of a complete 1-loop diagrammatic calculation. We give the analytical expressions and numerical results and compare them with the corresponding ones from the simpler and compact approximations of the effective potential method and the renormalization group approach.
[ { "created": "Thu, 15 Feb 1996 14:10:54 GMT", "version": "v1" } ]
2009-10-28
[ [ "Heinemeyer", "S.", "" ], [ "Hollik", "W.", "" ] ]
In the minimal supersymmetric standard model the decay $h^0 \to A^0A^0$ of the light neutral scalar $h^0$ is kinematically allowed for low values of $\tan\beta$ when radiative corrections to the neutral Higgs masses are taken into account. The width of this decay mode is revisited on the basis of a complete 1-loop diagrammatic calculation. We give the analytical expressions and numerical results and compare them with the corresponding ones from the simpler and compact approximations of the effective potential method and the renormalization group approach.
1804.01042
Shuai Zhao
Ji Xu, Qi-An Zhang, Shuai Zhao
Light-cone distribution amplitudes of vector meson in large momentum effective theory
15 pages, 1 figure, appendix B and references added
Phys. Rev. D 97, 114026 (2018)
10.1103/PhysRevD.97.114026
null
hep-ph hep-lat
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the leading twist light-cone distribution amplitudes (LCDAs) of vector meson in the framework of large momentum effective theory. We derive the matching equation for the LCDAs and quasi distribution amplitudes. The matching coefficients are determined to one loop accuracy, both in the ultraviolet cut-off and dimensional regularization schemes. This calculation provides the possibility of studying the full $x$ behavior of LCDAs and extracting LCDAs of vector mesons from lattice simulations.
[ { "created": "Tue, 3 Apr 2018 15:43:09 GMT", "version": "v1" }, { "created": "Thu, 5 Apr 2018 13:10:49 GMT", "version": "v2" } ]
2018-07-04
[ [ "Xu", "Ji", "" ], [ "Zhang", "Qi-An", "" ], [ "Zhao", "Shuai", "" ] ]
We investigate the leading twist light-cone distribution amplitudes (LCDAs) of vector meson in the framework of large momentum effective theory. We derive the matching equation for the LCDAs and quasi distribution amplitudes. The matching coefficients are determined to one loop accuracy, both in the ultraviolet cut-off and dimensional regularization schemes. This calculation provides the possibility of studying the full $x$ behavior of LCDAs and extracting LCDAs of vector mesons from lattice simulations.
1206.2207
Gilberto Ramalho
G. Ramalho, K. Tsushima and A. W. Thomas
Octet baryon electromagnetic form factors in nuclear medium
Version accepted for publication in J.Phys. G. Few changes. 40 pages, 14 figures and 8 tables
J. Phys. G: Nucl. Part. Phys. 40 (2013) 015102
10.1088/0954-3899/40/1/015102
ADP-12-25/T792
hep-ph hep-ex hep-lat nucl-ex nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the octet baryon electromagnetic form factors in nuclear matter using the covariant spectator quark model extended to the nuclear matter regime. The parameters of the model in vacuum are fixed by the study of the octet baryon electromagnetic form factors. In nuclear matter the changes in hadron properties are calculated by including the relevant hadron masses and the modification of the pion-baryon coupling constants calculated in the quark-meson coupling model. In nuclear matter the magnetic form factors of the octet baryons are enhanced in the low $Q^2$ region, while the electric form factors show a more rapid variation with $Q^2$. The results are compared with the modification of the bound proton electromagnetic form factors observed at Jefferson Lab. In addition, the corresponding changes for the bound neutron are predicted.
[ { "created": "Mon, 11 Jun 2012 13:59:13 GMT", "version": "v1" }, { "created": "Sun, 2 Dec 2012 21:01:06 GMT", "version": "v2" } ]
2012-12-04
[ [ "Ramalho", "G.", "" ], [ "Tsushima", "K.", "" ], [ "Thomas", "A. W.", "" ] ]
We study the octet baryon electromagnetic form factors in nuclear matter using the covariant spectator quark model extended to the nuclear matter regime. The parameters of the model in vacuum are fixed by the study of the octet baryon electromagnetic form factors. In nuclear matter the changes in hadron properties are calculated by including the relevant hadron masses and the modification of the pion-baryon coupling constants calculated in the quark-meson coupling model. In nuclear matter the magnetic form factors of the octet baryons are enhanced in the low $Q^2$ region, while the electric form factors show a more rapid variation with $Q^2$. The results are compared with the modification of the bound proton electromagnetic form factors observed at Jefferson Lab. In addition, the corresponding changes for the bound neutron are predicted.
2407.21700
Arnd Behring
Samuel Abreu, Arnd Behring, Andrew McLeod, Ben Page
Four-loop two-mass tadpoles and the $\rho$ parameter
Contribution to the proceedings of the Loops and Legs in Quantum Field Theory conference (LL2024), 14-19 April 2024, Wittenberg, Germany
null
null
CERN-TH-2024-129
hep-ph
http://creativecommons.org/licenses/by/4.0/
We calculate four-loop QCD corrections to the electroweak $\rho$ parameter with a non-vanishing $b$ quark mass. At three loops, it was observed that elliptic integrals contribute to this observable. This prompts the question of which classes of functions appear at the next order. We report on the status of our calculation with a focus on the mathematical structures that emerge at four loops.
[ { "created": "Wed, 31 Jul 2024 15:45:24 GMT", "version": "v1" } ]
2024-08-01
[ [ "Abreu", "Samuel", "" ], [ "Behring", "Arnd", "" ], [ "McLeod", "Andrew", "" ], [ "Page", "Ben", "" ] ]
We calculate four-loop QCD corrections to the electroweak $\rho$ parameter with a non-vanishing $b$ quark mass. At three loops, it was observed that elliptic integrals contribute to this observable. This prompts the question of which classes of functions appear at the next order. We report on the status of our calculation with a focus on the mathematical structures that emerge at four loops.
1910.09008
Shaikh Saad
Ilja Dor\v{s}ner, Shaikh Saad
Towards Minimal SU(5)
12 pages, 2 figures; References are updated
Phys. Rev. D 101, 015009 (2020)
10.1103/PhysRevD.101.015009
OSU-HEP-19-08
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a simple $SU(5)$ model that connects the neutrino mass generation mechanism to the observed disparity between the masses of charged leptons and down-type quarks. The model is built out of $5$-, $10$-, $15$-, $24$-, and $35$-dimensional representations of $SU(5)$ and comprises two (three) $3 \times 3$ ($3 \times 1$) Yukawa coupling matrices to accommodate all experimentally measured fermion masses and mixing parameters. The gauge coupling unification considerations, coupled with phenomenological constraints inferred from experiments that probe neutrino masses and mixing parameters and/or look for proton decay, fix all relevant mass scales of the model. The proposed scenario places several multiplets at the scales potentially accessible at the LHC and future colliders and correlates this feature with the gauge boson mediated proton decay signatures. It also predicts that one neutrino is massless.
[ { "created": "Sun, 20 Oct 2019 16:05:37 GMT", "version": "v1" }, { "created": "Thu, 31 Oct 2019 00:33:29 GMT", "version": "v2" }, { "created": "Fri, 17 Jan 2020 16:47:31 GMT", "version": "v3" } ]
2020-01-22
[ [ "Doršner", "Ilja", "" ], [ "Saad", "Shaikh", "" ] ]
We propose a simple $SU(5)$ model that connects the neutrino mass generation mechanism to the observed disparity between the masses of charged leptons and down-type quarks. The model is built out of $5$-, $10$-, $15$-, $24$-, and $35$-dimensional representations of $SU(5)$ and comprises two (three) $3 \times 3$ ($3 \times 1$) Yukawa coupling matrices to accommodate all experimentally measured fermion masses and mixing parameters. The gauge coupling unification considerations, coupled with phenomenological constraints inferred from experiments that probe neutrino masses and mixing parameters and/or look for proton decay, fix all relevant mass scales of the model. The proposed scenario places several multiplets at the scales potentially accessible at the LHC and future colliders and correlates this feature with the gauge boson mediated proton decay signatures. It also predicts that one neutrino is massless.
hep-ph/0008014
Richard Easther
Stephon Alexander, Robert Brandenberger, and Richard Easther
Attractive Forces Between Global Monopoles and Domain Walls
5 pages, 8 eps files
null
null
BROWN-HET-1207
hep-ph
null
We study the interaction between stable monopoles and domain walls in a $SO(3) \times Z(2)$ scalar field theory. Numerical simulations reveal that there is an attractive force between the monopole and the wall, but that after the monopole and the wall collide, the monopole does not unwind. We present an analytic explanation for the origin of the attractive force, and conclude that this is a generic feature of monopole-wall interactions which does not depend on the detailed structure of the model. The existence of the attractive force supports the hypothesis of Dvali {\em et al.} (hep-ph/9710301), who proposed that monopoles can be ``swept up'' by domain walls, thereby alleviating or solving the monopole problem associated with phase transitions occurring after or in the absence of inflation.
[ { "created": "Tue, 1 Aug 2000 22:06:04 GMT", "version": "v1" } ]
2007-05-23
[ [ "Alexander", "Stephon", "" ], [ "Brandenberger", "Robert", "" ], [ "Easther", "Richard", "" ] ]
We study the interaction between stable monopoles and domain walls in a $SO(3) \times Z(2)$ scalar field theory. Numerical simulations reveal that there is an attractive force between the monopole and the wall, but that after the monopole and the wall collide, the monopole does not unwind. We present an analytic explanation for the origin of the attractive force, and conclude that this is a generic feature of monopole-wall interactions which does not depend on the detailed structure of the model. The existence of the attractive force supports the hypothesis of Dvali {\em et al.} (hep-ph/9710301), who proposed that monopoles can be ``swept up'' by domain walls, thereby alleviating or solving the monopole problem associated with phase transitions occurring after or in the absence of inflation.
1205.0782
Juan M. Torres-Rincon
Juan M. Torres-Rincon
Hadronic Transport Coefficients from Effective Field Theories
PhD Dissertation, 220 pages. Defended at Universidad Complutense de Madrid on April 23rd 2012
null
null
null
hep-ph nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This dissertation focuses on the calculation of transport coefficients in the matter created in a relativistic heavy-ion collision after the chemical freeze-out. This matter can be well approximated by a pion gas out of equilibrium. We describe the theoretical framework to obtain the shear and bulk viscosities, the thermal and electrical conductivities and the flavor diffusion coefficients of a meson gas at low temperatures. To describe the interactions of the degrees of freedom, we use effective field theories with chiral and heavy quark symmetries. We introduce the unitarization methods in order to obtain a scattering amplitude that satisfies the unitarity condition exactly. We perform the calculation of the transport properties of the low temperature phase of quantum chromodynamics -the hadronic medium- that can be used in the hydrodynamic simulations of a relativistic heavy-ion collision and its subsequent evolution. We show that the shear viscosity over entropy density exhibits a minimum in a phase transition by studying this coefficient in atomic Argon (around the liquid-gas phase transition) and in the linear sigma model in the limit of large number of scalar fields (that presents a chiral phase transition). Finally, we provide an experimental method to estimate the bulk viscosity in relativistic heavy-ion collisions by performing correlations of the fluctuating components of the stress-energy tensor.
[ { "created": "Thu, 3 May 2012 18:09:53 GMT", "version": "v1" } ]
2012-05-04
[ [ "Torres-Rincon", "Juan M.", "" ] ]
This dissertation focuses on the calculation of transport coefficients in the matter created in a relativistic heavy-ion collision after the chemical freeze-out. This matter can be well approximated by a pion gas out of equilibrium. We describe the theoretical framework to obtain the shear and bulk viscosities, the thermal and electrical conductivities and the flavor diffusion coefficients of a meson gas at low temperatures. To describe the interactions of the degrees of freedom, we use effective field theories with chiral and heavy quark symmetries. We introduce the unitarization methods in order to obtain a scattering amplitude that satisfies the unitarity condition exactly. We perform the calculation of the transport properties of the low temperature phase of quantum chromodynamics -the hadronic medium- that can be used in the hydrodynamic simulations of a relativistic heavy-ion collision and its subsequent evolution. We show that the shear viscosity over entropy density exhibits a minimum in a phase transition by studying this coefficient in atomic Argon (around the liquid-gas phase transition) and in the linear sigma model in the limit of large number of scalar fields (that presents a chiral phase transition). Finally, we provide an experimental method to estimate the bulk viscosity in relativistic heavy-ion collisions by performing correlations of the fluctuating components of the stress-energy tensor.
1212.6939
Jon Chkareuli
J. L. Chkareuli
Emergent gauge theories and supersymmetry: a QED primer
10 pages, reported at the SUSY 2012 conference, to appear in Physics Letters B
null
10.1016/j.physletb.2013.02.053
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We argue that a generic trigger for photon and other gauge fields to emerge as massless Nambu-Goldstone modes could be spontaneously broken supersymmetry rather than physically manifested Lorentz violation. We consider supersymmetric QED model extended by an arbitrary polynomial potential of vector superfield that induces the spontaneous SUSY violation in the visible sector. As a consequence, massless photon appears as a companion of massless photino being Goldstone fermion state in tree approximation. Remarkably, the photon masslessness appearing at tree level is further protected against radiative corrections due to the simultaneously generated special gauge invariance in the broken SUSY phase. Meanwhile, photino being mixed with another goldstino appearing from a spontaneous SUSY violation in the hidden sector largely turns into light pseudo-goldstino whose physics seems to be of special interest.
[ { "created": "Mon, 31 Dec 2012 18:31:43 GMT", "version": "v1" }, { "created": "Thu, 3 Jan 2013 18:47:10 GMT", "version": "v2" }, { "created": "Sun, 20 Jan 2013 13:05:51 GMT", "version": "v3" }, { "created": "Thu, 21 Feb 2013 13:04:46 GMT", "version": "v4" } ]
2015-06-12
[ [ "Chkareuli", "J. L.", "" ] ]
We argue that a generic trigger for photon and other gauge fields to emerge as massless Nambu-Goldstone modes could be spontaneously broken supersymmetry rather than physically manifested Lorentz violation. We consider supersymmetric QED model extended by an arbitrary polynomial potential of vector superfield that induces the spontaneous SUSY violation in the visible sector. As a consequence, massless photon appears as a companion of massless photino being Goldstone fermion state in tree approximation. Remarkably, the photon masslessness appearing at tree level is further protected against radiative corrections due to the simultaneously generated special gauge invariance in the broken SUSY phase. Meanwhile, photino being mixed with another goldstino appearing from a spontaneous SUSY violation in the hidden sector largely turns into light pseudo-goldstino whose physics seems to be of special interest.
2308.01429
George Rupp
Maurizio Consoli and George Rupp
Second resonance of the Higgs field: motivations, experimental signals, unitarity constraints
Plain LaTeX, 36 pages, 12 figures, 4 tables; v2: plain two-column LaTeX, 13 figures, 7 tables, more discussion of theory and of experimental data
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Perturbative calculations predict that the Standard Model (SM) effective potential should have a new minimum, well beyond the Planck scale, much deeper than the electroweak vacuum. As it is not obvious that gravitational effects can get so strong to stabilize the potential, most authors have accepted the metastability scenario in a cosmological perspective. This perspective is needed to explain why the theory remains trapped into our electroweak vacuum, but requires to control the properties of matter in the extreme conditions of the early universe. Alternatively, one can consider the completely different idea of a non-perturbative effective potential which, as at the beginning of the SM, is restricted to the pure $\Phi^4$ sector yet consistent with the now existing analytical and numerical studies. In this approach, where the electroweak vacuum is the lowest-energy state, besides the resonance of mass $m_h=125$ GeV defined by the quadratic shape of the potential at its minimum, the Higgs field should exhibit a second resonance with mass $690\pm10({\rm stat})\pm20({\rm sys})$ GeV associated with the zero-point energy determining the potential depth. Despite its large mass, this would couple to longitudinal $W$s with the same typical strength as the low-mass state at 125 GeV and represent a relatively narrow resonance of width $\Gamma_H=30\div 38$ GeV, mainly produced at LHC by gluon-gluon fusion. So it is interesting that, in the LHC data, one can find various indications for a new resonance in the expected mass range with a non-negligible statistical significance. As this could become an important new discovery by just adding two missing samples of RUN2 data, we outline further refinements of the theoretical predictions that could be obtained by implementing unitarity constraints, in the presence of fermion and gauge fields, with coupled-channel calculations used for meson spectroscopy.
[ { "created": "Wed, 2 Aug 2023 21:02:05 GMT", "version": "v1" }, { "created": "Mon, 13 Nov 2023 16:07:41 GMT", "version": "v2" } ]
2023-11-14
[ [ "Consoli", "Maurizio", "" ], [ "Rupp", "George", "" ] ]
Perturbative calculations predict that the Standard Model (SM) effective potential should have a new minimum, well beyond the Planck scale, much deeper than the electroweak vacuum. As it is not obvious that gravitational effects can get so strong to stabilize the potential, most authors have accepted the metastability scenario in a cosmological perspective. This perspective is needed to explain why the theory remains trapped into our electroweak vacuum, but requires to control the properties of matter in the extreme conditions of the early universe. Alternatively, one can consider the completely different idea of a non-perturbative effective potential which, as at the beginning of the SM, is restricted to the pure $\Phi^4$ sector yet consistent with the now existing analytical and numerical studies. In this approach, where the electroweak vacuum is the lowest-energy state, besides the resonance of mass $m_h=125$ GeV defined by the quadratic shape of the potential at its minimum, the Higgs field should exhibit a second resonance with mass $690\pm10({\rm stat})\pm20({\rm sys})$ GeV associated with the zero-point energy determining the potential depth. Despite its large mass, this would couple to longitudinal $W$s with the same typical strength as the low-mass state at 125 GeV and represent a relatively narrow resonance of width $\Gamma_H=30\div 38$ GeV, mainly produced at LHC by gluon-gluon fusion. So it is interesting that, in the LHC data, one can find various indications for a new resonance in the expected mass range with a non-negligible statistical significance. As this could become an important new discovery by just adding two missing samples of RUN2 data, we outline further refinements of the theoretical predictions that could be obtained by implementing unitarity constraints, in the presence of fermion and gauge fields, with coupled-channel calculations used for meson spectroscopy.
hep-ph/0311367
Dan Hooper
Dan Hooper and Joseph Silk
Searching For Dark Matter with Neutrino Telescopes
For "Focus on Neutrino Physics" issue of New Journal of Physics
New.J.Phys.6:23,2004
10.1088/1367-2630/6/1/023
null
hep-ph astro-ph
null
One of the most interesting mysteries of astrophysics is the puzzle of dark matter. Although numerous techniques have been explored and developed to detect this elusive substance, its nature remains unknown. One such method uses large high-energy neutrino telescopes to look for the annihilation products of dark matter annihilations. In this summary article, we briefly review this technique. We describe the calculations used to find the rate of capture of WIMPs in the Sun or Earth and the spectrum of neutrinos produced in the resulting dark matter annihilations. We will discuss these calculations within the context of supersymmetry and models with universal extra dimensions, the lightest supersymmetric particle and lightest Kaluza-Klein particle providing the WIMP candidate in these cases, respectively. We will also discuss the status of some of the experiments relevant to these searches: AMANDA, IceCube and ANTARES.
[ { "created": "Fri, 28 Nov 2003 14:03:21 GMT", "version": "v1" }, { "created": "Thu, 4 Mar 2004 12:25:12 GMT", "version": "v2" } ]
2008-11-26
[ [ "Hooper", "Dan", "" ], [ "Silk", "Joseph", "" ] ]
One of the most interesting mysteries of astrophysics is the puzzle of dark matter. Although numerous techniques have been explored and developed to detect this elusive substance, its nature remains unknown. One such method uses large high-energy neutrino telescopes to look for the annihilation products of dark matter annihilations. In this summary article, we briefly review this technique. We describe the calculations used to find the rate of capture of WIMPs in the Sun or Earth and the spectrum of neutrinos produced in the resulting dark matter annihilations. We will discuss these calculations within the context of supersymmetry and models with universal extra dimensions, the lightest supersymmetric particle and lightest Kaluza-Klein particle providing the WIMP candidate in these cases, respectively. We will also discuss the status of some of the experiments relevant to these searches: AMANDA, IceCube and ANTARES.
hep-ph/0007215
Marcus Bleicher
M. Bleicher, W. Greiner, H. St\"ocker, N. Xu (LBNL, Frankfurt Univ.)
Strangeness enhancement from strong color fields at RHIC
null
Phys.Rev. C62 (2000) 061901
10.1103/PhysRevC.62.061901
LBNL-preprint: LBNL-46167
hep-ph
null
In ultra-relativistic heavy ion collisions, early stage multiple scatterings may lead to an increase of the color electric field strength. Consequently, particle production - especially heavy quark (and di-quark) production - is greatly enhanced according to the Schwinger mechanism. We test this idea via the Ultra-relativistic Quantum Molecular Dynamics model (UrQMD) for Au+Au collisions at the full RHIC energy ($\sqrt{s} = 200$ AGeV). Relative to p+p collisions, a factor of 60, 20 and 7 enhancement respectively, for $\Omega$ ($sss$), $\Xi$ ($ss$), and $\Lambda$, $\Sigma$ ($s$) is predicted for a model with increased color electric field strength.
[ { "created": "Wed, 19 Jul 2000 23:45:01 GMT", "version": "v1" } ]
2009-10-31
[ [ "Bleicher", "M.", "", "LBNL, Frankfurt Univ." ], [ "Greiner", "W.", "", "LBNL, Frankfurt Univ." ], [ "Stöcker", "H.", "", "LBNL, Frankfurt Univ." ], [ "Xu", "N.", "", "LBNL, Frankfurt Univ." ] ]
In ultra-relativistic heavy ion collisions, early stage multiple scatterings may lead to an increase of the color electric field strength. Consequently, particle production - especially heavy quark (and di-quark) production - is greatly enhanced according to the Schwinger mechanism. We test this idea via the Ultra-relativistic Quantum Molecular Dynamics model (UrQMD) for Au+Au collisions at the full RHIC energy ($\sqrt{s} = 200$ AGeV). Relative to p+p collisions, a factor of 60, 20 and 7 enhancement respectively, for $\Omega$ ($sss$), $\Xi$ ($ss$), and $\Lambda$, $\Sigma$ ($s$) is predicted for a model with increased color electric field strength.
hep-ph/0603147
Aleksey Khotyantsev N.
V. P. Efrosinin, A. N. Khotyantsev
About the quark currents in leptonic decaies of pseudoscalar mesons
7 pages, 2 figures
null
null
null
hep-ph
null
With usage of obvious mechanisms of quark currents the amplitudes of leptonic decaies of pseudoscalar mesons are investigated. The estimation for a constant of leptonic decay of the D+ meson is obtained, f_D+ ~ 0.23 GeV.
[ { "created": "Mon, 20 Mar 2006 13:11:06 GMT", "version": "v1" } ]
2007-05-23
[ [ "Efrosinin", "V. P.", "" ], [ "Khotyantsev", "A. N.", "" ] ]
With usage of obvious mechanisms of quark currents the amplitudes of leptonic decaies of pseudoscalar mesons are investigated. The estimation for a constant of leptonic decay of the D+ meson is obtained, f_D+ ~ 0.23 GeV.
hep-ph/0511063
Konstantin Chetyrkin G.
P.A. Baikov, K.G. Chetyrkin and J.H. K\"uhn
Scalar Correlator at O(alpha_s^4), Higgs Decay into b-quarks and Bounds on the Light Quark Masses
5 pages, REVTeX4. Few references updated. The final version, accepted for publication. The complete paper is also available via the www at http://www-ttp.physik.uni-karlsruhe.de/Preprints/
Phys.Rev.Lett.96:012003,2006
10.1103/PhysRevLett.96.012003
SFB/CPP-05-33, TTP05-11
hep-ph
null
We compute, for the first time, the absorptive part of the massless correlator of two quark scalar currents in five loops. As physical applications we consider the O(alpha_s^4) corrections to the decay rate of the Standard Model Higgs boson into quarks, as well as the constraints on the strange quark mass following from QCD sum rules.
[ { "created": "Mon, 7 Nov 2005 11:13:59 GMT", "version": "v1" }, { "created": "Mon, 19 Dec 2005 13:05:59 GMT", "version": "v2" } ]
2009-03-16
[ [ "Baikov", "P. A.", "" ], [ "Chetyrkin", "K. G.", "" ], [ "Kühn", "J. H.", "" ] ]
We compute, for the first time, the absorptive part of the massless correlator of two quark scalar currents in five loops. As physical applications we consider the O(alpha_s^4) corrections to the decay rate of the Standard Model Higgs boson into quarks, as well as the constraints on the strange quark mass following from QCD sum rules.
hep-ph/0501161
We-Fu Chang
We-Fu Chang and John N. Ng
Lepton Flavor Violation in Extra Dimension Models
16 pages, 4 figures
Phys.Rev.D71:053003,2005
10.1103/PhysRevD.71.053003
null
hep-ph
null
Models involving large extra spatial dimension(s) have interesting predictions on lepton flavor violating processes. We consider some 5D models which are related to neutrino mass generation or address the fermion masses hierarchy problem. We study the signatures in low energy experiments that can discriminate the different models. The focus is on muon-electron conversion in nuclei, $\mu\ra e \gamma$ and $\mu\ra 3e$ processes and their $\tau$ counterparts. Their links with the active neutrino mass matrix are investigated. We show that in the models we discussed the branching ratio of $\mu\ra e \gamma$ like rare process is much smaller than the ones of $\mu\ra 3e$ like processes. This is in sharp contrast to most of the traditional wisdom based on four dimensional gauge models. Moreover, some rare tau decays are more promising than the rare muon decays.
[ { "created": "Tue, 18 Jan 2005 06:51:04 GMT", "version": "v1" } ]
2011-07-19
[ [ "Chang", "We-Fu", "" ], [ "Ng", "John N.", "" ] ]
Models involving large extra spatial dimension(s) have interesting predictions on lepton flavor violating processes. We consider some 5D models which are related to neutrino mass generation or address the fermion masses hierarchy problem. We study the signatures in low energy experiments that can discriminate the different models. The focus is on muon-electron conversion in nuclei, $\mu\ra e \gamma$ and $\mu\ra 3e$ processes and their $\tau$ counterparts. Their links with the active neutrino mass matrix are investigated. We show that in the models we discussed the branching ratio of $\mu\ra e \gamma$ like rare process is much smaller than the ones of $\mu\ra 3e$ like processes. This is in sharp contrast to most of the traditional wisdom based on four dimensional gauge models. Moreover, some rare tau decays are more promising than the rare muon decays.
hep-ph/0609159
Zhang Hanzhong
Hanzhong Zhang, Zhongbo Kang, Ben-Wei Zhang and Enke Wang
Photon Radiation and Dilepton Production Induced by Rescattering in Strong Interacting Medium
10 pages, 10 figures, revised version
Eur.Phys.J.C67:445-454,2010
10.1140/epjc/s10052-010-1330-6
null
hep-ph
null
Using the opacity expansion technique we investigate the photon radiation and dilepton production induced by multiple rescattering as energetic parton jet passing through the strong interacting medium. The real photon radiation and dilepton invariant-mass spectrums of the bremsstrahlung contribution from an energetic quark jet are presented. The leading contribution of total energy loss by photon emmision in medium of a higher energy quark jet is found to be proportional to the jet energy and has a linear dependence on the thickness of the nuclear target. The rescattering contribution for the dilepton is important only for small value of the invariant-mass and for the not so fast jet. The contribution fraction of the dilepton induced by rescattering in medium is found to be nearly a constant when the ratio of jet energy to Debye screening mass $E/\mu$ is large.
[ { "created": "Sun, 17 Sep 2006 05:07:27 GMT", "version": "v1" }, { "created": "Sun, 27 Apr 2008 13:16:13 GMT", "version": "v2" } ]
2014-11-18
[ [ "Zhang", "Hanzhong", "" ], [ "Kang", "Zhongbo", "" ], [ "Zhang", "Ben-Wei", "" ], [ "Wang", "Enke", "" ] ]
Using the opacity expansion technique we investigate the photon radiation and dilepton production induced by multiple rescattering as energetic parton jet passing through the strong interacting medium. The real photon radiation and dilepton invariant-mass spectrums of the bremsstrahlung contribution from an energetic quark jet are presented. The leading contribution of total energy loss by photon emmision in medium of a higher energy quark jet is found to be proportional to the jet energy and has a linear dependence on the thickness of the nuclear target. The rescattering contribution for the dilepton is important only for small value of the invariant-mass and for the not so fast jet. The contribution fraction of the dilepton induced by rescattering in medium is found to be nearly a constant when the ratio of jet energy to Debye screening mass $E/\mu$ is large.
1102.4846
Giulia Zanderighi
Tom Melia, Paolo Nason, Raoul Rontsch and Giulia Zanderighi
W^+W^+ plus dijet production in the POWHEGBOX
16 pages, 5 figures
null
10.1140/epjc/s10052-011-1670-x
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present an implementation of the calculation of the production of W^+W^+ plus two jets at hadron colliders, at next-to-leading order (NLO) in QCD, in the POWHEG framework, which is a method that allows the interfacing of NLO calculations to shower Monte Carlo programs. This is the first 2 -> 4 process to be described to NLO accuracy within a shower Monte Carlo framework. The implementation was built within the POWHEGBOX package. We discuss a few technical improvements that were needed in the POWHEGBOX to deal with the computer intensive nature of the NLO calculation, and argue that further improvements are possible, so that the method can match the complexity that is reached today in NLO calculations. We have interfaced our POWHEG implementation with PYTHIA and HERWIG, and present some phenomenological results, discussing similarities and differences between the pure NLO and the POWHEG+PYTHIA calculation both for inclusive and more exclusive distributions. We have made the relevant code available at the POWHEGBOX web site.
[ { "created": "Wed, 23 Feb 2011 21:00:02 GMT", "version": "v1" } ]
2015-05-27
[ [ "Melia", "Tom", "" ], [ "Nason", "Paolo", "" ], [ "Rontsch", "Raoul", "" ], [ "Zanderighi", "Giulia", "" ] ]
We present an implementation of the calculation of the production of W^+W^+ plus two jets at hadron colliders, at next-to-leading order (NLO) in QCD, in the POWHEG framework, which is a method that allows the interfacing of NLO calculations to shower Monte Carlo programs. This is the first 2 -> 4 process to be described to NLO accuracy within a shower Monte Carlo framework. The implementation was built within the POWHEGBOX package. We discuss a few technical improvements that were needed in the POWHEGBOX to deal with the computer intensive nature of the NLO calculation, and argue that further improvements are possible, so that the method can match the complexity that is reached today in NLO calculations. We have interfaced our POWHEG implementation with PYTHIA and HERWIG, and present some phenomenological results, discussing similarities and differences between the pure NLO and the POWHEG+PYTHIA calculation both for inclusive and more exclusive distributions. We have made the relevant code available at the POWHEGBOX web site.
hep-ph/9507448
Mauro Donizeti Tonasse
Vicente Pleitez
The heavy top quark and right-handed currents
14 pages, Revtex, no figure, revised and extended version
null
null
IFT-P.035/95
hep-ph
null
We consider a modification of the standard electroweak model with the third quark generation and the $\tau$-lepton in vector representations of $SU(2)\otimes U(1)_Y$ electroweak symmetry. This is a new way to implement right-handed currents which are controlled by the usual Fermi constant, $G_F$, the weak mixing angle, $\sin\theta_W$, and also by the right-handed mixing matrices which survive when the Lagrangian density is written in terms of the mass eigenstates. In this case there are also new CP violation phases.
[ { "created": "Fri, 28 Jul 1995 12:35:00 GMT", "version": "v1" }, { "created": "Tue, 6 Jan 1998 18:40:30 GMT", "version": "v2" } ]
2008-02-03
[ [ "Pleitez", "Vicente", "" ] ]
We consider a modification of the standard electroweak model with the third quark generation and the $\tau$-lepton in vector representations of $SU(2)\otimes U(1)_Y$ electroweak symmetry. This is a new way to implement right-handed currents which are controlled by the usual Fermi constant, $G_F$, the weak mixing angle, $\sin\theta_W$, and also by the right-handed mixing matrices which survive when the Lagrangian density is written in terms of the mass eigenstates. In this case there are also new CP violation phases.
0806.0269
Umit Oktay Yilmaz
U. O. Yilmaz
Analysis of B_s->\phi \ell^+ \ell^- decay with new physics effects
28 pages, 14 figures
Eur.Phys.J.C58:555-568,2008
10.1140/epjc/s10052-008-0784-2
null
hep-ph
http://creativecommons.org/licenses/by/3.0/
The rare B_s-> \phi \ell^+ \ell^- decay is investigated by using the most general model independent effective Hamiltonian for $\ell= \mu, \tau$. The calculated $Br(B_s \rar \phi \mu^+ \mu^-) = 1.92 \times 10^{-6}$ is in consistent with the experimental upper bound. The dependencies of the branching ratios and polarization asymmetries of leptons and combined lepton-antilepton asymmetries on the new Wilson coefficients are presented. The analysis shows that the branching ratios and the lepton polarization asymmetries are very sensitive to the scalar and tensor type interactions. The results obtained in this work will be very useful in searching new physics beyond the standard model.
[ { "created": "Mon, 2 Jun 2008 13:04:46 GMT", "version": "v1" } ]
2008-12-18
[ [ "Yilmaz", "U. O.", "" ] ]
The rare B_s-> \phi \ell^+ \ell^- decay is investigated by using the most general model independent effective Hamiltonian for $\ell= \mu, \tau$. The calculated $Br(B_s \rar \phi \mu^+ \mu^-) = 1.92 \times 10^{-6}$ is in consistent with the experimental upper bound. The dependencies of the branching ratios and polarization asymmetries of leptons and combined lepton-antilepton asymmetries on the new Wilson coefficients are presented. The analysis shows that the branching ratios and the lepton polarization asymmetries are very sensitive to the scalar and tensor type interactions. The results obtained in this work will be very useful in searching new physics beyond the standard model.
hep-ph/9912295
Tommy Ohlsson
Tommy Ohlsson and Hakan Snellman
Neutrino oscillations with three flavors in matter: Applications to neutrinos traversing the Earth
14 pages, 4 figures (PostScript), Elsevier LaTeX
Phys.Lett. B474 (2000) 153-162
10.1016/S0370-2693(00)00008-3
null
hep-ph
null
Analytic formulas are presented for three flavor neutrino oscillations in matter in the plane wave approximation. We calculate in particular the time evolution operator in both mass and flavor bases. We also find the transition probabilities expressed as functions of the vacuum mass squared differences, the vacuum mixing angles, and the matter density parameter. The application of this to neutrino oscillations for both atmospheric and long baseline neutrinos in a mantle-core-mantle step function model of the Earth's matter density profile is discussed.
[ { "created": "Fri, 10 Dec 1999 13:05:35 GMT", "version": "v1" }, { "created": "Fri, 30 Jun 2000 19:36:30 GMT", "version": "v2" } ]
2009-10-31
[ [ "Ohlsson", "Tommy", "" ], [ "Snellman", "Hakan", "" ] ]
Analytic formulas are presented for three flavor neutrino oscillations in matter in the plane wave approximation. We calculate in particular the time evolution operator in both mass and flavor bases. We also find the transition probabilities expressed as functions of the vacuum mass squared differences, the vacuum mixing angles, and the matter density parameter. The application of this to neutrino oscillations for both atmospheric and long baseline neutrinos in a mantle-core-mantle step function model of the Earth's matter density profile is discussed.
0712.3311
Peter Zeiler Skands
J. Alwall, E. Boos, L. Dudko, M. Gigg, M. Herquet, A. Pukhov, P. Richardson, A. Sherstnev, P. Skands
A Les Houches Interface for BSM Generators
4 pages
null
null
FERMILAB-CONF-07-621-T
hep-ph
null
We propose to combine and slightly extend two existing "Les Houches Accords" to provide a simple generic interface between beyond-the-standard-model parton-level and event-level generators. All relevant information - particle content, quantum numbers of new states, masses, cross sections, parton-level events, etc - is collected in one single file, which adheres to the Les Houches Event File (LHEF) standard.
[ { "created": "Wed, 19 Dec 2007 23:59:27 GMT", "version": "v1" } ]
2007-12-21
[ [ "Alwall", "J.", "" ], [ "Boos", "E.", "" ], [ "Dudko", "L.", "" ], [ "Gigg", "M.", "" ], [ "Herquet", "M.", "" ], [ "Pukhov", "A.", "" ], [ "Richardson", "P.", "" ], [ "Sherstnev", "A.", "" ], [ "Skands", "P.", "" ] ]
We propose to combine and slightly extend two existing "Les Houches Accords" to provide a simple generic interface between beyond-the-standard-model parton-level and event-level generators. All relevant information - particle content, quantum numbers of new states, masses, cross sections, parton-level events, etc - is collected in one single file, which adheres to the Les Houches Event File (LHEF) standard.
2204.08546
Taylor Murphy
Linda M. Carpenter, Taylor Murphy, and Matthew J. Smylie
Changing patterns in electroweak precision with new color-charged states: Oblique corrections and the $W$ boson mass
11 pages, 4 figures. Updated to resemble Phys. Rev. D Version of Record
Phys. Rev. D 106, 055005 (2022)
10.1103/PhysRevD.106.055005
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The recent measurement by the CDF Collaboration of the $W$ boson mass is in significant tension with the Standard Model expectation, showing a discrepancy of seven standard deviations. A larger value of $m_W$ affects the global electroweak fit, particularly the best-fit values of the Peskin-Takeuchi parameters $S$, $T$ (and perhaps $U$) that measure oblique corrections from new physics. To meet this challenge, we propose some simple models capable of generating non-negative $S$ and $T$, the latter of which faces the greatest upward pressure from the CDF measurement in scenarios with $U=0$. Our models feature weak multiplets of scalars charged under $\mathrm{SU}(3)_{\text{c}} \times \mathrm{U}(1)_Y$, which cannot attain nonzero vacuum expectation values but nevertheless produce e.g. $T \neq 0$ given some other mechanism to split the electrically charged and neutral scalars. We compute the oblique corrections in these models and identify ample parameter space supporting the CDF value of $m_W$.
[ { "created": "Mon, 18 Apr 2022 20:20:21 GMT", "version": "v1" }, { "created": "Tue, 6 Sep 2022 19:23:54 GMT", "version": "v2" } ]
2022-09-08
[ [ "Carpenter", "Linda M.", "" ], [ "Murphy", "Taylor", "" ], [ "Smylie", "Matthew J.", "" ] ]
The recent measurement by the CDF Collaboration of the $W$ boson mass is in significant tension with the Standard Model expectation, showing a discrepancy of seven standard deviations. A larger value of $m_W$ affects the global electroweak fit, particularly the best-fit values of the Peskin-Takeuchi parameters $S$, $T$ (and perhaps $U$) that measure oblique corrections from new physics. To meet this challenge, we propose some simple models capable of generating non-negative $S$ and $T$, the latter of which faces the greatest upward pressure from the CDF measurement in scenarios with $U=0$. Our models feature weak multiplets of scalars charged under $\mathrm{SU}(3)_{\text{c}} \times \mathrm{U}(1)_Y$, which cannot attain nonzero vacuum expectation values but nevertheless produce e.g. $T \neq 0$ given some other mechanism to split the electrically charged and neutral scalars. We compute the oblique corrections in these models and identify ample parameter space supporting the CDF value of $m_W$.
2007.13122
Kun Xu
Kun Xu, Jingyi Chao, Mei Huang
Effect of the anomalous magnetic moment of quarks on magnetized QCD matter and meson spectra
14 pages, 9 figures
Phys. Rev. D 103, 076015 (2021)
10.1103/PhysRevD.103.076015
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We systematically investigate the effect of the anomalous magnetic moment(AMM) of quarks on the magnetized QCD matter, including the magnetic susceptibility, the inverse magnetic catalysis around the critical temperature and the neutral/charged pion and rho meson spectra under magnetic fields. The dynamical AMM of quarks, its coupling with magnetic field causes Zeeman splitting of the dispersion relation of quarks thus changes the magnetism properties and meson mass spectra under magnetic fields. It is found that including the AMM of quarks cannot fully understand lattice results of the magnetized matter: The AMM of quarks reduces the dynamical quark mass thus causes the inverse magnetic catalysis around $T_c$. The neutral pion mass is very sensitive to the AMM, it decreases with magnetic field quickly, and the charged pion mass shows a nonlinear behavior, i.e., firstly linearly increases with the magnetic field and then saturates at strong magnetic field. For rho meson, it is observed that AMM reduces the mass of neutral rho meson mass with different $s_z$, and reduces the mass of $s_z=+1,0$ component charged rho meson mass but enhances the $s_z=-1$ component charged rho meson mass. The magnetic susceptibility at low temperature can be either positive or negative with different AMM.
[ { "created": "Sun, 26 Jul 2020 12:57:24 GMT", "version": "v1" }, { "created": "Tue, 28 Jul 2020 12:14:31 GMT", "version": "v2" }, { "created": "Tue, 9 Feb 2021 05:43:10 GMT", "version": "v3" } ]
2021-04-28
[ [ "Xu", "Kun", "" ], [ "Chao", "Jingyi", "" ], [ "Huang", "Mei", "" ] ]
We systematically investigate the effect of the anomalous magnetic moment(AMM) of quarks on the magnetized QCD matter, including the magnetic susceptibility, the inverse magnetic catalysis around the critical temperature and the neutral/charged pion and rho meson spectra under magnetic fields. The dynamical AMM of quarks, its coupling with magnetic field causes Zeeman splitting of the dispersion relation of quarks thus changes the magnetism properties and meson mass spectra under magnetic fields. It is found that including the AMM of quarks cannot fully understand lattice results of the magnetized matter: The AMM of quarks reduces the dynamical quark mass thus causes the inverse magnetic catalysis around $T_c$. The neutral pion mass is very sensitive to the AMM, it decreases with magnetic field quickly, and the charged pion mass shows a nonlinear behavior, i.e., firstly linearly increases with the magnetic field and then saturates at strong magnetic field. For rho meson, it is observed that AMM reduces the mass of neutral rho meson mass with different $s_z$, and reduces the mass of $s_z=+1,0$ component charged rho meson mass but enhances the $s_z=-1$ component charged rho meson mass. The magnetic susceptibility at low temperature can be either positive or negative with different AMM.
2108.11931
Joachim Brod
Joachim Brod
Dark Matter Effective Theory
23 pages, 4 figures. Submitted to SciPost Physics Lecture Notes, Les Houches Summer School Series. Improved discussion, corrected typographical errors
SciPost Phys. Lect. Notes 38 (2022)
10.21468/SciPostPhysLectNotes.38
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
Les Houches 2021 lectures on dark matter effective field theory (short course). The aim of these two lectures is to calculate the DM-nucleus cross section for a simple example, and then generalize to the treatment of general effective interactions of spin-1/2 DM. Relativistic local operators, the heavy-DM effective theory, the chiral effective Lagrangian, and nuclear effective operators are briefly discussed.
[ { "created": "Thu, 26 Aug 2021 17:41:01 GMT", "version": "v1" }, { "created": "Fri, 19 Nov 2021 18:46:04 GMT", "version": "v2" } ]
2022-02-02
[ [ "Brod", "Joachim", "" ] ]
Les Houches 2021 lectures on dark matter effective field theory (short course). The aim of these two lectures is to calculate the DM-nucleus cross section for a simple example, and then generalize to the treatment of general effective interactions of spin-1/2 DM. Relativistic local operators, the heavy-DM effective theory, the chiral effective Lagrangian, and nuclear effective operators are briefly discussed.
2302.02203
Jingshu Li
Jingshu Li, Wanyue Wang, Xunye Cai, Chuxue Yang, Meng Lu, Zhengyun You, Sitian Qian, and Qiang Li
A Comparative Study of Z$^{\prime}$ mediated Charged Lepton Flavor Violation at future lepton colliders
11 pages, 5 figures
null
10.1007/JHEP03(2023)190
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Charged lepton flavor violation (CLFV) represents a transition between charged leptons of different generations that violates lepton flavor conservation, which is a clear signature of possible new physics beyond the standard model. By exploiting a typical example model of extra Z$^{\prime}$ gauge boson, we perform a detailed comparative study on CLFV searches at several future lepton colliders, including a 240 GeV electron-positron collider and a TeV scale muon collider. Based on detailed signal and background Monte-Carlo studies with fast detector simulations, we derive the potentials in searching for Z$^{\prime}$ mediated CLFV couplings with $e\mu$, $e\tau$ and $\mu\tau$ of different future colliders. The results are compared with the current limits set by either low-energy experiments or the high-energy LHC experiments. We find that the sensitivity of the $\tau$ related CLFV coupling strength at future lepton colliders will be significantly improved comparing with the current best constraints.
[ { "created": "Sat, 4 Feb 2023 17:03:46 GMT", "version": "v1" }, { "created": "Tue, 7 Feb 2023 16:37:50 GMT", "version": "v2" }, { "created": "Mon, 6 Mar 2023 08:40:30 GMT", "version": "v3" }, { "created": "Sun, 19 Mar 2023 12:51:10 GMT", "version": "v4" } ]
2023-04-12
[ [ "Li", "Jingshu", "" ], [ "Wang", "Wanyue", "" ], [ "Cai", "Xunye", "" ], [ "Yang", "Chuxue", "" ], [ "Lu", "Meng", "" ], [ "You", "Zhengyun", "" ], [ "Qian", "Sitian", "" ], [ "Li", "Qiang", "" ] ]
Charged lepton flavor violation (CLFV) represents a transition between charged leptons of different generations that violates lepton flavor conservation, which is a clear signature of possible new physics beyond the standard model. By exploiting a typical example model of extra Z$^{\prime}$ gauge boson, we perform a detailed comparative study on CLFV searches at several future lepton colliders, including a 240 GeV electron-positron collider and a TeV scale muon collider. Based on detailed signal and background Monte-Carlo studies with fast detector simulations, we derive the potentials in searching for Z$^{\prime}$ mediated CLFV couplings with $e\mu$, $e\tau$ and $\mu\tau$ of different future colliders. The results are compared with the current limits set by either low-energy experiments or the high-energy LHC experiments. We find that the sensitivity of the $\tau$ related CLFV coupling strength at future lepton colliders will be significantly improved comparing with the current best constraints.
hep-ph/0111410
Ismd31
J.Manjavidze, A.Sissakian
Why the Very High Multiplicity events are rare
5 pages, 3 figures (in eps) talk given at XXXI International Symposium on Multiparticle Dynamics, Sep. 1-7, 2001, Datong China URL http://ismd31.ccnu.edu.cn/
null
10.1142/9789812778048_0006
null
hep-ph
null
The possibility to suppress the nonperturbative effects choosing the vary high multiplicity final state is discussed. The theoretical uncertainties and the experimental observable consequence of this choice are discussed.
[ { "created": "Thu, 29 Nov 2001 12:34:30 GMT", "version": "v1" } ]
2017-08-23
[ [ "Manjavidze", "J.", "" ], [ "Sissakian", "A.", "" ] ]
The possibility to suppress the nonperturbative effects choosing the vary high multiplicity final state is discussed. The theoretical uncertainties and the experimental observable consequence of this choice are discussed.
1809.03446
Leonard Lesniak
L. Lesniak, F. Sobczuk, M. Silarski and F. Morawski
Near threshold kaon-kaon interaction in the reactions e+ e- --> K+ K- gamma and e+ e- --> K0 K0bar gamma
4 pages, 3 figures, contribution to 15th International Workshop on Meson Physics, Cracow, Poland, 7th - 12th June 2018
null
10.1051/epjconf/201919903002
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Strong interactions between pairs of the K+ K- and K0 K0bar mesons can be studied in radiative decays of phi(1020) mesons. We present a theoretical model of the reactions e+ e- --> phi --> K+ K- gamma and e+ e- --> phi --> K0 K0bar gamma. The K+ K- and K0 K0bar effective mass dependence of the differential cross sections is derived. The total cross sections and the branching fractions for the two radiative phi decays are calculated.
[ { "created": "Mon, 10 Sep 2018 16:34:26 GMT", "version": "v1" } ]
2019-02-20
[ [ "Lesniak", "L.", "" ], [ "Sobczuk", "F.", "" ], [ "Silarski", "M.", "" ], [ "Morawski", "F.", "" ] ]
Strong interactions between pairs of the K+ K- and K0 K0bar mesons can be studied in radiative decays of phi(1020) mesons. We present a theoretical model of the reactions e+ e- --> phi --> K+ K- gamma and e+ e- --> phi --> K0 K0bar gamma. The K+ K- and K0 K0bar effective mass dependence of the differential cross sections is derived. The total cross sections and the branching fractions for the two radiative phi decays are calculated.
hep-ph/0303011
Peter Schweitzer
P. Schweitzer (Pavia U.)
The chirally-odd twist-3 distribution function e(x) in the chiral quark-soliton model
16 pages, 6 figures, revtex, Ref.[50] and footnote 3 added
Phys.Rev. D67 (2003) 114010
10.1103/PhysRevD.67.114010
null
hep-ph
null
The chirally-odd twist-3 nucleon distribution e(x) is studied in the large-Nc limit in the framework of the chiral quark-soliton model at a low normalization point of about 0.6 GeV. The remarkable result is that in the model e(x) contains a delta-function-type singularity at x=0. The regular part of e(x) is found to be sizeable at the low scale of the model and in qualitative agreement with bag model calculations.
[ { "created": "Mon, 3 Mar 2003 16:38:01 GMT", "version": "v1" }, { "created": "Tue, 10 Jun 2003 09:44:10 GMT", "version": "v2" } ]
2009-11-10
[ [ "Schweitzer", "P.", "", "Pavia U." ] ]
The chirally-odd twist-3 nucleon distribution e(x) is studied in the large-Nc limit in the framework of the chiral quark-soliton model at a low normalization point of about 0.6 GeV. The remarkable result is that in the model e(x) contains a delta-function-type singularity at x=0. The regular part of e(x) is found to be sizeable at the low scale of the model and in qualitative agreement with bag model calculations.
1709.05978
Evgeny Uglov
D. Bardin, S. Bondarenko, P. Christova, L. Kalinovskaya, W. von Schlippe, E. Uglov
SANC: the process $ \gamma \gamma \rightarrow ZZ $
12 pages, 4 figures
null
10.1134/S1547477117060061
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The implementation of the process $\gamma\gamma \to ZZ$ at the one-loop level within {\tt SANC} system multi-channel approach is considered. The derived one-loop scalar form factors can be used for any cross channel after an appropriate permutation of their arguments -- Mandelstam variables $s,t,u$. To check of the correctness of the results we observe the independence of the scalar form factors on the gauge parameters and the validity of Ward identity (external photon transversality). We present the complete analytical results for the covariant and tensor structures and helicity amplitudes for this process. We make an extensive comparison of our analytical and numerical results with those existing in the literature.
[ { "created": "Mon, 18 Sep 2017 14:37:28 GMT", "version": "v1" }, { "created": "Wed, 27 Sep 2017 06:21:17 GMT", "version": "v2" } ]
2018-01-17
[ [ "Bardin", "D.", "" ], [ "Bondarenko", "S.", "" ], [ "Christova", "P.", "" ], [ "Kalinovskaya", "L.", "" ], [ "von Schlippe", "W.", "" ], [ "Uglov", "E.", "" ] ]
The implementation of the process $\gamma\gamma \to ZZ$ at the one-loop level within {\tt SANC} system multi-channel approach is considered. The derived one-loop scalar form factors can be used for any cross channel after an appropriate permutation of their arguments -- Mandelstam variables $s,t,u$. To check of the correctness of the results we observe the independence of the scalar form factors on the gauge parameters and the validity of Ward identity (external photon transversality). We present the complete analytical results for the covariant and tensor structures and helicity amplitudes for this process. We make an extensive comparison of our analytical and numerical results with those existing in the literature.
hep-ph/0604189
Hannes Jung
The Small x Collaboration, Jeppe R. Andersen Serguei Baranov, Jochen Bartels, Gergely G. Barnafoldi, Grigorios Chachamis, John Collins, Guenter Grindhammer, Goesta Gustafson, Magnus Hansson, Gunnar Ingelman, Hannes Jung, Leif Joensson, Albert Knutsson, Henri Kowalski, Krzysztof Kutak, Albrecht Kyrieleis, Peter Levai, Artem Lipatov, Leif Loennblad, Michael Lublinsky, Giuseppe Marchesini, Izabela Milcewicz, Christiane Risler, Agustin Sabio-Vera, Malin Sjoedahl, Anna Stasto, Jacek Turnau, Graeme Watt, Nikolai Zotov
Small x Phenomenology - summary of the 3rd Lund Small x Workshop in 2004
Edited by: Goesta Gustafson, Hannes Jung, Leif Joensson, Leif Loennblad
Eur.Phys.J.C48:53-105,2006
10.1140/epjc/s2006-02615-6
DESY 06-052
hep-ph
null
A third workshop on small-x physics, within the Small-x Collaboration, was held in Hamburg in May 2004 with the aim of overviewing recent theoretical progress in this area and summarizing the experimental status.
[ { "created": "Fri, 21 Apr 2006 15:42:12 GMT", "version": "v1" } ]
2010-03-25
[ [ "The Small x Collaboration", "", "" ], [ "Baranov", "Jeppe R. Andersen Serguei", "" ], [ "Bartels", "Jochen", "" ], [ "Barnafoldi", "Gergely G.", "" ], [ "Chachamis", "Grigorios", "" ], [ "Collins", "John", "" ], [ "Grindhammer", "Guenter", "" ], [ "Gustafson", "Goesta", "" ], [ "Hansson", "Magnus", "" ], [ "Ingelman", "Gunnar", "" ], [ "Jung", "Hannes", "" ], [ "Joensson", "Leif", "" ], [ "Knutsson", "Albert", "" ], [ "Kowalski", "Henri", "" ], [ "Kutak", "Krzysztof", "" ], [ "Kyrieleis", "Albrecht", "" ], [ "Levai", "Peter", "" ], [ "Lipatov", "Artem", "" ], [ "Loennblad", "Leif", "" ], [ "Lublinsky", "Michael", "" ], [ "Marchesini", "Giuseppe", "" ], [ "Milcewicz", "Izabela", "" ], [ "Risler", "Christiane", "" ], [ "Sabio-Vera", "Agustin", "" ], [ "Sjoedahl", "Malin", "" ], [ "Stasto", "Anna", "" ], [ "Turnau", "Jacek", "" ], [ "Watt", "Graeme", "" ], [ "Zotov", "Nikolai", "" ] ]
A third workshop on small-x physics, within the Small-x Collaboration, was held in Hamburg in May 2004 with the aim of overviewing recent theoretical progress in this area and summarizing the experimental status.
1208.5774
Chong Sheng Li
Hua Xing Zhu, Chong Sheng Li, Hai Tao Li, Ding Yu Shao, and Li Lin Yang
Transverse-momentum resummation for top-quark pairs at hadron colliders
5 pages, 4 figures, published version in PRL
Phys. Rev. Lett. 110, 082001 (2013)
10.1103/PhysRevLett.110.082001
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We develop a framework for a systematic resummation of the transverse momentum distribution of top-quark pairs produced at hadron colliders based on effective field theory. Compared to Drell-Yan and Higgs production, a novel soft function matrix is required to account for the soft gluon emissions from the final states. We calculate this soft function at the next-to-leading order, and perform the resummation at the next-to-next-to-leading logarithmic accuracy. We compare our results with parton shower programs and with the experimental data at the Tevatron and the LHC. We also discuss the implications for the top quark charge asymmetry.
[ { "created": "Tue, 28 Aug 2012 20:02:47 GMT", "version": "v1" }, { "created": "Tue, 4 Sep 2012 12:49:45 GMT", "version": "v2" }, { "created": "Wed, 23 Jan 2013 13:22:15 GMT", "version": "v3" }, { "created": "Sun, 24 Feb 2013 11:42:41 GMT", "version": "v4" } ]
2013-03-14
[ [ "Zhu", "Hua Xing", "" ], [ "Li", "Chong Sheng", "" ], [ "Li", "Hai Tao", "" ], [ "Shao", "Ding Yu", "" ], [ "Yang", "Li Lin", "" ] ]
We develop a framework for a systematic resummation of the transverse momentum distribution of top-quark pairs produced at hadron colliders based on effective field theory. Compared to Drell-Yan and Higgs production, a novel soft function matrix is required to account for the soft gluon emissions from the final states. We calculate this soft function at the next-to-leading order, and perform the resummation at the next-to-next-to-leading logarithmic accuracy. We compare our results with parton shower programs and with the experimental data at the Tevatron and the LHC. We also discuss the implications for the top quark charge asymmetry.
1710.03906
Lianbao Jia
Lian-Bao Jia
Explanation of the 511 keV line: Cascade annihilating dark matter with the $^8$Be anomaly
7 pages, 3 figures, in twocolumn
null
10.1140/epjc/s10052-018-5555-0
null
hep-ph astro-ph.CO astro-ph.HE
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A possible dark matter (DM) explanation about the long-standing issue of the Galactic 511 keV line is explored in this paper. For DM cascade annihilations of concern, a DM pair $\pi_d^{+} \pi_d^{-}$ annihilates into unstable $\pi_d^{0} \pi_d^{0}$, and $\pi_d^{0}$ decays into $e^+ e^-$ with new interactions suggested by the $^8$Be anomaly. Considering the constraints from the effective neutrino number $N_{\mathrm{eff}}$ and the 511 keV gamma-ray emission, a range of DM is obtained, $11.6 \lesssim m_{\pi_d^{\pm}} \lesssim 15$ MeV. The typical DM annihilation cross section today is about 3.3 $\times$ $10^{-29}$ cm$^3$ s$^{-1}$, which can give an explanation about the 511 keV line. The MeV scale DM may be searched by the DM-electron scattering, and the upper limit set by the CMB s-wave annihilation is derived in DM direct detections.
[ { "created": "Wed, 11 Oct 2017 04:33:06 GMT", "version": "v1" }, { "created": "Sat, 13 Jan 2018 17:32:58 GMT", "version": "v2" } ]
2018-03-14
[ [ "Jia", "Lian-Bao", "" ] ]
A possible dark matter (DM) explanation about the long-standing issue of the Galactic 511 keV line is explored in this paper. For DM cascade annihilations of concern, a DM pair $\pi_d^{+} \pi_d^{-}$ annihilates into unstable $\pi_d^{0} \pi_d^{0}$, and $\pi_d^{0}$ decays into $e^+ e^-$ with new interactions suggested by the $^8$Be anomaly. Considering the constraints from the effective neutrino number $N_{\mathrm{eff}}$ and the 511 keV gamma-ray emission, a range of DM is obtained, $11.6 \lesssim m_{\pi_d^{\pm}} \lesssim 15$ MeV. The typical DM annihilation cross section today is about 3.3 $\times$ $10^{-29}$ cm$^3$ s$^{-1}$, which can give an explanation about the 511 keV line. The MeV scale DM may be searched by the DM-electron scattering, and the upper limit set by the CMB s-wave annihilation is derived in DM direct detections.
hep-ph/0402159
Elzbieta Richter-Was
E. Richter-Was, T. Szymocha and Z. Was
Why do we need higher order fully exclusive Monte Carlo generator for Higgs boson production from heavy quark fusion at LHC?
14 pages, 22 figures
Phys.Lett. B589 (2004) 125-134
10.1016/j.physletb.2004.03.050
TPJU-3/2004, NSF-KITP-04-21, HNINP-V-04-03
hep-ph
null
In this paper we argue that having available higher order fully exclusive Monte Carlo generator for Higgs boson production from heavy quark fusion will be mandatory for data analysis at LHC. The H to tau tau channel, a key for early discovery of the Higgs boson in the MSSM scenario, is discussed. With simplified example and for mH = 120 GeV we show, that depending on choice among presently available approaches, used for simulation of Higgs boson production from b bbar H Yukawa coupling, final acceptance for the signal events being reconstructed inside mass window may differ by a factor of 3. The spread is even larger (up to a factor of 10) for other production mechanisms (promising for some regions of the MSSM parameter space). The complete analysis, which necessarily will add stringent requirements for background rejection (such as identification of b-jet or veto on b-jet) and which will require statistical combination of samples selected with different selection criteria may only enhance the uncertainty.
[ { "created": "Sun, 15 Feb 2004 16:31:48 GMT", "version": "v1" } ]
2015-06-25
[ [ "Richter-Was", "E.", "" ], [ "Szymocha", "T.", "" ], [ "Was", "Z.", "" ] ]
In this paper we argue that having available higher order fully exclusive Monte Carlo generator for Higgs boson production from heavy quark fusion will be mandatory for data analysis at LHC. The H to tau tau channel, a key for early discovery of the Higgs boson in the MSSM scenario, is discussed. With simplified example and for mH = 120 GeV we show, that depending on choice among presently available approaches, used for simulation of Higgs boson production from b bbar H Yukawa coupling, final acceptance for the signal events being reconstructed inside mass window may differ by a factor of 3. The spread is even larger (up to a factor of 10) for other production mechanisms (promising for some regions of the MSSM parameter space). The complete analysis, which necessarily will add stringent requirements for background rejection (such as identification of b-jet or veto on b-jet) and which will require statistical combination of samples selected with different selection criteria may only enhance the uncertainty.
hep-ph/9406370
Fontannaz
M. Fontannaz
Jets in Photon-Photon Collisions
12 pages,missing figures are sent on request, LPTHE-Orsay 94/44 ( This title and abstract replace the wrong title and abstract of paper hep-ph/9406370 )
null
null
null
hep-ph
null
We study jet production in photon-photon reactions at the next-to-leading logarithm accuracy. The discussion of the theoretical uncertainties and the role of the quark and gluon distributions in the photon is emphasized. The phenomenology at TRISTAN energies is discussed and predictions are made for LEP 200.
[ { "created": "Wed, 22 Jun 1994 18:55:03 GMT", "version": "v1" }, { "created": "Thu, 23 Jun 1994 11:32:27 GMT", "version": "v2" } ]
2009-09-25
[ [ "Fontannaz", "M.", "" ] ]
We study jet production in photon-photon reactions at the next-to-leading logarithm accuracy. The discussion of the theoretical uncertainties and the role of the quark and gluon distributions in the photon is emphasized. The phenomenology at TRISTAN energies is discussed and predictions are made for LEP 200.
hep-ph/9905394
Annelies Oosterhof-Meij
Wolfram Kittel
Interconnection Effects and W+W- Decays (a critical (p)(re)view)
11 pages, Latex, 12 figures (gzipped), 1 style-file
null
null
HEN-420
hep-ph
null
Color reconnection and Bose-Einstein correlations not only can have an influence on the measurement of the W-mass in the fully hadronic W+W- decay channel at LEP2, but also can give essential information on the structure of the QCD vacuum and the space-time development of a q_1\bar q_2 system. Recent developments are critically analyzed, with particular emphasis on the models used in this field. More sensitive variables are needed to distinguish between color reconnection models, while more experimental knowledge has to be built into the Bose-Einstein models and, above all, these two closely related phenomena have to be treated in common. Both effects are determined by the space-time overlap of the W+ and W- decay products. Vital experimental information on the space-time development of the decay of the q_1\bar q_2 system is becoming available from the high-statistics data on hadronic Z decay and models will have to be able to explain this evidence before being used to predict interference effects in hadronic W+W- decay.
[ { "created": "Wed, 19 May 1999 07:44:32 GMT", "version": "v1" }, { "created": "Tue, 29 Jun 1999 08:29:50 GMT", "version": "v2" } ]
2007-05-23
[ [ "Kittel", "Wolfram", "" ] ]
Color reconnection and Bose-Einstein correlations not only can have an influence on the measurement of the W-mass in the fully hadronic W+W- decay channel at LEP2, but also can give essential information on the structure of the QCD vacuum and the space-time development of a q_1\bar q_2 system. Recent developments are critically analyzed, with particular emphasis on the models used in this field. More sensitive variables are needed to distinguish between color reconnection models, while more experimental knowledge has to be built into the Bose-Einstein models and, above all, these two closely related phenomena have to be treated in common. Both effects are determined by the space-time overlap of the W+ and W- decay products. Vital experimental information on the space-time development of the decay of the q_1\bar q_2 system is becoming available from the high-statistics data on hadronic Z decay and models will have to be able to explain this evidence before being used to predict interference effects in hadronic W+W- decay.
0907.2332
Adisorn Adulpravitchai
A. Adulpravitchai, A. Blum, M. Lindner
Non-Abelian Discrete Groups from the Breaking of Continuous Flavor Symmetries
15 pages
JHEP 0909:018,2009
10.1088/1126-6708/2009/09/018
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss the possibility of obtaining a non-abelian discrete flavor symmetry from an underlying continuous, possibly gauged, flavor symmetry SU(2) or SU(3) through spontaneous symmetry breaking. We consider all possible cases, where the continuous symmetry is broken by small representations. "Small" representations are these which couple at leading order to the Standard Model fermions transforming as two- or three-dimensional representations of the flavor group. We find that, given this limited representation content, the only non-abelian discrete group which can arise as a residual symmetry is the quaternion group D_2'.
[ { "created": "Tue, 14 Jul 2009 11:45:24 GMT", "version": "v1" }, { "created": "Mon, 31 Aug 2009 13:18:23 GMT", "version": "v2" } ]
2009-09-28
[ [ "Adulpravitchai", "A.", "" ], [ "Blum", "A.", "" ], [ "Lindner", "M.", "" ] ]
We discuss the possibility of obtaining a non-abelian discrete flavor symmetry from an underlying continuous, possibly gauged, flavor symmetry SU(2) or SU(3) through spontaneous symmetry breaking. We consider all possible cases, where the continuous symmetry is broken by small representations. "Small" representations are these which couple at leading order to the Standard Model fermions transforming as two- or three-dimensional representations of the flavor group. We find that, given this limited representation content, the only non-abelian discrete group which can arise as a residual symmetry is the quaternion group D_2'.
hep-ph/0608065
Stefan Hesselbach
A. Bartl, H. Fraas, S. Hesselbach, K. Hohenwarter-Sodek, T. Kernreiter, G. Moortgat-Pick
CP asymmetries in chargino production and decay: the three-body decay case
22 pages, LaTeX, 8 figures; v2: structural changes and references added, main conclusions unchanged, published version
Eur.Phys.J.C51:149-161,2007
10.1140/epjc/s10052-007-0279-6
CERN-PH-TH/2006-130, DCPT-06-98, IPPP-06-49, UWThPh-2006-17
hep-ph
null
We study CP violation in chargino production and decay in the Minimal Supersymmetric Standard Model (MSSM) with complex parameters at an e^+ e^- linear collider with longitudinally polarized beams. We investigate CP-sensitive asymmetries by means of triple product correlations and study their dependence on the complex parameters M_1 and mu. We give numerical predictions for the asymmetries and their measurability at the future International Linear Collider. Our results show that the CP asymmetries can be measured in a large region of the MSSM parameter space.
[ { "created": "Fri, 4 Aug 2006 18:34:29 GMT", "version": "v1" }, { "created": "Thu, 24 May 2007 18:21:30 GMT", "version": "v2" } ]
2008-11-26
[ [ "Bartl", "A.", "" ], [ "Fraas", "H.", "" ], [ "Hesselbach", "S.", "" ], [ "Hohenwarter-Sodek", "K.", "" ], [ "Kernreiter", "T.", "" ], [ "Moortgat-Pick", "G.", "" ] ]
We study CP violation in chargino production and decay in the Minimal Supersymmetric Standard Model (MSSM) with complex parameters at an e^+ e^- linear collider with longitudinally polarized beams. We investigate CP-sensitive asymmetries by means of triple product correlations and study their dependence on the complex parameters M_1 and mu. We give numerical predictions for the asymmetries and their measurability at the future International Linear Collider. Our results show that the CP asymmetries can be measured in a large region of the MSSM parameter space.
1606.02915
Edward Shuryak
Edward Shuryak
Comment on measurement of the rotaion frequency and the magnetic field at the freezeout of heavy ion collisions
null
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We suggest other decays which can more effectively identify the effect of rotational motion and presence of the magnetic field, compared to $\Lambda,\bar\Lambda$ hyperon decayse used so far.
[ { "created": "Thu, 9 Jun 2016 11:33:40 GMT", "version": "v1" } ]
2016-06-10
[ [ "Shuryak", "Edward", "" ] ]
We suggest other decays which can more effectively identify the effect of rotational motion and presence of the magnetic field, compared to $\Lambda,\bar\Lambda$ hyperon decayse used so far.
1808.10136
Jun Seok Lee
Jun Seok Lee
Revisiting Supernova 1987A Limits on Axion-Like-Particles
15 pages, 7 figures
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Using recent supernova models, I revisit the Supernova 1987a constraints on scalar/pseudoscalar Axion-Like-Particles (ALPs). On the basis of the neutrino detections, the luminosity of ALPs must be $\lesssim 5\times10^{52} \,\mathrm{erg}/s$ after the core-bounce, and this bound limits ALPs couplings. Contrary to the QCD axion models where all couplings are $\sim 1/f_a$, it has been shown recently that a radion/dilaton could have far different coupling strength to photons and to nucleons. This fact has raised a need to establish the limits on each coupling independently. The bounds from ALPs emission by nucleon-nucleon bremsstrahlung through a two-nucleon coupling and by the Primakoff process through a two-photon coupling are updated considering the total volume emission. I find the bounds on the two-photon coupling from the Primakoff process differ from previous bounds by an order of magnitude. Through the volume emission study, trapping regimes for $m_a\gtrsim10\,\mathrm{MeV}$ are also alleviated, which need to be probed by future experiments.
[ { "created": "Thu, 30 Aug 2018 06:33:56 GMT", "version": "v1" } ]
2018-08-31
[ [ "Lee", "Jun Seok", "" ] ]
Using recent supernova models, I revisit the Supernova 1987a constraints on scalar/pseudoscalar Axion-Like-Particles (ALPs). On the basis of the neutrino detections, the luminosity of ALPs must be $\lesssim 5\times10^{52} \,\mathrm{erg}/s$ after the core-bounce, and this bound limits ALPs couplings. Contrary to the QCD axion models where all couplings are $\sim 1/f_a$, it has been shown recently that a radion/dilaton could have far different coupling strength to photons and to nucleons. This fact has raised a need to establish the limits on each coupling independently. The bounds from ALPs emission by nucleon-nucleon bremsstrahlung through a two-nucleon coupling and by the Primakoff process through a two-photon coupling are updated considering the total volume emission. I find the bounds on the two-photon coupling from the Primakoff process differ from previous bounds by an order of magnitude. Through the volume emission study, trapping regimes for $m_a\gtrsim10\,\mathrm{MeV}$ are also alleviated, which need to be probed by future experiments.
hep-ph/0207036
Gino Isidori
G. D'Ambrosio, G.F. Giudice, G. Isidori, A. Strumia
Minimal Flavour Violation: an effective field theory approach
32 pages, 6 figures. Version 2: new section discussing MFV in supersymmetric models added; updated experimental data; few minor changes
Nucl.Phys.B645:155-187,2002
10.1016/S0550-3213(02)00836-2
CERN-TH/2002-147, IFUP-TH/2002-17
hep-ph
null
We present a general analysis of extensions of the Standard Model which satisfy the criterion of Minimal Flavour Violation (MFV). We define this general framework by constructing a low-energy effective theory containing the Standard Model fields, with one or two Higgs doublets and, as the only source of SU(3)^5 flavour symmetry breaking, the background values of fields transforming under the flavour group as the ordinary Yukawa couplings. We analyse present bounds on the effective scale of dimension-six operators, which range between 1 and 10 TeV, with the most stringent constraints imposed by B -> X_s gamma. In this class of theories, it is possible to relate predictions for FCNC processes in B physics to those in K physics. We compare the sensitivity of various experimental searches in probing the hypothesis of MFV. Within the two-Higgs-doublet scenario, we develop a general procedure to obtain all tan(beta)-enhanced Higgs-mediated FCNC amplitudes, discussing in particular their impact in B -> l^+l^-, Delta M_B and B -> X_s gamma. As a byproduct, we derive some two-loop tan(beta)-enhanced supersymmetric contributions to B -> X_s gamma previously unknown.
[ { "created": "Tue, 2 Jul 2002 18:12:04 GMT", "version": "v1" }, { "created": "Thu, 8 Aug 2002 15:35:47 GMT", "version": "v2" } ]
2009-10-09
[ [ "D'Ambrosio", "G.", "" ], [ "Giudice", "G. F.", "" ], [ "Isidori", "G.", "" ], [ "Strumia", "A.", "" ] ]
We present a general analysis of extensions of the Standard Model which satisfy the criterion of Minimal Flavour Violation (MFV). We define this general framework by constructing a low-energy effective theory containing the Standard Model fields, with one or two Higgs doublets and, as the only source of SU(3)^5 flavour symmetry breaking, the background values of fields transforming under the flavour group as the ordinary Yukawa couplings. We analyse present bounds on the effective scale of dimension-six operators, which range between 1 and 10 TeV, with the most stringent constraints imposed by B -> X_s gamma. In this class of theories, it is possible to relate predictions for FCNC processes in B physics to those in K physics. We compare the sensitivity of various experimental searches in probing the hypothesis of MFV. Within the two-Higgs-doublet scenario, we develop a general procedure to obtain all tan(beta)-enhanced Higgs-mediated FCNC amplitudes, discussing in particular their impact in B -> l^+l^-, Delta M_B and B -> X_s gamma. As a byproduct, we derive some two-loop tan(beta)-enhanced supersymmetric contributions to B -> X_s gamma previously unknown.
1205.4830
George Lazarides
George Lazarides (Aristotle U., Thessaloniki)
How to remedy the eta-problem of SUSY GUT hybrid inflation via vector backreaction
10 pages, talk given at the International Workshop on Grand Unified Theories (GUT2012), Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto, Japan, March 15-17, 2012 (to appear in the proceedings)
null
10.1063/1.4742095
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
It is shown that, in supergravity models of inflation where the gauge kinetic function of a gauge field is modulated by the inflaton, we can obtain a new inflationary attractor solution, in which the roll-over of the inflaton suffers additional impedance due to the vector field backreaction. As a result, directions of the scalar potential which, due to strong Kaehler corrections, become too steep and curved to normally support slow-roll inflation can now naturally do so. This solves the infamous eta-problem of inflation in supergravity and also keeps the spectral index of the curvature perturbation mildly red despite eta of order unity. This mechanism is applied to a model of hybrid inflation in supergravity with a generic Kaehler potential. The spectral index of the curvature perturbation is found to be 0.97 - 0.98, in excellent agreement with data. The gauge field can act as vector curvaton generating statistical anisotropy in the curvature perturbation. However, this anisotropy could be possibly observable only if the gauge coupling constant is unnaturally small.
[ { "created": "Tue, 22 May 2012 07:49:17 GMT", "version": "v1" } ]
2015-06-05
[ [ "Lazarides", "George", "", "Aristotle U., Thessaloniki" ] ]
It is shown that, in supergravity models of inflation where the gauge kinetic function of a gauge field is modulated by the inflaton, we can obtain a new inflationary attractor solution, in which the roll-over of the inflaton suffers additional impedance due to the vector field backreaction. As a result, directions of the scalar potential which, due to strong Kaehler corrections, become too steep and curved to normally support slow-roll inflation can now naturally do so. This solves the infamous eta-problem of inflation in supergravity and also keeps the spectral index of the curvature perturbation mildly red despite eta of order unity. This mechanism is applied to a model of hybrid inflation in supergravity with a generic Kaehler potential. The spectral index of the curvature perturbation is found to be 0.97 - 0.98, in excellent agreement with data. The gauge field can act as vector curvaton generating statistical anisotropy in the curvature perturbation. However, this anisotropy could be possibly observable only if the gauge coupling constant is unnaturally small.
hep-ph/0203092
Ed Berger
Edmond L. Berger and Jungil Lee (Argonne)
Hadronic decays of $\bm{\chi_{bJ}}$ into light bottom squarks
19 pages, REVTeX 4, 3 figures. A few equations corrected; figures modified slightly; some additional explanatory material; references updated; typographical errors remedied. Accepted for publication in Phys Rev D
Phys.Rev.D65:114003,2002
10.1103/PhysRevD.65.114003
ANL-HEP-PR-02-021
hep-ph hep-ex
null
We calculate the rates for inclusive hadronic decay of the three $\chi_{bJ}$ states into a pair of light bottom squarks as a function of the masses of the bottom squark and the gluino. We include color-singlet and color-octet configurations. The color-octet contribution is found to be insignificant for the $\chi_{b0}$ but can dominate in the $\chi_{b2}$ case if current lattice estimates are used for the color-octet matrix element. In comparison with the standard model values, bottom squark decays can increase the predicted hadronic width of the $\chi_{b0}$ by as much as 35%, for very small bottom squark masses and gluino masses in the range of 12 GeV, but make a small contribution in the cases of $\chi_{b1}$ and $\chi_{b2}$. Data from decays of the $\chi_{bJ}$ states could provide significant new bounds on the existence and masses of supersymmetric particles.
[ { "created": "Fri, 8 Mar 2002 23:29:15 GMT", "version": "v1" }, { "created": "Mon, 15 Apr 2002 18:45:55 GMT", "version": "v2" } ]
2011-01-27
[ [ "Berger", "Edmond L.", "", "Argonne" ], [ "Lee", "Jungil", "", "Argonne" ] ]
We calculate the rates for inclusive hadronic decay of the three $\chi_{bJ}$ states into a pair of light bottom squarks as a function of the masses of the bottom squark and the gluino. We include color-singlet and color-octet configurations. The color-octet contribution is found to be insignificant for the $\chi_{b0}$ but can dominate in the $\chi_{b2}$ case if current lattice estimates are used for the color-octet matrix element. In comparison with the standard model values, bottom squark decays can increase the predicted hadronic width of the $\chi_{b0}$ by as much as 35%, for very small bottom squark masses and gluino masses in the range of 12 GeV, but make a small contribution in the cases of $\chi_{b1}$ and $\chi_{b2}$. Data from decays of the $\chi_{bJ}$ states could provide significant new bounds on the existence and masses of supersymmetric particles.
2307.05340
Christophe Royon
C. Royon
Jet separated by a large rapidity gap at the Tevatron and the LHC
Proceedings of the DIS 2023 workshop
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We compare the recent measurements of gap between jets at the Tevatron and the LHC with the Balitski Fadin Kuraev Lipatov framework. While a good agreement is obtained with Tevatron data, some discrepancies especially for the rapidity separation between jets are found that can be explained by an excess of initial state radiation in PYTHIA.
[ { "created": "Tue, 11 Jul 2023 15:27:46 GMT", "version": "v1" } ]
2023-07-12
[ [ "Royon", "C.", "" ] ]
We compare the recent measurements of gap between jets at the Tevatron and the LHC with the Balitski Fadin Kuraev Lipatov framework. While a good agreement is obtained with Tevatron data, some discrepancies especially for the rapidity separation between jets are found that can be explained by an excess of initial state radiation in PYTHIA.
1711.09875
Raquel Gomez-Ambrosio
M. Boggia (Freiburg U.), J. M. Cruz-Martinez (Durham U., IPPP), Hjalte Frellesvig (KIT-TTP), E. W. N. Glover (Durham U., IPPP), Raquel Gomez-Ambrosio (Durham U., IPPP), Giulia Gonella (Freiburg U.), Y. Haddad (Durham U., IPPP), Agnieszka Ilnicka (Zurich U., ETH and PSI Villigen), S. P. Jones (MPI Munich), Z. Kassabov (Milano U., INFN), F. Krauss (Durham U., IPPP), T. Megy (Freiburg U.), D. Melini (IFIC Valencia, Granada U.), D. Napoletano (Durham U., IPPP), G. Passarino (Turin U., INFN), S. Patel (KIT-ITP, KIT-IKP), M. Rodriguez-Vazquez (CNRS Paris) and T. Wolf (NIKHEF)
The HiggsTools Handbook: Concepts and observables for deciphering the Nature of the Higgs Sector
142 pages + references
null
null
IPPP/17/90
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This Report summarizes some of the activities of the HiggsTools Initial Training Network working group in the period 2015-2017. The main goal of this working group was to produce a document discussing various aspects of state-of-the-art Higgs physics at the Large Hadron Collider (LHC) in a pedagogic manner. The first part of the Report is devoted to a description of phenomenological searches for New Physics at the LHC. As the experimental measurements become more and more precise, there is a pressing need for a consistent framework in which deviations from the SM predictions can be computed precisely. We critically review the use of the \k{appa}-framework, fiducial and simplified template cross sections, effective field theories, pseudo-observables and phenomenological Lagrangians. In the second part of the Report, we propose $\varphi_{\eta}^*$ as a new and complementary observable for studying Higgs boson production at large transverse momentum in the case where the Higgs boson decays to two photons. We make a detailed study of the phenomenology of the $\varphi_{\eta}^*$ variable, contrasting the behaviour with the Higgs transverse momentum distribution using a variety of theoretical tools including event generators and fixed order perturbative computations.
[ { "created": "Mon, 27 Nov 2017 18:46:21 GMT", "version": "v1" } ]
2017-11-28
[ [ "Boggia", "M.", "", "Freiburg U." ], [ "Cruz-Martinez", "J. M.", "", "Durham U., IPPP" ], [ "Frellesvig", "Hjalte", "", "KIT-TTP" ], [ "Glover", "E. W. N.", "", "Durham U., IPPP" ], [ "Gomez-Ambrosio", "Raquel", "", "Durham U., IPPP" ], [ "Gonella", "Giulia", "", "Freiburg U." ], [ "Haddad", "Y.", "", "Durham U., IPPP" ], [ "Ilnicka", "Agnieszka", "", "Zurich U., ETH and PSI Villigen" ], [ "Jones", "S. P.", "", "MPI Munich" ], [ "Kassabov", "Z.", "", "Milano U., INFN" ], [ "Krauss", "F.", "", "Durham U.,\n IPPP" ], [ "Megy", "T.", "", "Freiburg U." ], [ "Melini", "D.", "", "IFIC Valencia, Granada U." ], [ "Napoletano", "D.", "", "Durham U., IPPP" ], [ "Passarino", "G.", "", "Turin U., INFN" ], [ "Patel", "S.", "", "KIT-ITP, KIT-IKP" ], [ "Rodriguez-Vazquez", "M.", "", "CNRS Paris" ], [ "Wolf", "T.", "", "NIKHEF" ] ]
This Report summarizes some of the activities of the HiggsTools Initial Training Network working group in the period 2015-2017. The main goal of this working group was to produce a document discussing various aspects of state-of-the-art Higgs physics at the Large Hadron Collider (LHC) in a pedagogic manner. The first part of the Report is devoted to a description of phenomenological searches for New Physics at the LHC. As the experimental measurements become more and more precise, there is a pressing need for a consistent framework in which deviations from the SM predictions can be computed precisely. We critically review the use of the \k{appa}-framework, fiducial and simplified template cross sections, effective field theories, pseudo-observables and phenomenological Lagrangians. In the second part of the Report, we propose $\varphi_{\eta}^*$ as a new and complementary observable for studying Higgs boson production at large transverse momentum in the case where the Higgs boson decays to two photons. We make a detailed study of the phenomenology of the $\varphi_{\eta}^*$ variable, contrasting the behaviour with the Higgs transverse momentum distribution using a variety of theoretical tools including event generators and fixed order perturbative computations.
hep-ph/0308129
C. Hanhart
V. Baru, J. Haidenbauer, C. Hanhart, Yu. Kalashnikova, A. Kudryavtsev
Evidence that the a0(980) and f0(980) are not elementary particles
15 pages, 4 Figures
Phys.Lett.B586:53-61,2004
10.1016/j.physletb.2004.01.088
FZJ-IKP(TH)-2003-13
hep-ph
null
We study the interesting problem of whether it is possible to distinguish composite from elementary particles. In particular we generalize a model-independent approach of S. Weinberg to the case of unstable particles. This allows us to apply our formalism to the case of the a0(980) and f0(980) resonances and to address the question whether these particles are predominantly genuine, confined quark states (of $\bar q q$ or $qq\bar q\bar q$ structure) or governed by mesonic components.
[ { "created": "Tue, 12 Aug 2003 09:10:31 GMT", "version": "v1" } ]
2008-11-26
[ [ "Baru", "V.", "" ], [ "Haidenbauer", "J.", "" ], [ "Hanhart", "C.", "" ], [ "Kalashnikova", "Yu.", "" ], [ "Kudryavtsev", "A.", "" ] ]
We study the interesting problem of whether it is possible to distinguish composite from elementary particles. In particular we generalize a model-independent approach of S. Weinberg to the case of unstable particles. This allows us to apply our formalism to the case of the a0(980) and f0(980) resonances and to address the question whether these particles are predominantly genuine, confined quark states (of $\bar q q$ or $qq\bar q\bar q$ structure) or governed by mesonic components.
2102.02607
Chu-Wen Xiao
C. W. Xiao, J. J. Wu and B. S. Zou
Molecular nature of $P_{cs} (4459)$ and its heavy quark spin partners
Some comments and corrections have been made
Phys. Rev. D 103, 054016 (2021)
10.1103/PhysRevD.103.054016
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
Inspired by the observation of the $P_{cs} (4459)$ state by LHCb recently, we reexamine the results of the interaction of the $J/\psi \Lambda$ channel with its coupled channels, exploiting the coupled channel unitary approach combined with heavy quark spin and local hidden gauge symmetries. By tuning the only free parameter, we find a pole of $(4459.07+i6.89)$ MeV below the $\bar D^* \Xi_c$ threshold, which was consistent well with the mass and width of the $P_{cs} (4459)$ state. Thus, we assume the $P_{cs} (4459)$ state to be a $\bar D^* \Xi_c$ bound state with the uncertainties on its degeneracy with $J^P = \frac{1}{2}^-$ and $J^P = \frac{3}{2}^-$. For the degeneracy, it would have two-poles structure, like $P_c (4450)$ before. There is another pole in the $J^P = \frac{1}{2}^-$ sector, $(4310.53+i8.23)$ MeV, corresponding to a deep bound state of $\bar D \Xi_c$. Furthermore, the previously predicted loose bound states of $\bar D \Xi'_c$, $\bar D^* \Xi'_c$, $\bar D^* \Xi^*_c$ with $J=1/2,~I=0$ and $\bar D^* \Xi'_c$, $\bar D \Xi^*_c$, $\bar D^* \Xi_c^*$ with $J=3/2,~I=0$ may exist as either bound states or unbound virtual states. We hope that future experiments can search for the $\bar D^{(*)} \Xi_c$ molecular states in their dominant decay channels of $\bar D^{(*)}_s \Lambda_c$, also in the $J/\psi \Lambda$ and $\eta_c \Lambda$ channels to reveal their different nature.
[ { "created": "Thu, 4 Feb 2021 13:41:11 GMT", "version": "v1" }, { "created": "Sun, 7 Feb 2021 16:08:54 GMT", "version": "v2" } ]
2021-03-24
[ [ "Xiao", "C. W.", "" ], [ "Wu", "J. J.", "" ], [ "Zou", "B. S.", "" ] ]
Inspired by the observation of the $P_{cs} (4459)$ state by LHCb recently, we reexamine the results of the interaction of the $J/\psi \Lambda$ channel with its coupled channels, exploiting the coupled channel unitary approach combined with heavy quark spin and local hidden gauge symmetries. By tuning the only free parameter, we find a pole of $(4459.07+i6.89)$ MeV below the $\bar D^* \Xi_c$ threshold, which was consistent well with the mass and width of the $P_{cs} (4459)$ state. Thus, we assume the $P_{cs} (4459)$ state to be a $\bar D^* \Xi_c$ bound state with the uncertainties on its degeneracy with $J^P = \frac{1}{2}^-$ and $J^P = \frac{3}{2}^-$. For the degeneracy, it would have two-poles structure, like $P_c (4450)$ before. There is another pole in the $J^P = \frac{1}{2}^-$ sector, $(4310.53+i8.23)$ MeV, corresponding to a deep bound state of $\bar D \Xi_c$. Furthermore, the previously predicted loose bound states of $\bar D \Xi'_c$, $\bar D^* \Xi'_c$, $\bar D^* \Xi^*_c$ with $J=1/2,~I=0$ and $\bar D^* \Xi'_c$, $\bar D \Xi^*_c$, $\bar D^* \Xi_c^*$ with $J=3/2,~I=0$ may exist as either bound states or unbound virtual states. We hope that future experiments can search for the $\bar D^{(*)} \Xi_c$ molecular states in their dominant decay channels of $\bar D^{(*)}_s \Lambda_c$, also in the $J/\psi \Lambda$ and $\eta_c \Lambda$ channels to reveal their different nature.
2111.08354
Martin Rohrmoser
M. Rohrmoser, K. Kutak, W. P{\l}aczek, E. Blanco, and R. Straka
Influence of scattering versus coherent parton branching on the $k_T$ broadening of QCD cascades in a medium
submitted as proceedings for "The European Physical Society Conference on High Energy Physics (EPS-HEP2021)"
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We studied the evolution of jets within a medium that contains both, transverse kicks as well as medium induced coherent radiation. In this framework parton branching occurs simultaneously to scatterings within the medium, leading to the interference effects that reproduce the well known BDMPS-Z emission rates and sizeable transverse momentum broadening. We examined the relative importances of transverse momentum broadening from the coherent splittings and different types of in-medium scatterings and found a clear hierarchy of the influences from different scattering effects and deflections during branchings.
[ { "created": "Tue, 16 Nov 2021 10:56:05 GMT", "version": "v1" } ]
2021-11-17
[ [ "Rohrmoser", "M.", "" ], [ "Kutak", "K.", "" ], [ "Płaczek", "W.", "" ], [ "Blanco", "E.", "" ], [ "Straka", "R.", "" ] ]
We studied the evolution of jets within a medium that contains both, transverse kicks as well as medium induced coherent radiation. In this framework parton branching occurs simultaneously to scatterings within the medium, leading to the interference effects that reproduce the well known BDMPS-Z emission rates and sizeable transverse momentum broadening. We examined the relative importances of transverse momentum broadening from the coherent splittings and different types of in-medium scatterings and found a clear hierarchy of the influences from different scattering effects and deflections during branchings.
1804.01112
Quentin Bonnefoy
Quentin Bonnefoy, Emilian Dudas and Stefan Pokorski
Axions in a highly protected gauge symmetry model
Version accepted in EPJC. Discussion extended in the introduction and in section 3.2. 13 pages + appendices, 7 Figures
null
10.1140/epjc/s10052-018-6528-z
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study QCD axion or cosmological axion-like particles (ALPs) in a model inspired by the recent interest in 4-dimensional clockwork models, with the global symmetry being accidentally enforced by a gauge abelian quiver with scalar bifundamental fields. For the QCD axion, we analyze the connection between the degree of protection of the axion mass against gravitational corrections, the explanation of the hierarchy $f_a \ll M_P$ and the number of colored fermions needed to generate anomalous couplings to gluons, all linked together by the underlying gauge symmetries. Based on that model and on the comparison with earlier models in the literature, we derive certain general conclusions on QCD axion models that use accidental global symmetries. For the ALPs, assuming that their mass is solely given by gravitational corrections, we identify the parameter space where the decay constant and the mass are consistent with the DM abundance, and we show that this clockwork-inspired model is a particularly economical model for a very light ALP DM candidate.
[ { "created": "Tue, 3 Apr 2018 18:11:46 GMT", "version": "v1" }, { "created": "Sat, 29 Dec 2018 17:23:32 GMT", "version": "v2" } ]
2019-01-21
[ [ "Bonnefoy", "Quentin", "" ], [ "Dudas", "Emilian", "" ], [ "Pokorski", "Stefan", "" ] ]
We study QCD axion or cosmological axion-like particles (ALPs) in a model inspired by the recent interest in 4-dimensional clockwork models, with the global symmetry being accidentally enforced by a gauge abelian quiver with scalar bifundamental fields. For the QCD axion, we analyze the connection between the degree of protection of the axion mass against gravitational corrections, the explanation of the hierarchy $f_a \ll M_P$ and the number of colored fermions needed to generate anomalous couplings to gluons, all linked together by the underlying gauge symmetries. Based on that model and on the comparison with earlier models in the literature, we derive certain general conclusions on QCD axion models that use accidental global symmetries. For the ALPs, assuming that their mass is solely given by gravitational corrections, we identify the parameter space where the decay constant and the mass are consistent with the DM abundance, and we show that this clockwork-inspired model is a particularly economical model for a very light ALP DM candidate.
2004.03220
Artem Lipatov
S.P. Baranov, A.V. Lipatov
$\chi_{c1}$ and $\chi_{c2}$ polarization as a probe of color octet channel
12 pages, 5 figures, 1 table
null
10.1140/epjc/s10052-020-08617-0
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We analyze the first LHC data on $\chi_{c1}$ and $\chi_{c2}$ polarization obtained very recently by the CMS Collaboration at $\sqrt s = 8$~TeV. We describe the perturbative production of $c\bar c$ pair with $k_T$-factorization approach and use nonrelativistic QCD formalism for the formation of bound states. We demonstrate that the polar anisotropy of $\chi_{c1}$ and $\chi_{c2}$ mesons is strongly sensitive to the color octet contributions. We extract the long-distance matrix elements for $\chi_{c1}$ and $\chi_{c2}$ mesons from the first CMS polarization measurement %on the polarization parameters $\lambda_{\theta}^{\chi_{c1}}$ and $\lambda_{\theta}^{\chi_{c2}}$ obtained at $\sqrt s = 8$~TeV together with available LHC data on the $\chi_{c1}$ and $\chi_{c2}$ transverse momentum distributions (and their ratios) collected at $\sqrt s = 7$~TeV. Our fit points to unequal color singlet wave functions of $\chi_{c1}$ and $\chi_{c2}$ states.
[ { "created": "Tue, 7 Apr 2020 09:21:28 GMT", "version": "v1" } ]
2020-12-02
[ [ "Baranov", "S. P.", "" ], [ "Lipatov", "A. V.", "" ] ]
We analyze the first LHC data on $\chi_{c1}$ and $\chi_{c2}$ polarization obtained very recently by the CMS Collaboration at $\sqrt s = 8$~TeV. We describe the perturbative production of $c\bar c$ pair with $k_T$-factorization approach and use nonrelativistic QCD formalism for the formation of bound states. We demonstrate that the polar anisotropy of $\chi_{c1}$ and $\chi_{c2}$ mesons is strongly sensitive to the color octet contributions. We extract the long-distance matrix elements for $\chi_{c1}$ and $\chi_{c2}$ mesons from the first CMS polarization measurement %on the polarization parameters $\lambda_{\theta}^{\chi_{c1}}$ and $\lambda_{\theta}^{\chi_{c2}}$ obtained at $\sqrt s = 8$~TeV together with available LHC data on the $\chi_{c1}$ and $\chi_{c2}$ transverse momentum distributions (and their ratios) collected at $\sqrt s = 7$~TeV. Our fit points to unequal color singlet wave functions of $\chi_{c1}$ and $\chi_{c2}$ states.
hep-ph/0408345
Christian Weiss
M. Strikman, C. Weiss
The nucleon's gluonic transverse size: From exclusive J/psi photoproduction to high-energy pp collisions
6 pages, 3 figures. To appear in Proceedings of the XII International Workshop on Deep Inelastic Scattering (DIS 2004), Strbske Pleso, Slovakia, Apr. 14-18, 2004
null
null
JLAB-THY-04-267
hep-ph
null
We summarize what is known about the transverse spatial distribution of gluons in the nucleon and its x-dependence from exclusive J/psi photo/electroproduction in e-p fixed-target and collider experiments (HERA H1 and ZEUS). This information can be used to predict the impact parameter dependence of the cross section for certain hard QCD processes (dijet production) in pbar-p and p-p collisions at the Tevatron and LHC.
[ { "created": "Tue, 31 Aug 2004 01:16:34 GMT", "version": "v1" } ]
2007-05-23
[ [ "Strikman", "M.", "" ], [ "Weiss", "C.", "" ] ]
We summarize what is known about the transverse spatial distribution of gluons in the nucleon and its x-dependence from exclusive J/psi photo/electroproduction in e-p fixed-target and collider experiments (HERA H1 and ZEUS). This information can be used to predict the impact parameter dependence of the cross section for certain hard QCD processes (dijet production) in pbar-p and p-p collisions at the Tevatron and LHC.
1705.02149
Jinmian Li
Teruki Kamon, P. Ko, Jinmian Li
Characterizing Higgs portal dark matter models at the ILC
26 pages, 9 figures, version accepted for publication in EPJC
null
10.1140/epjc/s10052-017-5240-8
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We study the Dark Matter (DM) discovery prospect and its spin discrimination in the theoretical framework of gauge invariant and renormalizable Higgs portal DM models at the ILC with $\sqrt{s} = 500$ GeV. In such models, the DM pair is produced in association with a $Z$ boson. In case the singlet scalar DM, the mediator is just the SM Higgs boson, whereas for the fermion or vector DM there is an additional singlet scalar mediator that mixes with the SM Higgs boson, which produces significant observable differences. After careful investigation of the signal and backgrounds both at parton level and at detector level, we find the signal with hadronically decaying $Z$ boson provides a better search sensitivity than the signal with leptonically decaying $Z$ boson. Taking the fermion DM model as a benchmark scenario, when the DM-mediator coupling $g_\chi$ is relatively small, the DM signals are discoverable only for benchmark points with relatively light scalar mediator $H_2$. And the spin discriminating from scalar DM is always promising while it is difficult to discriminate from vector DM. As for $g_\chi$ approaching the perturbative limit, benchmark points with the mediator $H_2$ in the full mass region of interest are discoverable. And the spin discriminating from both the scalar and fermion DM are quite promising.
[ { "created": "Fri, 5 May 2017 09:46:21 GMT", "version": "v1" }, { "created": "Mon, 18 Sep 2017 00:29:32 GMT", "version": "v2" } ]
2017-10-25
[ [ "Kamon", "Teruki", "" ], [ "Ko", "P.", "" ], [ "Li", "Jinmian", "" ] ]
We study the Dark Matter (DM) discovery prospect and its spin discrimination in the theoretical framework of gauge invariant and renormalizable Higgs portal DM models at the ILC with $\sqrt{s} = 500$ GeV. In such models, the DM pair is produced in association with a $Z$ boson. In case the singlet scalar DM, the mediator is just the SM Higgs boson, whereas for the fermion or vector DM there is an additional singlet scalar mediator that mixes with the SM Higgs boson, which produces significant observable differences. After careful investigation of the signal and backgrounds both at parton level and at detector level, we find the signal with hadronically decaying $Z$ boson provides a better search sensitivity than the signal with leptonically decaying $Z$ boson. Taking the fermion DM model as a benchmark scenario, when the DM-mediator coupling $g_\chi$ is relatively small, the DM signals are discoverable only for benchmark points with relatively light scalar mediator $H_2$. And the spin discriminating from scalar DM is always promising while it is difficult to discriminate from vector DM. As for $g_\chi$ approaching the perturbative limit, benchmark points with the mediator $H_2$ in the full mass region of interest are discoverable. And the spin discriminating from both the scalar and fermion DM are quite promising.
hep-ph/0412253
Malgorzata Worek dr
Piotr H. Chankowski, Jan Kalinowski, Zbigniew Was, Malgorzata Worek
CP violation in B0_d --> tau+ tau- decays
1+20 pages, 5 figures, LaTeX
Nucl.Phys.B713:555-574,2005
10.1016/j.nuclphysb.2005.02.010
IFT-2004/30, IPPP/04/85, DCPT/04/170
hep-ph
null
Establishing CP violation in B0 (bar{B0}) --> l+ l- decays requires a measurement of polarization of the final lepton pair, or a precise determination of the B0 --> l+ l- and bar{B0} --> l+ l- rates. We first argue that if the amplitudes of these decays are dominated by the scalar and pseudoscalar Higgs penguin diagrams, as happens e.g. in supersymmetry with large tan(beta), the CP asymmetries depend practically on only one CP violating phase. This phase can be large, of the order of the CKM phase, leading to large CP asymmetries in the tau+ tau- decay channel of B0_d (bar{B0}_d) mesons, potentially measurable in BELLE or BABAR experiments. Secondly, we show that the existing TAUOLA tau-lepton decay library supplemented by its universal interface can efficiently be used to search for B0 (bar{B0}) --> tau+ tau- decays, and to investigate how the CP asymmetry is reflected in realistic experimental observables.
[ { "created": "Fri, 17 Dec 2004 15:04:21 GMT", "version": "v1" }, { "created": "Sun, 19 Dec 2004 17:18:24 GMT", "version": "v2" } ]
2014-11-18
[ [ "Chankowski", "Piotr H.", "" ], [ "Kalinowski", "Jan", "" ], [ "Was", "Zbigniew", "" ], [ "Worek", "Malgorzata", "" ] ]
Establishing CP violation in B0 (bar{B0}) --> l+ l- decays requires a measurement of polarization of the final lepton pair, or a precise determination of the B0 --> l+ l- and bar{B0} --> l+ l- rates. We first argue that if the amplitudes of these decays are dominated by the scalar and pseudoscalar Higgs penguin diagrams, as happens e.g. in supersymmetry with large tan(beta), the CP asymmetries depend practically on only one CP violating phase. This phase can be large, of the order of the CKM phase, leading to large CP asymmetries in the tau+ tau- decay channel of B0_d (bar{B0}_d) mesons, potentially measurable in BELLE or BABAR experiments. Secondly, we show that the existing TAUOLA tau-lepton decay library supplemented by its universal interface can efficiently be used to search for B0 (bar{B0}) --> tau+ tau- decays, and to investigate how the CP asymmetry is reflected in realistic experimental observables.
0912.3081
Shashank Bhatnagar Dr.
Shashank Bhatnagar, Shi-Yuan Li, Jorge Mahecha
Arranging Dirac covariants in hadronic Bethe-Salpeter wave functions for pseudoscalar meson decays
article and four figures
Int.J.Mod.Phys.E20:1437-1454,2011
10.1142/S0218301311018460
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We have employed the framework of Bethe-Salpeter equation under covariant instantaneous ansatz to calculate leptonic decay constants of unequal mass pseudoscalar mesons like pi, K, D, Ds and B and radiative decay constants of neutral pseudoscalar mesons like pi and etac in two photon decays of these mesons. In the Dirac structure of hadronic BS wave function, the covariants are incorporated from their complete set in accordance with a recently proposed power counting rule, order-by-order in powers of inverse of meson mass. The decay constants are calculated with the incorporation of both Leading order (LO) and the Next-to-leading order (NLO) Dirac covariants. The contribution of both LO as well as NLO Dirac covariants are studied in detail in this paper. The results are found to improve dramatically and hence validating the power counting rule which also provides a practical means of incorporating Dirac covariants in the BS wave function for a hadron.
[ { "created": "Wed, 16 Dec 2009 09:04:35 GMT", "version": "v1" }, { "created": "Wed, 23 Dec 2009 10:01:33 GMT", "version": "v2" } ]
2011-07-15
[ [ "Bhatnagar", "Shashank", "" ], [ "Li", "Shi-Yuan", "" ], [ "Mahecha", "Jorge", "" ] ]
We have employed the framework of Bethe-Salpeter equation under covariant instantaneous ansatz to calculate leptonic decay constants of unequal mass pseudoscalar mesons like pi, K, D, Ds and B and radiative decay constants of neutral pseudoscalar mesons like pi and etac in two photon decays of these mesons. In the Dirac structure of hadronic BS wave function, the covariants are incorporated from their complete set in accordance with a recently proposed power counting rule, order-by-order in powers of inverse of meson mass. The decay constants are calculated with the incorporation of both Leading order (LO) and the Next-to-leading order (NLO) Dirac covariants. The contribution of both LO as well as NLO Dirac covariants are studied in detail in this paper. The results are found to improve dramatically and hence validating the power counting rule which also provides a practical means of incorporating Dirac covariants in the BS wave function for a hadron.
hep-ph/9311222
null
M. Carena, M. Olechowski, S. Pokorski and C.E.M. Wagner
Radiative Electroweak Symmetry Breaking and the Infrared Fixed Point of the Top Quark Mass
17 pages, 5 figures, CERN-TH.7060/93
Nucl.Phys.B419:213-239,1994
10.1016/0550-3213(94)90040-X
null
hep-ph
null
The infrared quasi fixed point solution for the top quark mass in the Minimal Supersymmetric Standard Model explains in a natural way large values of the top quark mass and appears as a prediction in many interesting theoretical schemes. Moreover, as has been recently pointed out, for moderate values of $\tan\beta$, in order to achieve gauge and bottom-tau Yukawa coupling unification, the top quark mass must be within $10 \%$ of its fixed point value. In this work we show that the convergence of the top quark mass to its fixed point value has relevant consequences for the (assumed) universal soft supersymmetry breaking parameters at the grand unification scale. In particular, we show that the low energy parameters do not depend on $A_0$ and $B_0$ but on the combination $\delta = B_0 - A_0/2$. Hence, there is a reduction in the number of independent parameters. Most interesting, the radiative $SU(2)_L \times U(1)_Y$ breaking condition implies strong correlations between the supersymmetric mass parameter $\mu$ and the supersymmetry breaking parameters $\delta$ and $M_{1/2}$ or $m_0$. These correlations, which become stronger for $\tan\beta < 2$, may have some fundamental origin, which would imply the need of a reformulation of the naive fine tuning criteria.
[ { "created": "Thu, 4 Nov 1993 00:35:56 GMT", "version": "v1" } ]
2009-09-25
[ [ "Carena", "M.", "" ], [ "Olechowski", "M.", "" ], [ "Pokorski", "S.", "" ], [ "Wagner", "C. E. M.", "" ] ]
The infrared quasi fixed point solution for the top quark mass in the Minimal Supersymmetric Standard Model explains in a natural way large values of the top quark mass and appears as a prediction in many interesting theoretical schemes. Moreover, as has been recently pointed out, for moderate values of $\tan\beta$, in order to achieve gauge and bottom-tau Yukawa coupling unification, the top quark mass must be within $10 \%$ of its fixed point value. In this work we show that the convergence of the top quark mass to its fixed point value has relevant consequences for the (assumed) universal soft supersymmetry breaking parameters at the grand unification scale. In particular, we show that the low energy parameters do not depend on $A_0$ and $B_0$ but on the combination $\delta = B_0 - A_0/2$. Hence, there is a reduction in the number of independent parameters. Most interesting, the radiative $SU(2)_L \times U(1)_Y$ breaking condition implies strong correlations between the supersymmetric mass parameter $\mu$ and the supersymmetry breaking parameters $\delta$ and $M_{1/2}$ or $m_0$. These correlations, which become stronger for $\tan\beta < 2$, may have some fundamental origin, which would imply the need of a reformulation of the naive fine tuning criteria.
hep-ph/0502245
Biswajit Adhikary
Biswajit Adhikary
Analysis of a model with a common source of CP violation
20 pages, no figures New materials and references have been added. Text has been modified. To be appear in J.Phys. G
J.Phys.G32:23-38,2006
10.1088/0954-3899/32/1/003
null
hep-ph
null
We work in a model where all CP violating phenomena have a common source. CP is spontaneously broken at a large scale $V$ through the phase of a complex singlet scalar. An additional $SU(2)_L$ singlet vector-like down-type quark relates this high scale CP violation to low energy. We quantitatively analyze this model in the quark sector. We obtain the numerical values of the parameters of the Lagrangian in the quark sector for a specific ansatz of the $4\times4$ down-type quark mass matrix where the weak phase is generated minimally. $Z \bar b b$ vertex will modify in presence of the extra vector-like down-type quark. From the experimental lower bound of the partial decay width $Z\to \bar b b$ we find out the lower bound of the additional down-type quark mass. Tree level flavor changing neutral current appears in this model due to the presence of the extra vector-like down-type quark. We give the range of values of the mass splitting $\Delta m_{B_q}$ in $B^0_q-{\bar B}^0_q$ system using SM box, $Z$ mediating tree level and $Z$ mediating one loop diagrams together for both $q=d, s$. We find out the analytical expression for $\Gamma_{12}^q$ in this model from standard box, $Z$ and Higgs mediated penguin diagrams for $B^0_q-{\bar B}^0_q$ system, $q=d,s$. From this we numerically evaluate the decay width difference $|\Delta\Gamma_{B_q}/\Gamma_{B_q}|$. We also find out the numerical values of the CP asymmetry parameters $a_J$ and $a_\pi$ for the decays $B^0_d\to J/\psi K_s$ and $B^0_d\to \pi^+ \pi^-$ respectively. We get the lower bound of the scale $V$ through the upper bound of the strong CP phase.
[ { "created": "Mon, 28 Feb 2005 12:57:55 GMT", "version": "v1" }, { "created": "Tue, 15 Nov 2005 08:35:45 GMT", "version": "v2" } ]
2014-11-18
[ [ "Adhikary", "Biswajit", "" ] ]
We work in a model where all CP violating phenomena have a common source. CP is spontaneously broken at a large scale $V$ through the phase of a complex singlet scalar. An additional $SU(2)_L$ singlet vector-like down-type quark relates this high scale CP violation to low energy. We quantitatively analyze this model in the quark sector. We obtain the numerical values of the parameters of the Lagrangian in the quark sector for a specific ansatz of the $4\times4$ down-type quark mass matrix where the weak phase is generated minimally. $Z \bar b b$ vertex will modify in presence of the extra vector-like down-type quark. From the experimental lower bound of the partial decay width $Z\to \bar b b$ we find out the lower bound of the additional down-type quark mass. Tree level flavor changing neutral current appears in this model due to the presence of the extra vector-like down-type quark. We give the range of values of the mass splitting $\Delta m_{B_q}$ in $B^0_q-{\bar B}^0_q$ system using SM box, $Z$ mediating tree level and $Z$ mediating one loop diagrams together for both $q=d, s$. We find out the analytical expression for $\Gamma_{12}^q$ in this model from standard box, $Z$ and Higgs mediated penguin diagrams for $B^0_q-{\bar B}^0_q$ system, $q=d,s$. From this we numerically evaluate the decay width difference $|\Delta\Gamma_{B_q}/\Gamma_{B_q}|$. We also find out the numerical values of the CP asymmetry parameters $a_J$ and $a_\pi$ for the decays $B^0_d\to J/\psi K_s$ and $B^0_d\to \pi^+ \pi^-$ respectively. We get the lower bound of the scale $V$ through the upper bound of the strong CP phase.
1802.04814
Rahul Srivastava
Renato M. Fonseca, Martin Hirsch, Rahul Srivastava
$\Delta L = 3$ processes: Proton decay and LHC
8 pages, 5 figures, Published Version
Phys. Rev. D 97, 075026 (2018)
10.1103/PhysRevD.97.075026
IFIC/18-03
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We discuss lepton number violation in three units. From an effective field theory point of view, $\Delta L=3$ processes can only arise from dimension 9 or higher operators. These operators also violate baryon number, hence many of them will induce proton decay. Given the high dimensionality of these operators, in order to have a proton half-life in the observable range, the new physics associated to $\Delta L=3$ processes should be at a scale as low as 1 TeV. This opens up the possibility of searching for such processes not only in proton decay experiments but also at the LHC. In this work we analyze the relevant $d=9,11,13$ operators which violate lepton number in three units. We then construct one simple concrete model with interesting low- and high-energy phenomenology.
[ { "created": "Tue, 13 Feb 2018 19:00:10 GMT", "version": "v1" }, { "created": "Mon, 23 Apr 2018 18:05:09 GMT", "version": "v2" } ]
2018-04-25
[ [ "Fonseca", "Renato M.", "" ], [ "Hirsch", "Martin", "" ], [ "Srivastava", "Rahul", "" ] ]
We discuss lepton number violation in three units. From an effective field theory point of view, $\Delta L=3$ processes can only arise from dimension 9 or higher operators. These operators also violate baryon number, hence many of them will induce proton decay. Given the high dimensionality of these operators, in order to have a proton half-life in the observable range, the new physics associated to $\Delta L=3$ processes should be at a scale as low as 1 TeV. This opens up the possibility of searching for such processes not only in proton decay experiments but also at the LHC. In this work we analyze the relevant $d=9,11,13$ operators which violate lepton number in three units. We then construct one simple concrete model with interesting low- and high-energy phenomenology.
2107.03945
Bruno Scheihing Hitschfeld
Tobias Binder, Kyohei Mukaida, Bruno Scheihing-Hitschfeld and Xiaojun Yao
Non-Abelian Electric Field Correlator at NLO for Dark Matter Relic Abundance and Quarkonium Transport
86 pages, 13 figures
JHEP01(2022)137
10.1007/JHEP01(2022)137
KEK-TH-2334, MIT-CTP/5313
hep-ph astro-ph.CO nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We perform a complete next-to-leading order calculation of the non-Abelian electric field correlator in a SU($N_c$) plasma, which encodes properties of the plasma relevant for heavy particle bound state formation and dissociation, and is different from the correlator for the heavy quark diffusion coefficient. The calculation is carried out in the real-time formalism of thermal field theory and includes both vacuum and finite temperature contributions. By working in the $R_\xi$ gauge, we explicitly show the results are gauge independent, infrared and collinear safe. The renormalization group equation of this electric field correlator is determined by that of the strong coupling constant. Our next-to-leading order calculation can be directly applied to any dipole singlet-adjoint transition of heavy particle pairs. For example, it can be used to describe dissociation and (re)generation of heavy quarkonia inside the quark-gluon plasma well below the melting temperature, as well as heavy dark matter pairs (or charged co-annihilating partners) in the early universe.
[ { "created": "Thu, 8 Jul 2021 16:17:06 GMT", "version": "v1" }, { "created": "Mon, 29 Nov 2021 19:09:35 GMT", "version": "v2" }, { "created": "Fri, 11 Feb 2022 21:39:38 GMT", "version": "v3" } ]
2022-09-20
[ [ "Binder", "Tobias", "" ], [ "Mukaida", "Kyohei", "" ], [ "Scheihing-Hitschfeld", "Bruno", "" ], [ "Yao", "Xiaojun", "" ] ]
We perform a complete next-to-leading order calculation of the non-Abelian electric field correlator in a SU($N_c$) plasma, which encodes properties of the plasma relevant for heavy particle bound state formation and dissociation, and is different from the correlator for the heavy quark diffusion coefficient. The calculation is carried out in the real-time formalism of thermal field theory and includes both vacuum and finite temperature contributions. By working in the $R_\xi$ gauge, we explicitly show the results are gauge independent, infrared and collinear safe. The renormalization group equation of this electric field correlator is determined by that of the strong coupling constant. Our next-to-leading order calculation can be directly applied to any dipole singlet-adjoint transition of heavy particle pairs. For example, it can be used to describe dissociation and (re)generation of heavy quarkonia inside the quark-gluon plasma well below the melting temperature, as well as heavy dark matter pairs (or charged co-annihilating partners) in the early universe.
hep-ph/9311234
null
Richard F. Lebed
Baryon decuplet mass relations in chiral perturbation theory
33 pages in LaTeX, 2 figures included in one Postscript uuencoded compressed tar file, LBL-34704 and UCB-PTH-93/27
Nucl.Phys.B430:295-318,1994
10.1016/0550-3213(94)00375-0
null
hep-ph
null
Baryon decuplet masses within an $SU(3)_L \times SU(3)_R$ chiral Lagrangian formalism are found to satisfy four relations at second order in flavor breaking. As a result, the one-loop corrections from Lagrangian terms up to first order in flavor breaking are observed to give finite and calculable corrections to these relations. The formal expressions for these corrections are presented, followed by numerical evaluations. We find consistency between the experimental values of breaking of the relations and the loop corrections of these relations as predicted by chiral perturbation theory.
[ { "created": "Sun, 7 Nov 1993 06:54:15 GMT", "version": "v1" } ]
2011-07-19
[ [ "Lebed", "Richard F.", "" ] ]
Baryon decuplet masses within an $SU(3)_L \times SU(3)_R$ chiral Lagrangian formalism are found to satisfy four relations at second order in flavor breaking. As a result, the one-loop corrections from Lagrangian terms up to first order in flavor breaking are observed to give finite and calculable corrections to these relations. The formal expressions for these corrections are presented, followed by numerical evaluations. We find consistency between the experimental values of breaking of the relations and the loop corrections of these relations as predicted by chiral perturbation theory.
0802.1792
Marco Guzzi
Claudio Coriano, Alon E. Faraggi, Marco Guzzi
Searching for Extra Z' from Strings and Other Models at the LHC with Leptoproduction
33 pages, 14 figures
Phys.Rev.D78:015012,2008
10.1103/PhysRevD.78.015012
LTH-780
hep-ph hep-th
null
Discovery potentials for extra neutral interactions at the Large Hadron Collider in forthcoming experiments are analyzed using resonant leptoproduction. For this purpose we use high precision next-to-next-to-leading order (NNLO) determinations of the QCD background in this channel, at the tail of the Drell-Yan distributions, in the invariant mass region around $ 0.8< Q < 2.5 $ TeV. We focus our analysis primarily on a novel string-inspired $Z^\prime$, obtained in left-right symmetric free fermionic heterotic string models and whose existence at low energies is motivated by its role in suppressing proton decay mediation. We analyze the parametric dependence of the predictions and perform comparison with other models based on bottom up approaches, that are constructed by requiring anomaly cancellation and enlarged Higgs structure. We show that the results are not particularly sensitive to the specific charge assignments. This may render quite difficult the extraction of significant information from the forward-backward asymmetries on the resonance, assuming that these are possible due to a sizeable width. The challenge to discover extra (non anomalous) $Z^\prime$ in this kinematic region remains strongly dependent on the size of the new gauge coupling. Weakly coupled extra $Z^\prime$ will not be easy to identify even with a very good theoretical determination of the QCD background through NNLO.
[ { "created": "Wed, 13 Feb 2008 20:54:11 GMT", "version": "v1" }, { "created": "Wed, 13 Feb 2008 22:58:41 GMT", "version": "v2" }, { "created": "Tue, 19 Feb 2008 11:07:16 GMT", "version": "v3" }, { "created": "Tue, 13 May 2008 12:58:30 GMT", "version": "v4" } ]
2008-11-26
[ [ "Coriano", "Claudio", "" ], [ "Faraggi", "Alon E.", "" ], [ "Guzzi", "Marco", "" ] ]
Discovery potentials for extra neutral interactions at the Large Hadron Collider in forthcoming experiments are analyzed using resonant leptoproduction. For this purpose we use high precision next-to-next-to-leading order (NNLO) determinations of the QCD background in this channel, at the tail of the Drell-Yan distributions, in the invariant mass region around $ 0.8< Q < 2.5 $ TeV. We focus our analysis primarily on a novel string-inspired $Z^\prime$, obtained in left-right symmetric free fermionic heterotic string models and whose existence at low energies is motivated by its role in suppressing proton decay mediation. We analyze the parametric dependence of the predictions and perform comparison with other models based on bottom up approaches, that are constructed by requiring anomaly cancellation and enlarged Higgs structure. We show that the results are not particularly sensitive to the specific charge assignments. This may render quite difficult the extraction of significant information from the forward-backward asymmetries on the resonance, assuming that these are possible due to a sizeable width. The challenge to discover extra (non anomalous) $Z^\prime$ in this kinematic region remains strongly dependent on the size of the new gauge coupling. Weakly coupled extra $Z^\prime$ will not be easy to identify even with a very good theoretical determination of the QCD background through NNLO.
1907.05893
Samuel Witte
Carlos Blanco, Miguel Escudero, Dan Hooper, and Samuel J. Witte
$Z'$ Mediated WIMPs: Dead, Dying, or Soon to be Detected?
v2: Published version. Modified text, no significant changes. v1:46 pages, 17 figures
null
10.1088/1475-7516/2019/11/024
null
hep-ph astro-ph.CO hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Although weakly interacting massive particles (WIMPs) have long been among the most studied and theoretically attractive classes of candidates for the dark matter of our universe, the lack of their detection in direct detection and collider experiments has begun to dampen enthusiasm for this paradigm. In this study, we set out to appraise the status of the WIMP paradigm, focusing on the case of dark matter candidates that interact with the Standard Model through a new gauge boson. After considering a wide range of $Z'$ mediated dark matter models, we quantitatively evaluate the fraction of the parameter space that has been excluded by existing experiments, and that is projected to fall within the reach of future direct detection experiments. Despite the existence of stringent constraints, we find that a sizable fraction of this parameter space remains viable. More specifically, if the dark matter is a Majorana fermion, we find that an order one fraction of the parameter space is in many cases untested by current experiments. Future direct detection experiments with sensitivity near the irreducible neutrino floor will be able to test a significant fraction of the currently viable parameter space, providing considerable motivation for the next generation of direct detection experiments.
[ { "created": "Fri, 12 Jul 2019 18:00:00 GMT", "version": "v1" }, { "created": "Sat, 23 Nov 2019 14:06:17 GMT", "version": "v2" } ]
2019-11-27
[ [ "Blanco", "Carlos", "" ], [ "Escudero", "Miguel", "" ], [ "Hooper", "Dan", "" ], [ "Witte", "Samuel J.", "" ] ]
Although weakly interacting massive particles (WIMPs) have long been among the most studied and theoretically attractive classes of candidates for the dark matter of our universe, the lack of their detection in direct detection and collider experiments has begun to dampen enthusiasm for this paradigm. In this study, we set out to appraise the status of the WIMP paradigm, focusing on the case of dark matter candidates that interact with the Standard Model through a new gauge boson. After considering a wide range of $Z'$ mediated dark matter models, we quantitatively evaluate the fraction of the parameter space that has been excluded by existing experiments, and that is projected to fall within the reach of future direct detection experiments. Despite the existence of stringent constraints, we find that a sizable fraction of this parameter space remains viable. More specifically, if the dark matter is a Majorana fermion, we find that an order one fraction of the parameter space is in many cases untested by current experiments. Future direct detection experiments with sensitivity near the irreducible neutrino floor will be able to test a significant fraction of the currently viable parameter space, providing considerable motivation for the next generation of direct detection experiments.
1504.01487
Ying Zhang
Kai Fu, Ying Zhang
Statistical Constraints on the Error of the Leptonic CP Violation of Neutrinos
9 pages, 5 figures
null
10.1016/j.physletb.2015.04.061
null
hep-ph
http://creativecommons.org/licenses/by/3.0/
A constraint on the error of leptonic CP violation, which require the phase $\delta_{CP}$ to be less than $\pi/4$ for it to be distinguishable on a $2\pi$ cycle, is presented. Under this constraint, the effects of neutrino detector 's distance, beam energy, and energy resolution are discussed with reference to the present values of these parameters in experiments. Although an optimized detector performances can minimize the deviation to yield a larger distinguishable range of the leptonic CP phase on a $2\pi$ cycle, it is not possible to determine an arbitrary leptonic CP phase in the range of $2\pi$ with the statistics from a single detector because of the existence of two singular points. An efficiency factor $\eta$ is defined to characterize the distinguishable range of $\delta_{CP}$. To cover the entire possible $\delta_{CP}$ range, a combined efficiency factor $\eta^*$ corresponding to multiple sets of detection parameters with different neutrino beam energies and distances is proposed. The combined efficiency factors $\eta^*$ of various major experiments are also presented.
[ { "created": "Tue, 7 Apr 2015 06:29:29 GMT", "version": "v1" }, { "created": "Tue, 28 Apr 2015 03:02:26 GMT", "version": "v2" } ]
2015-05-20
[ [ "Fu", "Kai", "" ], [ "Zhang", "Ying", "" ] ]
A constraint on the error of leptonic CP violation, which require the phase $\delta_{CP}$ to be less than $\pi/4$ for it to be distinguishable on a $2\pi$ cycle, is presented. Under this constraint, the effects of neutrino detector 's distance, beam energy, and energy resolution are discussed with reference to the present values of these parameters in experiments. Although an optimized detector performances can minimize the deviation to yield a larger distinguishable range of the leptonic CP phase on a $2\pi$ cycle, it is not possible to determine an arbitrary leptonic CP phase in the range of $2\pi$ with the statistics from a single detector because of the existence of two singular points. An efficiency factor $\eta$ is defined to characterize the distinguishable range of $\delta_{CP}$. To cover the entire possible $\delta_{CP}$ range, a combined efficiency factor $\eta^*$ corresponding to multiple sets of detection parameters with different neutrino beam energies and distances is proposed. The combined efficiency factors $\eta^*$ of various major experiments are also presented.
hep-ph/0012239
Fugao Wang
Jiao Lin Xu
A Phenomenological Model of the Baryons The Body Center Cubic Model of the Vacuum Material
28 pages, 5 eps figures
null
null
null
hep-ph
null
From the quark confinement idea, we conjecture that the quarks compose colorless particles (uud and udd - the Lee Particles) and then the Lee Particles construct a body center cubic lattice in the vacuum. In terms of the energy band theory, from the symmetries of the body center cubic periodic field, we deduce the baryon spectrum (with a united mass formula) using only 2 flavored quarks u and d. We also predict some new baryons: $\Lambda^{0}$(2559), $\Lambda_{C}^{+}$(6659), $\Lambda_{b}^{0}$(10159).... The experiments to find the long lifetime baryon $\Lambda^{0}$(2559) should be done first.
[ { "created": "Tue, 19 Dec 2000 00:44:22 GMT", "version": "v1" } ]
2007-05-23
[ [ "Xu", "Jiao Lin", "" ] ]
From the quark confinement idea, we conjecture that the quarks compose colorless particles (uud and udd - the Lee Particles) and then the Lee Particles construct a body center cubic lattice in the vacuum. In terms of the energy band theory, from the symmetries of the body center cubic periodic field, we deduce the baryon spectrum (with a united mass formula) using only 2 flavored quarks u and d. We also predict some new baryons: $\Lambda^{0}$(2559), $\Lambda_{C}^{+}$(6659), $\Lambda_{b}^{0}$(10159).... The experiments to find the long lifetime baryon $\Lambda^{0}$(2559) should be done first.
1105.5513
Bingfang Yang
Jinzhong Han and Xuelei Wang
Pair production of charged top-pions in the $\gamma\gamma$ collisions at the ILC
null
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The top-color assisted technicolor (TC2) mode predicts the existence of a pair of charged top-pions $\pi^{\pm}_t$. In this paper, we study the production of the charged top-pions pair $\pi^{\pm}_t$ at next generation $\gamma\gamma$ colliders. The results show that the production rates can reach the level of $10^2$ fb with reasonable parameter space. With a large number of events and the clean background, the charged top-pion should be observable at the $\gamma\gamma$ colliders. Therefore, our studies can help us to search for charged top-pion, and furthermore, to test the TC2 model.
[ { "created": "Fri, 27 May 2011 09:54:37 GMT", "version": "v1" } ]
2011-05-30
[ [ "Han", "Jinzhong", "" ], [ "Wang", "Xuelei", "" ] ]
The top-color assisted technicolor (TC2) mode predicts the existence of a pair of charged top-pions $\pi^{\pm}_t$. In this paper, we study the production of the charged top-pions pair $\pi^{\pm}_t$ at next generation $\gamma\gamma$ colliders. The results show that the production rates can reach the level of $10^2$ fb with reasonable parameter space. With a large number of events and the clean background, the charged top-pion should be observable at the $\gamma\gamma$ colliders. Therefore, our studies can help us to search for charged top-pion, and furthermore, to test the TC2 model.
hep-ph/0402018
Laurent Favart
L. Favart (ULB - Belgium) and M.V.T. Machado (IF-UFRGS - Brazil)
QCD evolution and skewedness effects in color dipole description of DVCS
LaTeX, 6 pages, 5 Figs. Vers 2: Minor modifications. Accepted by EPJC
Eur.Phys.J.C34:429-433,2004
10.1140/epjc/s2004-01733-5
null
hep-ph
null
We show the role played by QCD evolution and skewedness effects in the DVCS cross section at large $Q^2$ within the color dipole description of the process at photon level. The dipole cross section is given by the saturation model, which can be improved by DGLAP evolution at high photon virtualities. We investigate both possibilities as well as the off-forward effect through a simple phenomenological parametrisation. The results are compared to the recent ZEUS DVCS data.
[ { "created": "Mon, 2 Feb 2004 13:44:15 GMT", "version": "v1" }, { "created": "Wed, 25 Feb 2004 09:11:53 GMT", "version": "v2" } ]
2014-11-17
[ [ "Favart", "L.", "", "ULB - Belgium" ], [ "Machado", "M. V. T.", "", "IF-UFRGS - Brazil" ] ]
We show the role played by QCD evolution and skewedness effects in the DVCS cross section at large $Q^2$ within the color dipole description of the process at photon level. The dipole cross section is given by the saturation model, which can be improved by DGLAP evolution at high photon virtualities. We investigate both possibilities as well as the off-forward effect through a simple phenomenological parametrisation. The results are compared to the recent ZEUS DVCS data.
1403.5583
Jose Miguel No
Glauber C. Dorsch, Stephan J. Huber and Jose Miguel No
Cosmological Signatures of a UV-Conformal Standard Model
null
Phys. Rev. Lett. 113, 121801 (2014)
10.1103/PhysRevLett.113.121801
null
hep-ph astro-ph.CO
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Quantum scale invariance in the UV has been recently advocated as an attractive way of solving the gauge hierarchy problem arising in the Standard Model. We explore the cosmological signatures at the electroweak scale when the breaking of scale invariance originates from a hidden sector and is mediated to the Standard Model by gauge interactions (Gauge Mediation). These scenarios, while being hard to distinguish from the Standard Model at LHC, can give rise to a strong electroweak phase transition leading to the generation of a large stochastic gravitational wave background in possible reach of future space-based detectors such as eLISA and BBO. This relic would be the cosmological imprint of the breaking of scale invariance in Nature.
[ { "created": "Fri, 21 Mar 2014 22:45:20 GMT", "version": "v1" } ]
2014-09-24
[ [ "Dorsch", "Glauber C.", "" ], [ "Huber", "Stephan J.", "" ], [ "No", "Jose Miguel", "" ] ]
Quantum scale invariance in the UV has been recently advocated as an attractive way of solving the gauge hierarchy problem arising in the Standard Model. We explore the cosmological signatures at the electroweak scale when the breaking of scale invariance originates from a hidden sector and is mediated to the Standard Model by gauge interactions (Gauge Mediation). These scenarios, while being hard to distinguish from the Standard Model at LHC, can give rise to a strong electroweak phase transition leading to the generation of a large stochastic gravitational wave background in possible reach of future space-based detectors such as eLISA and BBO. This relic would be the cosmological imprint of the breaking of scale invariance in Nature.
hep-ph/0111111
Barbieri Riccardo
Riccardo Barbieri
Quark masses and weak couplings in the Standard Model and beyond
9 pages, 3 figures, Talk given at Lepton Photon 2001, Rome, July 2001
Int.J.Mod.Phys.A17:3059-3067,2002
10.1142/S0217751X02012594
null
hep-ph
null
I discuss two topics: i) the empirical adequacy of the Standard Model in the Flavour Sector in view of recent data; ii) the possible existence of a hidden structure in the quark masses and mixings based on textures.
[ { "created": "Fri, 9 Nov 2001 14:54:56 GMT", "version": "v1" } ]
2010-11-23
[ [ "Barbieri", "Riccardo", "" ] ]
I discuss two topics: i) the empirical adequacy of the Standard Model in the Flavour Sector in view of recent data; ii) the possible existence of a hidden structure in the quark masses and mixings based on textures.
hep-ph/0411248
Romulus Godang
R. Godang, S. Bracker, M. Cavaglia, L. Cremaldi and D. Summers (University of Mississippi-Oxford) D. Cline (University of California-Los Angeles)
Resolution of Nearly Mass Degenerate Higgs Bosons and Production of Black Hole Systems of Known Mass at a Muon Collider
Latex, 5 pages, 2 figures, proceedings to the DPF 2004: Annual Meeting of the Division of Particles and Fields of APS, 26 August-31 August 2004, Riverside, CA, USA
Int.J.Mod.Phys.A20:3409-3412,2005
10.1142/S0217751X05026674
MUC-CONF-PHYSICS-299
hep-ph hep-ex physics.acc-ph
null
The direct s-channel coupling to Higgs bosons is 40000 times greater for muons than electrons; the coupling goes as mass squared. High precision scanning of the lighter $h^0$ and the higher mass $H^0$ and $A^0$ is thus possible with a muon collider. The $H^0$ and $A^0$ are expected to be nearly mass degenerate and to be CP even and odd, respectively. A muon collider could resolve the mass degeneracy and make CP measurements. The origin of CP violation in the $K^{0}$ and $B^{0}$ meson systems might lie in the the $H^0/A^0$ Higgs bosons. If large extra dimensions exist, black holes with lifetimes of $\sim 10^{-26}$ seconds could be created and observed via Hawking radiation at the LHC. Unlike proton or electron colliders, muon colliders can produce black hole systems of known mass. This opens the possibilities of measuring quantum remnants, gravitons as missing energy, and scanning production turn on. Proton colliders are hampered by parton distributions and CLIC by beamstrahlung. The ILC lacks the energy reach.
[ { "created": "Thu, 18 Nov 2004 23:28:47 GMT", "version": "v1" } ]
2008-11-26
[ [ "Godang", "R.", "", "University of Mississippi-Oxford" ], [ "Bracker", "S.", "", "University of Mississippi-Oxford" ], [ "Cavaglia", "M.", "", "University of Mississippi-Oxford" ], [ "Cremaldi", "L.", "", "University of Mississippi-Oxford" ], [ "Summers", "D.", "", "University of Mississippi-Oxford" ], [ "Cline", "D.", "", "University of California-Los\n Angeles" ] ]
The direct s-channel coupling to Higgs bosons is 40000 times greater for muons than electrons; the coupling goes as mass squared. High precision scanning of the lighter $h^0$ and the higher mass $H^0$ and $A^0$ is thus possible with a muon collider. The $H^0$ and $A^0$ are expected to be nearly mass degenerate and to be CP even and odd, respectively. A muon collider could resolve the mass degeneracy and make CP measurements. The origin of CP violation in the $K^{0}$ and $B^{0}$ meson systems might lie in the the $H^0/A^0$ Higgs bosons. If large extra dimensions exist, black holes with lifetimes of $\sim 10^{-26}$ seconds could be created and observed via Hawking radiation at the LHC. Unlike proton or electron colliders, muon colliders can produce black hole systems of known mass. This opens the possibilities of measuring quantum remnants, gravitons as missing energy, and scanning production turn on. Proton colliders are hampered by parton distributions and CLIC by beamstrahlung. The ILC lacks the energy reach.
hep-ph/0408132
Ayres Freitas
A. Freitas (Fermilab)
How to study weakly coupled neutral vector bosons
4 pp., to appear in the proceedings of the International Conference on Linear Colliders (LCWS 04), Paris, France (April 19-23, 2004)
null
null
FERMILAB-Conf-04-150-T
hep-ph
null
A weakly coupled new neutral gauge boson, forming a narrow resonance, can be efficiently produced at e+e- colliders through radiative return processes if the collider energy is larger than the gauge boson mass. This contribution analyzes the sensitivity of a future linear collider for weakly coupled gauge bosons and briefly discusses how, in case of discovery, its properties can be determined with high precision.
[ { "created": "Tue, 10 Aug 2004 16:27:15 GMT", "version": "v1" } ]
2007-05-23
[ [ "Freitas", "A.", "", "Fermilab" ] ]
A weakly coupled new neutral gauge boson, forming a narrow resonance, can be efficiently produced at e+e- colliders through radiative return processes if the collider energy is larger than the gauge boson mass. This contribution analyzes the sensitivity of a future linear collider for weakly coupled gauge bosons and briefly discusses how, in case of discovery, its properties can be determined with high precision.
hep-ph/0203041
Naveen Gaur
S.Rai Choudhury, Naveen Gaur and Namit Mahajan
Lepton polarization asymmetry in radiative dileptonic B-meson decays in MSSM
typos corrected to match with published version
Phys.Rev. D66 (2002) 054003
10.1103/PhysRevD.66.054003
null
hep-ph
null
In this paper we study the polarization asymmetries of the final state lepton in the radiative dileptonic decay of B meson (\bsllg) in the framework of Minimal Supersymmetric Standard Model (MSSM) and various other unified models within the framework of MSSM e.g. mSUGRA, SUGRA (where condition of universality of scalar masses is relaxed) etc. Lepton polarization, in addition of having a longitudinal component (\pl), can have two other components, \pt and \pn, lying in and perpendicular to the decay plane, which are proportional to \ml and hence are significant for final state being $\mu^+ ~ \mu^-$ or $\tau^+ \~\tau^-$. We analyse the dependence of these polarization asymmetries on the parameters of the various models.
[ { "created": "Tue, 5 Mar 2002 10:44:43 GMT", "version": "v1" }, { "created": "Thu, 11 Jul 2002 06:54:31 GMT", "version": "v2" }, { "created": "Thu, 3 Oct 2002 05:10:48 GMT", "version": "v3" } ]
2009-11-07
[ [ "Choudhury", "S. Rai", "" ], [ "Gaur", "Naveen", "" ], [ "Mahajan", "Namit", "" ] ]
In this paper we study the polarization asymmetries of the final state lepton in the radiative dileptonic decay of B meson (\bsllg) in the framework of Minimal Supersymmetric Standard Model (MSSM) and various other unified models within the framework of MSSM e.g. mSUGRA, SUGRA (where condition of universality of scalar masses is relaxed) etc. Lepton polarization, in addition of having a longitudinal component (\pl), can have two other components, \pt and \pn, lying in and perpendicular to the decay plane, which are proportional to \ml and hence are significant for final state being $\mu^+ ~ \mu^-$ or $\tau^+ \~\tau^-$. We analyse the dependence of these polarization asymmetries on the parameters of the various models.
2006.16277
David Curtin
Rodolfo Capdevilla, David Curtin, Yonatan Kahn, Gordan Krnjaic
A Guaranteed Discovery at Future Muon Colliders
7 pages, 2 figures. Minor correction to plot fig. 2, no significant change in results or conclusions
Phys. Rev. D 103, 075028 (2021)
10.1103/PhysRevD.103.075028
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The longstanding muon g-2 anomaly may indicate the existence of new particles that couple to muons, which could either be light (< GeV) and weakly coupled, or heavy (>> 100 GeV) with large couplings. If light new states are responsible, upcoming intensity frontier experiments will discover further evidence of new physics. However, if heavy particles are responsible, many candidates are beyond the reach of existing colliders. We show that, if the g-2 anomaly is confirmed and no explanation is found at low-energy experiments, a high-energy muon collider program is guaranteed to make fundamental discoveries about our universe. New physics scenarios that account for the anomaly can be classified as either "Singlet" or "Electroweak" (EW) models, involving only EW singlets or new EW-charged states respectively. We argue that a TeV-scale future muon collider will discover all possible singlet model solutions to the anomaly. If this does not yield a discovery, the next step would be a O(10 TeV) muon collider. Such a machine would either discover new particles associated with high-scale EW model solutions to the anomaly, or empirically prove that nature is fine-tuned, both of which would have profound consequences for fundamental physics.
[ { "created": "Mon, 29 Jun 2020 18:02:11 GMT", "version": "v1" }, { "created": "Mon, 25 Jan 2021 20:27:12 GMT", "version": "v2" } ]
2021-04-28
[ [ "Capdevilla", "Rodolfo", "" ], [ "Curtin", "David", "" ], [ "Kahn", "Yonatan", "" ], [ "Krnjaic", "Gordan", "" ] ]
The longstanding muon g-2 anomaly may indicate the existence of new particles that couple to muons, which could either be light (< GeV) and weakly coupled, or heavy (>> 100 GeV) with large couplings. If light new states are responsible, upcoming intensity frontier experiments will discover further evidence of new physics. However, if heavy particles are responsible, many candidates are beyond the reach of existing colliders. We show that, if the g-2 anomaly is confirmed and no explanation is found at low-energy experiments, a high-energy muon collider program is guaranteed to make fundamental discoveries about our universe. New physics scenarios that account for the anomaly can be classified as either "Singlet" or "Electroweak" (EW) models, involving only EW singlets or new EW-charged states respectively. We argue that a TeV-scale future muon collider will discover all possible singlet model solutions to the anomaly. If this does not yield a discovery, the next step would be a O(10 TeV) muon collider. Such a machine would either discover new particles associated with high-scale EW model solutions to the anomaly, or empirically prove that nature is fine-tuned, both of which would have profound consequences for fundamental physics.
1207.3073
Yan-Qing Ma
Yan-Qing Ma
General Form of $s$, $t$, $u$ Symmetric Polynomial and Heavy Quarkonium physics
19 pages, 1 figure, corresponds to published version
Phys. Rev. D 87, 034001 (2013)
10.1103/PhysRevD.87.034001
BNL-98309-2012-JA
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Induced by three gluons symmetry, Mandelstam variables $s$, $t$, $u$ symmetric expressions are widely involved in collider physics, especially in heavy quarkonium physics. In this work we study general form of $s$, $t$, $u$ symmetric polynomials, and find that they can be expressed as polynomials where the symmetry is manifest. The general form is then used to simplify expressions which asymptotically reduces the length of original expression to one-sixth. Based on the general form, we reproduce the exact differential cross section of $J/\psi$ hadron production at leading order in $v^2$ up to four unknown constant numbers by simple analysis. Furthermore, we prove that differential cross section at higher order in $v^2$ is proportional to that at leading order. This proof explains the proportion relation at next-to-leading order in $v^2$ found in previous work and generalizes it to all order.
[ { "created": "Thu, 12 Jul 2012 19:47:33 GMT", "version": "v1" }, { "created": "Mon, 4 Feb 2013 22:08:18 GMT", "version": "v2" } ]
2013-05-30
[ [ "Ma", "Yan-Qing", "" ] ]
Induced by three gluons symmetry, Mandelstam variables $s$, $t$, $u$ symmetric expressions are widely involved in collider physics, especially in heavy quarkonium physics. In this work we study general form of $s$, $t$, $u$ symmetric polynomials, and find that they can be expressed as polynomials where the symmetry is manifest. The general form is then used to simplify expressions which asymptotically reduces the length of original expression to one-sixth. Based on the general form, we reproduce the exact differential cross section of $J/\psi$ hadron production at leading order in $v^2$ up to four unknown constant numbers by simple analysis. Furthermore, we prove that differential cross section at higher order in $v^2$ is proportional to that at leading order. This proof explains the proportion relation at next-to-leading order in $v^2$ found in previous work and generalizes it to all order.
hep-ph/9705221
Dave Robertson
S. J. Brodsky, C.-R. Ji, A. Pang and D. G. Robertson
Optimal Renormalization Scale and Scheme for Exclusive Processes
22 pages, Latex, 7 Latex figures. Several references added, discussion of scale fixing revised for clarity. Final version to appear in Phys. Rev. D
Phys.Rev.D57:245-252,1998
10.1103/PhysRevD.57.245
SLAC-PUB-7473
hep-ph
null
We use the BLM method to fix the renormalization scale of the QCD coupling in exclusive hadronic amplitudes such as the pion form factor and the photon-to-pion transition form factor at large momentum transfer. Renormalization-scheme-independent commensurate scale relations are established which connect the hard scattering subprocess amplitudes that control exclusive processes to other QCD observables such as the heavy quark potential and the electron-positron annihilation cross section. The commensurate scale relation connecting the heavy quark potential, as determined from lattice gauge theory, to the photon-to-pion transition form factor is in excellent agreement with $\gamma e \to \pi^0 e$ data assuming that the pion distribution amplitude is close to its asymptotic form $\sqrt{3}f_\pi x(1-x)$. We also reproduce the scaling and normalization of the $\gamma \gamma \to \pi^+ \pi^-$ data at large momentum transfer. Because the renormalization scale is small, we argue that the effective coupling is nearly constant, thus accounting for the nominal scaling behavior of the data. However, the normalization of the space-like pion form factor $F_\pi(Q^2)$ obtained from electroproduction experiments is somewhat higher than that predicted by the corresponding commensurate scale relation. This discrepancy may be due to systematic errors introduced by the extrapolation of the $\gamma^* p \to \pi^+ n$ electroproduction data to the pion pole.
[ { "created": "Fri, 2 May 1997 22:00:47 GMT", "version": "v1" }, { "created": "Tue, 20 May 1997 21:54:43 GMT", "version": "v2" }, { "created": "Mon, 17 Nov 1997 20:22:57 GMT", "version": "v3" } ]
2008-11-26
[ [ "Brodsky", "S. J.", "" ], [ "Ji", "C. -R.", "" ], [ "Pang", "A.", "" ], [ "Robertson", "D. G.", "" ] ]
We use the BLM method to fix the renormalization scale of the QCD coupling in exclusive hadronic amplitudes such as the pion form factor and the photon-to-pion transition form factor at large momentum transfer. Renormalization-scheme-independent commensurate scale relations are established which connect the hard scattering subprocess amplitudes that control exclusive processes to other QCD observables such as the heavy quark potential and the electron-positron annihilation cross section. The commensurate scale relation connecting the heavy quark potential, as determined from lattice gauge theory, to the photon-to-pion transition form factor is in excellent agreement with $\gamma e \to \pi^0 e$ data assuming that the pion distribution amplitude is close to its asymptotic form $\sqrt{3}f_\pi x(1-x)$. We also reproduce the scaling and normalization of the $\gamma \gamma \to \pi^+ \pi^-$ data at large momentum transfer. Because the renormalization scale is small, we argue that the effective coupling is nearly constant, thus accounting for the nominal scaling behavior of the data. However, the normalization of the space-like pion form factor $F_\pi(Q^2)$ obtained from electroproduction experiments is somewhat higher than that predicted by the corresponding commensurate scale relation. This discrepancy may be due to systematic errors introduced by the extrapolation of the $\gamma^* p \to \pi^+ n$ electroproduction data to the pion pole.
2306.07395
Melek Y{\i}lmaz \c{S}eng\"ul
Melek Yilmaz \c{S}eng\"ul
Bound-free pair production mechanism in Pb-p collisions at LHC
null
null
10.5506/APhysPolB.54.4-A4
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
In this work, cross section calculations of bound-free pair production (BFPP) are done for the mechanism in Pb-p collisions at LHC. BFPP cross section for the asymmetric collisions of Pb-p at the center of mass energies of $\sqrt{s_{NN}}=5,02 TeV$ and $\sqrt{s_{NN}}=8,16 TeV$ is computed. In order to reach the exact results, Monte Carlo integration techniques are utilized to calculate the lowest-order Feynman diagrams amplitudes via the lowest order perturbation theory. Also, in this work our cross section results for BFPP mechanism in Pb-p collisions at LHC are compared with BFPP cross section results obtained in literature, which are reached for Pb-p collisions by using a simple scaling applied to scale BFPP cross section results in Pb-Pb collisions at LHC.
[ { "created": "Mon, 12 Jun 2023 19:48:36 GMT", "version": "v1" } ]
2023-06-28
[ [ "Şengül", "Melek Yilmaz", "" ] ]
In this work, cross section calculations of bound-free pair production (BFPP) are done for the mechanism in Pb-p collisions at LHC. BFPP cross section for the asymmetric collisions of Pb-p at the center of mass energies of $\sqrt{s_{NN}}=5,02 TeV$ and $\sqrt{s_{NN}}=8,16 TeV$ is computed. In order to reach the exact results, Monte Carlo integration techniques are utilized to calculate the lowest-order Feynman diagrams amplitudes via the lowest order perturbation theory. Also, in this work our cross section results for BFPP mechanism in Pb-p collisions at LHC are compared with BFPP cross section results obtained in literature, which are reached for Pb-p collisions by using a simple scaling applied to scale BFPP cross section results in Pb-Pb collisions at LHC.
2401.15926
Hai-Yang Cheng
Huiling Zhong, Fanrong Xu, Hai-Yang Cheng
Topological Diagrams and Hadronic Weak Decays of Charmed Baryons
5 pages, 1 figure, Tables II-IV revised
null
null
null
hep-ph hep-ex
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Inspired by the recent BESIII measurement of the decay asymmetry and the phase shift between $S$- and $P$-wave amplitudes in the decay $\Lambda_c^+\to \Xi^0K^+$, we perform a global fit to the experimental data of charmed baryon decays based on the topological diagrammatic approach (TDA) which has the advantage that it is more intuitive and easier to implement model calculations. The measured branching fractions and decay asymmetries are well accommodated in TDA except for three modes, in particular, the predicted ${\cal B}(\Xi_c^0\to \Xi^-\pi^+)=(2.83\pm0.10)\%$ is larger than its current value. The predicted magnitudes of $S$- and $P$-wave amplitudes and their phase shifts are presented for measured and yet-measured modes which can be tested in forthcoming experiments.
[ { "created": "Mon, 29 Jan 2024 07:34:10 GMT", "version": "v1" }, { "created": "Fri, 2 Feb 2024 02:06:54 GMT", "version": "v2" }, { "created": "Mon, 4 Mar 2024 11:41:25 GMT", "version": "v3" } ]
2024-03-05
[ [ "Zhong", "Huiling", "" ], [ "Xu", "Fanrong", "" ], [ "Cheng", "Hai-Yang", "" ] ]
Inspired by the recent BESIII measurement of the decay asymmetry and the phase shift between $S$- and $P$-wave amplitudes in the decay $\Lambda_c^+\to \Xi^0K^+$, we perform a global fit to the experimental data of charmed baryon decays based on the topological diagrammatic approach (TDA) which has the advantage that it is more intuitive and easier to implement model calculations. The measured branching fractions and decay asymmetries are well accommodated in TDA except for three modes, in particular, the predicted ${\cal B}(\Xi_c^0\to \Xi^-\pi^+)=(2.83\pm0.10)\%$ is larger than its current value. The predicted magnitudes of $S$- and $P$-wave amplitudes and their phase shifts are presented for measured and yet-measured modes which can be tested in forthcoming experiments.
hep-ph/0110040
Koshiro Suzuki
Yasunori Nomura, Koshiro Suzuki
Gauge Mediation Models with Neutralino Dark Matter
22 pages, LaTeX, 8 ps figures
Phys.Rev.D68:075005,2003
10.1103/PhysRevD.68.075005
UCB-PTH-00/45, LBNL-47230, UT-955
hep-ph astro-ph
null
We study gauge mediation models of supersymmetry breaking with neutralino LSP. These models are naturally realized by embedding the usual four-dimensional gauge mediation models into a higher-dimensional spacetime such as $M^4 \times S^1 / Z_{2}$. We calculate the relic abundance of the neutralino LSP in these models and show that there exist wide parameter regions where the neutralino LSP constitutes the dominant component of the cold dark matter. These regions evade constraints from collider experiments such as Higgs mass bounds and $b \ra s \gamma$, and also provide the value for the muon anomalous magnetic moment which is consistent with the SUSY explanation of the deviation from the standard model prediction.
[ { "created": "Wed, 3 Oct 2001 07:36:37 GMT", "version": "v1" } ]
2009-09-29
[ [ "Nomura", "Yasunori", "" ], [ "Suzuki", "Koshiro", "" ] ]
We study gauge mediation models of supersymmetry breaking with neutralino LSP. These models are naturally realized by embedding the usual four-dimensional gauge mediation models into a higher-dimensional spacetime such as $M^4 \times S^1 / Z_{2}$. We calculate the relic abundance of the neutralino LSP in these models and show that there exist wide parameter regions where the neutralino LSP constitutes the dominant component of the cold dark matter. These regions evade constraints from collider experiments such as Higgs mass bounds and $b \ra s \gamma$, and also provide the value for the muon anomalous magnetic moment which is consistent with the SUSY explanation of the deviation from the standard model prediction.
1703.07791
Da Liu
Da Liu, Ian Low and Carlos E. M. Wagner
Modification of Higgs Couplings in Minimal Composite Models
42 pages, 14 figures; Added references
Phys. Rev. D 96, 035013 (2017)
10.1103/PhysRevD.96.035013
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a comprehensive study of the modifications of Higgs couplings in the SO(5)/SO(4) minimal composite model. We focus on three couplings of central importance to Higgs phenomenology at the LHC: the couplings to top and bottom quarks and the coupling to two gluons. We consider three possible embeddings of the fermionic partners in 5, 10 and 14 of SO(5) and find tth and bbh couplings to be always suppressed in 5 and 10, while in 14 they can be either enhanced or suppressed. Assuming partial compositeness, we analyze the interplay between the tth coupling and the top sector contribution to the Coleman-Weinberg potential for the Higgs boson, and the correlation between tth and ggh couplings. In particular, if the electroweak symmetry breaking is triggered radiatively by the top sector, we demonstrate that the ratio of the tth coupling in composite Higgs models over the Standard Model expectation is preferred to be less than the corresponding ratio of the ggh coupling.
[ { "created": "Wed, 22 Mar 2017 18:01:06 GMT", "version": "v1" }, { "created": "Tue, 18 Apr 2017 20:39:19 GMT", "version": "v2" } ]
2017-08-23
[ [ "Liu", "Da", "" ], [ "Low", "Ian", "" ], [ "Wagner", "Carlos E. M.", "" ] ]
We present a comprehensive study of the modifications of Higgs couplings in the SO(5)/SO(4) minimal composite model. We focus on three couplings of central importance to Higgs phenomenology at the LHC: the couplings to top and bottom quarks and the coupling to two gluons. We consider three possible embeddings of the fermionic partners in 5, 10 and 14 of SO(5) and find tth and bbh couplings to be always suppressed in 5 and 10, while in 14 they can be either enhanced or suppressed. Assuming partial compositeness, we analyze the interplay between the tth coupling and the top sector contribution to the Coleman-Weinberg potential for the Higgs boson, and the correlation between tth and ggh couplings. In particular, if the electroweak symmetry breaking is triggered radiatively by the top sector, we demonstrate that the ratio of the tth coupling in composite Higgs models over the Standard Model expectation is preferred to be less than the corresponding ratio of the ggh coupling.
1201.0115
Roman Nevzorov
R. Nevzorov
Phenomenological aspects of Supersymmetry: SUSY models and electroweak symmetry breaking
Course lectures presented at the Dynasty Foundation Summer School, Protvino, Moscow region, Russia, 10-20 August, 2009; published in the Proceedings of the Dynasty Foundation Summer School, p.108-154 (2011)
null
null
UH511-1184-2011
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
These lectures are a very brief introduction to low energy supersymmetry (SUSY). The approach to the construction of SUSY Lagrangians based on the superfield formalism is considered. The minimal supersymmetric standard model (MSSM) is specified. The breakdown of gauge symmetry and Higgs phenomenology within the simplest SUSY extensions of the standard model (SM) are briefly reviewed. The upper bound on the mass of the lightest Higgs boson and little hierarchy problem in SUSY models are discussed.
[ { "created": "Fri, 30 Dec 2011 12:38:34 GMT", "version": "v1" } ]
2012-01-04
[ [ "Nevzorov", "R.", "" ] ]
These lectures are a very brief introduction to low energy supersymmetry (SUSY). The approach to the construction of SUSY Lagrangians based on the superfield formalism is considered. The minimal supersymmetric standard model (MSSM) is specified. The breakdown of gauge symmetry and Higgs phenomenology within the simplest SUSY extensions of the standard model (SM) are briefly reviewed. The upper bound on the mass of the lightest Higgs boson and little hierarchy problem in SUSY models are discussed.
1512.01963
Anders Tranberg
P. H. Damgaard, A. Haarr, D. O'Connell, A. Tranberg
Effective Field Theory and Electroweak Baryogenesis in the Singlet-Extended Standard Model
18 pages + App. 17 figures. v2, References added
null
10.1007/JHEP02(2016)107
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Electroweak baryogenesis is a simple and attractive candidate mechanism for generating the observed baryon asymmetry in the Universe. Its viability is sometimes investigated in terms of an effective field theory of the Standard Model involving higher dimension operators. We investigate the validity of such an effective field theory approach to the problem of identifying electroweak phase transitions strong enough for electroweak baryogenesis to be successful. We identify and discuss some pitfalls of this approach due to the modest hierarchy between mass scales of heavy degrees or freedom and the Higgs, and the possibility of dimensionful couplings violating the decoupling between light and heavy degrees of freedom.
[ { "created": "Mon, 7 Dec 2015 10:18:01 GMT", "version": "v1" }, { "created": "Tue, 22 Dec 2015 20:14:55 GMT", "version": "v2" } ]
2016-03-23
[ [ "Damgaard", "P. H.", "" ], [ "Haarr", "A.", "" ], [ "O'Connell", "D.", "" ], [ "Tranberg", "A.", "" ] ]
Electroweak baryogenesis is a simple and attractive candidate mechanism for generating the observed baryon asymmetry in the Universe. Its viability is sometimes investigated in terms of an effective field theory of the Standard Model involving higher dimension operators. We investigate the validity of such an effective field theory approach to the problem of identifying electroweak phase transitions strong enough for electroweak baryogenesis to be successful. We identify and discuss some pitfalls of this approach due to the modest hierarchy between mass scales of heavy degrees or freedom and the Higgs, and the possibility of dimensionful couplings violating the decoupling between light and heavy degrees of freedom.
2301.07049
Joshua Martin
Joshua D. Martin, A. Roggero, Huaiyu Duan, J. Carlson
Many-body neutrino flavor entanglement in a simple dynamic model
6 pages, 5 figures
null
null
LA-UR-23-20394
hep-ph astro-ph.HE nucl-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Dense neutrino gases form in extreme astrophysical sites, and the flavor content of the neutrinos likely has an important impact on the subsequent dynamical evolution of their environment. Through coherent forward scattering among neutrinos, the flavor content of the gas evolves under a time-dependent potential which can be modeled in a quantum many-body formalism as an all-to-all coupled spin-spin interaction. This two-body potential generically introduces entanglement and greatly complicates the study of these systems. In this work we study the evolution of the quantum many-body problem as well as the typically employed mean-field approximation to it for a small number of neutrinos ($N = 16$). We consider randomly chosen one- and two-body couplings in the Hamiltonian, and the resulting evolution of several initial product states. We subsequently compare many-body and mean-field predictions for one-body observables, and we consider one- and two-body entanglement to assess under what conditions the many-body and mean-field predictions are likely to disagree. Except for a special category of prototypical initial conditions, we find that the typically employed mean-field approximation is insufficient to capture the evolution of one-body operators in the systems we consider. We also observe a loss of coherence in one- and two-body trace-reduced subsystems which suggests that the evolution may be well approximated as a classical mixture of separable states.
[ { "created": "Tue, 17 Jan 2023 18:02:33 GMT", "version": "v1" } ]
2023-01-18
[ [ "Martin", "Joshua D.", "" ], [ "Roggero", "A.", "" ], [ "Duan", "Huaiyu", "" ], [ "Carlson", "J.", "" ] ]
Dense neutrino gases form in extreme astrophysical sites, and the flavor content of the neutrinos likely has an important impact on the subsequent dynamical evolution of their environment. Through coherent forward scattering among neutrinos, the flavor content of the gas evolves under a time-dependent potential which can be modeled in a quantum many-body formalism as an all-to-all coupled spin-spin interaction. This two-body potential generically introduces entanglement and greatly complicates the study of these systems. In this work we study the evolution of the quantum many-body problem as well as the typically employed mean-field approximation to it for a small number of neutrinos ($N = 16$). We consider randomly chosen one- and two-body couplings in the Hamiltonian, and the resulting evolution of several initial product states. We subsequently compare many-body and mean-field predictions for one-body observables, and we consider one- and two-body entanglement to assess under what conditions the many-body and mean-field predictions are likely to disagree. Except for a special category of prototypical initial conditions, we find that the typically employed mean-field approximation is insufficient to capture the evolution of one-body operators in the systems we consider. We also observe a loss of coherence in one- and two-body trace-reduced subsystems which suggests that the evolution may be well approximated as a classical mixture of separable states.
1409.4954
Michio Hashimoto
Michio Hashimoto
Composite Z'
6 pages, 4 figures; version published in PRD
Phys. Rev. D 90, 096004 (2014)
10.1103/PhysRevD.90.096004
null
hep-ph hep-th
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate a possibility of a composite Z' vector boson. For the compositeness, the required gauge coupling g in low energy is not so big, g^2/(4\pi) > 0.015 in the case of the U(1)_{B-L} model. We show that the Stueckelberg model is effectively induced in low energy via the fermion loop from the Nambu-Jona-Lasinio (NJL) model having the vectorial four-fermion interaction. In terms of the renormalization group equations (RGE's), this situation is expressed by the compositeness conditions. We find that the solutions of the RGE's with the compositeness conditions are determined by the infrared fixed points. As a result, the ratio of the masses of the extra electroweak singlet scalar and the right-handed neutrino is fixed. The mass of the composite Z' boson contains the contribution \Delta of the Stueckelberg mass term. This nonzero \Delta might be a remnant of a strongly interacting theory in high energy.
[ { "created": "Wed, 17 Sep 2014 11:44:21 GMT", "version": "v1" }, { "created": "Fri, 19 Sep 2014 10:55:01 GMT", "version": "v2" }, { "created": "Sun, 23 Nov 2014 10:02:59 GMT", "version": "v3" } ]
2014-11-25
[ [ "Hashimoto", "Michio", "" ] ]
We investigate a possibility of a composite Z' vector boson. For the compositeness, the required gauge coupling g in low energy is not so big, g^2/(4\pi) > 0.015 in the case of the U(1)_{B-L} model. We show that the Stueckelberg model is effectively induced in low energy via the fermion loop from the Nambu-Jona-Lasinio (NJL) model having the vectorial four-fermion interaction. In terms of the renormalization group equations (RGE's), this situation is expressed by the compositeness conditions. We find that the solutions of the RGE's with the compositeness conditions are determined by the infrared fixed points. As a result, the ratio of the masses of the extra electroweak singlet scalar and the right-handed neutrino is fixed. The mass of the composite Z' boson contains the contribution \Delta of the Stueckelberg mass term. This nonzero \Delta might be a remnant of a strongly interacting theory in high energy.
hep-ph/9604422
null
Bo-Qiang Ma (IHEP, Academia Sinica, Beijing)
Parton Sum Rules and Nucleon Structure Functions
4 pages, latex, no figure
null
null
null
hep-ph nucl-th
null
A brief summary on the Wigner rotation effect in the understanding of the proton spin ``crisis" related with the Ellis-Jaffe sum rule violation, and on the proton-neutron isospin symmetry breaking explanation of the Gottfried sum rule violation. The proton spin could be fully provided by the spin sum of quarks if one considers the Wigner rotation effect in the measured quark helicity distributions.
[ { "created": "Mon, 29 Apr 1996 22:13:39 GMT", "version": "v1" } ]
2007-05-23
[ [ "Ma", "Bo-Qiang", "", "IHEP, Academia Sinica, Beijing" ] ]
A brief summary on the Wigner rotation effect in the understanding of the proton spin ``crisis" related with the Ellis-Jaffe sum rule violation, and on the proton-neutron isospin symmetry breaking explanation of the Gottfried sum rule violation. The proton spin could be fully provided by the spin sum of quarks if one considers the Wigner rotation effect in the measured quark helicity distributions.
2401.00770
Yuxiao Yan
Liangliang Shang, Yuxiao Yan, Stefano Moretti, Bingfang Yang
Single production of an exotic vector-like $Y$ quark at future high energy $pp$ colliders
28 pages + references, 7 figures, 5 tables; matches version published in PRD
null
null
null
hep-ph
http://creativecommons.org/licenses/by/4.0/
Vector-like quarks have been predicted in various new physics scenarios beyond the Standard Model (SM). In a simplified modelling of a $(B,Y)$ doublet including a vector-like quark $Y$, with charge $-\frac{4}{3}$e, there are only two free parameters: the $Y$ coupling $\kappa_{Y}$ and mass $m_Y$. In the five flavor scheme, we investigate the single production of the $Y$ state decaying into $Wb$ at the Large Hadron Collider (LHC) Run-III and High-Luminosity LHC (HL-LHC) operating at $\sqrt{s}$ = 14 TeV, the possible High-Energy LHC (HE-LHC) with $\sqrt{s}$ = 27 TeV as well as the Future Circular Collider in hadron-hadron mode (FCC-hh) with $\sqrt{s}$ = 100 TeV. Through detailed signal-to-background analyses and detector simulations, we assess the exclusion capabilities of the $Y$ state at the different colliders. We find that this can be improved significantly with increasing collision energy, especially at the HE-LHC and FCC-hh, both demonstrating an obvious advantage with respect to the HL-LHC in the case of high $m_Y$. Assuming a 10\% systematic uncertainty on the background event rate, the exclusion capabilities are summarized as follows: (1) the LHC Run-III can exclude the correlated regions of $\kappa_{Y} \in [0.06,0.5]$ and $m_{Y} \in [1500\text{ GeV},3800\text{ GeV}]$ with integrated luminosity $L = 300\text{ fb}^{-1}$; (2) the HL-LHC can exclude the correlated regions of $\kappa_{Y} \in [0.05,0.5]$ and $m_{Y} \in [1500\text{ GeV},3970\text{ GeV}]$ with $L = 3$ ab$^{-1}$; (3) the HE-LHC can exclude the correlated regions of $\kappa_Y \in [0.06,0.5]$ and $m_{Y} \in [1500\text{ GeV} , 6090\text{ GeV}]$ with $L = 3$ ab$^{-1}$; (4) the FCC-hh can exclude the correlated regions of $\kappa_{Y} \in [0.08,0.5]$ and $m_{Y} \in [1500\text{ GeV} , 10080\text{ GeV}]$ with $L = 3$ ab$^{-1}$.
[ { "created": "Mon, 1 Jan 2024 14:25:11 GMT", "version": "v1" }, { "created": "Mon, 8 Jan 2024 06:59:08 GMT", "version": "v2" }, { "created": "Wed, 22 May 2024 08:22:53 GMT", "version": "v3" } ]
2024-05-24
[ [ "Shang", "Liangliang", "" ], [ "Yan", "Yuxiao", "" ], [ "Moretti", "Stefano", "" ], [ "Yang", "Bingfang", "" ] ]
Vector-like quarks have been predicted in various new physics scenarios beyond the Standard Model (SM). In a simplified modelling of a $(B,Y)$ doublet including a vector-like quark $Y$, with charge $-\frac{4}{3}$e, there are only two free parameters: the $Y$ coupling $\kappa_{Y}$ and mass $m_Y$. In the five flavor scheme, we investigate the single production of the $Y$ state decaying into $Wb$ at the Large Hadron Collider (LHC) Run-III and High-Luminosity LHC (HL-LHC) operating at $\sqrt{s}$ = 14 TeV, the possible High-Energy LHC (HE-LHC) with $\sqrt{s}$ = 27 TeV as well as the Future Circular Collider in hadron-hadron mode (FCC-hh) with $\sqrt{s}$ = 100 TeV. Through detailed signal-to-background analyses and detector simulations, we assess the exclusion capabilities of the $Y$ state at the different colliders. We find that this can be improved significantly with increasing collision energy, especially at the HE-LHC and FCC-hh, both demonstrating an obvious advantage with respect to the HL-LHC in the case of high $m_Y$. Assuming a 10\% systematic uncertainty on the background event rate, the exclusion capabilities are summarized as follows: (1) the LHC Run-III can exclude the correlated regions of $\kappa_{Y} \in [0.06,0.5]$ and $m_{Y} \in [1500\text{ GeV},3800\text{ GeV}]$ with integrated luminosity $L = 300\text{ fb}^{-1}$; (2) the HL-LHC can exclude the correlated regions of $\kappa_{Y} \in [0.05,0.5]$ and $m_{Y} \in [1500\text{ GeV},3970\text{ GeV}]$ with $L = 3$ ab$^{-1}$; (3) the HE-LHC can exclude the correlated regions of $\kappa_Y \in [0.06,0.5]$ and $m_{Y} \in [1500\text{ GeV} , 6090\text{ GeV}]$ with $L = 3$ ab$^{-1}$; (4) the FCC-hh can exclude the correlated regions of $\kappa_{Y} \in [0.08,0.5]$ and $m_{Y} \in [1500\text{ GeV} , 10080\text{ GeV}]$ with $L = 3$ ab$^{-1}$.
hep-ph/0112045
Filip Moortgat
D. Denegri, V. Drollinger, R. Kinnunen, K. Lassila-Perini, S. Lehti, F. Moortgat, A. Nikitenko, S. Slabospitsky, N. Stepanov
Summary of the CMS Discovery Potential for the MSSM SUSY Higgses
19 pages, 27 figures
null
null
CMS NOTE 2001/032
hep-ph
null
This work summarises the present understanding of the expected MSSM SUSY Higgs reach for CMS. Many of the studies presented here result from detailed detector simulations incorporating final CMS detector design and response. With 30 fb-1 the h -> gamma,gamma and h -> bb channels allow to cover most of the MSSM parameter space. For the massive A,H,H+ MSSM Higgs states the channels A,H -> tau,tau and H+ -> tau,nu turn out to be the most profitable ones in terms of mass reach and parameter space coverage. Consequently CMS has made a big effort to trigger efficiently on taus. Provided neutralinos and sleptons are not too heavy, there is an interesting complementarity in the reaches for A,H -> tau,tau and A,H -> chi,chi.
[ { "created": "Tue, 4 Dec 2001 11:05:35 GMT", "version": "v1" } ]
2007-05-23
[ [ "Denegri", "D.", "" ], [ "Drollinger", "V.", "" ], [ "Kinnunen", "R.", "" ], [ "Lassila-Perini", "K.", "" ], [ "Lehti", "S.", "" ], [ "Moortgat", "F.", "" ], [ "Nikitenko", "A.", "" ], [ "Slabospitsky", "S.", "" ], [ "Stepanov", "N.", "" ] ]
This work summarises the present understanding of the expected MSSM SUSY Higgs reach for CMS. Many of the studies presented here result from detailed detector simulations incorporating final CMS detector design and response. With 30 fb-1 the h -> gamma,gamma and h -> bb channels allow to cover most of the MSSM parameter space. For the massive A,H,H+ MSSM Higgs states the channels A,H -> tau,tau and H+ -> tau,nu turn out to be the most profitable ones in terms of mass reach and parameter space coverage. Consequently CMS has made a big effort to trigger efficiently on taus. Provided neutralinos and sleptons are not too heavy, there is an interesting complementarity in the reaches for A,H -> tau,tau and A,H -> chi,chi.
2207.13735
Alexander Huss
D. Britzger, A. Gehrmann-De Ridder, T. Gehrmann, E.W.N. Glover, C. Gwenlan, A. Huss, J. Pires, K. Rabbertz, D. Savoiu, M.R. Sutton, J. Stark
NNLO interpolation grids for jet production at the LHC
19 pages, 10 figures, 6 tables
null
null
CERN-TH-2022-125, IPPP/22/53, MPP-2022-80, ZU-TH 34/22
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Fast interpolation-grid frameworks facilitate an efficient and flexible evaluation of higher-order predictions for any choice of parton distribution functions or value of the strong coupling $\alpha_s$. They constitute an essential tool for the extraction of parton distribution functions and Standard Model parameters, as well as studies of the dependence of cross sections on the renormalisation and factorisation scales. The APPLfast project provides a generic interface between the parton-level Monte Carlo generator NNLOJET and both the APPLgrid and the fastNLO libraries for the grid interpolation. The extension of the project to include hadron-hadron collider processes at next-to-next-to-leading order in perturbative QCD is presented, together with an application for jet production at the LHC.
[ { "created": "Wed, 27 Jul 2022 18:25:28 GMT", "version": "v1" } ]
2022-07-29
[ [ "Britzger", "D.", "" ], [ "Ridder", "A. Gehrmann-De", "" ], [ "Gehrmann", "T.", "" ], [ "Glover", "E. W. N.", "" ], [ "Gwenlan", "C.", "" ], [ "Huss", "A.", "" ], [ "Pires", "J.", "" ], [ "Rabbertz", "K.", "" ], [ "Savoiu", "D.", "" ], [ "Sutton", "M. R.", "" ], [ "Stark", "J.", "" ] ]
Fast interpolation-grid frameworks facilitate an efficient and flexible evaluation of higher-order predictions for any choice of parton distribution functions or value of the strong coupling $\alpha_s$. They constitute an essential tool for the extraction of parton distribution functions and Standard Model parameters, as well as studies of the dependence of cross sections on the renormalisation and factorisation scales. The APPLfast project provides a generic interface between the parton-level Monte Carlo generator NNLOJET and both the APPLgrid and the fastNLO libraries for the grid interpolation. The extension of the project to include hadron-hadron collider processes at next-to-next-to-leading order in perturbative QCD is presented, together with an application for jet production at the LHC.
hep-ph/0108074
Gudrun Hiller
G. Hiller (SLAC), A. Kagan (Cincinnati)
Probing for New Physics in Polarized $\Lambda_b$ decays at the Z
18 pages, 2 figures, comments and references on 1/m effects added, conclusions unchanged, version to appear in PRD
Phys.Rev. D65 (2002) 074038
10.1103/PhysRevD.65.074038
SLAC-PUB-8752
hep-ph
null
Polarized $\Lambda_b \to \Lambda \gamma$ decays at the Z pole are shown to be well suited for probing a large variety of New Physics effects. A new observable is proposed, the angular asymmetry between the $\Lambda_b$ spin and photon momentum, which is sensitive to the relative strengths of the opposite chirality and Standard Model chirality $b \to s \gamma$ dipole operators. Combination with the $\Lambda $ decay polarization asymmetry and comparison with the $\Lambda_b$ polarization extracted from semileptonic decays allows important tests of the $V-A$ structure of the Standard Model. Modifications of the rates and angular asymmetries which arise at next-to-leading order are discussed. Measurements for $\Lambda_b \to \Lambda \gamma$ and the CP conjugate mode, with branching ratios of a few times $10^{-5}$, are shown to be sensitive to non-standard sources of CP violation in the $\Lambda_b \to \Lambda \gamma$ matrix element. Form factor relations for heavy-to-light baryon decays are derived in the large energy limit, which are of general interest.
[ { "created": "Wed, 8 Aug 2001 10:52:35 GMT", "version": "v1" }, { "created": "Tue, 29 Jan 2002 20:35:26 GMT", "version": "v2" } ]
2009-11-07
[ [ "Hiller", "G.", "", "SLAC" ], [ "Kagan", "A.", "", "Cincinnati" ] ]
Polarized $\Lambda_b \to \Lambda \gamma$ decays at the Z pole are shown to be well suited for probing a large variety of New Physics effects. A new observable is proposed, the angular asymmetry between the $\Lambda_b$ spin and photon momentum, which is sensitive to the relative strengths of the opposite chirality and Standard Model chirality $b \to s \gamma$ dipole operators. Combination with the $\Lambda $ decay polarization asymmetry and comparison with the $\Lambda_b$ polarization extracted from semileptonic decays allows important tests of the $V-A$ structure of the Standard Model. Modifications of the rates and angular asymmetries which arise at next-to-leading order are discussed. Measurements for $\Lambda_b \to \Lambda \gamma$ and the CP conjugate mode, with branching ratios of a few times $10^{-5}$, are shown to be sensitive to non-standard sources of CP violation in the $\Lambda_b \to \Lambda \gamma$ matrix element. Form factor relations for heavy-to-light baryon decays are derived in the large energy limit, which are of general interest.
1604.04251
Hoernisa Iminniyaz
Hoernisa Iminniyaz
Asymmetric Dark Matter in the Shear--dominated Universe
12 pages, 6 figures
null
10.1016/j.physletb.2016.11.006
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We explore the relic abundance of asymmetric Dark Matter in shear--dominated universe in which it is assumed the universe is expanded anisotropically. The modified expansion rate leaves its imprint on the relic density of asymmetric Dark Matter particles if the asymmetric Dark Matter particles are decoupled in shear dominated era. We found the relic abundances for particle and anti--particle are increased. The particle and anti--particle abundances are almost in the same amount for the larger value of the shear factor $x_e$ which makes the indirect detection possible for asymmetric Dark Matter. We use the present day Dark Matter density from the observation to find the constraints on the parameter space in this model.
[ { "created": "Thu, 14 Apr 2016 18:28:30 GMT", "version": "v1" }, { "created": "Mon, 1 Aug 2016 15:04:31 GMT", "version": "v2" } ]
2016-12-07
[ [ "Iminniyaz", "Hoernisa", "" ] ]
We explore the relic abundance of asymmetric Dark Matter in shear--dominated universe in which it is assumed the universe is expanded anisotropically. The modified expansion rate leaves its imprint on the relic density of asymmetric Dark Matter particles if the asymmetric Dark Matter particles are decoupled in shear dominated era. We found the relic abundances for particle and anti--particle are increased. The particle and anti--particle abundances are almost in the same amount for the larger value of the shear factor $x_e$ which makes the indirect detection possible for asymmetric Dark Matter. We use the present day Dark Matter density from the observation to find the constraints on the parameter space in this model.
hep-ph/0312031
Stefan Michalski
J. Baacke, Stefan Michalski
O(N) linear sigma model beyond the Hartree approximation at finite temperature
6 pages. To appear in the proceedings of International Workshop on Quantum Field Theory Under the Influence of External Conditions (QFEXT '03). Norman OK (USA), September 2003
null
null
null
hep-ph hep-th
null
We study the O(N) linear sigma model with spontaneous symmetry breaking at finite temperature in the framework of the two-particle point-irreducible (2PPI) effective action. We go beyond the Hartree approximation by including the two-loop contribution, i.e., the sunset diagram. A phase transition of second order is found, whereas it is of first order in the one-loop Hartree approximation. Furthermore, we show the temperature-dependence of the variational mass parameters and comment on their relation to the physical sigma and pion masses.
[ { "created": "Tue, 2 Dec 2003 13:53:57 GMT", "version": "v1" } ]
2007-05-23
[ [ "Baacke", "J.", "" ], [ "Michalski", "Stefan", "" ] ]
We study the O(N) linear sigma model with spontaneous symmetry breaking at finite temperature in the framework of the two-particle point-irreducible (2PPI) effective action. We go beyond the Hartree approximation by including the two-loop contribution, i.e., the sunset diagram. A phase transition of second order is found, whereas it is of first order in the one-loop Hartree approximation. Furthermore, we show the temperature-dependence of the variational mass parameters and comment on their relation to the physical sigma and pion masses.
1512.01222
Jose Ramon Espinosa
Jose R. Espinosa
Implications of the top (and Higgs) mass for vacuum stability
Long version of proceedings for the 8th International Workshop on Top Quark Physics, TOP2015. 14-18 September, 2015. Ischia, Italy
null
null
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The discovery of the Higgs boson by the LHC and the measurement of its mass at around 125 GeV, taken together with the absence of signals of physics beyond the standard model, make it possible that we might live in a metastable electroweak vacuum. Intriguingly, we seem to be very close to the boundary of stability and this near-criticality makes our vacuum extremely long-lived. In this talk I describe the state-of-the-art calculation leading to these results, explaining what are the ingredients and assumptions that enter in it, with special emphasis on the role of the top mass. I also discuss possible implications of this metastability for physics beyond the standard model and comment on the possible impact of physics at the Planck scale on near-criticality.
[ { "created": "Thu, 3 Dec 2015 20:45:35 GMT", "version": "v1" } ]
2015-12-04
[ [ "Espinosa", "Jose R.", "" ] ]
The discovery of the Higgs boson by the LHC and the measurement of its mass at around 125 GeV, taken together with the absence of signals of physics beyond the standard model, make it possible that we might live in a metastable electroweak vacuum. Intriguingly, we seem to be very close to the boundary of stability and this near-criticality makes our vacuum extremely long-lived. In this talk I describe the state-of-the-art calculation leading to these results, explaining what are the ingredients and assumptions that enter in it, with special emphasis on the role of the top mass. I also discuss possible implications of this metastability for physics beyond the standard model and comment on the possible impact of physics at the Planck scale on near-criticality.
hep-ph/9712452
Name
M. Genovese, J.-M.Richard, FL. Stancu and S. Pepin
Heavy-Flavour Pentaquarks in a Chiral Constituent Quark Model
10 pages + tables
Phys.Lett.B425:171-176,1998
10.1016/S0370-2693(98)00187-7
ISN 98.04
hep-ph nucl-th
null
Within the chiral constituent quark model of Glozman and Riska, we discuss the stability of heavy pentaquarks, i.e. hadrons containing four light quarks and a heavy antiquark. The spin-dependent part of the Hamiltonian is dominated by the short-range part of the Goldstone-boson-exchange interaction. We find that these systems are not bound, having an energy above the lowest dissociation threshold into a baryon and a meson.
[ { "created": "Fri, 19 Dec 1997 12:17:38 GMT", "version": "v1" } ]
2014-11-17
[ [ "Genovese", "M.", "" ], [ "Richard", "J. -M.", "" ], [ "Stancu", "FL.", "" ], [ "Pepin", "S.", "" ] ]
Within the chiral constituent quark model of Glozman and Riska, we discuss the stability of heavy pentaquarks, i.e. hadrons containing four light quarks and a heavy antiquark. The spin-dependent part of the Hamiltonian is dominated by the short-range part of the Goldstone-boson-exchange interaction. We find that these systems are not bound, having an energy above the lowest dissociation threshold into a baryon and a meson.
2003.03770
Hao Sun
Xuan Luo, Hao Sun and Yi-Ling Xie
Single spin asymmetry $A_{UL}^{\sin(\phi_h-\phi_R)}$ in dihadron semi-inclusive DIS
12pages, 6figures. arXiv admin note: substantial text overlap with arXiv:1906.05674
Phys. Rev. D 101, 054020 (2020)
10.1103/PhysRevD.101.054020
null
hep-ph
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we study the single longitudinal spin asymmetry $A_{UL}^{\sin(\phi_h-\phi_R)}$ of dihadron production in semi-inclusive deep inelastic scattering (SIDIS) via helicity-dependent dihadron fragmentation function (DiFF), which describes the correlation of the longitudinal polarization of a fragmenting quark with the transverse momenta of the produced hadron pair. Recently experimental searching for this azimuthal asymmetry in dihadron SIDIS by the COMPASS Collaboration yielded a very small signal. Here we calculate this unknown T-odd DiFF $G_1^\perp$ using a spectator model to access the asymmetry and clarify why the signal is very small. The transverse momentum dependent (TMD) factorization method, in which the transverse momentum of the final state hadron pair leaves unintegrated, has been applied. We estimate the $\sin(\phi_h-\phi_R)$ asymmetry at the kinematics of COMPASS experiments and compare with the data. What's more, the predictions on the same asymmetry are also made at the Electron Ion Collider (EIC).
[ { "created": "Sun, 8 Mar 2020 12:18:42 GMT", "version": "v1" } ]
2020-04-14
[ [ "Luo", "Xuan", "" ], [ "Sun", "Hao", "" ], [ "Xie", "Yi-Ling", "" ] ]
In this paper we study the single longitudinal spin asymmetry $A_{UL}^{\sin(\phi_h-\phi_R)}$ of dihadron production in semi-inclusive deep inelastic scattering (SIDIS) via helicity-dependent dihadron fragmentation function (DiFF), which describes the correlation of the longitudinal polarization of a fragmenting quark with the transverse momenta of the produced hadron pair. Recently experimental searching for this azimuthal asymmetry in dihadron SIDIS by the COMPASS Collaboration yielded a very small signal. Here we calculate this unknown T-odd DiFF $G_1^\perp$ using a spectator model to access the asymmetry and clarify why the signal is very small. The transverse momentum dependent (TMD) factorization method, in which the transverse momentum of the final state hadron pair leaves unintegrated, has been applied. We estimate the $\sin(\phi_h-\phi_R)$ asymmetry at the kinematics of COMPASS experiments and compare with the data. What's more, the predictions on the same asymmetry are also made at the Electron Ion Collider (EIC).